DOE-HDBK-1122-2009 Part 5, Radiological Control Technician Training Site Academic Training Instructor's Guide Phase I
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Section 1
Part 5 of 9
Radiological Control Technician Training
Site Academic Training Instructor’s Guide Phase I
Coordinated and Conducted
for the
Office of Health, Safety and Security
U.S. Department of Energy
DOE-HDBK-1122-2009
Radiological Control Technician Instructor’s Guide
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Radiological Control Technician Instructor’s Guide
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Table of Contents
Page
Module 2.01 Radiological Documentation ............................................................................2.01-1
Module 2.02 Communication Systems ..................................................................................2.02-1
Module 2.03 Counting Errors and Statistics ..........................................................................2.03-1
Module 2.04 Dosimetry .........................................................................................................2.04-1
Module 2.05 Contamination Control .....................................................................................2.05-1
Module 2.06 Airborne Sampling Program/Methods .............................................................2.06-1
Module 2.07 Respiratory Protection ......................................................................................2.07-1
Module 2.08 Radioactive Source Control .............................................................................2.08-1
Module 2.09 Environmental Monitoring ...............................................................................2.09-1
Module 2.10 Access Control and Work Area Setup..............................................................2.10-1
Module 2.11 Radiological Work Coverage ...........................................................................2.11-1
Module 2.12 Shipment and Receipt of Radioactive Material................................................2.12-1
Module 2.13 Radiological Incidents and Emergencies..........................................................2.13-1
Module 2.14 Personnel Decontamination..............................................................................2.14-1
Module 2.15 Radiological Considerations for First Aid........................................................2.15-1
Module 2.16 Radiation Survey Instrumentation....................................................................2.16-1
Module 2.17 Contamination Monitoring Instrumentation.....................................................2.17-1
Module 2.18 Air Sampling Equipment..................................................................................2.18-1
Module 2.19 Counting Room Equipment..............................................................................2.19-1
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DOE-HDBK-1122-2009
Module 2.01 Radiological Documentation Instructor’s Guide
2.01-1
Course Title: Radiological Control Technician
Module Title: Radiological Documentation
Module Number: 2.01
Objectives:
→ 2.01.01 List the types of records/reports that the Radiological Control group is responsible
for maintaining at your site.
→ 2.01.02 Describe the types of records and reports used at your site by the Radiological
Control Group, to include but should not be limited to:
a. Radiological Work Permits
b. Survey Reports
c. Analysis Reports
d. Radiological Deficiency Reports
e. ALARA Documentation
f. Exposure Reports
Section 2
→ 2.01.03 Explain the requirements for the records management system, such as QC,
auditability/retrievability, management information at your site.
References:
1. 10 CFR Part 835 (2007) "Occupational Radiation Protection".
2. "Radiological Control Standard," DOE-STD-1098-2008.
Instructional Aids:
1. Overheads
2. Overhead projector/screen
3. Chalkboard/whiteboard
4. Lessons learned
DOE-HDBK-1122-2009
Module 2.01 Radiological Documentation Instructor’s Guide
2.01-2
I. MODULE INTRODUCTION
A. Self Introduction
1. Name
2. Phone number
3. Background
4. Emergency procedure review
B. Motivation
A good Radiological Control Program must have a sound
documentation process. RCTs are involved daily in
creating records through surveys, RWPs, and procedures
that give a history of actual conditions and operations.
C. Module Overview
1. Purpose and requirements
2. Radiological records management program
3. Radiological record keeping standards
4. Types of radiological records
5. Records management
6. Radiological reporting
D. Introduce Objectives
II. MODULE OUTLINE
NOTE: Most of the material for this section will come from
specific site procedures. The instructor must be
thoroughly knowledgeable in and have available for
student use, procedures for RWP's, Radiological
Occurrences, Records Maintenance, Inventories, and
O.H.: Objectives
DOE-HDBK-1122-2009
Module 2.01 Radiological Documentation Instructor’s Guide
2.01-3
any other RC procedure related to administration. In
addition, any other procedure or procedural change can be
covered in this section.
A. Purpose/Requirements
Discuss the purpose and requirements for records and
reports at DOE facilities based on 10 CFR 835 and DOE
RCS. Discuss any additional site requirements.
B. Radiological Records Management Program
1. Discuss the types of radiological records that should
be included in the records management program.
a. Quality Control
b. Audits
c. Records retrieval
d. Management information
0. (Insert site specific information here.)
C. Radiological Record Keeping Standards
2. List the standards for record keeping.
3. Discuss the justifications for record keeping standards.
D. Types of Radiological Records
1. Identify and define the record categories:
a. Employment History Records
Objective 2.01.01
Ask the students why it
is considered necessary
to include facility,
specific location and
function on
documentation. Ask
trainees why it makes
sense to initial and date
corrections.
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Module 2.01 Radiological Documentation Instructor’s Guide
2.01-4
b. Personnel Radiological Records
c. Medical Records
e. Radiological Training and Qualification Records
f. Instrumentation and Calibration Records
g. Radiological Control Procedures
2. (Insert site specific information here.)
E. Records Management
4. Discuss storage requirements
5. (Insert site specific information here.)
F. Radiological Exposure Reports
1. Purpose
2. Process
3. Examples of filled-out exposure reports
III. SUMMARY
A. Review major points
0. Purpose and requirements
1. Radiological records management program
2. Radiological record keeping standards
3. Types of radiological records
4. Records management
5. Radiological reporting
B. Review learning objectives
Objective 2.01.02
Objective 2.01.03
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Module 2.01 Radiological Documentation Instructor’s Guide
2.01-5
IV. EVALUATION
Section 3
Evaluation should consist of a written examination comprised of
multiple choice, fill-in the blank, matching and/or short answer
questions. 80% should be the minimum passing criteria for
examinations.
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Module 2.01 Radiological Documentation Instructor’s Guide
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DOE-HDBK-1122-2009
Module 2.02 Communication Systems Instructor’s Guide
2.02-1
Course Title: Radiological Control Technician
Module Title: Communication Systems
Module Number: 2.02
Objectives:
2.02.01 Explain the importance of good communication.
2.02.02 Identify two methods of communication and be able to determine
different types of each.
2.02.03 Describe different types of communication systems.
2.02.04 Describe the FCC and DOE guidelines regarding proper use of
communication systems.
2.02.05 Describe general attributes of good communications.
2.02.06 Explain the importance of knowing how to contact key personnel.
→ 2.02.07 Identify the communication systems available at your site and
methods available to contact key personnel.
→ 2.02.08 Describe the emergency communication systems available at your
site.
Instructional Aids:
1. Overheads
2. Overhead projector/screen
3. Chalkboard/whiteboard
4. Recommended - radio, telephone, pager, warning alarms, phonetic alphabet handout
5. Lessons learned
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Module 2.02 Communication Systems Instructor’s Guide
2.02-1
I. MODULE INTRODUCTION
A. Self-Introduction
1. Name
2. Phone number
3. Background
4. Emergency procedure review
B. Motivation
Good communication skills are essential to an RCT. Each
RCT should develop an ability to communicate using both
verbal and non-verbal media. This skill will ensure important
information is transmitted to the proper individuals in a clear
and concise manner.
C. Overview of Lesson
1. Importance of communication
2. Methods of communication
3. Communication systems
4. FCC and DOE guidelines
5. General attributes of good communications
6. Contact of key personnel
7. Site communication systems
8. Site emergency communications
D. Introduce Objectives
O.H.: Objectives
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Module 2.02 Communication Systems Instructor’s Guide
2.02-2
II. MODULE OUTLINE
A. Importance of Communications
1. Clear
2. Understood
3. Received
B. Two Methods of Communication
1. Verbal
2. Nonverbal
C. Communication Systems
1. Public Address
2. Telephones
3. Two-way Radios
4. Pagers
5. Computer Mail Systems
6. Computer Bulletin Boards
D. FCC and DOE Guidelines
1. When using communication systems licensed by the
Federal Communications Commission and operated by
the Department of Energy, one cannot: Stress importance
of complying with these restrictions.
a. Use profane, indecent, or obscene language.
Objective 2.02.01
Objective 2.02.02
Ask the student to name
the two ways to
communicate and
examples.
Objective 2.02.03
Ask students to name
communication systems
available in everyday
use at home and work.
Objective 2.02.04
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Module 2.02 Communication Systems Instructor’s Guide
2.02-3
b. Willfully damage or permit radio equipment damage.
c. Cause malicious interference with any radio
communications.
d. Intercept and use or publish the contents of any radio
message without the permission of the proper
authorities.
e. Make unnecessary or unidentified transmissions.
Section 4
f. Transmit without first making sure that the
transmission will not cause harmful interference.
g. Make any adjustments, repairs, or alterations to a
radio transmitter without licensing by the FCC or
acceptable equivalent.
h. Transmit a call sign, letter, or numeral which has not
been assigned to your station.
i. Rebroadcast another transmission (i.e., radio station
music).
E. General Attributes of Good Communications
1. Minimize the use of abbreviations and acronyms.
2. Make all oral instructions clear and concise.
3. Ensure the identity of the person(s) is/are clearly
understood.
4. Use clear, precise terminology.
5. Repeat back messages, either paraphrased or verbatim.
6. Speak distinctly and deliberately.
Objective 2.02.05
Stress importance of
good habits and
technique.
See Table 1 - "Phonetic
Alphabet and Numbers”.
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Module 2.02 Communication Systems Instructor’s Guide
2.02-4
7. Acknowledge all communications.
F. Contacting Key Personnel
1. Getting knowledgeable people to locations is necessary
for routine, emergency, and non-routine circumstances.
2. Important for the protection of personnel, equipment and
to prevent radiological releases.
3. RCTs should be aware of communication equipment.
G. Site Communication Systems
(Insert site specific information here.)
H. Emergency Communication Systems
(Insert site specific information here.)
III. SUMMARY
A. Review major topics
1. Importance of communication
2. Methods of communication
3. Communication systems
4. FCC and DOE guidelines
5. General attributes of good communications
6. Contact of key personnel
7. Site communication systems
8. Site emergency communication
B. Review learning objectives
Objective 2.02.06
Objective 2.02.07
Objective 2.02.08
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Module 2.02 Communication Systems Instructor’s Guide
2.02-5
IV. EVALUATION
Evaluation should consist of a written examination comprised of multiple choice, fill-in the blank,
matching and/or short answer questions. 80% should be the minimum passing criteria for
examinations.
DOE-HDBK-1122-2009
Module 2.02 Communication Systems Instructor’s Guide
2.02-6
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DOE-HDBK-1122-2009
Module 2.03 Counting Errors and Statistics Instructor’s Guide
2.03-1
Course Title: Radiological Control Technician
Module Title: Counting Errors and Statistics
Module Number: 2.03
Objectives:
2.03.01. Identify five general types of errors that can occur when analyzing radioactive
samples, and describe the effect of each source of error on sample measurements.
2.03.02. State two applications of counting statistics in sample analysis.
2.03.03. Define the following terms:
a. mode
b. median
c. mean
2.03.04. Given a series of data, determine the mode, median, or mean.
2.03.05. Define the following terms:
a. variance
b. standard deviation
2.03.06. Given the formula and a set of data, calculate the standard deviation.
2.03.07. State the purpose of a Chi-squared test.
→ 2.03.08. State the criteria for acceptable Chi-squared values at your site.
2.03.09. State the purpose of creating quality control (QC) charts.
→ 2.03.10. State the requirements for maintenance and review of QC charts at your site.
2.03.11. State the purpose of calculating warning and control limits.
2.03.12. State the purpose of determining efficiencies and correction factors.
Section 5
2.03.13. Given counting data and source assay information, calculate efficiencies and
correction factors.
2.03.14. State the meaning of counting data reported as x ± y.
2.03.15. Given counting results and appropriate formulas, report results to desired
confidence level.
2.03.16. State the purpose of determining background.
→ 2.03.17. State the method and requirements for determining background for counting
systems at your site.
2.03.18. State the purpose of performing sample planchet maintenance.
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Module 2.03 Counting Errors and Statistics Instructor’s Guide
2.03-2
→ 2.03.19. State the method and requirements for performing planchet maintenance for
counting systems at your site.
2.03.20. Explain methods to improve the statistical validity of sample measurements.
2.03.21. Define "detection limit," and explain the purpose of using detection limits in the
analysis of radioactive samples.
→ 2.03.22. Given the formula and necessary information, calculate detection limit values for
counting systems at your site.
2.03.23. State the purpose and method of determining crosstalk.
→ 2.03.24. State the criteria for acceptable values of crosstalk for counting systems at your
site.
2.03.25. State the purpose of performing a voltage plateau.
→ 2.03.26. State the method of performing a voltage plateau on counting systems at your site.
References:
1. Chase & Rabinowitz, "Principles of Radioisotope Methodology," 3rd Edition, Burgess
Publishing, 1987.
2. "Basic Radiation Protection Technology"; Gollnick, Daniel; 5th ed.; Pacific Radiation
Corporation; 2008.
3. "Radiation Detection and Measurement"; Knoll, Glenn F.; Wiley & Sons; 2000.
4. "Webster's New World Dictionary," 4rd College Edition, Webster's New World,
Cleveland & New York, 1999.
5. Moe, Harold, "Operational Health Physics Training," ANL-88-26; DOE; Argonne
National Laboratory, Chicago, 1988.
Instructional Aids:
1. Overheads
2. Overhead projector/screen
3. Chalkboard/whiteboard
4. Lessons learned
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Module 2.03 Counting Errors and Statistics Instructor’s Guide
2.03-3
I. MODULE INTRODUCTION
A. Self-Introduction
1. Name
2. Phone number
3. Background
4. Emergency procedure review
B. Motivation
Radiological sample analysis involves observation of a random
process, one that may or may not occur, and estimation of the
amount of radioactive material present based on that observation.
All over the country radiological control personnel are using the
activity measurements to make decisions that may affect the health
and safety of workers at those facilities and their surrounding
environments.
C. Overview of Lesson
1. This unit will present an overview of measurement processes,
and statistical evaluation of both measurements and equipment
performance.
2. In addition, this unit will address some of the actions to take to
minimize the sources of error in count room operations.
D. Introduce Objectives
II. MODULE OUTLINE
A. General Sources of Error
Assuming the counting system is calibrated correctly, there are five
general sources of error associated with counting a sample: self-
absorption, backscatter, resolving time, geometry, and random
disintegration (of radioactive atoms).
1. Self-absorption
a. When a sample has an abnormally large amount of
material on the sample media, it could introduce a
counting error due to self-absorption, with is absorption of
the emitted radiation by the sample material itself.
Section 6
O.H.: Objectives
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Module 2.03 Counting Errors and Statistics Instructor’s Guide
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b. Self-absorption could occur for:
1) Liquid samples with a high solid content
2) Air samples from a high dust area
3) Use of improper filter paper may introduce a type of
self-absorption, especially in alpha counting (i.e.,
absorption by the media, or filter).
c. Personnel counting samples should ensure the correct
sample media is used, and that the sample does not
become too heavily loaded with sample material.
d. Count room personnel should be routinely checking
samples for improper media or heavily loaded samples.
2. Backscatter
a. Counting errors due to backscatter occur when the emitted
radiation traveling away from the detector is reflected, or
scattered back to the detector, by the material in back of
the sample.
b. The amount of radiation that is scattered back will depend
upon the type and energy of the radiation and the type of
backing material (reflector).
c. The amount of backscattered radiation increases as the
energy of the radiation increases and as the atomic number
of the backing material increases.
d. Generally, backscatter error is only a consideration for
particulate radiation, such as alpha and beta particles.
Because beta particles are more penetrating than alpha
particles, backscatter error will be more pronounced for
beta radiation.
e. The ratio of measured activity of a beta source counted
with a reflector compared to counting the same source
without a reflector is called the backscatter factor (BF).
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Module 2.03 Counting Errors and Statistics Instructor’s Guide
2.03-5
reflectorwithoutcounts
reflectorwithcountsBF
−−
−−
=
f. Normally, backscatter error is accounted for in the
efficiency or conversion factor of the instrument.
g. However, if different reflector materials, such as
aluminum and stainless steel, are used in calibration and
operation, an additional unaccounted error is introduced.
h. This additional error will be about 6% for stainless steel
versus aluminum. Count room personnel must be aware
of the reflector material used during calibration of the
counting equipment.
i. Any deviation from that reflector material will introduce
an unaccounted error and reduce confidence in the
analysis results.
3. Resolving Time
a. Resolving time is the time interval which must elapse after
a detector pulse is counted before another full-size pulse
can be counted.
b. Any radiation entering the detector during the resolving
time will not be recorded as a full size pulse; therefore, the
information on that radiation interaction is lost.
c. As the activity, or decay rate, of the sample increases, the
amount of information lost during the resolving time of
the detector is increased.
d. As the losses from resolving time increase, an additional
error in the measurement is introduced. Typical resolving
time losses are shown in Table 1 of the Study Guide.
e. Resolving time losses can be corrected by using the
equation:
1
o
o
RR
R τ
=
−
(Eq.2)
Refer students to
Table 1 in Study
Guide.
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Module 2.03 Counting Errors and Statistics Instructor’s Guide
2.03-6
where: R = "true" count rate, in cpm
Ro = observed count rate, in cpm
τ = resolving time of the detector, in minutes
("tau")
f. Count room personnel should be aware of the limitations
Section 7
for sample count rate, based upon procedures and the type
of detector in use, to prevent the introduction of additional
resolving time losses. This is especially true for counting
equipment that uses GM detectors.
4. Geometry
a. Geometry related counting errors result from the
positioning of the sample in relation to the detector.
b. Normally, only a fraction of the radiation emitted by the
sample is emitted in the direction of the detector because
the detector does not surround the sample.
c. If the distance between the sample and the detector is
varied, then the fraction of emitted radiation which hits the
detector will change.
d. This fraction will also change if the orientation of the
sample under the detector (i.e., side-to-side) is varied.
e. An error in the measurement can be introduced if the
geometry of the sample and detector is varied from the
geometry used during instrument calibration.
f. This is especially critical for alpha counting where any
change in the sample to detector distance also increases or
decreases the chance of shielding the alpha particles by the
air between the sample and detector.
g. Examples of geometry-related errors are:
1) Piling smears and/or filters on top of each other in the
same sample holder. Piling of the samples moves the
top sample closer to the detector and varies the
calibration geometry.
2) Using deeper or shallower sample holders than
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Module 2.03 Counting Errors and Statistics Instructor’s Guide
2.03-7
those used during calibration changes the sample-to-
detector distance.
3) Adjusting movable bases in the counting equipment
sliding drawer changes the sample to detector distance.
4) Using too many or not using the appropriate sample
holder or planchet changes the sample to detector
distance. Sources not fixed in position can change
can change geometry and reduce reproducibility.
5) Plexiglass shelving in counting chamber is improperly
set.
5. Random disintegration
The fifth source of general counting error is the random
disintegration of the radioactive atoms and constitutes the
remainder of the lesson.
B. Statistics
1. Statistics is a branch of mathematics that deals with the
organization, analysis, collection, and interpretation of
statistical data.
2. No definition of statistical data is given. However, Webster's
does define a statistic as "an estimate of a variable, as an
average or a mean, made on the basis of a sample taken from a
larger set of data."
3. This last definition is applicable to our discussion of counting
statistics. After all, when we take samples, we use the data
derived from analysis of those samples to make determinations
about conditions in an area, in water, or in air, etc., assuming
that the sample is representative.
4. So, we have estimated conditions (a variable) on the basis of a
sample (our smear, water sample, air sample) taken from a
larger set of data.
5. Over the years, various methods and observations have
identified three models which can be applied to observations of
events that have two possible outcomes (binary processes).
7. Luckily, we can define most observations in terms of two
possible outcomes. (See table 2).
Refer students to
Table 2
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7. For each of the processes that we want to study, we have
defined a trial (our test), a success and a failure (two possible
outcomes), and have determined the probability of observing
our defined success.
Section 8
8. Now, to study these processes, we can use proven, statistical
models to evaluate our observations for error.
9. Consider the possibilities when throwing two dice. There are
36 possible outcomes when throwing two dice, as indicated in
Table 3.
10. If, in our study of this process, we define a success as throwing
a number between 2 and 12, the outcome is academic. All
trials will be successful, and we can describe the probabilities
of throwing any individual number between the range of 2 and
12 inclusive would add up to 1.
11. If we define a success as throwing a particular number, we can
define the probability of our success in terms of the number of
possible outcomes that would give us that number in
comparison to the total number of possible outcomes.
12. If we were to take two dice, roll the dice a large number of
times, and graph the results in the same manner, we would
expect these results to produce a curve such as the one should
in Figure 1.
13. The area under the curve can be mathematically determined
and would correspond to the probability of success of a
particular outcome.
14. For example, to determine the probability of throwing a
particular number between 2 and 12 we would calculate the
area under the curve between 2 and 12. The results of that
calculation would be 36.
15. This is what statistics is all about; random binomial processes
that should produce results in certain patterns that have been
proven over the years.
16. The three models that are used are distribution functions of
binomial processes with different governing parameters.
These functions and their restrictions are:
Refer students to
Figure 1 in Study
Guide.
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a. Binomial distribution
1) This is the most general of the statistical models and
is widely applicable to all processes with a constant
probability.
2) It is not widely used in nuclear applications because
the mathematics are too complex.
b. Poisson distribution
1) A simplified version of binomial distribution is the
Poisson (pronounced "pwusówn") distribution, which
is valid when the probability of success, P(x), is small.
2) If we graphed a Poisson distribution function, we
would expect to see the predicted number of successes
at the lower end of the curve, with successes over the
entire range if sufficient trials were attempted.
3) Thus, the curve would appear as seen in Figure 2.
4) The Poisson model is used mainly for applications
involving counting system background and detection
limits, where the population (i.e., number of counts) is
small.
c. Gaussian distribution
1) Also called the "normal distribution," the Gaussian
(pronounced "Gowziun") distribution is a further
simplification which is applicable if the average
number of successes is relatively large, but the
probability of success is still low.
2) Note that the highest number of successes is at the
center of the curve, the curve is a bell shaped curve,
and the relative change in success from one point to
the adjacent is small.
3) Also note that the mean, or average number of
successes, is at the highest point, or at the center of
the curve.
Refer students to
Figure 2 in Study
Guide.
This will be discussed
in greater detail later.
Refer students to
Figure 3 in Study
Guide
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Section 9
4) The Gaussian, or normal, distribution is applied to
counting applications where the mean success is expected
to be greater than 20.
a) It is used for counting system calibrations and
operational checks, as well as for normal samples
containing activity.
b) It may or may not include environmental samples
(i.e., samples with very low activity).
17. Application of Statistical Models
Application of specific statistical methods and models to
nuclear counting operations is termed counting statistics and is
essentially used to do two things:
a. Predict the inherent statistical uncertainty associated with
a single measurement, thus allowing us to estimate the
precision associated with that measurement.
b. Serve as a check on the normal function of nuclear
counting equipment.
18. Definitions
a. Mode - An individual data point that is repeated the most
in a particular data set.
b. Median - The center value in a data set arranged in
ascending order.
c. Mean - Average value of all the values in the data set.
19. Determination of mode, median and mean
a. Determination of the Mode: In the set of test scores in
Figure 4, a score of 95 occurs (i.e., is repeated) more often
than any other score.
b. Determination of the Median: In the same set of test
scores, this is the score in the middle - where one half of
the scores are below, and the other half are above the
median. The median for the test scores is 90.
Objective 2.03.02
Objective 2.03.03
Objective 2.03.04
Refer students to
Figure 4 in the Study
Guide.
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2.03-11
c. Determination of the Mean: This is found by adding all of
the values in the set together, and dividing by the number
of values in the set. The mean of the test scores is 89.
Mean determination is often expressed using special
symbols, as illustrated in the following equation:
ixx
n
∑
= (Eq. 3)
where: x = mean (sometimes pronounced "x bar")
xi = data point with index i
n = number of data points
Σ = summation symbol
∑
=
n
i 1
xi = x1 + x2 + x3 + ...+ xn
20. Variance and Standard Deviation
Using the Gaussian distribution model depicted in Figure 5 of
the Study Guide, we need to define the terms "variance" and
"standard deviation" which are both used as discriptors of the
spread of the population (or the data set) in a normal
distribution.
a. Variance
1) The amount of scatter of data points around the mean
is defined as the sample variance.
2) In other words, it tells how much the data "varies"
from the mean.
b. Standard deviation
1) A more precise term is the standard deviation,
represented by σ (pronounced "sigma").
2) Mathematically, in a normal distribution, the standard
deviation is the square root of the variance.
3) The standard deviation of a population is defined
mathematically as:
Objective 2.03.05 a.
Objective 2.03.05 b.
Objective 2.03.06
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2.03-12
( )2
σ
ix x
n
∑ −
= (Eq.4)
where: σ = biased standard deviation of the population
xi = sample counts for each data point
x = mean
n = number of data points
4) If most of the data points are located close to the
mean, the curve will be tall and steep and have a low
numerical value for a standard deviation.
5) If data points are scattered, the curve will be lower
and not as steep and have a larger numerical value for
a standard deviation.
Section 10
6) In a Gaussian distribution, it has been determined
mathematically that 68.2% of the area under the curve
falls within the data point located at the mean ± (plus
or minus) one standard deviation (1 σ ); 95.4% of the
area under the curve falls between the data point
located at ± two standard deviations (2 σ ), etc.
7) What this means to us in terms of counting processes
is that if the distribution (as depicted in Figure 5) is
representative of a counting function with a mean
observable success >20 (Gaussian distribution):
a) 68.2% of the time the observed successes (or
counts) will be within ±1 standard deviation of
the mean.
b) 95.4% of the time the observed successes (or
counts) will be within ±2 standard deviations of
the mean.
c) 99.97% of the time the observed successes (or
counts) will be within ±3 standard deviations of
the mean.
8) Remember, the area of the curve represents the
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probability of success in a random process. In
radiation protection this random process is the decay
of a radioactive sample.
9) The known statistical distribution is used in radiation
protection when setting up a counting system and in
evaluating its operation by means of daily pre-
operational source checks.
10) In performing the calibration of the system, a
radioactive source with a known activity is counted
twenty times for one minute each time.
11) Using the data from the twenty counts, the mean and
standard deviation can be calculated.
a) The mean can then be used to determine the
efficiency of the system while allowing for a
certain number of standard deviations during
operation.
b) The twenty counts can also be used to perform
another required test of the system's performance,
the Chi-squared test.
21. Chi-squared Test
a. The Chi-squared test (pronounced "ki") is used to
determine the precision of a counting system.
1) Precision is a measure of exactly how a result is
determined without regard to its accuracy.
2) It is a measure of the reproducibility of a result, or in
other words, how often that result can be repeated, or
how often a "success" can be obtained.
b. This test results in a numerical value, called the Chi-
squared value (X2) which is then compared to a range of
values for a specified number of observations or trials.
c. This range represents the expected (or predicted)
probability for the chosen distribution.
Refer students to
Example 1 in Study
Guide.
Objective 2.03.07
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1) If the X2 value is lower than the expected range, this
tells us that there is not a sufficient degree of
randomness in the observed data.
2) If the value is too high, it tells us that there is too
much randomness in the observed data.
d. The Chi-squared test is often referred to as a
"goodness-of-fit" test. It answers the question: How well
does this data fit a Poisson distribution curve?
e. If it does not fit a curve indicating sufficient randomness,
then the counting instrument may be malfunctioning.
f. The Chi-squared value is calculated as follows:
( )2
2X
ix x
x
∑ −
= (Eq.5)
g. Criteria for acceptable Chi-squared values:
(Insert site specific information here.)
Assuming a given set of data passes the Chi-squared test,
the data can than be used to prepare quality control charts
for use in verifying the consistent performance of the
system.
Section 11
C. Quality Control Charts
1. Quality control charts are prepared using source counting data
obtained during system calibration. The source used for daily
checks should be identical to the one used during system
calibration.
2. Obviously since this test verifies that the equipment is still
operating within an expected range of response, we cannot
change the conditions of the test in mid-stream.
3. QC charts, then, enable us to track the performance of the
system while in use.
Refer students to
Example 2 in Study
Guide.
Objective 2.03.08
Objective 2.03.09
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4. Data that can be used for quality control charts include gross
counts, counts per unit time, and efficiency. Most nuclear
laboratories use a set counting time corresponding to the
normal counting time for the sample geometry being tested.
If smears are counted for one minute, then all statistical
analysis should be based on one-minute counts.
5. When the system is calibrated and the initial calculations
performed, the numerical values of the mean ± 1, 2, and 3
standard deviations are also determined.
6. Using standard graph paper, paper designed specifically for
this purpose, or a computer graphing software, lines are drawn
all the way across the paper at those points corresponding to
the mean, the mean plus 1, 2, and 3 standard deviations, and
the mean minus 1, 2, and 3 standard deviations. The mean is
the center line of the paper.
7. Quality control charts should be maintained in the area of the
radioactivity counting system such that they will be readily
accessible to those who operate the system.
8. These charts can then be used by operators to determine if
routine periodic checks (typically daily) have been completed
before system use.
(Insert site specific information here.)
9. System Operating Limits
a. The values corresponding to ±2 and ±3 standard
deviations are called the lower and upper warning and
control limits, respectively.
b. The results of the daily source counts are graphed daily in
many countrooms.
c. Most of the time our results will lie between the lines
corresponding to ±1 standard deviation (68.2%).
d. We also know that 95.4% of the time our count will be
between ±2 standard deviations and that 99.97% of the
time our count will be between ±3 standard deviations.
e. Counts that fall outside the warning limit (±2 σ ) are
Objective 2.03.10
Objective 2.03.11
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not necessarily incorrect. Statistical distribution models
say that we should get some counts in that area.
1) Counts outside the warning limits indicate that
something may be wrong.
f. The same models say that we will also get some outside
the control limits (±3 σ ). However, not very many
measurements will be outside those limits.
g. We use 3 σ as the control, a standard for acceptable
performance. In doing so we say that values outside of ±3
σ indicate unacceptable performance, even though those
values may be statistically valid.
h. True randomness also requires that there be no patterns in
the data that are obtained; some will be higher than the
mean, some will be lower, and some will be right on the
mean.
i. When patterns do show up in quality control charts, they
are usually indicators of systematic error. For example:
1) Multiple points outside two sigma
Section 12
2) Repetitive points (n out of n) outside one sigma
3) Multiple points, in a row, on the same side of the mean
4) Multiple points, in a row, going up or down.
j. The assumption is made that systematic error is present in
our measurements, and that our statistical analysis has
some potential for identifying its presence.
k. However, industry assumption is that systematic error that
is present is very small in comparison to random error.
D. Counter Efficiency
1. A detector intercepts and registers only a fraction of the total
number of radiations emitted by a radioactive source.
2. The major factors determining the fraction of radiations
Objective 2.03.12
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emitted by a source that are detected include:
a. The fraction of radiations emitted by the source which
travel in the direction of the detector window
b. The fraction emitted in the direction of the detector
window which actually reach the window
c. The fraction of radiations incident on the window which
actually pass through the window and produce an
ionization
d. The fraction scattered into the detector window
3. All radiation detectors will, in principle, produce an output
pulse for each particle or photon which interacts within its
active volume.
4. The detector then would be said to be 100 percent "efficient,"
because 100 percent of the activity was detected and reported.
5. In practice, because of the factors outlined above, the actual
(or total) activity emitted from the source is not detected.
6. Therefore, there is only a certain fraction of the disintegrations
occurring that results in counts reported by the detector.
7. Using a calibrated source with a known activity, a precise
figure can be determined for this fraction.
8. This value can then be used as a ratio in order to relate the
number of pulses counted to the number of particles and/or
photons incident on the detector.
9. This ratio is called the efficiency.
It can also be referred to as the detector yield, since the
detector yields a certain percentage of the actual counts.
10. The detector efficiency gives us the fraction of counts detected
per disintegration, or c/d.
11. Since activity is the number of disintegrations per unit time,
and the number of counts are detected in a finite time, the two
rates can be used to determine the efficiency if both rates are in
the same units of time.
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12. Counts per minute (cpm) and disintegrations per minute (dpm)
are the most common.
13. Thus, the efficiency, E, can be determined as shown in
Equation 6. Used in this manner the time units will cancel,
resulting in counts/disintegration (c/d).
cpm cE
dpm d
= = (Eq.6)
a. The efficiency obtained in the formula above will be in
fractional or decimal form.
b. To calculate the percent efficiency, the fraction can be
multiplied by 100.
1) For example, an efficiency of 0.25 would mean 0.25 ×
100, or 25%.
14. By algebraic manipulation, Equation 6 can be solved for the
disintegration rate (see Equation 7).
15. The system efficiency is determined as part of the calibration.
When analyzing samples, a count rate is reported by the
counting system.
16. Using Equation 7, the activity (A) of the sample can then be
determined in dpm, and then converted to any other units of
activity (e.g., Ci, Bq).
Section 13
dpm
cpm cpmdpm A
E E
= ⎯⎯→ = (Eq.7)
17. As seen in Equation 7 above, the net count rate is divided by
the efficiency.
Objective 2.03.13
Review Example 3 in
Study Guide with
students.
Review Example 4 in
Study Guide with
students.
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18. A correction factor (CF), which is simply the inverse of the
efficiency, is used by multiplying it by the net count rate to
determine the activity, as in Equation 8.
1CF
E
= (Eq.8)
19. This count-rate correction factor should not to be confused
with a geometry correction factor used with some radiation
instruments, such as the beta correction factor for a Cutie Pie
(RO-3C).
E. Error Calculations
1. The error present in a measurement governed by a statistical
model can be calculated using known parameters of that model.
2. Nuclear laboratories are expected to operate at a high degree of
precision and accuracy. However, since we know that there is
some error in our measurements, we are tasked with reporting
measurements to outside agencies in a format that identifies
that potential error.
3. The format that is used should specify the activity units and a
range in which the number must fall. In other words, the
results would be reported as a given activity plus or minus the
error in the measurement.
4. Since nuclear laboratories prefer to be right more than they are
wrong, counting results are usually reported in a range that
would be correct 95% of the time, or at a 95% confidence level.
5. In order to do this, the reported result should be in the format:
x.xx ± yy (K σ ) (Eq. 9)
where: x.xx = measured activity, in units of dpm, Ci, or
Bq
yy = associated potential (or possible) error in
the measurement
K = multiple of counting error
Review Example 5 in
Study Guide with
students.
Objective 2.03.14
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σ = standard deviation at stated confidence
level (CL)
Note: Use of K σ is only required for confidence levels other
than 68% (see Table 6).
Therefore:
σ = 1× σ 68% CL (optional)
1.64 σ = 1.64 × σ 90% CL (sometimes used)
2 σ = 1.96 × σ 95% CL (normally used)
6. For example, a measurement of 150 ± 34 dpm (2 σ ) indicates
the activity as 150 dpm; however, it could be as little as 116
dpm or as much as 184 dpm with 95% confidence (at 2 σ ).
7. The calculations of the actual range of error is based on the
standard deviation for the distribution.
8. In the normal (or Gaussian) distribution, the standard deviation
of a single count is defined as the square root of the mean, or
σ = x
9. The error, e, present in a single count is some multiplier, K,
multiplied by the square root of that mean, i.e., some multiple
times the standard deviation, K σ .
10. The value of K used is based on the confidence level that is
desired, and is derived from the area of the curve included at
that confidence level (see Figure 5).
11. Common values for K are given in Table 4.
12. To calculate the range to the point at which you would expect
to be right 95% of the time, you would multiply the standard
deviation by 1.96, and report the results of the measurement as
x.xx dpm ± yy dpm (2 σ ).
13. Note that using a 68% or 50% confidence level introduces an
expected error a large percentage of the time. Therefore, for
reasonable accuracy a higher confidence level must be used.
Section 14
Refer students to
Table 4 in Study
Guide.
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14. The simple standard deviation (σ ) of the single count (x) is
usually determined as a count rate (counts per unit time). This
is done by dividing the count rate (R) by the count time (T).
Subscripts can be applied to distinguish sample count rates
from background count rates.
σ RK
T
= (Eq.8)
F. Background
1. Determination of Background
a. Radioactivity measurements cannot be made without
consideration of the background.
b. Background, or background radiation, is the radiation that
enters the detector concurrently with the radiation emitted
from the sample being analyzed.
c. This radiation can be from natural sources, either external
to the detector (e.g., cosmic or terrestrial) or radiation
originating inside the detector chamber that is not part of
the sample.
d. In practice, the total counts are recorded by the counter.
This total includes the counts contributed by both the
sample and the background.
e. Therefore, the contribution of the background will produce
an error in radioactivity measurements unless the
background count rate is determined by a separate
operation and subtracted from the total activity, or gross
count rate.
f. The difference between the gross and the background rates
is called the net count rate (sometimes given units of ccpm,
or corrected counts per minute).
g. This relationship is seen in the following equation:
S S B BR R R+= − (Eq.11)
where: RS = net sample count rate (cpm)
Objective 2.03.15
Review Example 6 in
Study Guide with
students.
Objective 2.03.16
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RS+B = gross sample count rate (cpm)
RB = background count rate (cpm)
h. The background is determined as part of the system
calibration by counting a background (empty) planchet for
a given time.
i. The background count rate is determined in the same way
as any count rate, where the gross counts are divided by
the count time, as seen in Equation 12 below.
B
B
B
NR
T
= (Eq.12)
where: RB = background count rate (counts per time,
i.e., cpm)
NB = gross counts, background
TB = background count time
j. For low-background counting systems two background
values must be determined: one for alpha and one for
beta-gamma.
These two values are used to determine background
alpha and beta-gamma sample count rates,
respectively, during calibration and when analyzing
samples.
k. In practice, background values should be kept as low as
possible.
As a guideline, background on automatic counting
systems should not be allowed to exceed 0.5 cpm
alpha and 1 cpm beta-gamma.
2. Reducing background
a. Typically, the lower the system background the more
reliable the analysis of samples will be.
b. In low-background counting systems the detector housing
is surrounded by lead shielding so as to reduce the
background.
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c. Nonetheless, some background still manages to reach the
detector. Obviously, little can be done to reduce the actual
source of background due to natural sources.
On many systems a second detector is incorporated to
detect penetrating background radiation. When a sample
is analyzed the counts detected by this second detector
during the same time period are internally subtracted from
the gross counts for the sample.
Section 15
d. Background originating inside the detector chamber can
be, for the most part, more easily controlled. The main
contributors of this type of background are:
1) Radiation emitted from detector materials
2) Radioactive material on inside detector surfaces
3) Radioactive material on the sample slide assembly
4) Contamination in or on the sample planchet or
planchet carrier
e. There are, unfortunately, trace amounts of radioisotopes in
the materials of which detectors and their housings are
made. This is simply a fact of life in the atomic age.
1) However, the contribution to background from this
source is negligible, but should nonetheless be
acknowledged.
f. Radioactive material can be transferred from contaminated
samples to the inside surfaces of the detector chamber
during counting.
1) This usually occurs when samples having gross
amounts of material on them are counted in a low
background system.
2) During the insertion and withdrawal of the sample
into the detector chamber, loose material can be
spread into the chamber.
3) In order to prevent this, these samples should be
counted using a field survey instrument or a mini-
scaler.
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4) Low-background systems are designed for counting
lower-activity samples. Counting of a high-activity
sample on these systems should be avoided unless it is
a sealed radioactive source.
g. Radioactive material can also be transferred from
contaminated samples to the slide assembly upon which
samples are inserted into, and withdrawn from, the
detector chamber.
1) This can be prevented in the same way as stated above.
In addition, when loading and stacking samples for
counting, ensure that the slide assembly cover is in
place.
2) The slide assembly should also be cleaned on a
routine basis (e.g., weekly).
h. When loading and unloading samples into and from
planchets, material from the samples can be spread to the
planchet and/or the carrier.
1) Most smears and air samples are 47-mm diameter and
are counted in a planchet that is almost the same size.
2) The planchet is placed in a carrier which surrounds
and supports the planchet and allows for automatic
sample exchange by the counting system.
3) When a sample is counted, the entire carrier is placed
under the detector window inside the detector
chamber.
4) Any contamination on the carrier (or in the planchet)
is counted with, and attributed to, the sample.
5) A paper disc can be placed in the bottom of the
planchet as a step in preventing transfer of material
from samples to the planchet.
6) Care should be taken when loading and unloading
samples such that material remains on the sample
media.
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(Insert site specific information here.)
3. Planchet maintenance
a. Planchets and carriers should be inspected, cleaned, and
counted on a routine basis.
1) All in-use planchets and carriers must read less than
established site limits.
2) Planchets exceeding these limits should be
decontaminated and recounted as necessary.
b. By maintaining planchets clean and as free from
contamination as possible, sample result reliability will be
increased because the amount of error introduced in the
sample analysis will be reduced.
(Insert site specific information here.)
G. Propagation of Error
Section 16
1. The error present in a measurement includes the error present
in the sample count, which contains both sample and
background, and the error present in the background count.
Rules for propagation of error preclude merely adding the two
errors together.
2. The total error in the measurement is calculated by squaring
the error in the background and adding that to the square of the
error in the sample count, and taking the square root of the sum,
as shown in Equation 13.
22
BBSs eee += + (Eq.13)
where: eS = error present in the measurement (sample)
eS+B = error in sample count (sample plus
background)
eB = error present in background count
3. Since we normally use this equation in terms of a count rate,
the formula is slightly modified as follows, and the error stated
as the sample standard deviation (σ S):
Objective 2.03.17
Objective 2.03.18
Objective 2.03.19
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S B B
S
S B
R RK K
T T
σ += + (Eq.14)
where: RS+B = gross sample count rate (sample plus
background)
RB = background count rate
TS = sample count time
TB = background count time
K = confidence level multiple (see Table 4)
4. The error in the sample count is the standard deviation of the
count, which is the square root of that count (see Equation 13
above). If we square a square root we get the number we
started with.
5. If the sample counting time and the background counting time
is the same, the formula can be simplified even more to:
S B B
S
R RK K
T
σ + +
= (Eq.15)
H. Improving Statistical Validity of Count Room Measurements
1. Minimizing the statistical error present in a single sample
count is limited to several options. If we look at the factors
present in the calculation below (same as Equation 14), we can
see that there are varying degrees of control over these factors.
2. The standard deviation is calculated here in terms of count rate.
S B B
S B
R Rrate
T T
σ += +
a. RS+B is the sample count rate. We really have no control
over this.
b. RB is the background count rate. We do have some control
over this.
Review Example 7 in
Study Guide with
students.
Review Example 8 in
Study Guide with
students.
Objective 2.03.20
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1) On any counting equipment the background should be
maintained as low as possible.
2) In most of our counting applications, however, the
relative magnitude of the background count rate
should be extremely small in comparison to the
sample count rate if proper procedures are followed.
3) This really becomes an issue when counting samples
for free release or environmental samples.
4) However, some reduction in error can be obtained by
increasing the background counting time, as discussed
below.
c. TB and TS are the background and sample counting times,
respectively. These are the factors that we have absolute
control over.
1) In the previous section we talked about the reliability
of the count itself. We have been able to state that a
count under given circumstances may be reproduced
with a certain confidence level, and that the larger the
number of counts the greater the reliability.
2) The condition we have been assuming is that our
count is taken within a given time. In order to get
more precise results, many counts must be observed.
Therefore, if we have low count rates, the counting
time must be increased in order to obtain many counts,
thereby making the result more precise (or
reproducible).
Section 17
d. The total counting time required depends upon both the
sample and background count rates.
1) For high sample activities the sample count time can
be relatively short compared to the background count
time.
2) For medium count rates we must increase the sample
count time in order to increase precision.
3) As the sample activity gets even lower, we approach
the case where we must devote equal time to the
background and source counts.
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a) In other words, by counting low activity samples
for the same amount of time as that of the
background determination, we increase the
precision of our sample result.
b) However, we must never count a sample for a
period of time longer than that of the system
background.
3. In summary, by minimizing the potential error present, we
improve statistical validity of our measurements.
I. Detection Limits
1. The detection limit of a measurement system refers to the
statistically determined quantity of radioactive material (or
radiation) that can be measured (or detected) at a preselected
confidence level.
This limit is a factor of both the instrumentation and
technique/procedure being used.
2. The two parameters of interest for a detector system with a
background response greater than zero are:
a. LC Critical detection level: the response level at which the
detector output can be considered "above background"
b. LD Minimum significant activity level, i.e., the activity
level that can be seen with a detector with a fixed level of
certainty
3. These detection levels can be calculated by the use of Poisson
statistics, assuming random errors and systematic errors are
separately accounted for, and that there is a background
response.
4. For these calculations, two types of statistical counting errors
must be considered quantitatively in order to define acceptable
probabilities for each type of error:
a. Type I
1) occurs when a detector response is considered above
background when in fact it is not
2) associated with LC
Objective 2.03.21
Refer students to
Figure 6 in Study
Guide.
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b. Type II
1) occurs when a detector response is considered to be
background when in fact it is greater than background
2) associated with LD
5. If the two probabilities (areas labeled I and II in Figure 6) are
assumed to be equal, and the background of the counting
system is not well-known, then the critical detection level (LC)
and the minimum significant activity level (LD) can be
calculated.
6. The two values would be derived using the equations LC = kσB
and LD = k2 + 2kσB, respectively.
7. If 5% false positives (Type I error) and 5% false negatives
(Type II error) are selected to be acceptable levels, i.e., 95%
confidence level, then if for example k = 1.645 and the two
equations can be written as:
1.645 B B
C
B S
R RL
T T
= + (Eq.16)
where: LC = Critical detection level
LD = a priori detection limit [minimum
significant activity level]
k = Poisson probability sum for I and II
(assuming I and II probabilities are equal)
RB = background counts
T = count time (sample and background)
8. The minimum significant activity level, LD, is the a priori
(before the fact) activity level that an instrument can be
expected to detect 95% of the time.
a. In other words, it is the smallest amount of activity that
Section 18
can be detected at a 95% confidence level.
b. When stating the detection capability of an instrument,
this value should be used.
9. The critical detection level, LC, is the lower bound on the 95%
detection interval defined for LD, and is the level at which there
is a 5% chance of calling a background value "greater than
background."
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a. This value (LC) should be used when actually counting
samples or making direct radiation measurements.
b. Any response above this level should be counted as
positive and reported as valid data. This will ensure 95%
detection capability for LD.
10. If the sample count time (TS) is the same as the background
count time (TB), then equations 16 and 17 can be simplified as
follows:
2.32 B
C
RL
T
= (Eq.18)
2.71 4.65 B
D
RL
T
= + (Eq.19)
11. Therefore, the full equations for LC and LD must be used for
samples with count times differing from the background
determination time (95% CL used).
These equations assume that the standard deviation of the
sample planchet/carrier background during the sample count
(the planchet/carrier assumed to be 0 activity) is equal to the
standard deviation of the system background (determined
using the background planchet/carrier).
12. The critical detection level, LC, is used when reporting survey
results.
a. It is used to say that at a 95% confidence level, samples
above this value are radioactive.
b. This presupposes, then, that 5% of the time clean samples
will be considered radioactive.
13. The minimum significant activity level, LD, [also referred to as
the LLD (Lower Limit of Detection) in some texts] is
calculated prior to counting samples.
DOE-HDBK-1122-2009
Module 2.03 Counting Errors and Statistics Instructor’s Guide
2.03-31
a. This value is used to determine minimum count times
based on release limits and airborne radioactivity levels.
b. In using this value we are saying that at a 95% CL,
samples counted for at least the minimum count time
calculated using the LD that are positive will indeed be
radioactive (above the LC). This presupposes, then, that
5% of the time samples considered clean will actually be
radioactive.
(Insert site specific information here.)
J. Crosstalk
1. Discrimination
a. Crosstalk is a phenomenon that occurs on proportional
counting systems (such as a Tennelec) that employ
electronic, pulse-height discrimination, thereby allowing
the simultaneous analysis for alpha and beta-gamma
activity.
b. Discrimination is accomplished by establishing two
thresholds, or windows, which can be set in accordance
with the radiation energies of the isotopes of concern.
c. Recall that the pulses generated by alpha radiation will be
much larger than those generated by beta or gamma.
1) This makes the discrimination between alpha and
beta-gamma possible.
2) Beta and gamma events are difficult to distinguish;
hence, they are considered as one and the same type
by such counting systems.
d. In practice, the lower window is set such that electronic
noise and ultra-low-energy photon events are filtered out.
e. Any pulse generated whose size is greater than the setting
for the lower window is considered an event, or a count.
f. The upper window is then set such that any pulses which
surpass the upper discriminator setting will be considered
an alpha count.
Review Example 9 in
Study Guide with
students.
Objective 2.03.22
Section 19
Objective 2.03.23
Refer students to
Figure 7 in Study
Guide.
DOE-HDBK-1122-2009
Module 2.03 Counting Errors and Statistics Instructor’s Guide
2.03-32
g. For output purposes, the system routes each count to a
series of channels which simply keep a total of the counts
routed to them.
1) Channel A is for alpha counts
2) Channel B is beta-gamma counts
3) Channel C is total counts. As a sample is being
counted, all valid counts registered (i.e., those which
surpass the lower discriminator setting) are routed to
the C-channel.
h. In addition, if the count was considered an alpha count
(i.e., it surpassed the upper discriminator setting) it is
routed to the A-channel; else it is tallied in the B-channel.
i. In effect, what occurs is that the number of beta-gamma
counts (Channel B) are determined by subtracting the
number of alpha counts (Channel A) from the total counts
(Channel C), or B = C - A.
2. Origin of Crosstalk
a. Now that we understand the process involved, there is a
dilemma that stems from the fact that events are identified
by the system as either alpha or beta-gamma according to
the size of the pulse generated inside the detector.
b. The system cannot really tell what type of radiation has
generated the pulse.
c. Rather, the pulse is labeled as "alpha" or "beta-gamma" by
comparing the size of the pulse to the discriminator setting.
It is the setting of the discriminator that poses the dilemma.
d. Alpha particles entering the detector chamber generally
are attenuated by the detector fill-gas because of their high
LET, thereby producing a large pulse.
e. Low-energy beta particles and photons will also lose all
their energy within the detector gas, but nevertheless
produce a smaller pulse because of their lower energies.
DOE-HDBK-1122-2009
Module 2.03 Counting Errors and Statistics Instructor’s Guide
2.03-33
f. High energy beta particles can still retain some of their
energy even after having produced a pulse while
traversing the detector volume.
1) Rather than leaving the detector, as would a photon,
the beta is reflected off of the detector wall and
reenters the volume of gas, causing ionizations and
generating a second pulse.
2) These two pulses can be so close together that the
detector sees them as one large pulse.
3) Because of the large pulse size it can surpass the
upper discriminator setting and is, therefore, counted
as an alpha, and not as a beta.
g. The result is that alpha activity can be reported for a
sample when in fact there was little or no alpha present.
h. Conversely, if a true alpha-generated pulse is not large
enough so as to exceed the upper discriminator, it would
be counted as a beta-gamma event. This is crosstalk.
i. The solution is not a simple one. The setting of the upper
discriminator depends on the radiations and energies of the
sources and samples being analyzed.
1) If high energy beta radiations are involved, a
significant portion of them could be counted as alpha
events if the setting is too low.
2) If the setting is too high, lower-energy alpha events
could be counted as beta-gamma.
j. Typically, the setting of the discriminator will usually be
some "happy medium."
k. A discussion of how this can be dealt with is in order.
3. Calibration Sources and Crosstalk
a. For calibrations of Tennelec counting systems, the
manufacturer provides the following general
recommendations for discriminator settings:
Section 20
DOE-HDBK-1122-2009
Module 2.03 Counting Errors and Statistics Instructor’s Guide
2.03-34
b. First, using a Strontium-90 beta source, set the upper (α)
discriminator such that there is 1% beta-to-alpha crosstalk.
c. Then, using a Polonium-210 alpha source, set the α+β
discriminator such that there is less than 3% alpha-to-beta
crosstalk.
d. Energies of sources used to calibrate counting systems
should be the same as, or as close as possible to, the
energies of isotopes in the samples analyzed.
e. Wherever possible they should be a pure emitter of the
radiation of concern.
f. For beta-gamma sources the most popular isotope in
radiation protection is Sr-90.
1) It has a relatively long half-life of 29.1 years, but
emits betas of only 546 keV.
2) However, Sr-90 decays to Yttrium-90, another beta
emitter which has a short half-life of only 2.67 days
and emits a 2.281 MeV beta.
3) Y-90 decays to Zirconium-90m which emits a 2.186
Mev gamma almost instantaneously to become stable.
4) The daughters reach equilibrium with the strontium
parent within a number of hours after source assay.
5) Hence, for every Sr beta emitted a Y beta is also
emitted, thereby doubling the activity.
6) These sources are often listed as Sr/Y-90 for obvious
reasons.
7) This makes Sr/Y-90 sources an excellent choice and
are used by many sites for calibrations and
performance testing.
g. Po-210 is essentially a pure alpha emitter. This is
primarily the reason why it is recommended for
calibrations and performance testing.
1) It yields a strong alpha, but it also has a short half-life.
A comparison of some alpha emitters is given in
Table 5.
Refer students to Table 5 in
Study Guide.
DOE-HDBK-1122-2009
Module 2.03 Counting Errors and Statistics Instructor’s Guide
2.03-35
(Insert site specific information here.)
K. Voltage Plateaus
1. Very simply put, a voltage plateau is a graph that indicates a
detector's response to an isotope with variations of high
voltage.
a. The x-axis represents the high voltage and the y-axis the
response (i.e., counts).
b. The resulting curve gives an indication of detector quality,
and can indicate problems with the counting gas should
they be present.
c. The curve can also be used to determine the optimum
operating high voltage for the system.
2. Most automatic low-background counting systems provide
several different analysis modes. These modes count samples
at certain pre-determined voltages.
3. Counting systems generally provide three analysis modes:
• Alpha only
• Alpha then Beta
• Alpha and Beta (simultaneous)
4. There are usually two voltage settings used in conjunction with
these analysis modes:
• Alpha voltage (lower)
• [Alpha plus] Beta voltage (higher)
5. Recall that in a proportional counter the amount of voltage
determines the amount of gas multiplication.
6. Because of the high LET of alpha radiation, at a lower voltage,
even though the gas amplification will be lower, alpha pulses
will still surpass the lower discriminator and some will even
pass the upper discriminator.
7. Because of the lower gas amplification beta-gamma pulses will
not be large enough to be seen. Therefore, any counts reported
for the sample will be alpha counts.
Objective 2.03.24
Objective 2.03.25
DOE-HDBK-1122-2009
Module 2.03 Counting Errors and Statistics Instructor’s Guide
2.03-36
8. In the Alpha only mode, the sample is counted once, at the
alpha voltage. Counts may appear in either the A or B
channels.
Section 21
a. Upon output, the A and B channels will be added together
and placed in Channel A and, therefore, reported as alpha
counts; the B channel will be cleared to zero, thereby
resulting in no beta-gamma counts.
9. In the Alpha then Beta mode, the sample is counted twice.
a. The first count interval determines the alpha counts using
the alpha voltage.
b. The second count is done at the beta voltage.
c. The determination of alpha and beta-gamma counts in this
mode is based strictly on the operating characteristics of
the detector at the different voltages.
d. For this reason, the A and B counts are summed during
both counting intervals to attain the total counts.
e. The separation of alpha and beta-gamma counts is then
calculated and reported according to the following
formula:
( )
1 1
α
2 2
α
β α
A B
CF
A B
+
=
= − −
(Eq.20)
where: α = reported gross alpha counts
β = reported gross beta-gamma counts
A1,B1 = accumulated channel counts respectively,
1st interval
A2,B2 = accumulated channel counts respectively,
2nd interval
CFα = alpha correction factor (ratio of alpha
efficiency at alpha voltage to efficiency at
beta voltage)
DOE-HDBK-1122-2009
Module 2.03 Counting Errors and Statistics Instructor’s Guide
2.03-37
10. In the Alpha and Beta (simultaneous) mode, the sample is
counted once using the beta voltage.
a. Alpha events are reported in the A channel, while beta-
gamma counts are reported in the B channel.
b. This is the mode used most often.
11. As can be seen, the setting of the two voltages will have a
direct impact on the number of counts reported for a given
sample.
12. The determination of what these voltage settings should be
must be done such that the optimum performance of the
detector is obtained for those voltage regions. This is the
purpose of a plateau.
(Insert site specific information here. The information that
follows may be used as applicable.)
13. In conjunction with initial system setup and calibration by the
vendor, two voltages plateaus are performed--alpha voltage
and beta voltage.
14. For P-10 gas the alpha plateau is started at about 400 volts and
the beta plateau at about 900 volts.
15. Alpha and beta plateaus are defined by the isotope being used
and not by the channel being used to accumulate the counts.
16. More appropriately, the gross counts are accumulated and
plotted for each type of isotope.
17. Each time that a count is completed, the high voltage is
incremented a specific amount, typically 25 to 50 volts, and
another count is accumulated.
18. This is repeated until the end of the range is reached, typically
about 1800 volts.
19. With the high voltage set at the starting point, few or no counts
are observed because of insufficient ion production within the
detector.
20. As the voltage is increased, a greater number of pulses are
produced with sufficient amplitude to exceed the discriminator
threshold, and are then accumulated in the counter.
Objective 2.03.26
DOE-HDBK-1122-2009
Module 2.03 Counting Errors and Statistics Instructor’s Guide
2.03-38
21. There will be a high voltage setting where the increase in
counts levels off (see Figure 8).
22. This area is the detector plateau. Further increases in high
voltage result in little change in the overall count rate.
23. The plateau should remain flat for at least 200 volts using a
Sr/Y-90 source, and this indicates the plateau length.
24. Between 1750 and 1850 volts the count rate will start to
Section 22
increase dramatically. This is the avalanche region, and the
high voltage should not be increased any further.
25. The region where the counts level off is called the knee of the
plateau.
26. The operating voltage is chosen by viewing the plateau curve
and selecting a point 50 to 75 volts above the knee and where
the slope per 100 volts is less than 2.5%.
27. This ensures that minor changes in high voltage will have
negligible effects on the sample count. Poor counting gas or
separation of the methane and argon in P-10 can result in a
very high slope of the plateau.
28. Upon initial system setup and calibration the vendor
determines and sets the optimum operating voltages for the
system. Thereafter, plateaus should be generated each time the
counting gas is changed.
III. SUMMARY
This unit addressed the measures used to minimize error, fundamentals
of binomial statistics and application of these fundamentals in a nuclear
counting environment.
IV. EVALUATION
Evaluation should consist of a written examination comprised of
multiple choice, fill-in the blank, matching and/or short answer
questions. 80% should be the minimum passing criteria for
examinations.
[If used, refer students to
Beta voltage figure in
student guide]
DOE-HDBK-1122-2008
Module 2.04 Dosimetry Instructor’s Guide
2.04-1
Course Title: Radiological Control Technician
Module Title: Dosimetry
Module Number: 2.04
Objectives:
2.04.01 Identify the DOE external exposure limits for general employees.
2.04.02 Identify the DOE limits established for the embryo/fetus of a declared pregnant female
general employee.
→ 2.04.03 Identify the administrative exposure control guidelines at your site, including those for
the:
a. General Employee
b. Member of the Public/Minor
c. Incidents and emergencies
d. Embryo/Fetus
→ 2.04.04 Identify the requirements for a female general employee who has notified her employer
in writing that she is pregnant.
2.04.05 Determine the theory of operation of a thermoluminescent dosimeter (TLD).
2.04.06 Determine how a TLD reader measures the radiation dose from a TLD.
2.04.07 Identify the advantages and disadvantages of a TLD compared to a film badge.
→ 2.04.08 Identify the types of beta-gamma TLDs used at your site.
→ 2.04.09 Identify the types of neutron TLDs used at your site.
→ 2.04.10 Determine the requirements for use of TLDs used at your site.
→ 2.04.11 Determine the principle of operation, and the types used, for the personnel neutron
dosimeters used at your site.
→ 2.04.12 Determine the principle of operation of self-reading dosimetry (SRD) used at your site.
→ 2.04.13 Determine the principle of operation, and guidelines for use, for the alarming dosimeters
used at your site.
→ 2.04.14 List the types of bioassay monitoring methods at your site.
2.04.15 List different uses of area monitoring dosimeters.
DOE-HDBK-1122-2008
Module 2.04 Dosimetry Instructor’s Guide
2.04-2
References:
1. "Basic Radiation Protection Technology"; Gollnick, Daniel; 5th ed.; Pacific Radiation
Corporation; 2008.
2. ANL-88-26 (1988) "Operational Health Physics Training"; Moe, Harold; Argonne
National Laboratory, Chicago.
3. "DOE Radiological Control Standard"; U.S. Department of Energy, 2008.
4. 10 CFR Part 835 (2007) "Occupational Radiation Protection".
Instructional Aids:
1. Overheads
2. Overhead projector/screen
3. Chalkboard/whiteboard
4. Lessons learned
DOE-HDBK-1122-2009
Module 2.04 Dosimetry Instructor’s Guide
Section 23
2.04-3
I. MODULE INTRODUCTION
A. Self-Introduction
1. Name
2. Phone number
3. Background
4. Emergency procedure review
B. Motivation
This lesson will introduce the types of instruments used to
measure external and internal radiation to people. Dosimetry is
the quantitative assessment of radiation received by the human
body. There are several types of dosimeters in use worldwide.
This material is valuable to all radiological control personnel
since dosimeters are the only direct method to measure and
document personnel radiation exposure and ensure regulatory
compliance with applicable limits.
C. Overview of Lesson
1. Dosimetry terms
2. DOE limits
3. Site administrative guidelines
4. TLDs
5. Site dosimetry
6. Bioassay assessment methods
D. Introduce Objectives
II. LESSON OUTLINE
A. DOSIMETRY TERMS
Understanding the terminology used in discussing dosimetry and
exposure to ionizing radiation is essential for RCTs to do their
job.
1. Absorbed Dose (D)
O.H.: Objectives
Majority from 835.2
Refer to the definitions
provided in the Study
Guide and review terms
with class.
DOE-HDBK-1122-2009
Module 2.04 Dosimetry Instructor’s Guide
2.04-4
2. Equivalent Dose (HT)
3. Whole Body
4. Extremity
7. Committed Equivalent Dose (HT,50)
8. Radiation Weighting Factor (wR)
9. Committed Effective Dose (E50)
10. Total Effective Dose (TED)
11. Annual Limit on Intake (ALI)
12. Derived Air Concentration (DAC)
13. Bioassay
14. In Vivo
15. In Vitro
16. Background
17. Declared Pregnant Worker
B. DOE LIMITS
1. Limits are the legal maximum values stated in 10 CFR 835.
To exceed these values is to violate the law. Programs must
be in place to ensure that exposures to ionizing radiation are
kept below these levels. To accomplish this Administrative
Control Levels are selected well below the regulatory limits.
These control levels are usually multi-tiered with increasing
levels of authority required to approve higher Administrative
Control Levels.
2. Annual dose limits are based on a calendar year (January 1st
through December 31st). For assigning internal equivalent
dose received from intakes (committed effective dose and
committed equivalent dose), the total 50-year committed dose
received is assigned to the time of the intake even though the
actual dose is proportionally received over the 50-year period.
3. See Table 3 for dosimetric equivalencies for circumstances
when an individual conducts multiple activities involving
both activities under 10 CFR 835.1(b)(1) and excluded
activities, e.g., activities involving NRC licensed activities.
Explain that the terms
were revised in the 2007
amendment to 10 CFR
835
Objective 2.04.01
See Table 2
See Table 3
DOE-HDBK-1122-2009
Module 2.04 Dosimetry Instructor’s Guide
2.04-5
a. General Employees
1) Whole body (internal + external) - 5 rems (0.05
sievert)
2) Lens of the eye - 15 rems (0.15 sievert)
3) Extremities - 50 rems (0.5 sievert)
4) Organ or tissue and skin - 50 rems (0.5 sievert)
b. Minors/Public - 0.1 rem (0.001 sievert)
c. Embryo/Fetus of Declared Pregnant Workers - 0.5 rems
(0.005 sievert) per gestation period
d. Emergency Exposures
e. Planned Special Exposures
C. SITE ADMINISTRATIVE GUIDELINES
1. Radiological Workers
(Insert site specific information here)
2. Non-Radiation Worker
(Insert site specific information here)
3. Exposure from Incidents or Emergencies
(Insert site specific information here)
4. Embryo/fetus
Section 24
(Insert site specific information here)
D. TYPES OF DOSIMETRY
1. As a result of irradiation, some solid substances undergo
changes in some of their physical properties.
2. These changes amount to storage of the energy from the
radiation.
3. Since the energy is stored, these materials can be used for
dosimeters. The features that have been studied include:
10 CFR 835.202
10 CFR 835.207 & .208
10 CFR 835.206
Objective 2.04.02
DOE G 151.1-4,
Chapter 7
10 CFR 835.204
Objective 2.04.03.a
Objective 2.04.03.b
Objective 2.04.03.c
Objective 2.04.03.d
DOE-HDBK-1122-2009
Module 2.04 Dosimetry Instructor’s Guide
2.04-6
a. Optical density changes
1) Optical density changes involve a change in the color
of some types of plastics and glass.
2) In glass, the dose range is 103 to 106 rads (10 to 104
gray). The range for plastics is 106 to 109 rads (104 to
107 gray).
3) An example, film badges, provides low range, 10 mR
to 10 R, for personnel and high range, 1 R to 1,000 R
for accident readings.
b. Thermoluminescence
1) Thermoluminescence (TL) is the ability of some
materials to convert the energy from radiation to a
radiation of a different wavelength, normally in the
visible light range.
2) There are two categories of thermoluminescence.
a) Fluorescence - This is emission of light during or
immediately after irradiation (within fractions of
a second) of the phosphor. This is not a
particularly useful reaction for TLD use.
b) Phosphorescence - This is the emission of light
after the irradiation period. The delay time can
be from a few seconds to weeks or months. This
is the principle of operation used for
thermoluminescent dosimeters.
3) The property of thermoluminescence of some
materials is the main method used for personnel
dosimeters at DOE facilities and will be discussed in
further detail.
E. TLD OPERATION
1. TLD's use phosphorescence as their means of detection of
radiation.
2. Electrons in some solids can exist in two energy states, called
the valence band and the conduction band. The difference
between the two bands is called the band gap.
3. Electrons in the conduction band or in the band gap have
more energy than the valence band electrons.
Example - TV or
computer monitor screen
Objective 2.04.05
DOE-HDBK-1122-2009
Module 2.04 Dosimetry Instructor’s Guide
2.04-7
4. Normally in a solid, no electrons exist in energy states
contained in the band gap. This is a "forbidden region."
5. In some materials, or if impurities are added, defects in the
material exist or are made that can trap electrons in the band
gap and hold them there. These trapped electrons represent
stored energy for the time that the electrons are held. This
energy is given up if the electron returns to the valence band.
6. In most materials, this energy is given up as heat in the
surrounding material, however, in some materials a portion of
energy is emitted as light photons. This property is called
luminescence.
F. TLD Reader
1. Basic principle of operation
a. Heating of the TL material causes the trapped electrons
to return to the valence band. When this happens, energy
is emitted in the form of visible light.
b. The light output is detected and measured by a
photomultiplier tube and a dose is then calculated.
c. A typical basic TLD reader contains the following
components:
1) Heater
2) Photomultiplier tube
3) Meter/recorder
2. Glow curve
a. Obtained from heating process.
Section 25
b. The light output from TL material is not easily
interpreted. Multiple peaks result.
1) As the material is heated, electrons trapped in
"shallow" traps are released. This results in a peak as
these traps are emptied. The light output drops off as
these traps are depleted.
See figure 1 - "Electron
Entrapment"
See figure 2 -
"Thermoluminescence"
Objective 2.04.06
See figure 3 - "TLD
Reader"
See figure 4 - "Glow
curve"
DOE-HDBK-1122-2009
Module 2.04 Dosimetry Instructor’s Guide
2.04-8
2) As heating continues, the electrons in deeper traps
are released. This results in additional peaks.
Usually the highest peak is used for calculations.
The area under the curve represents the radiation
energy deposited.
c. After the readout is complete, the TLD is annealed at a
high temperature. This process essentially zeroes the TL
material by releasing all trapped electrons. The TLD is
then ready for reuse.
G. ADVANTAGES AND DISADVANTAGES OF TLDs
1. Advantages (primarily as compared to film badges)
a. Able to measure a greater range of doses.
b. Doses may be easily obtained.
c. They can be read on site instead of being sent away for
developing.
d. Quicker turnaround time for readout.
e. Reusable.
2. Disadvantages
a. Each dose cannot be read out more than once.
b. The readout process effectively "zeroes" the TLD.
H. SITE BETA/GAMMA TLDs
(Insert site specific information here)
I. SITE NEUTRON TLDs
(Insert site specific information here)
J. DOE EXTERNAL DOSIMETRY GENERAL PROVISIONS
1. Dosimetry shall be provided to and used by:
a. General employee expected equivalent dose to the whole
body > 0.1 rem (0.001 sieverts); or > 10% of limits for
extremities, organs, and other tissues.
b. Declared pregnant worker expected to receive 0.05 rem
(0.0005 sievert) or more during the gestation period.
Objective 2.04.07
Objective 2.04.08
Objective 2.04.09
10 CFR 835
DOE-HDBK-1122-2009
Module 2.04 Dosimetry Instructor’s Guide
2.04-9
c. Minors likely to receive 50% of Occupational Dose
Limits or more in a year.
d. Public entering controlled areas likely to receive external
equivalent dose to the whole body of 0.05 rem (0.0005
sievert) or more in one year.
e. Individuals entering a high or very high radiation area.
2. Neutron dosimetry provided when applicable threshold is
likely to exceeded due to neutron radiation.
3. Issued to individuals knowledgeable of proper use and worn
only by assignee.
4. Issuance of dosimeters should be discouraged for individuals
other than those where there is a likelihood of being
occupationally exposed to levels above monitoring thresholds.
5. Dosimeters should be returned at required intervals.
Individuals not returning dosimeters should be restricted.
6. Primary dosimeters should be worn on the chest area or
between the waist and the neck.
7. Individuals should not be assigned multiple primary
dosimeters during different periods of the dosimeter process
year (exchange of primary dosimeter for multi-badging is
acceptable); and avoid exposure of dosimeter to non-
occupational sources.
8. When dosimeters are lost, damaged, or contaminated, the
individual should place work in a safe condition, exit and
notify the RCO. Reenter only after review and approval.
K. SITE REQUIREMENTS FOR USE OF TLDs
(Insert site specific information here)
L. SITE PERSONNEL NEUTRON DOSIMETERS
(Insert site specific information here)
M. POCKET AND ELECTRONIC DOSIMETERS
Section 26
1. Provide real time dose indication.
2. Shall be issued for entry into High or Very High Radiation
Area.
Objective 2.04.10
Objective 2.04.11
DOE-HDBK-1122-2009
Module 2.04 Dosimetry Instructor’s Guide
2.04-10
3. Should be issue when planned activity levels exceed 0.05 rem
(0.0005 sievert) or 10% of control levels.
4. Should be issued when required by RWP.
5. Worn with primary dosimetry and located on chest area, on
or between the waist and the neck.
6. Should be read periodically and should not exceed 75% of
full scale.
7. Authorized work should cease when supplemental dosimeter
indicates total dose or dose rate is > than expected.
8. When supplemental dosimeters differ by more than 50%
from primary dosimeters and the primary result is >0.1 rem
(0.001 sievert), an investigation should be initiated.
N. SITE SELF-READING DOSIMETERS
(Insert site specific information here)
1. Self Reading Pocket Dosimeters (SRPD)
a. Direct reading ion chamber.
b. Utilizes two electrodes:
1) Fiber electrometer (fixed and moveable components)
2) Metal frame
c. As chamber is ionized the charge is decreased on the
movable and fixed fiber.
d. The movement of the fiber is proportional to the dose
received.
O. SITE ALARMING DOSIMETRY
(Insert site specific information here)
P. INTERNAL DOSIMETRY REQUIREMENTS
Objective 2.04.12
See figure 5 - "SRPD"
Note: SRPDs with steel
walls are usually
insensitive to beta and
low energy gamma
See figure 6 -"SRPD
Reading"
Objective 2.04.13
Re-enforce difference
between "internal" and
"external" dose
DOE-HDBK-1122-2009
Module 2.04 Dosimetry Instructor’s Guide
2.04-11
1. Internal dose evaluation programs shall be conducted for:
a. General employees - likely to receive 0.1 rem (0.001
sievert) or more committed effective dose.
b. Declared pregnant workers - likely to receive an intake
resulting in an equivalent dose of 10% of the limit (or
0.05 rem [0.0005 sievert]).
c. Minors - likely to receive a committed effective dose in
excess of 50% of limit (or 0.05 rem [0.0005 sievert]).
d. Public - likely to receive a committed effective dose in
excess of 50% of limit (or 0.05 rem [0.0005 sievert]).
2. Estimation shall be based on bioassay results rather than air
concentration values unless air concentration values are more
reliable or bioassay results are unavailable.
3. Follow-up bioassay monitoring is typically required when
results indicate a committed effective dose of 0.1 rem (0.001
sievert) or more.
4. A bioassay program should be considered for personnel
routinely exposed to surface or airborne contamination or to
radionuclides readily absorbed through the skin.
5. Personnel are required to submit bioassay samples.
6. Personnel shall be notified of positive bioassay results.
Q. BIOASSAY ASSESSMENT METHODS
1. General
a. Today's technology has not produced a device that allows
accurate determination of internal exposure following the
entry of radioactive materials into the body.
b. The method that is used to determine internal dose
contributions relies on calculation of dose to affected
portions of the body based on the quantities of
radioactive materials in the body. Thus, the real problem
becomes one of quantifying the amount of material
present.
c. Bioassay is the term that is used to describe the
assessment of the quantity of radioactive material present
in the body. There are currently two types of bioassay
measurements employed in nuclear industries:
Section 27
10 CFR 835.402
DOE-HDBK-1122-2009
Module 2.04 Dosimetry Instructor’s Guide
2.04-12
1) In vivo - analysis of living tissue.
2) In vitro - analysis of excreted samples.
d. Bioassay programs are designed to fulfill two needs:
1) Evaluate effectiveness of contamination control
practices.
a) Routine bioassay programs utilize submission
and analysis of samples from workers in facilities
where the likelihood of intake exists.
b) Primarily limited to urinalysis due to ease of
sample collection.
c) Also includes initial, routine, and termination
whole body counts.
2) Evaluate potential consequences of accidental
inhalation or ingestion of large quantities of
radioactive materials.
a) Can involve all types of bioassay measurements
with collection and analysis of nasal, urine, and
fecal samples.
b) Whole body counts provide immediate
indications for given radionuclides if
individual(s) involved are free of external
contamination.
2. In vivo measurements
a. The amount of materials is estimated by counting
radiation emitted by radioactive materials in the body.
b. Only good for radioactive materials which emit gamma
radiation of sufficient abundance and energy to be
detected and statistically measured.
c. With use of expensive, sophisticated spectroscopy, most
contributors (radionuclides present) can be identified.
d. Site In vivo methods
(Insert site specific information here)
e. Advantages
Objective 2.04.14
DOE-HDBK-1122-2009
Module 2.04 Dosimetry Instructor’s Guide
2.04-13
1) No sample required.
2) Results obtained quickly.
3) Some equipment design allows field use.
4) Time and manpower requirements minimized.
f. Disadvantages
1) Limited to detection and measurement of gamma
emitters.
2) Individual must be free of external contamination.
3) Long count times for identification.
4) Effects of background.
5) Complex calibration procedure and calibration
equipment.
6) Expense.
7) Quantification error due to differences in tissue
structure from one person to another as compared to
calibration phantom.
3. In Vitro Measurements
a. The amount of material present in the body is estimated
using the amount of materials present in excretions or
secretions from the body.
b. Samples include urine, feces, blood, sputum, saliva, hair
and nasal discharges.
c. Calculation requires knowledge of and use of metabolic
models which allow use of activity in samples to be
related to activity present in the body.
d. Resulting dose calculations to quantify committed and
effective doses are estimates.
1) This is due partly to use of default values for
measurements that cannot be readily made such as
mass of particular organs, volumes of particular
fluids, etc., in lieu of actual values for individual
involved. Remember that reference man is an
average.
DOE-HDBK-1122-2009
Module 2.04 Dosimetry Instructor’s Guide
2.04-14
2) Another contributing factor is different metabolism
from one individual to another.
e. Types of analysis
1) Urinalysis - indicates intake of primarily soluble
material.
2) Fecal analysis - primarily indicates intake of
insoluble material. Provides relatively rapid
indication.
3) Sputum - may contain insoluble material initially
deposited in the lung and later eliminated by ciliary
action.
4) Saliva - may be use to estimate uptake of tritium
oxide.
5) Nasal discharge - indication of the deposition of the
coarsest inhaled particles in the nose.
Section 28
f. Site in vitro methods
(Insert site specific information here)
g. Advantages of in vitro measurements
1) Can be used for estimation of neutron doses using
activation product concentration in hair and blood
(32P and 24Na).
2) Can be used to quantify presence of materials which
decay by alpha and beta emission to allow detection
and measurement with external detector systems.
h. Disadvantages
1) Requires sample submission and analysis.
2) Time and manpower requirements.
3. Bioassay Scheduling Program
a. Contamination found at a given site will depend on the
materials that are used and produced at the site. Thus,
the materials that internal dosimetrists are primarily
concerned with will change from one site to another as
well.
Objective 2.04.14
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Module 2.04 Dosimetry Instructor’s Guide
2.04-15
b. Baseline/Routine/Exit Evaluations
(Insert site specific information here)
c. Special Evaluations
(Insert site specific information here)
d. Investigation Levels
(Insert site specific information here)
e. Medical Uses
(Insert site specific information here)
R. AREA MONITORING DOSIMETERS
1. Area monitoring dosimeters are often used to record and
document radiation levels in routinely occupied areas
adjacent to areas where radiation or radiological operations
exist.
Note: This type of monitoring does not apply when the
radiation hazard of concern arises from low-energy beta
sources (e.g., 14C, 3H).
2. Establishment and maintenance of a comprehensive area
monitoring program can demonstrate that doses outside
Radiological Buffer Areas are negligible, and help to
minimize the number of areas requiring the issuance/use of
personnel dosimeters.
Minimizing the number of personnel dosimeters issued saves
in the costs of operating the dosimetry program and reduces
costs associated with maintaining personnel with enhanced
training and qualifications.
3. Area monitoring dosimeters are also used to help characterize
workplace conditions to verify the effectiveness of physical
design features, engineering controls, and administrative
controls. In addition, area monitoring dosimeter results can
be used to support dosimetry investigations where personnel
express concerns about their work environments and
exposure to ionizing radiation.
4. Finally, area (and equipment) monitoring dosimeters are
useful for the determination of dose rates and/or integrated
doses for:
Objective 2.04.15
DOE-HDBK-1122-2009
Module 2.04 Dosimetry Instructor’s Guide
2.04-16
a. equipment and/or areas with suspected high dose rates;
b. devices emitting pulsed radiation not accurately
measured with portable survey instruments;
c. highly collimated beams of radiation; and
d. radiological incidents.
III. SUMMARY
A. Review major topics
1. Dosimetry terms
2. DOE limits
3. Site administrative guidelines
4. TLDs
5. Site dosimetry
6. Bioassay assessment methods
B. Review learning objectives
IV. EVALUATION
Evaluation shall consist of a written examination comprised of
multiple choice, fill-in the blank, matching and/or short answer
questions. 80% shall be the minimum passing criteria for
examinations.
DOE-HDBK-1122-2009
Module 2.05 Contamination Control Instructor’s Guide
2.05-1
Course Title: Radiological Control Technician
Module Title: Contamination Control
Module Number: 2.05
Objectives:
2.05.01 Define the terms "removable and fixed surface
contamination," state the difference between them
and list common methods used to measure each.
Section 29
2.05.02 State the components of a radiological monitoring
program for contamination control and common
methods used to accomplish them.
2.05.03 State the basic goal of a contamination control
program and list actions that contribute to its
success.
2.05.04 State the basic principles of contamination control
and list examples of implementation methods.
2.05.05 List and describe the possible engineering control
methods used for contamination control.
2.05.06 State the purpose of using protective clothing in
contamination areas.
2.05.07 List the basic factors which determine protective
clothing requirements for personnel protection.
References:
1. "DOE Radiological Control Standard"; U.S. Department of
Energy, 2008.
2. "The Health Physics and Radiological Health Handbook,"
Shleien; 1992.
3. 10 CFR Part 835 (2007) "Occupational Radiation
Protection".
Instructional Aids:
1. Overheads
2. Overhead projector/screen
3. Chalkboard/whiteboard
4. Lessons learned
DOE-HDBK-1122-2009
Module 2.05 Contamination Control Instructor’s Guide
2.05-2
I. MODULE INTRODUCTION
A. Self-Introduction
1. Name
2. Phone number
3. Background
4. Emergency procedure review
B. Motivation
Contamination control is probably one of the most difficult and
challenging tasks the Radiological Control Technician will
encounter.
C. Overview of Lesson
1. Types of Contamination
2. Assessing Contamination Hazards
3. Basic Goal of Contamination Control
4. Contamination Control Measures
5. Basis for Establishing Protective Clothing Requirements
D. Introduce Objectives
II. MODULE OUTLINE
A. TYPES OF CONTAMINATION
Contamination is simply defined as radioactive material in an
unwanted location, e.g., personnel work areas, etc. Two types are
possible:
1. Fixed Contamination - Radioactive surface contamination
that is not easily transferred to other personnel or equipment
through normal contact.
2. Removable Contamination - Radioactive surface
contamination that is easily transferred to other personnel or
equipment through normal contact.
O.H.: Objectives
Objective 2.05.01
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Module 2.05 Contamination Control Instructor’s Guide
2.05-3
3. Removable contamination is measured by a transfer test
using a suitable sampling material. Common materials used
for the monitoring are the standard paper disk smear or cloth
smear. The standard technique involves wiping
approximately 100 cm2 of the surface of interest using
moderate pressure. A common sampling practice used to
ensure a 100 cm2 sample is to wipe a 16 square inch "S"
shape on the surface (i.e., four inches by four inches).
Qualitative, large area wipe surveys may be taken using other
materials, such as Masslin cloth or Kimwipe, to indicate the
presence of removable contamination. These are commonly
used when exact levels of contamination are not required.
4. Fixed contamination is measured by use of a direct survey
technique. This technique, commonly referred to as
"frisking," indicates the total contamination on a surface
apparent to the detector from both fixed and removable. To
evaluate the fixed component the removable level must be
subtracted from the total, when non-removable levels are to
be recorded.
Appendix D to 10 CFR 835 lists contamination levels in units
of dpm/100 cm2. Typical evaluation of fixed contamination
monitoring includes adjusting the portable instrument count
rate (counts per minute) to account for the area of the
monitoring instrument (probe area) and the instrument
efficiency to obtain units of dpm/100 cm2.
Section 30
Footnote 4 to Appendix D states that when “removable
contamination on objects of surface area less than 100 cm2 is
determined, the activity per unit area shall be based on the
actual area and the entire surface shall be wiped”. For
example, for an object with a total surface area of 50 cm2, the
entire object would be wiped and the count result would be
divided by the counting efficiency and multiplied by an area
adjustment factor of two (100 cm2/50 cm2) to get a result in
units of dpm/100 cm2. A similar approach may be used for
fixed contamination monitoring of objects with surface area
less than 100 cm2. However, care must be taken in
monitoring very small objects and the sensitivity of the
monitoring protocol should be evaluated.
DOE-HDBK-1122-2009
Module 2.05 Contamination Control Instructor’s Guide
2.05-4
B. ASSESSING CONTAMINATION HAZARDS
In order to acquire the radiological information necessary for
contamination control, the presence of contamination must be
identified. In order to achieve this, a radiological monitoring
program must be applied. The components are:
• Constant monitoring
• Area and equipment surveys
• External personnel surveys
• Personnel internal monitoring and bioassay
1. Constant monitoring - There are various types of constant
monitoring instruments installed throughout facilities to warn
personnel of radiation and contamination hazards. Identify
the types of instrumentation used in the constant monitoring.
a. Some instruments are permanently installed, and some
instruments are portable to allow movement from place
to place as deemed appropriate.
b. Continuous air monitor (CAM) - These instruments
sample the air in specific locations continuously for
radioactive contamination. Other methods of
continuously monitoring for airborne contamination are
also used.
Objective 2.05.02
DOE-HDBK-1122-2009
Module 2.05 Contamination Control Instructor’s Guide
2.05-5
1) Filter monitors draw air through a moving particulate
filter, which is then monitored by a detector system.
2) Direct monitors pull air flow through an internal
detector to directly identify radioactive materials
present.
3) CAMs can give both a visual and audible alarm to
warn personnel of the presence of airborne
contamination.
c. Process monitoring systems - These systems monitor
certain operations in various facilities to alert operators of
abnormal conditions which might lead to the release of
excessive amounts of radioactivity to the facility or
environment.
2. Area and equipment surveys - Surveys are conducted
routinely throughout facilities to locate sources of radiation
and contamination. Pre-job surveys are performed to
evaluate hazards and determine work limitations and physical
safeguards within locations identified.
a. Direct instrument surveys
1) Various types of portable survey instrumentation are
used to measure the presence of radioactive
contamination on a floor or surface.
2) This is the only method available to detect "fixed"
surface contamination.
b. Smear surveys
1) A disk smear is wiped over an area of 100 square
centimeters and counted with proper instrumentation
to determine the activity of the nuclides present in
units of dpm/100 cm2.
a) Disk smears are small so they are usually used in
an area of suspected contamination.
b) Experience will dictate to the surveyor where
contamination is most likely to occur and hence
those areas that should be surveyed with disk
smears.
Section 31
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Module 2.05 Contamination Control Instructor’s Guide
2.05-6
2) Many routine contamination surveys are taken
with a chemically treated cloth called a masslinn.
a) Cloth is lightly pushed over a specified area and
scanned with an appropriate detector to detect the
presence of contamination.
b) If contamination is detected, a more thorough
disk smear survey should be performed.
c) Large area wipes are used only as an indication
of removable surface contamination.
d) Disk smears are required if contamination levels
are to be quantified.
3. External Personnel Surveys - Personnel surveys are either
performed by the individual (self-monitoring) using hand-
held or automated instruments or by a RCT. Monitoring by a
RCT is usually conducted whenever contamination of the
body or clothing is suspected, or as required by exit
monitoring when self-monitoring is not allowed. The
following describes the general types of hand-held or
automated instruments that are commercially available.
a. Personnel monitors - Sensitive hand held detectors used
by personnel to identify contamination on themselves
whenever contamination is suspected.
1) Portable Geiger-Mueller (GM) or scintillation
detectors that are installed at strategic locations
throughout the facilities.
2) These monitors are used whenever exiting
contaminated areas or RBAs.
b. PCMs (Personnel Contamination Monitors) provide
personnel with an external whole body monitoring
system.
1) PCMs are typically located at the RBA exits in
facilities with a high occupancy factor.
2) Contamination detectors within the monitors are
capable of performing a survey of the whole body in
a period of a few seconds, dependent upon
background radiation levels and the personnel
contamination limit of concern.
DOE-HDBK-1122-2009
Module 2.05 Contamination Control Instructor’s Guide
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3) These systems provide a more reliable method of
locating personnel contamination over hand-held
instruments.
c. Portal monitors - Portal monitors are "door frame" type
devices which provide a final monitoring point to ensure
contamination is not spread outside the facility to other
facilities or the general public.
Personnel are required to use (pause and walk through)
this type of monitoring system prior to exiting specified
areas.
d. Personnel surveys - These are performed by RCTs
whenever contamination of clothing or the body is
suspected, or as required when friskers or automated
instruments are not available.
1) The whole body should be surveyed with special
attention given to areas which are more likely to
become contaminated.
2) A minimum survey of the hands, arms, and front
portions of the body must be performed upon
completion of work or prior to leaving the area for
glovebox, laboratory fume hood, sample station, or
localized benchtop operations.
3) Contamination of the feet (shoes) would indicate
removable surface contamination on the floor just
traversed.
4) The nose and mouth should be surveyed upon
discovery of facial contamination or if airborne
contamination was detected in the work area to
determine if bioassay sampling is required.
5) The nose can be swabbed with Q-tips and the swab
counted in a smear counter.
6) Contamination of the nose or mouth may indicate
airborne contamination.
7) All open wounds must be monitored since
contaminants can be readily absorbed into the body.
Section 32
8) Upon detecting personnel contamination, follow-up
area and/or equipment surveys may be necessary to
determine the source of contamination and the extent
the contamination has spread, if any.
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Module 2.05 Contamination Control Instructor’s Guide
2.05-8
4. Personnel internal monitoring - A routine program of internal
contamination monitoring is conducted as a final check on
contamination control procedures.
Typical programs consist of external whole/partial body
counting and/or urinalysis.
a. In-vivo bioassay (whole/partial body counting) -
Individual is placed inside an array of very sensitive
detectors to measure the activity and energies of gamma
ray emissions from inside the body.
Information can be used to determine the amount and
identify the type of nuclides present.
b. In- vitro bioassays - Performed by collection of urine or
feces samples from an individual to determine type and
activity of the nuclides present in bodily waste.
1) Information is used to approximate the amount of
nuclides present in the body by their calculated rate
of elimination.
2) Can be used to assess the presence of non-gamma
emitting nuclides.
C. BASIC GOAL OF CONTAMINATION CONTROL
Once the presence of radioactive material has been located, the
basic goal underlying any effective contamination control
program is to minimize contaminated areas and maintain
contamination levels as low as reasonably achievable.
1. If the presence of removable contamination is discovered,
decontamination is a valuable means of control.
a. In some situations, this is not always possible.
1) Economical conditions: Cost of time and labor to
decontaminate a location out- weighs the hazards of
the contamination present.
2) Radiological conditions: Radiation dose rates or
other radiological conditions present hazards which
far exceed the benefits of decontamination.
3) Operating conditions: Some areas, e.g., hot cells,
will be contaminated due to normal operations.
b. Other means of control, such as engineering controls,
administrative procedures, or personnel protective
equipment, must be initiated when decontamination is not
possible.
Objective 2.05.03
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Module 2.05 Contamination Control Instructor’s Guide
2.05-9
2. "Good Housekeeping" is a prime factor in an effective
contamination control program. It involves the interactions
of all groups within the facility. Each individual must be
dedicated to keeping "his house clean" to control the spread
of contamination.
Every possible effort should be made in all operations to
confine the spread of radioactive materials to the smallest
possible area.
3. A sound preventive maintenance program can prevent many
radioactive material releases.
4. All material taken into or out of contaminated areas should be
controlled.
5. Regardless of the precautions taken, radioactive materials
will occasionally escape and contaminate an area.
6. Radiological Control Technicians should always be alert for
potential violations to the basic principle of contamination
control.
a. Use of improper contamination control methods
b. Bad work practices
c. Basic rule or procedure violations
d. Radioactive material releases or liquid spills
7. Radiological Control Technicians should always ensure that
the proper procedures to avoid the spread of contamination
are followed or implemented.
D. CONTAMINATION CONTROL MEASURES
Section 33
Controlling the spread of contamination is probably the most
difficult and challenging task the Radiological Control
Technician will encounter. The basic principles of contamination
control are:
• Access/Administrative Controls
• Engineering Controls
• Personnel Protective Measures
• Decontamination
• Preventive Methods
1. Access/Administrative Control
Objective 2.05.04
Objective 2.05.05
DOE-HDBK-1122-2009
Module 2.05 Contamination Control Instructor’s Guide
2.05-10
Once the location of contamination has been identified and
quantified and radiological areas have been established, we
must adequately control access to these areas.
Boundaries of radiological areas must be clearly marked.
This is accomplished by using radiological postings and tags
identifying entrances into these areas to restrict access.
Two basic access control points are used in contamination
control.
a. The primary access control point in a facility is the
entry and exit portal between the clean area and the
radiologically controlled area or RBA. The success of
a control program is based on controlling the movement
of personnel and equipment between these areas to
prevent release of contamination to a clean location.
b. Secondary access control points (perhaps the most
important) are set up within the RBAs to control access
between surface contamination areas and non-
contaminated areas. Yellow and magenta rope, tape,
chain, or similar barriers are used to identify boundaries.
Step-off-pads provide a recognizable demarcation to
personnel between the contaminated area and the RBA.
1) Special requirements will always be established for
entry and exit through these access control points.
2) When radiological conditions are severe, the access
control point will be continuously manned by
Radiological Control Technician.
3) Proper procedures must be established and observed
for crossing the SOP to prevent spread of
contamination out of the area.
4) All tools and/or equipment used in contaminated
areas which are unmonitored shall be placed in
plastic bags or securely wrapped in plastic before
being removed from the area.
5) All personnel and materials exiting the area shall be
monitored to ensure they are free of contamination.
2. Engineering Controls - There are several specific methods of
engineering control which can be utilized.
DOE-HDBK-1122-2009
Module 2.05 Contamination Control Instructor’s Guide
2.05-11
a. Ventilation - The design of permanent or temporary
ventilation systems needs to be such that air flow is from
clean areas to RBAs, to areas of moderate contamination,
to areas of high contamination, and finally to a exhaust
system capable of removing any contamination from the
air. Slight negative pressure is typically maintained in
buildings/rooms where potential contamination exists.
b. Containment - On jobs with very high contamination
potential, a plastic tent, (greenhouse or hut) can be built
around the work area to confine all contamination to as
small an area as possible.
1) A portable ventilation exhaust system (such as
HEPAs) may be used to control air flow in the
containment hut and remove airborne contamination.
2) Where possible, small containment devices, such as
glove boxes, glove bags, or hoods can be used to
contain the contamination depending on the nature
and location of the work being performed.
3) Contaminated tools or equipment are placed in
Section 34
plastic bags, or securely wrapped in plastic, before
being moved outside a contaminated area.
4) When possible, wrapping tools or equipment prior to
entry can help control contamination during use
inside the contaminated area.
c. Design and Control - Design of facilities should be such
that efficiency of maintenance, operations, and
decontamination is maximized.
1) Components should be selected that minimizes the
buildup of radioactivity.
2) Support facilities should be included that provide for
the donning and doffing of protective clothing and
for personnel monitoring.
3) Personnel traffic should be routed away from
contaminated areas.
3. Personnel Protective Measures - If engineering methods are
not adequate, then personnel protective measures, such as
protective clothing and respiratory equipment, will be used.
Objective 2.05.06
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a. The purpose of protective clothing is to keep
contamination off the skin and clothing of the workers.
1) Protective clothing allows personnel to work inside a
contaminated area with removable contamination and
to exit the area without spreading contamination to
uncontrolled areas.
2) Use of protective clothing alone will not guarantee
complete elimination of personnel contamination and
is not a substitute for implementing proper controls,
but if used properly, protective clothing will afford a
high degree of protection.
3) All personnel entering contaminated areas with
removable contamination will be required to wear
certain items of protective clothing.
4) Types of clothing required will vary depending upon
the contamination levels and the nature of the work
to be performed.
b. Some type of respiratory protective equipment will be
required for work in areas where very high contamination
levels exist or airborne contamination is present.
3. Decontamination - Line management is responsible for
ensuring prompt decontamination, where practical, of
facilities, tools, equipment, and material so that
contamination can be minimized in the workplace.
Reasonable efforts should be directed toward the
decontamination and unconditional release of these items
rather than their disposal as radioactive waste.
4. Preventive Methods - The following are practical methods
used for the prevention/control of contamination.
a. Identify and repair leaks before they become a serious
problem.
b. Establish adequate work controls before starting jobs.
c. While conducting pre-job briefs, discuss measures that
will help reduce or prevent contamination spread.
d. Change out gloves or protective gear as necessary to
prevent cross-contamination of equipment.
DOE-HDBK-1122-2009
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2.05-13
e. Pre-stage areas to prevent contamination spread from
work activities.
f. Cover piping/equipment below a work area to prevent
dripping contamination onto less contaminated areas.
g. Cover/tape tools or equipment used during the job to
minimize decontamination after the job.
h. Follow good work practices such as good housekeeping
and cleaning up after jobs.
i. Confine the spread of radioactive material releases by a
sound preventive maintenance program.
j. Control and minimize all material taken into or out of
contaminated areas.
E. BASIS FOR ESTABLISHING PROTECTIVE CLOTHING
REQUIREMENTS
1. The basic factors that determine the type and extent of
protective clothing required are:
Section 35
a. type and form of contamination
b. levels of contamination
c. type of work being performed
d. potential for increased levels of contamination
e. the area of the body at risk
f. competing hazards, i.e., asbestos, heat stress, etc.
2. Once the types of protection needed are established, the most
efficient protective clothing must be selected from the
different articles of protective clothing available for use.
a. Whole body protection
1) Laboratory coat
a) Provides protection from low levels of
contamination.
b) Only applicable when the potential for body
contact with contaminated surfaces is very low.
Objective 2.05.07
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Module 2.05 Contamination Control Instructor’s Guide
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c) Lab Coats are generally worn for hands-off tours
and inspections in areas with removable
contamination at levels 1 to 10 times the values
in Table 2-2 of the Radiological Control
Standard.
d) Lab coats may also be worn during benchtop,
laboratory fume hood, sample station, and
glovebox operations.
2) Coveralls
a) Provides protection from low to moderate levels
of DRY contamination.
b) Protection is low when body contact with
contaminated surfaces is prolonged (since
contamination can be ground into the cloth).
c) Protection is low when the surface is wet.
d) Degree of protection can be increased by use of
more than one pair at a time to protect the body.
e) Not effective against radionuclides with high
permeation properties (gases, tritium, etc.).
3) Plastic coveralls
a) Provides protection from high levels of dry
contamination.
b) Provides protection from wet forms of
contamination.
c) Provides limited protection from tritium and
other highly permeating radionuclides being
transported through the coveralls to the skin
surface.
4) Disposable coveralls
a) Used for work involving mixed hazards, i.e.,
asbestos, PCBs, etc., where reuse is not desirable.
b) Types of suits are tyvek, gortex, etc. which
provide moderate protection from radioactive
contamination.
DOE-HDBK-1122-2009
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2.05-15
c) Disposable coveralls can be easily torn.
b. Hand protection
1) Surgical gloves
a) Minimal requirement
b) Normally used in only light contamination work
areas
c) High degree of dexterity
d) Fairly easily torn or punctured
2) Rubber gloves
a) Lightweight
b) Provides good gripping surface
c) Normally used in moderate to heavy
contamination locations
d) Greater puncture, abrasion and solvent resistance,
but afford a lower degree of dexterity than
surgical gloves.
3) Neoprene gloves
a) Synthetic rubber gloves mounted to various
containment devices to allow access by the
wearer into the device.
b) Used to provide protection for the wearer when
working inside a containment device in which
highly contaminated materials are present.
c) Usually of arm length attached to dry boxes,
glove boxes and bags, or other cabinets.
d) Provides a gas tight seal to the structure.
e) Gloves are normally taped to the sleeve of the lab
coat, coveralls, plastic suit, etc. and are tabbed to
permit easy removal.
4) Cotton glove liners
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Module 2.05 Contamination Control Instructor’s Guide
2.05-16
May be worn inside standard gloves for comfort, but
should not be worn alone or considered as a layer of
protection.
5) Leather or canvas work gloves
Should be worn in lieu of or in addition to standard
gloves for work activities requiring additional
strength or abrasion resistance.
Section 36
c. Foot protection
1) Booties: Used to protect lower leg area below
coveralls from contamination. Different
constructions used:
a) Plastic
b) Cloth (sometimes called cloth shoe covers)
2) Shoe covers: Worn over booties to provide a second
layer of protection and provide traction to wearer.
Normally are constructed of plastic or rubber.
3. Respiratory protection
a. Full-face masks: Used to filter particulate radionuclides
and/or radioactive Iodine from the breathing air of the
wearer when the surrounding atmosphere is not
immediately dangerous to the life and health of the
wearer.
b. Supplied air systems: Used to prevent inhalation of
particulate and gaseous radionuclides by the wearer in a
non-life threatening atmosphere.
c. Self-contained breathing apparatus (SCBA): Used to
provide a portable source of breathing air to the user
when entering an atmosphere which may be immediately
dangerous to life and health.
d. Medical approval, training, and fit testing are required
prior to respiratory protection use.
1) Systems should be in place to verify these criteria in
the field.
2) The wearer should be clean shaven in the area of fit.
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Module 2.05 Contamination Control Instructor’s Guide
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3.) The wearer should perform fit checks of their
respirators to ensure a proper seal.
4. Facility Protective Clothing Requirements
(Insert facility specific material here)
III. SUMMARY
A. Review major topics
1. Types of Contamination
2. Assessing Contamination Hazards
3. Basic Goal of Contamination Control
4. Contamination Control Measures
5. Basis for Establishing Protective Clothing Requirements
B. Review learning objectives
IV. EVALUATION
Evaluation should consist of a written examination comprised of
multiple choice, fill-in the blank, matching and/or short answer
questions. 80% should be the minimum passing criteria for
examinations.
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DOE-HDBK-1122-2009
Module 2.06 Air Sampling Program/Methods Instructor’s Guide
2.06-1
Course Title: Radiological Control Technician
Module Title: Air Sampling Program/Methods
Module Number: 2.06
Objectives:
2.06.01 State the primary objectives of an air monitoring
program.
2.06.02 Describe the three physical states of airborne
radioactive contaminants.
2.06.03 List and describe the primary considerations to
ensure a representative air sample is obtained.
2.06.04 Define the term "isokinetic sampling" as
associated with airborne radioactivity sampling.
2.06.05 Identify the six general methods for obtaining
samples or measurements of airborne
radioactivity concentrations and describe the
principle of operation for each method.
a. Filtration
b. Volumetric
c. Impaction/impingement
d. Adsorption
e. Condensation/dehumidification
f. In-line/flow-through detection
2.06.06 Describe the general considerations for selection
of an air monitoring method.
2.06.07 State the purpose of the five primary types of
airborne radioactivity samplers/monitors:
a. Personal air samplers (breathing zone)
b. High volume/flow rate air samplers
c. Low volume/flow rate air samplers
d. Portable continuous air monitors
e. Installed continuous air monitoring
systems
2.06.08 List the factors that affect the accuracy of
airborne radioactivity measurements and
describe how these factors affect sample
accuracy.
Section 37
→ 2.06.09 Describe the site air monitoring program that
includes monitoring frequencies, calculational
methods, applicable derived air concentration
limits, and methods for determining radon
interference.
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Module 2.06 Air Sampling Program/Methods Instructor’s Guide
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References:
1. "Introduction to Health Physics"; Cember, Herman; 4nd
ed.; McGraw-Hill Medical; 2008.
2. "Basic Radiation Protection Technology"; Gollnick,
Daniel; 5th ed.; Pacific Radiation Corporation; 2008.
3. Moe Harold, Operational Health Physics Training, ANL-
88-26, Department of Energy, Argonne National
Laboratory, Chicago, 1988.
4. "Air Monitoring", Chapter 10 of Implementation Guide
for Use with 10 CFR 835, "Occupational Radiation
Protection".
Instructional Aids:
1. Overheads
2. Overhead projector/screen
3. Chalkboard/whiteboard
4. Lessons learned
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I. MODULE INTRODUCTION
A. Self-Introduction
1. Name
2. Phone number
3. Background
4. Emergency procedure review
B. Motivation
Before the proper internal exposure control methods can be
determined for personnel, an estimate of the airborne
radioactivity concentration must be obtained. Additionally,
airborne radioactivity measurements are necessary to ensure
that the control measures assigned are effective and continue to
be effective.
C. Overview of Lesson
1. Purpose and objectives of airborne radioactivity sampling
2. The nature of airborne radioactivity
3. Representative air samples
4. Basic sampling methods
5. Selection of the air sampling method
6. Primary types of air samplers
7. Basic air sample calculations
D. Introduce Objectives
II. MODULE OUTLINE
A. PURPOSE AND OBJECTIVES OF AIRBORNE
RADIOACTIVITY SAMPLING
1. Airborne radioactive contaminants are of concern to the
radiological control organization due to the biological
effects of the ionizing radiation emitted by those
contaminants.
O.H.: Objectives
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2. Inhalation of radioactive airborne particles is one of the
most important routes of entry of radionuclides into the
human body.
3. This represents a relatively complicated process that
depends on particle size distribution of the airborne particles,
their dynamical behavior in air, and the physical and
chemical properties of the particles after deposition in the
respiratory tract.
4. Air monitoring is performed to identify and monitor
airborne radioactive material in order to control the intake
of airborne radioactive material by workers.
5. Regulations govern the allowable or limiting doses to an
individual.
a. The total effective dose of an individual is determined
by combining the external and internal effective dose
values.
b. Typically, airborne radioactivity levels are maintained
well below allowable levels to keep the internal dose
contribution to the total effective dose small.
c. Confirmation that airborne radioactivity levels are
maintained low is accomplished by the airborne
radioactivity sampling program.
d. It is important to note that the individual equivalent
dose from internal sources is not normally determined
from air sampling analysis data, unless other
information, such as bioassay data, is unavailable,
inadequate, or internal dose estimates based on
representative air concentration values are
demonstrated to be as or more accurate.
Section 38
6. It is necessary to be aware that the air monitoring program
is only one element of a comprehensive radiation protection
program.
a. Individuals involved with the air monitoring program
should interact with personnel working in other
elements of the radiation protection program,
particularly with individuals involved in contamination
control and internal dosimetry.
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7. The primary objectives of an air monitoring program are:
a. To measure the concentration of the radioactive
contaminant(s) in the air by collection and analysis
b. To identify the type and physical characteristics of the
radioactive contaminant to help evaluate the hazard
potential to the worker
c. To evaluate the performance of airborne radioactivity
control measures
d. To assess air concentration data in order to determine if
bioassay sampling should be initiated to verify whether
an exposure has occurred, and if so, to determine the
magnitude of the exposure.
8. Additionally, the air monitoring program must demonstrate
that airborne radioactivity released to the general
environment is maintained as low as reasonably achievable
and below the allowable limits established by regulatory
agencies.
9. The primary goal of the air monitoring program is to
determine if the level of protection provided to the worker is
sufficient to minimize the internal equivalent dose.
a. Allowable concentration values, such as DACs, are
used as an index of the degree of control needed and
achieved.
b. Documented measurements of the airborne
radioactivity concentrations are required to demonstrate
that satisfactory control is achieved and maintained.
10. Air sampling is required when an individual is likely to
receive an exposure of 40 or more DAC-hours in a year.
Other situations requiring sampling are:
a. to establish the need for posting of airborne
radioactivity areas and to determine the need for
respiratory protection for workers.
b. to assess unknown hazards during maintenance on
systems contaminated with radioactive material or
when there is a loss of process controls.
Objective 2.06.01
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c. to assist in determining the type and frequency of
bioassay measurements needed for a worker.
d. to provide an estimate of worker exposures for
situations where bioassay measurements may not be
available or their validity is questionable.
e. to develop baseline airborne radioactivity levels and
verify containment integrity as necessary during startup
of a new facility or new operation within an existing
facility.
f. where respiratory protection devices for protection
against airborne radionuclides have been used.
g. real-time monitoring is needed as necessary to detect
and provide warning of increases in airborne
radioactivity levels that warrant immediate actions to
terminate the inhalation of airborne radioactive material.
B. THE NATURE OF AIRBORNE RADIOACTIVITY
1. Airborne radioactive contaminants are generally divided
into three categories, based on the physical state of the
contaminant.
a. Particulates
b. Gases
c. Vapors
2. Particulate contaminates are solid and liquid particles,
ranging upward from molecular sizes (approximately
10-3 um), suspended in the air.
a. Solids may be subdivided into fumes, dusts, and
smokes, which are distinguished mainly by their mode
of generation.
Section 39
b. Liquids are subdivided into mists and fogs, depending
on the dispersion of the liquid particulates.
c. The term "aerosols" is used to collectively refer to
relatively stable suspensions of either solid or liquid
particles in a gaseous medium.
Objective 2.06.02
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d. Generally, particulates are more readily retained in the
lungs than are gases, but retention of particulates is
highly dependent on particle size and solubility in the
lung.
e. While this suggests that particulate airborne
contaminant sampling should measure particle size, this
is not practically accomplished on a routine basis.
f. Certain sampling instruments utilize the characteristics
of particle size to separate larger particles from smaller
particles (e.g., impactors.)
g. This is an important factor in that the size range of
particles retained in the respiratory tract is generally 1-
10 um.
h. The retention of inhaled radioactive particles after
deposition in the pulmonary region of the lung is
strongly influenced by the dissolution characteristics of
the particles.
1) Dissolution in the lungs allows clearance into the
blood and the rest of the systemic circulation.
2) For this reason, the various chemical forms of
radioactive particles are classified with respect to
their potential solubility in the lungs.
3) These are Type S for the very insoluble particle
that takes years to clear from the lungs; Type M for
the somewhat more soluble particles that take
weeks to dissolve and clear into the systemic
circulation; and Type F for the relatively soluble
particles that dissolve in a matter of days in the
lung.
3. Gases are substances that, under normal conditions of
temperature and pressure, exist in the gaseous phase.
a. The retention of the gases in the body from poor
inhalation is so radioactive gases are usually treated as
an external source of exposure.
b. Radioactive gases typically found are the fission
product gases, such as xenon and krypton, and naturally
occurring radon.
c. While the gases contribute primarily to external
exposure, the particulate daughters to which they decay
can contribute to internal exposure.
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4. Vapors are considered the gaseous phase of a substance that
is normally a solid or liquid under normal conditions of
temperature and pressure.
a. Airborne vapor sampling is most commonly done for
radioiodine and tritium.
b. The contaminant may be dispersed in vapor form at
abnormal conditions of temperature and pressure.
c. However, as the temperature and pressure conditions
return to "normal," the contaminant will return to its
normal solid or liquid form, or become a particulate.
d. Sampling methods for vapors should isolate or measure
the contaminant regardless of whether the vapor or
particulate form is present.
C. REPRESENTATIVE AIR SAMPLES
1. To ensure that the sample is representative of the actual
conditions.
a. The airborne radioactivity concentration entering the
sample line must be representative of the airborne
radioactivity concentration in the air near the sampling
device.
b. The airborne radioactivity concentration entering the
sampling inlet must be representative of the airborne
radioactivity concentration at the point of concern, or
the air that is breathed, i.e., breathing zone.
Section 40
2. When obtaining an air sample, care must be taken to ensure
that the sample obtained is representative of the air around
the sampling device.
a. This is particularly important for sample lines that
directly sample an air flow, such as a stack or duct
monitor.
b. Air flow into sampling lines needs to be balanced with
respect to the flow of air around the probe or sample
inlet.
c. If there is not a relative balance between these
velocities, particles may be thrown in or out of a
sampling probe rather than being sampled in a
representative fashion.
Objectives 2.06.03
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2.06-9
d. To ensure the sample is representative, the flow rate in
the sample line or inlet must be the same as the flow
rate in the system, such as the duct or stack.
1) When the sample line velocity is equal to the
system velocity at the sample point, it is called
isokinetic sampling
e. If the velocities are not the same, or isokinetic, then
discrimination can occur for smaller or larger particles.
This occurs because the inertia of the more massive
particles prevents them from following an airstream
that makes an abrupt directional change.
1) If the velocity of the sample airstream is > the
velocity of the system airstream, then the larger
particles can not make the abrupt change and are
discriminated against in the sample, i.e., the
smaller particles are collected more efficiently.
2) If the velocity of the sample airstream is < the
velocity of the system airstream, then the small
particles do make the abrupt change and are
discriminated against in the sample, i.e., the larger
particles are collected more efficiently.
f. To minimize particle losses, sampling lines should be
as short (less than six feet preferred) and straight as
possible to avoid sample deposition along the walls of
the tube. When possible, sample lines should be
vertical instead of horizontal to prevent gravimetric
settling of large particles.
g. The sampling line should have no more than one bend
and be made of conducting material.
3. There are other factors to consider for maximizing the
efficiency of airborne radioactivity detection.
a. Self-absorption losses, e.g., dust loading, should be
minimized. This is especially critical for alpha
detection.
b. Air in-leakage between the sample intake and the
sample collection medium should be eliminated to the
greatest degree possible by instrument design.
Objective 2.06.04
See Fig. 1 - "Isokinetic
Sampling"
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c. The system and mechanisms within the instrument for
sample collection should be designed and constructed
to minimize deterioration and to facilitate
decontamination. This is more critical in areas with
corrosive atmospheres.
4. When obtaining an air sample, care must be taken to ensure
that the sample obtained is representative of the air at the
point of interest (the breathing zone).
a. Depending on the source of the airborne contaminant,
the concentrations within a work area can vary over
several orders of magnitude.
b. The sample taken should be representative of the air
entering the nose and mouth of the individual workers
since the data obtained may be used to estimate
potential worker intakes.
c. The best method to ensure a representative breathing
zone sample is to sample the air at the individual's nose
and mouth.
Section 41
d. This sampling method may not always be practical and
general work area sampling may be the alternative.
e. Care must be exercised in the selection of the number
and placement of the general area air samplers to ensure
that the sample is as representative as possible.
D. BASIC SAMPLING METHODS
1. Basically, three types of samples are collected:
a. A volumetric sample in which part of the atmosphere is
isolated in a suitable container, providing the original
concentration of the contaminant at a particular place
and time.
b. An integrated sample which concentrates the
contaminant on some collecting medium, providing an
average concentration over the collection time.
(Sometimes called a "grab" sample if collected in a
short period of time.)
c. A continuous sample where the sample air flow is
directed past or through a detection device providing a
measurement of the activity per unit volume of air.
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2. Breathing zone air monitoring should be performed
continuously in areas where workers are likely to exceed 40
DAC-hr exposure in a year.
Breathing zone air monitoring is used to identify possible
worker internal exposure and the need for follow-up
bioassay measurements.
3. Source-specific air sampling is performed near an actual, or
likely, release point in a work area.
This is typically used to verify containment integrity,
documenting airborne radioactivity levels, and providing
guidance on personnel protective measures (e.g.,
determining when respiratory protection is required).
4. Grab air sampling is used for temporary or nonroutine (e.g.,
emergency response) situations and as a backup for other
types of air sampling in the event of equipment failure.
a. Portable air sampling equipment is typically used for
operations requiring a grab sample.
b. Sample flow rates may vary depending upon the
specific application, but should always allow collection
of a sample volume adequate to ensure the minimum
detectable activity of the sampling and counting system
is no greater than 2% of an ALI.
5. There are six general methods for obtaining samples or
measurements of airborne radioactivity concentrations.
a. Filtration
b. Volumetric
c. Impaction/impingement
d. Adsorption
e. Condensation/dehumidification
f. In-line/flow-through detection
6. Filter samplers employ filtration of the air as the method of
concentrating the airborne radioactive particulate (aerosol)
contaminants.
Objective 2.06.05
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Module 2.06 Air Sampling Program/Methods Instructor’s Guide
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a. Filtration is the most common sampling method
employed for particulates because it is relatively simple
and efficient, but is ineffective as a sampling method
for gases and vapors.
b. The filter sampling technique employs an air mover,
such as a vacuum pump, to draw air through the
removable filter medium at a known flow rate for a
known length of time.
1) If the flow rate and sample time are known, the
total volume collected can be calculated.
2) After analysis of the filter medium to determine the
amount of radioactive material collected on the
filter at the time of the sample, the airborne
concentration can also be calculated.
c. The filtration medium selected for a sample depends on
Section 42
several factors: the collection efficiency required, the
flow resistance of the medium, and the mechanical
strength of the filter, pore size, the area of the filter, the
background radioactive material of the filter, cost, self-
absorption within the filter, and chemical solubility.
d. A wide choice of filters is available. The most common
types are:
1) Cellulose-asbestos filters
2) Glass fiber filters
3) Membrane filters
Membrane filters are manufactured with various
pore sizes and can be dissolved in organic solvents
and analyzed in a counter, e.g., a liquid scintillation
counter.
7. Volumetric samplers employ a sample container into which
the sample is drawn, by some method, and isolated for
analysis.
a. Several methods are employed to draw the sample into
the container.
1) The container may be evacuated by a vacuum
pump and isolated away from the sample location.
The container is opened at the sample location to
draw the air into the container. The sample is
sealed in the container and removed for analysis.
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2) An air mover, such as a vacuum pump, may be
employed at the sample location to draw a
representative atmospheric sample into the
container.
3) The container could be filled with water, isolated
and taken to the sample location. The water is
poured out of the container, drawing the air sample
into the container as the water pours out.
b. This method can be employed for particulates, gases,
and vapors.
8. Impingers or impactors concentrate particulate
contaminants on a prepared surface by abruptly changing
the direction of the sample air flow at some point in the
sampler.
a. Particles are collected on a selected surface as the
airstream is sharply deflected. Due to their inertia, the
particles are unable to follow abrupt changes in
airstream direction.
b. The surface on which the particles are collected must be
able to trap the particles and retain them after impaction.
Several methods are commonly used to trap the
particles, such as:
1) Coating the collection surface with a thin layer of
grease or adhesive.
2) Immersing the collection surface in a fluid, such as
water or alcohol, which is then analyzed after the
sample is collected.
c. Impingers and impactors may utilize several stages or
impingement distances to discriminate for or against
different particle sizes.
d. Impactors are frequently used to isolate particles larger
than the undesired smaller particles, such as
transuranics over radon daughters, or radon daughters
over fission products.
9. Adsorber sampling devices concentrate the contaminants by
causing them to adhere to the surface of the adsorption
medium.
a. Adsorption is the adhesion of a substance to the surface
of another substance through bonding.
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b. The adsorption medium is granulated or porous to
increase the surface area available for trapping of the
contaminant.
c. The technique employs an air mover to draw and
collect the sample through the adsorption media.
d. Adsorbers, such as activated charcoal, silica gel, and
silver zeolite, are commonly used to collect organic
vapors and non-reactive gases and vapors.
1) Activated charcoal is used primarily for radioiodine
sampling, but does trap noble gases, such as xenon,
krypton and argon.
2) Silica gel is primarily used for tritium oxide vapor
Section 43
sampling.
3) Silver zeolite is used for radioiodine sampling
when trapped noble gases would interfere with the
radioiodine analysis.
e. Particulates would be "filtered" by the absorption media
and must be filtered out before the adsorption process
to prevent interference during the analysis of the media.
10. Condensation or dehumidifier sampling devices employ a
"cold trap" to condense water vapors in the sampled
atmosphere and provide a liquid sample for further analysis.
a. Some means, such as liquid nitrogen or a refrigeration
unit is utilized to cool the condensation surface and
cause condensation of the water vapor as it passes over
the cold surface.
b. The collected water is frequently analyzed using a
liquid scintillation counter.
c. Calculations must include the relative humidity and
temperature of the air at the time the sample is taken to
determine the concentration of water vapor per unit
volume of air.
d. This technique is normally only applied for sampling
tritium oxide vapor (HTO or T2O).
11. In-line or flow-through samplers employ an air mover to
direct the sample air flow through or past the detection
device.
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a. This method is employed for radionuclides which are
difficult to collect or detect by other means.
b. Because the air flow passes directly outside the detector
or actually through the inside of the detector, the air
must be filtered for particulates or vapors that could
accumulate on or in the detector.
c. In-line detectors are used to measure gaseous activity
after filtration and adsorption have been accomplished.
d. Flow-through detectors are employed for radionuclides,
such as tritium, which emit low-energy radiation, that
could not otherwise pass through the detector window.
12. The various sampling methods may be combined into one
sampler or monitor.
a. Some samplers employ the filtration method for
particulates, the adsorption method for vapors and the
volumetric grab-sample method for gases (in that order).
Some advantages of combining these methods are:
1) One vacuum pump supplies the air flow for all the
samples.
2) All the samples are drawn at the same time to
minimize the amount of time spent by the
technician drawing samples.
b. In addition, some monitors have detectors installed to
monitor each sample and provide an immediate readout
as well as other capabilities, such as alarms, data
records, process controls, and trending.
E. SELECTION OF THE AIR SAMPLING METHOD
1. It is critical that the proper air sampling method and
equipment be selected because:
a. The data obtained must be meaningful and accurate to
adequately assign radiological control measures.
b. Improper selection and use may incorrectly indicate a
safe environment where an airborne radiological hazard
exists or leads to unneeded postings where no hazard
exists.
2. The general considerations for the selection of an air
sampling method include several factors.
Objective 2.06.06
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a. The environmental conditions in the area where the
sample is to be obtained.
1) Humid conditions may preclude the use of some
methods, such as paper filtration devices or
charcoal canisters, because water vapor loading of
the medium will change the collection efficiency
and flow rate.
2) High temperature environments may cause some
Section 44
samplers to overheat if run for long periods of time.
3) Explosive gases may be present which could
present an explosion hazard for samplers with
electric motors not designed for such environments.
4) Dusty areas could cause excessive sample loading
which will reduce sampler flow rates and
potentially overheat the sampler.
5) Corrosive environments may lead to the
deterioration of the sampling device.
b. The physical characteristics of the area in which the
sample is to be obtained.
1) An electrical outlet may not be available or close,
and a battery powered sampler would be better
suited.
2) Close spaces or passages may preclude the use of
movable CAMs or heavy samplers.
c. The energy and type of radiation of the radionuclide
being monitored. This will dictate the type of CAM or
analysis equipment required to determine the airborne
radioactivity concentration.
d. The expected concentration level. This will determine
the length of sample time and type of sampler required.
1) Low-level concentrations will require larger
volumes to reduce statistical errors and meet
minimum sensitivity levels of the analysis
equipment.
2) Large volume samples obtained over a long time
period are best obtained by samplers designed to
run for long periods.
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3) If immediate readout of information is needed, then
collection and analysis are done at the same time.
4) If not, then samples may be taken and removed to a
central analysis location.
e. The physical state of the airborne contaminant.
Dependent upon whether the contaminant is either gas,
vapor or aerosol, will dictate the type of sampler and
sample medium that is required.
f. The type of survey required. Specific methods, such as
breathing zone samples, routine general area samples,
general work area samples, general trending over time,
etc., also determines the type of equipment that is
selected.
g. Procedural requirements. This may dictate a particular
type of sample method and/or sample medium for a
given application.
1) Check the appropriate procedures prior to sampler
selection.
2) Ask supervision and experienced technicians for
their input.
F. PRIMARY TYPES OF AIR SAMPLERS
1. The five primary types of airborne radioactivity
samplers/monitors are:
a. Personal air samplers (breathing zone)
b. High volume/flow rate air samplers
c. Low volume flow rate air samplers
d. Portable continuous air monitors (CAMs)
e. Installed continuous air monitoring systems
2. Personal air samplers (PAS) provide an estimate of the
airborne radioactivity concentration in the air the worker is
breathing during the sampling period.
a. The PAS may also be used to determine if the
protection factor for respiratory equipment is exceeded,
to compare with other workplace air samples, and to
verify the effectiveness of engineered and
administrative controls.
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b. Personal air samplers are small portable battery-
powered devices which sample the air in the breathing
zone of the worker's environment, making allowances
to eliminate interferences the sampler's themselves may
have on a worker's activities. Some characteristics are:
1) The device contains a small battery-powered pump
that is calibrated to a flow rate approximately 1/10
(2 liters per minute) the breathing rate of a worker
performing light activity.
Section 45
2) The sampling line terminates in a filter cassette
which contains the filtration medium for the
radioactive particulate contaminants.
3) The sample filter cassette is attached close to the
nose and mouth of the individual.
3. Portable high volume/flow rate samplers provide an
estimate of the airborne radioactivity concentration at a
particular location in a short period of time.
a. Portable high flow rate samplers are used to collect
airborne aerosols on a filter paper (filtration) or on a
greased planchet (impaction).
b. Portable high flow rate samplers can also be used to
collect radioiodine samples using activated charcoal
cartridges (adsorption) as long as the maximum flow
rate of the cartridge is not exceeded or a correction
factor is used.
c. These samplers do not have installed detectors and the
sample must be removed from the sampler and
analyzed on separate analysis equipment.
d. The high volume/flow rate samplers may be used to:
1) Provide a routine "slice of time" estimate of the
general area airborne radioactivity
2) Verify boundaries of areas posted for airborne
radioactivity
3) Or monitor the airborne radioactivity related to a
specific work activity.
e. High volume samplers typically use flow rates of at
least 10 cubic feet per minute (cfm).
See Fig. 2 - "High Volume
Sampler"
DOE-HDBK-1122-2009
Module 2.06 Air Sampling Program/Methods Instructor’s Guide
2.06-19
1) Although these samplers are noisy and not intended
for continuous duty, the shorter sample times allow
for greater sensitivity.
4. Low volume/flow rate samplers provide an estimate of
airborne radioactivity concentrations averaged over a longer
period of time at a particular location.
a. Portable low volume/flow rate samplers are used to
collect samples for aerosols on filter paper (filtration)
and radioiodine on an adsorption medium, such as an
activated charcoal cartridge.
b. Low volume/flow rate samplers may be used to provide
average airborne radioactivity estimates over a period
of time for:
1) Commonly traversed areas that normally have a
low probability of airborne radioactivity problems
2) Areas not commonly traversed with a higher
probability of airborne radioactivity problems
3) Backup samples in areas where airborne
radioactivity problems are discovered by other
means
4) Work maintenance activities normally
characterized by low airborne radioactivity
concentrations.
c. Low volume samplers generally have flow rates set at
approximately 20 lpm, the breathing rate of a worker
performing light activity.
1) Although these samplers must run longer for
reasonable sensitivity, they are generally quiet and
can be used for continuous duty.
5. Portable CAMs provide an estimate of airborne
radioactivity concentrations averaged over time at a
particular location, and provide immediate readout and
alarm capabilities for preset concentrations.
a. These air monitors are portable low flow rate (~20 lpm)
sampling systems, containing the necessary sampling
devices and built-in detection systems to monitor the
activity on the filters, cartridges, planchettes and/or
chambers in the system.
See Fig. 3 - "Low Volume
Sampler"
DOE-HDBK-1122-2009
Module 2.06 Air Sampling Program/Methods Instructor’s Guide
2.06-20
b. The system may provide a visual readout device for
each type of sample medium, a recording system for
data, and computer functions such as data trending,
preset audible and visual alarms/warning levels and
alerts for system malfunctions.
Section 46
c. Typical CAMs provide information on alpha and/or
beta/gamma particulates (filtration), radioiodine activity
(adsorption) and noble gas activity (volumetric
chamber or in-line detector).
d. Portable CAMs can be utilized as:
1) Low volume general area samplers
2) Monitors with alarm capabilities for areas where
airborne radioactivity conditions may quickly
degrade
3) Trending devices in selected areas
4) Devices to locate system leaks, if used with the
appropriate length hose or tubing.
6. Installed CAMs provide an estimate of airborne
radioactivity concentrations averaged over time at a fixed,
designated location, and provide immediate local and
remote readout and alarm capabilities for preset
concentrations.
a. These air monitors are fixed low flow rate sampling
systems, and contain the necessary sampling devices
and built-in detection systems to monitor the activity of
selected areas or airstreams.
b. The system may provide a local and remote visual
readout device, a recording system for data, and
computer functions such as data trending, preset
audible and visual alarms/warning levels and alerts for
system malfunctions.
c. Installed CAM applications include:
1) Fixed installations capable of sampling several
locations through valved sample lines.
2) Stack monitors
3) Duct monitors
DOE-HDBK-1122-2009
Module 2.06 Air Sampling Program/Methods Instructor’s Guide
2.06-21
7. Factors affecting the accuracy of airborne radioactivity
measurements include:
a. Sample is not representative of the atmosphere being
sampled
b. Sample is not representative of the air being breathed
by the worker
c. Incorrect or improperly installed sampling media for
the selected sampler, causing leak or improper flow
rates
d. Malfunctioning, miss-operated, or miscalibrated
sampling device, causing errors in flow rate
measurements
e. Accuracy and operation of the timing device, causing
errors in the time value
f. Accuracy and operation of the flow rate measuring
device, causing errors in the flow rate value
g. Mishandling of the sample media causing cross-
contamination or removal of sample material
h. Changes in the collection efficiency of the medium due
to sample loading, humidity and other factors
i. Improper use or selection of analysis equipment
j. Inherent errors in the counting process due to sample
geometry, self-absorption, resolving time, backscatter
and statistical variations
k. Mathematical errors during calculations due to
rounding of numbers and simple mistakes
l. Incorrect marking of samples and inaccurate recording
of data
8. It is important that the personnel performing the sample
collection and analysis minimize the magnitude of these
errors to ensure that accurate and reliable data is obtained
for the assignment of internal exposure control methods.
Objective 2.06.08
DOE-HDBK-1122-2009
Module 2.06 Air Sampling Program/Methods Instructor’s Guide
2.06-22
G. BASIC AIR SAMPLE CALCULATIONS
1. Once the air sample is collected and analyzed, calculations
must be performed to determine the amount of activity per
unit volume.
2. The specific calculations for particular sampling methods
are not covered in this lesson; however, some basics are
necessary for each calculation.
3. The analysis of the sample provides the activity of the
sample at the time of the sample analysis.
a. This value may be corrected for decay for the time
period between when the sample was taken to when it
was analyzed.
Section 47
1) This is especially true for short-lived radionuclides.
2) This correction may not be necessary for very long-
lived radionuclides.
b. The volume of the sample must be determined from the
sample data recorded, such as flow rates at the
beginning and end of the sample, and sample time
period.
c. The basic calculation listed below would also include
the conversions necessary for the desired units such as
dpm/liter to µCi/cc.
d. The calculation would also include correction factors,
as necessary, for:
1) Interference of other radionuclides, such as radon
and thoron daughters
2) Collection efficiency
3) Counter efficiency
4) Self-absorption by the sample media
5) Counter background.
6) Temperature and pressure as applied to flow rate
4. Many errors are inherent or induced in the sampling
analysis process and affect the accuracy of the resulting data.
DOE-HDBK-1122-2009
Module 2.06 Air Sampling Program/Methods Instructor’s Guide
2.06-23
5. The operator of the sampling and analysis equipment must
be aware of these points of error to ensure the resulting data
is as accurate as possible.
(Insert site specific material here)
III. SUMMARY
A. Review major points
1. Purpose and objectives of airborne radioactivity sampling
2. The nature of airborne radioactivity
3. Representative air samples
4. Basic sampling methods
5. Selection of the air sampling method
6. Primary types of air samplers
7. Basic air sample calculations
B. Review learning objectives
IV. EVALUATION
Evaluation should consist of a written examination comprised of
multiple choice, fill-in the blank, matching and/or short answer
questions. 80% should be the minimum passing criteria for
examinations.
Objective 2.06.09
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2.06-24
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DOE-HDBK-1122-2009
Module 2.07 Respiratory Protection Instructor’s Guide
2.07-1
Course Title: Radiological Control Technician
Module Title: Respiratory Protection
Module Number: 2.07
Objectives:
2.07.01 Explain the purpose of respiratory protection standards and regulations.
2.07.02 Identify the OSHA, ANSI, and DOE respiratory protection program requirements.
2.07.03 Identify the standards which regulate respiratory protection.
2.07.04 Describe the advantages and disadvantages (limitations) of each of the following
respirators:
a. Air purifying, particulate removing filter respirators
b. Air purifying, Chemical Cartridge and Canister respirators for Gases and
Vapors
c. Full-face, supplied-air respirators
d. Self-contained breathing apparatus (SCBA)
e. Combination atmosphere supplying respirators
2.07.05 Define the term protection factor (PF).
2.07.06 State the difference between a qualitative and quantitative fit test.
2.07.07 State the recommended physical functions the subject must perform during a
respirator fit test.
2.07.08 State how the term protection factor (PF) is applied to the selection of respiratory
protection equipment.
2.07.09 State the general considerations and considerations for the nature of the hazard
when selecting the proper respiratory protection equipment.
→ 2.07.10 Identify the types of respiratory equipment available for use at your site.
2.07.11 Identify the quality specification breathing air must meet.
References:
1. "Basic Radiation Protection Technology"; Gollnick, Daniel; 5th ed.; Pacific Radiation
Corporation; 2008.
Section 48
2. "Introduction to Health Physics"; Cember, Herman; 4nd ed.; McGraw-Hill Medical; 2008.
3. "Limits for Inhalation of Radon Daughters by Workers", ICRP Publication 32.
4. "Operational Health Physics Training Course", Moe, H.J., et. al., Argonne National
Laboratory, Argonne, 88-26.
5. "Radiation Detection and Measurement", Knoll, G., John Wiley and Sons, New York,
2000.
6. 10 CFR 835, "Occupational Radiation Protection", 2007.
7. "Practices of Respiratory Protection", ANSI Z88.2, 1992.
8. "Manual of Respiratory Protection Against Airborne Radioactive Material",NUREG-0041,
1976.
9. Respiratory Protection, Federal OSHA, 29 CFR 1910, 134.
DOE-HDBK-1122-2009
Module 2.07 Respiratory Protection Instructor’s Guide
2.07-2
10. DOE-STD-1167-2003, DOE Respiratory Acceptance Program for Supplied-Air Suits
11. CGA G7.1-1989, Breathing Air, Commodity Specification for Air
12. 10 CFR 851, “Worker Protection Programs”, 2007.
13. DOE Order 440.1B (2007), Worker Protection Management for DOE (including National
Nuclear Security Administration) Federal Employees
14. ANSI Z88.2 (1992)
Instructional Aids:
1. Overheads
2. Overhead projector/screen
3. Chalkboard/whiteboard
4. Lessons learned
DOE-HDBK-1122-2009
Module 2.07 Respiratory Protection Instructor’s Guide
2.07-3
I. MODULE INTRODUCTION
A. Self-Introduction
1. Name
2. Phone number
3. Background
4. Emergency procedure review
B. Motivation
Internal dosimetry controls require the use of engineering
controls to prevent the internal deposition of radioactive and
non-radiological contaminants. However, when engineering
and administrative controls are not available or feasible,
respiratory protection may be necessary. The RCT should
know and apply the considerations used in determining the
respiratory protection equipment that is most appropriate for
the job. Inappropriate use of or the use of the wrong respiratory
protection equipment may result in undesirable health effects.
C. Overview of Lesson
1. Requirements and regulations
2. Types of equipment
3. Protection factors
4. Fit testing
5. Selection of respirators
6. Site respiratory equipment
7. Supplied air quality testing
8. Sorbents and protection against radioiodines
9. Communications
D. Introduce Objectives
O.H.: Objectives
DOE-HDBK-1122-2009
Module 2.07 Respiratory Protection Instructor’s Guide
2.07-4
II. MODULE OUTLINE
A. REQUIREMENTS AND REGULATIONS
1. DOE Requirements
10 CFR 851, for contractors, and DOE Order 440.1B, for
Federal employees, mandates the requirements for a
respiratory protection program contained in ANSI Z88.2
and 29 CFR 1910.134.
2. OSHA REGULATIONS - 29 CFR 1910.134
Purpose: Specify the minimal acceptable program which
must contain or address the following:
a. Written procedures and program
b. Respirator selection
c. The user shall be instructed and trained in proper use of
respirators
d. Respirators shall be cleaned and disinfected after each
use
e. Respirators stored in a clean, sanitary location
f. Respirators inspected routinely and replaced when
necessary
g. Appropriate surveillance of work area conditions and
degree of employee exposure or stress
h. Regular evaluation of program
i. Persons should be physically able to use respiratory
protection equipment as certified by a licensed health
care practitioner
j. NIOSH approved respirators shall be used
3. ANSI Z88.2 - 1992: Further specifies the minimal
acceptable program
Section 49
a. Individual exposures limited by both inhalation and
skin absorption
b. Air sampling and bioassays
Objective 2.07.01
Objective 2.07.02
Objective 2.07.03
DOE-HDBK-1122-2009
Module 2.07 Respiratory Protection Instructor’s Guide
2.07-5
c. Engineering controls are primary method
d. When an individual is exposed to greater than the
specified DAC or other exposure limits
e. Respiratory protection equipment must be NIOSH
approved
f. If allowance for use of respiratory protection equipment
is made,
1) Protection factor must be sufficient to limit the
annual dose considering the anticipated peak
exposure concentration and associated DAC
2) If exposure is later found to be greater than
estimated, corrected value shall be used
3) Surveys and bioassays conducted as appropriate to
evaluate actual exposures
4) Written procedures must be established
5) Determination by a qualified health care
professional of a user's physical capability
6) A written policy statement must be issued
a) Engineering controls
b) Routine, non-routine and emergency use
c) Periods of use
7) Each user must be advised upon failure of
equipment, physical stress or deterioration of
operating conditions
8) Equipment is appropriate for environment and
special equipment, such as communication devices
issued when needed
9) Emergency use equipment must be specifically
certified as such by NIOSH
If less than estimated, the
corrected value may be
used
Objective 2.07.04
DOE-HDBK-1122-2009
Module 2.07 Respiratory Protection Instructor’s Guide
2.07-6
B. TYPES OF EQUIPMENT
1. Air purifying, particulate-removing filter respirators
a. Description
1) Filtering action removes particulate
2) Operate in negative pressure (NP) mode
3) Exception is a special type of powered air purifying
respirator that is designed to never be negative
pressure.
b. Limitations
1) Do not provide oxygen
2) No protection against gases or vapors
3) Should not be used for abrasive blasting operations
4) Battery operated respirators are limited by battery
life
5) High humidity may increase breathing resistance as
paper elements become water saturated
6) Not to be used in IDLH atmospheres
2. Air Purifying, Chemical Cartridge and Canister Respirators
for Gases and Vapors
a. Description - use cartridges or canisters containing
chemicals to remove specific vapors and gases.
b. Limitations
1) Do not provide oxygen
"dust," "mist" or "fume"
respirators
NEVER to be worn in
oxygen-deficient
atmospheres
The difference between a
cartridge and a canister is
the volume of the sorbent.
Canisters have longer
capacity and are used in
gas masks.
NEVER to be worn in
oxygen deficient
atmospheres
DOE-HDBK-1122-2009
Module 2.07 Respiratory Protection Instructor’s Guide
2.07-7
2) Unless approved by DOE, no credit for protection
against radioactive gases and vapors
3) High humidity shortens life of the sorbent material
and increases breathing resistance
4) Not to be used in IDLH atmospheres
3. Atmosphere Supplying Respirators - Air
a. Description
1) Use central source of breathing air delivered to
wearer through a line or hose
2) Either tight-fitting facepiece or loose-fitting
hood/suit
3) Demand device - during inhalation there may be
negative pressure in the mask
4) Pressure demand device - positive air pressure
inside mask is maintained at all times
5) Continuous-flow air line - is designed to create
positive pressure in facepiece
Section 50
b. Limitations
1) Not used in IDLH atmospheres
2) Trailing air supply hose severely limits mobility
3) Length of hose, number of potential users and
pressure of the supply system are interdependent.
No more than five sections of hose with a
maximum length of 250 feet.
4) Control of air quality is essential
5) "Bubble suits" must be tested for exact conditions
of use
(not for emergency escape
or rescue)
DOE-HDBK-1122-2009
Module 2.07 Respiratory Protection Instructor’s Guide
2.07-8
c. Special Considerations
1) Follow all manufacturers instruction and written
facility/site procedures
2) If all hoses and fittings are same then a single
pressure gauge is appropriate
3) For situations where each user has different hose
lengths, different number of connection or different
air pressure requirements then a separate pressure
gauge should be used
4. Atmosphere Supplying Respirators - Self-Contained
Breathing Apparatus (SCBA)
a. Description
1) Allows the user to carry a respirable breathing
supply
2) There are two groups of SCBAs closed circuit and
open circuit
a) Closed circuit SCBAs - "rebreathing" device
b) Open circuit SCBA exhausts the exhaled air to
the atmosphere
c) Two types of open circuit SCBA are available,
"demand" or "pressure demand"
• Demand SCBA - air flows into facepiece
only on demand of the wearer
Pressure demand - maintains positive
pressure in facepiece at all times regardless
of "demand" of user
Air supply may last 3
minutes to four hours
Designed primarily for 1-4
hours use in toxic
atmospheres
Service life is shorter
When the person inhales
note: demand-type SCBA
does not provide any
higher degree of protection
against airborne
contaminants than air-
purifying respirator with
same facepiece, but it does
provide protection against
oxygen deficiency
Recommended for
emergency use, escape and
rescue
DOE-HDBK-1122-2009
Module 2.07 Respiratory Protection Instructor’s Guide
2.07-9
b. Combination atmosphere supplying respirators
1) Combination Pressure Demand Breathing
Apparatus provides respiratory protection for
personnel who must work in atmospheres that are
IDLH
2) Dual-purpose Breathing Apparatus combines all
capabilities of SCBA and an air line respirator in
one unit
c. Limitations of the pressure and demand SCBA
1) Air supply is limited
2) Bulky and heavy
3) Demand type not for fire fighting
d. Special considerations of the pressure demand SCBA
1) Only pressure-demand type SCBA should be
selected for emergency use, rescue and reentry into
contaminated area
2) Performance of SCBAs in high temperature
environments, such as fires may lead to rapid
deterioration of components
B. PROTECTION FACTORS
1. Overall protection afforded by a given respirator design is
defined in terms of its protection factor (PF)
2. An assigned PF is defined as the level of protection that
would be expected from a class or type of respirator to a
properly fitted and trained user.
3. Application of PFs
4. 29 CFR 1910.134 Protection Factors
Equipped with small air
cylinder in case primary
air supply (hose line) is
interrupted
10CFR20 Appendix R
Section H
Section 5.5 of NUREG
0041
Objective 2.07.05
Table 1 - “Assigned
Protection Factors”
DOE-HDBK-1122-2009
Module 2.07 Respiratory Protection Instructor’s Guide
2.07-10
C. FIT TESTING
1. Definitions
a. Qualitative fit test:
Test to determine if there is any mask leakage, usually
using irritant smoke
Section 51
b. Quantitative fit test:
Test to determine quantity of mask leakage and assign a
"fit factor," an oil or dust particles are the typical
challenge atmospheres used
2. Qualitative fit tests are sometimes performed in lieu of
quantitative fit tests
a. Can use challenge atmospheres such as Isoamyl Acetate
(banana oil) or irritant smoke (e.g. stannic chloride or
titanium tetrachloride)
b. A qualitative fit test uses the same series of exercises as
quantitative fit testing
c. An abbreviated qualitative “fit check” may be used
prior to entry into a contaminated area
3. At least a qualitative test must be performed - a negative
pressure type is typical.
4. Additional factors to be considered
a. Use of communication devices
b. Sorbent canisters with respirators
5. Respirator face pieces and cartridges must be periodically
tested
a. Test a portion of particulate cartridges upon
procurement
b. Test all particulate cartridges prior to re-use
c. Respirator facepieces are tested annually using:
1) Test head mannequin
Objective 2.07.06
Irritant smoke tests are
most effective
Minimum requirement -
each site may be more
restrictive
Penetration value of less
than or equal to 0.003% is
acceptable
DOE-HDBK-1122-2009
Module 2.07 Respiratory Protection Instructor’s Guide
2.07-11
2) Challenge atmosphere with a light scattering
photometer
3) Fit check by user
6. Fit testing of individual is normally quantitative
a. Involves measurement of a challenge atmosphere both
inside and outside respiratory facepiece
b. A "fit factor" is determined by dividing concentration
of challenge atmosphere outside respirator by
concentration inside facepiece
c. An oil mist may be used as a challenge atmosphere or
particle measuring instrument (e.g., Portacount)
d. Oil mist apparatus uses photometry as system for
measuring challenge and breathing zone atmospheres
e. Subject generally performs the following functions
during fit testing:
1) Normal breathing
2) Deep breathing
3) Moving head from side to side
4) Moving head up and down
5) Frown
6) Talking
7) Running in place
8) Normal breathing
D. SELECTION OF RESPIRATORS
1. Most critical factor: the protection factor for respirator
device to be used needs to be adequate to control radiation
dose, considering the work area concentration
2. Only NIOSH approved respirators shall be selected.
3. General considerations. The selection of a proper respirator
for any given situation shall require consideration of the
following factors:
Objective 2.07.07
Note: DOP has been
discontinued as a
challenge atmosphere
since it is a potential
carcinogen
Highlight significance of
functions as related to job
performance
Objective 2.07.08
29 CFR 1910.134
Objective 2.07.09
DOE-HDBK-1122-2009
Module 2.07 Respiratory Protection Instructor’s Guide
2.07-12
a. The nature of the hazard
b. The characteristics of the hazardous operation or
process
c. The location of the hazardous area with respect to a
safe area having respirable air
d. The period of time for which respirator protection may
be provided
e. The activity of workers in the hazardous area
f. The physical characteristics, functional capabilities, and
limitations of respirators of various types
g. The respirator-protection factors and respirator fit
h. Requirement of facility/site written procedures
4. Nature of Hazard. The following factors concerning the
nature of the hazard requiring the use of respirators shall be
considered in respirator selection:
Section 52
a. Type of hazard
• Oxygen deficiency
• Contaminant
b. Physical properties
c. Chemical properties
d. Physiological effects on the body
e. Actual concentration of a toxic material or airborne
radioactivity level both average and peak
f. Whether the hazard is an immediately-dangerous-to-
life-or-health (IDLH) concentration
g. Warning properties
5. Recognition and evaluation of the respiratory hazard
(oxygen deficiency or contaminant(s)) shall be an essential
part of selecting a respirator except in emergency or rescue
operations. Initial monitoring of the respiratory hazard shall
be carried out to obtain data needed for the selection of
proper respiratory protection. The data should include:
DOE-HDBK-1122-2009
Module 2.07 Respiratory Protection Instructor’s Guide
2.07-13
a. Identification of the type of respiratory hazard
1) Oxygen deficiency
2) Specific contaminant(s)
b. Nature of contaminant(s)
1) Particulate matter
2) Vapor(s) or gas(es)
c. Concentration of respiratory hazard
6. The following factors concerning the hazardous operation
or process shall be taken into account in selecting the proper
respirator:
a. Operation or process characteristics both as-built and
modified
b. Work-area characteristics
c. Materials, including raw materials, end products, and
byproducts (actual and potential)
d. Worker activities
E. SITE RESPIRATORY EQUIPMENT
(Insert site specific material here)
F. SUPPLIED AIR QUALITY TESTING
1. Referenced in 29 CFR 1910.134
a. Compressed breathing air shall meet at least quality
specification for Grade D breathing air
b. Breathing air specifications are listed in Compressed
Gas Association G 7.1-1989
2. No explicit limit for water vapor but it is a contaminant
3. Acceptable analytical procedures for measuring the
respirable air components
Objective 2.07.10
Objective 2.07.11
DOE-HDBK-1122-2009
Module 2.07 Respiratory Protection Instructor’s Guide
2.07-14
4. Frequency of performing air quality tests is recommended
by ANSI Z88.2-1992
a. For bottled air systems received from a supplier that
does not fill cylinders with any other gasses, the tests
should check 10% of the cylinders from each lot for
ppm CO and odor. In addition, if the supplier fills
cylinders with gas other than air, analyze all cylinders
for percent oxygen.
b. For facilities which generate respirable air, the
sampling should be performed:
1) Prior to each lot fill
2) Once during the lot fill
3) Once upon completion of the lot fill
c. For compressed air supply systems sampling frequency
is best performed prior to each use of a specific
manifold system
5. Separate breathing air supply and distribution system is the
ideal source or worker-supplied air
G. SORBENTS AND PROTECTION AGAINST RADIOIODINES
1. The regulations specifically prohibit the use of PFs for
canister sorbents as protection against radioiodine
atmospheres
The efficiency of the charcoal canister is dependent upon:
a. chemical form of the radioiodine,
b. humidity of the atmosphere,
c. and breathing rate of the user.
2. Approval may be obtained to use PF's for sorbent cartridges
3. Examples of limiting conditions of use (user must follow
manufactures instructions and DOE approval criteria):
a. Total challenge in the work place (radioactive iodine,
non-radioactive iodine or the halogenated compounds)
may not exceed 1 ppm
In cases of heavy usage
then a daily check of the
system may be more
appropriate.
Section 53
DOE-HDBK-1122-2009
Module 2.07 Respiratory Protection Instructor’s Guide
2.07-15
b. Temperature in the work area may not exceed 100 ΕF.
c. Respirator wearers must have demonstrated a fit factor
greater than 100 for half mask, 1000 for full face piece.
d. Service life is 8 hours maximum. This is calculated
from the time the canister is unsealed and includes
periods of non-use.
e. Canisters will not be used in the presence of organic
solvents, vapors, or chemicals.
f. Canisters must be stored in sealed humidity-barrier
packaging in a cool, dry environment.
H. COMMUNICATIONS
1. Conventional respirators distort the human voice to some
extent
2. Special attachments are often needed to ensure adequate
communications
a. Speaking diaphragm
b. Various methods of electronically transmitting and
amplifying speech through the respirator
c. Any communication device that is an integral part of
respirator must be part of NIOSH approval
IV. SUMMARY
A. Review major topics
1. Requirements and regulations
2. Types of equipment
3. Protection factors
4. Fit testing
5. Selection of respirators
6. Site respiratory equipment
7. Supplied air quality testing
DOE-HDBK-1122-2009
Module 2.07 Respiratory Protection Instructor’s Guide
2.07-16
8. Sorbents and protection against radioiodines
9. Communications
B. Review learning objectives
V. EVALUATION
Evaluation should consist of a written examination comprised of
multiple choice, fill-in the blank, matching and/or short answer
questions. 80% should be the minimum passing criteria for
examinations.
DOE-HDBK-1122-2009
Module 2.08 Radioactive Source Control Instructor’s Guide
2.08-1
Course Title: Radiological Control Technician
Module Title: Radioactive Source Control
Module Number: 2.08
Objectives:
2.08.01 Describe the requirements for radioactive sources per 10 CFR 835.
→ 2.08.02 Identify the characteristics of radioactive sources that must be controlled at your
site.
→ 2.08.03 Identify the packaging, marking, and labeling requirements for radioactive
sources.
→ 2.08.04 Describe the approval and posting requirements for radioactive materials areas.
→ 2.08.05 Describe the process and procedures used at your site for storage and
accountability of radioactive sources.
References:
1. 10 CFR 835, “Occupational Radiation Protection,” (2007).
Instructional Aids:
1. Overheads
2. Overhead projector/screen
3. Chalkboard/whiteboard
4. Lessons learned
DOE-HDBK-1122-2009
Module 2.08 Radioactive Source Control Instructor’s Guide
2.08-2
I. MODULE INTRODUCTION
A. Self-Introduction
1. Name
2. Phone number
3. Background
4. Emergency procedure review
B. Motivation
Radioactive sources are used for response checks in the field,
functional checks, and calibration of instruments and monitors
to traceable standards. To ensure the safety and welfare of all
personnel it is important to maintain control of radioactive
sources. Radioactive sources are controlled to minimize the
potential for:
• Spread of contamination
• Unnecessary exposure to personnel
• Loss or theft
• Improper disposal
C. Overview of Lesson
1. Requirements
2. Control of sources
3. Receipt
4. Radioactive Materials Storage Areas
5. Inventory and transfer
6. Surveys
7. Leak test
8. Source disposal
D. Introduce Objectives
O.H.: Objectives
DOE-HDBK-1122-2009
Module 2.08 Radioactive Source Control Instructor’s Guide
2.08-3
II. MODULE OUTLINE
Section 54
A. 10 CFR 835
In accordance with the 10 CFR 835 Subpart M, the following
provisions apply to sealed sources:
1. §835.1201 Sealed Radioactive Source Control
Sealed radioactive sources shall be used, handled, and
stored in a manner commensurate with the hazards
associated with operations involving the sources.
2. §835.1202 Accountable Sealed Radioactive Sources
(a) Each accountable sealed radioactive source shall be
inventoried at intervals no to exceed six months. This
inventory shall:
(1) Establish the physical location of each accountable
sealed radioactive source;
(2) Verify the presence and adequacy of associated
postings and labels; and
(3) Establish the adequacy of storage locations,
containers, and devices.
(b) Except for sealed radioactive sources consisting solely
of gaseous radioactive material or tritium, each
accountable sealed radioactive source shall be subject
to a source leak test upon receipt, when damage is
suspected, and at intervals not to exceed six months.
Source leak tests shall be capable of detecting
radioactive material leakage equal to or exceeding
0.005 microcurie.
(c) An accountable sealed radioactive source is not subject
to periodic source leak testing if that source has been
removed from service. Such sources shall be stored in
a controlled location, subject to periodic inventory and
subject to source leak testing prior to being returned to
service.
(d) An accountable sealed radioactive source is not subject
to periodic inventory and source leak testing if that
source is located in an area that is unsafe for human
entry or otherwise inaccessible.
Objective 2.08.01
DOE-HDBK-1122-2009
Module 2.08 Radioactive Source Control Instructor’s Guide
2.08-4
(e) An accountable sealed radioactive source found to be
leaking radioactive material shall be controlled in a
manner that minimizes the spread of radioactive
contamination.
B. CONTROL OF SOURCES
(Insert site specific information here)
1. Types of Sources:
a. Accountable sealed radioactive source means a sealed
radioactive source having a half-life equal to or greater
than 30 days and an isotopic activity equal to or greater
than the corresponding value provided in Appendix E
of 10 CFR 835.
b. Sealed radioactive source means a radioactive source
manufactured, obtained, or retained for the purpose of
utilizing the emitted radiation. The sealed radioactive
source consists of a known or estimated quantity of
radioactive material contained within a sealed capsule,
sealed between layer(s) of non-radioactive material, or
firmly fixed to a non-radioactive surface by
electroplating or other means intended to prevent
leakage or escape of the radioactive material.
c. Source leak test means a test to determine if a sealed
radioactive source is leaking radioactive material.
2. Responsibilities:
a. It is important that the following actions be done:
1) establishing the program
2) maintaining records related to the accountability
and control of accountable sealed radioactive
sources for a facility
3) providing each source custodian with an inventory
list of accountable sealed radioactive sources
assigned to him or her
4) assisting the source custodian in training source
users
Objective 2.08.02
DOE-HDBK-1122-2009
Module 2.08 Radioactive Source Control Instructor’s Guide
2.08-5
b. The source custodian:
1) should be responsible for ensuring that tests to
Section 55
establish the integrity of an accountable sealed
radioactive source are conducted and inventory
checks are performed at least every 6 months.
2) should maintain records of the storage and use
locations of all assigned accountable sealed
radioactive sources.
3) should be trained as a radiological worker prior to
being designated as a source custodian.
4) should notify and obtain approval of the RCO prior
to:
a) any major changes in the use of a sealed
radioactive source
b) on-site transfer of a sealed radioactive source
to a new permanent storage location
c) modification of a device containing a sealed
radioactive source
d) disposal or off-site transfer of a sealed
radioactive source
e) any procurement or acquisition of additional
sealed radioactive sources
5) should also notify the RCO in the event of the loss
or damage to any accountable sealed radioactive
source
c. The source user:
1) should be an individual trained by the RCO and the
source custodian to use either accountable or
exempt sealed radioactive sources
2) should be trained as a radiological worker and
receive appropriate training on handling their
specific sealed radioactive source(s).
C. RECEIPT
Prior to receipt of accountable sealed radioactive sources, the
RCO should assign the sources to the proper source custodians.
Immediately upon receipt of accountable sealed radioactive
DOE-HDBK-1122-2009
Module 2.08 Radioactive Source Control Instructor’s Guide
2.08-6
sources, the RCO should be notified. The packaging should be
inspected for damage and a contamination and radiation survey
performed. The RCO should perform receipt surveys (RCS
431.3). A source integrity test shall be performed upon receipt
if visible damage to the package exists (10 CFR 835.405), or
prior to initial use. The source custodian should be notified of
the arrival of the sealed sources to ensure that proper
accountability and control are initiated. The sources should be
placed into storage or into the device in which they will be used.
The source custodian and site's records should be updated to
include the new sources received.
D. LABELING AND STORAGE OF RADIOACTIVE
MATERIAL
(Insert site specific information here)
1. §835.605 Labeling items and containers.
Except as provided in §835.606, each item or container of
radioactive material shall bear a durable, clearly visible
label bearing the standard radiation warming trefoil and the
words “Caution Radioactive Material” or “Danger”,
Radioactive Material.” The label shall also provide
sufficient information to permit individuals handling or
using the items or containers, or working in the vicinity of
the items or containers, to take precautions to avoid or
minimize exposures.
2. §835.606 Exceptions to labeling requirements.
(a) Items and containers may be excepted from the
radioactive material labeling requirements of §835.605
when:
(1) Used handled, or stored in areas posted and
controlled in accordance with this subpart and
sufficient information is provided to permit
individuals to take appropriate protective actions to
avoid or control exposures; or
(2) The quantity of radioactive material is below 1/10
the values specified in Appendix E to 10 CFR 835
and less than 0.1 Ci; or
(3) Packaged, labeled, and marked in accordance with
the regulations of the Department of Transportation
or DOE Orders governing radioactive material
transportation; or
Objective: 2.08.03
DOE-HDBK-1122-2009
Module 2.08 Radioactive Source Control Instructor’s Guide
Section 56
2.08-7
(4) Inaccessible, or accessible only to individuals
authorized to handle or use them, or to work in the
vicinity; or
(5) Installed in manufacturing, process, or other
equipment, such as reactor components, piping,
and tanks; or
(6) The radioactive material consists solely of nuclear
weapons or their components.
(b) Radioactive material labels applied to sealed
radioactive sources may be excepted from the color
specifications of 10 CFR 835.601 (a).
E. RADIOACTIVE MATERIAL AREAS
(Insert site specific information here)
1. Definitions
(a) Radioactive Material Area means any area within a
Controlled Area, accessible to individuals, in which
items or containers of radioactive material exist and the
total activity of radioactive material exceeds the
applicable values provided in Appendix E to 10 CFR
835.
(b) Radioactive Material Area Posting The words “Caution,
Radioactive Material(s)” shall be posted at each
Radioactive Material Area [835.603(g)].
2. §835.604 Exceptions to posting requirements
(a) Areas may be excepted from the posting requirements
of §835.603 for periods of less than 8 continuous hours
when placed under continuous observation and control
of an individual knowledgeable of, and empowered to
implement, required access and exposure control
measures.
(b) The following areas may be excepted from the
radioactive material area posting requirement of
§835.603(g) when:
(1) Posted in accordance with §835.603(a) through (f);
or
Objective: 2.08.04
DOE-HDBK-1122-2009
Module 2.08 Radioactive Source Control Instructor’s Guide
2.08-8
(2) Each item or container of radioactive material is
labeled in accordance with requirements in 10 CFR
835 such that individuals entering the area are
made aware of the hazard; or
(3) The radioactive material of concern consists solely
of structures or installed components which have
been activated (i.e., such as by being exposed to
neutron radiation or particles produced by an
accelerator).
(c) Areas containing only packages received from
radioactive material transportation need not be posted
in accordance §835.603 until the packages are
monitored in accordance with §835.405.
3. In addition, storage rooms or cabinets containing
radioactive sources should meet the following
requirements:
a. Locked and posted
b. Located to minimize damage from fire
c. Free of flammable substances
d. Isolated from occupied areas or located in radiological
areas or radiological buffer areas
e. When selected in continuously occupied controlled
areas, the radiation level at the closest approach is as
low as reasonably achievable and does not exceed 0.5
millirem per hour on average
F. SOURCE DISPOSAL
Obsolete, excess, or leaking accountable sealed radioactive
sources should be disposed of according to RCO instructions.
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Module 2.08 Radioactive Source Control Instructor’s Guide
2.08-9
III. SUMMARY
A. Review major points
1. Requirements
2. Control of sources
3. Receipt
4. Radioactive Materials Storage Areas
5. Inventory and transfer
6. Surveys
7. Leak test
8. Source disposal
B. Review learning objectives
IV. EVALUATION
Evaluation should consist of a written examination comprised of
multiple choice, fill-in the blank, matching and/or short answer
questions. 80% should be the minimum passing criteria for
examinations.
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Section 57
DOE-HDBK-1122-2009
Module 2.09 Environmental Monitoring Instructor’s Guide
2.09-1
Course Title: Radiological Control Technician
Module Title: Environmental Monitoring
Module Number: 2.09
Objectives:
2.09.01 State the goals of an environmental monitoring program.
2.09.02 State the exposure limits to the general public as they apply to environmental
monitoring.
2.09.03 Define the term "critical nuclide."
2.09.04 Define the term "critical pathway."
→ 2.09.05 State locations frequently surveyed for radiological contamination at outdoor
waste sites associated with your site and the reasons for each.
2.09.06 Define the term "suspect waste site," and how they can be identified.
→ 2.09.07 Describe the methods used for environmental monitoring at your site.
References:
1. "Basic Radiation Protection Technology"; Gollnick, Daniel; 5th ed.; Pacific Radiation
Corporation; 2008.
2. NCRP Report #50, "Environmental Radiation Measurements," (1976).
3. DOE Order 5400.5.
4. 40 CFR 61.
5. 40 CFR 141 (Safe Drinking Water Act).
6. 40 CFR 191.
Instructional Aids:
1. Overheads
2. Overhead projector/screen
3. Chalkboard/whiteboard
4. Lessons learned
DOE-HDBK-1122-2009
Module 2.09 Environmental Monitoring Instructor’s Guide
2.09-2
I. MODULE INTRODUCTION
A. Self-Introduction
1. Name
2. Phone number
3. Background
4. Emergency procedure review
B. Motivation
Environmental monitoring plays a large role in the field of
radiological control. Environmental monitoring is used to
estimate human population doses, determine the impact a site
has on the environment, monitor for unplanned releases as well
as quantifying planned releases, and gives us data useful in
determining pathway data.
C. Overview of Lesson
1. Environmental monitoring goals
2. Principles of program design
3. Radiological control responsibilities
4. Analysis of environmental samples
5. Site environmental monitoring methods
6. Transport mechanisms
D. Introduce learning objectives
II. MODULE OUTLINE
A. GOALS OF ENVIRONMENTAL MONITORING
PROGRAMS
1. Estimate Human Population Doses
a. ALARA dictates that we must be aware of changes in
radiation exposure to the general population which
results from nuclear operations
O.H.: Objectives
Objective 2.09.01
DOE-HDBK-1122-2009
Module 2.09 Environmental Monitoring Instructor’s Guide
2.09-3
b. Issuing TLDs to population is not practical. In addition
the TLDs are not sensitive enough to detect changes in
environmental radiation levels
c. The only practical way to determine population
exposure is by measurement of environmental radiation
levels:
1) External radiation level
2) Radioactivity present in air
3) Radioactivity present in food
4) Radioactivity present in water
d. Population exposure can then be determined by using
these values combined with a knowledge of the
drinking water sources and the types of food consumed
in the region
2. Determine Site Impact
a. Environmental levels are determined prior to beginning
site operations. A pre-operational survey (or
characterization) is required for a minimum of 1 year,
and preferably 2 years, prior to the startup of any new
site or waste site
b. Environmental levels are then measured during site
operation and changes are tracked to determine site
impact
c. The exposure of members of the public, outside of
Section 58
controlled areas, to radiation sources as a consequence
of all routine DOE activities shall not cause, in a year,
an effective dose equivalent greater than 100 mrem (1
mSv). The 100 mrem effective dose equivalent in a
year is the sum of the effective dose equivalent from
exposures to radiation sources external to the body
during the year plus the committed effective dose
equivalent from radionuclides taken into the body
during the year.
Note: Refer to Module 2.04 for discussion of
equivalencies in the dosimetric terms between ICRP
26/30 and 60/68 and limits for members of the public
inside controlled areas.
Objective 2.09.02
The DOE primary standard
of 100 mrem to members of
the public in a year is lower
than the previous primary
limit of 500 mrem. The
lower value was selected in
recognition of the ICRP
recommendation to limit the
long-term average effective
dose equivalent to 100 mrem
per year, or less.
Experience suggests that the
lower dose is readily
achievable for normal
operations of DOE facilities.
DOE-HDBK-1122-2009
Module 2.09 Environmental Monitoring Instructor’s Guide
2.09-4
d. A higher dose limit, not to exceed the 500 mrem
effective dose equivalent recommended by the ICRP as
an occasional annual limit, may be authorized for a
limited period if it is justified by unusual operating
conditions.
e. For airborne emissions from all DOE sources of
radionuclides, the exposure of members of the public to
radioactive materials released to the atmosphere as a
consequence of routine DOE activities shall not cause
members of the public to receive, in a year, an effective
dose equivalent greater than 10 mrem.
f. For exposure from sources from the management and
storage of spent nuclear fuel, high-level, and
transuranic wastes at disposal facilities, the exposure of
members of the public to direct radiation or radioactive
material released shall not cause members of the public
to receive, in a year, a dose equivalent greater than 25
mrem to the whole body or a committed dose
equivalent greater than 75 mrem to any organ.
g. For the drinking water pathway, it is the policy of DOE
to provide a level of protection for persons consuming
water from a public drinking water supply operated by
the DOE that is equivalent to that provided to the
public by the public community drinking water
standards of 40 CFR 141. These systems shall not
cause persons consuming the water to receive an
effective dose equivalent greater than 4 mrem in a year.
3. Detect and Quantify an Unplanned Release
a. Although adequate Radiation Safety programs are
maintained at all licensed sites, there is always the
possibility of an "unknown release."
b. Environmental monitoring can serve as a secondary
backup system to the primary defense of a good
Radiation Safety program
1) Windscale reactor fire in 1957 detected by I-131
detected downwind of the site
2) Chernobyl detected by the Western powers through
environmental monitoring programs in Europe
DOE-HDBK-1122-2009
Module 2.09 Environmental Monitoring Instructor’s Guide
2.09-5
4. Meet Legal or Regulatory Requirements
a. DOE regulations dictate environmental monitoring
requirements for that site
b. Larger facilities and plants are required to maintain
continuous, extensive monitoring programs according
to DOE requirements, Federal and State regulations,
and regulatory guides
c. Monitor all inactive, existing, and new low-level waste
(LLW) disposal sites to assess both radiological and
nonradiological hazards (DOE Order 5820.2A)
Section 59
d. Monitor and maintain all surplus facilities prior to
decontaminating or decommissioning
(DOE Order 5820.2)
5. Create and Maintain a Good Public Image
a. Operating an environmental monitoring program more
extensively than required by law shows the site to be a
"good neighbor"
b. Extensive environmental monitoring also provides
added protection against lawsuits
6. Obtaining Pathway Data
a. A critical nuclide is one of a group of nuclides which
cause the largest dose contribution to the actual
population at risk near the site. Typical operational
reactor "critical nuclides" include:
1) Actinium-227
2) Barium/Lanthanum-140
3) Cesium-137
4) Cobalt-60
5) Hydrogen-3 (Tritium)
6) Iodine-131
7) Manganese-54
Objective 2.09.03
Objective 2.09.04
DOE-HDBK-1122-2009
Module 2.09 Environmental Monitoring Instructor’s Guide
2.09-6
8) Plutonium-238
9) Plutonium-239
10) Radium-226
11) Strontium-89
12) Strontium-90
13) Thorium-230
14) Thorium-232
b. A "pathway" is any route that radioactivity can follow
in passing from a licensee to a person in the general
population where it becomes internally deposited or
contributes external dose
c. A critical pathway is the route taken, from the point of
release to body entry, of a critical radionuclide which
causes human exposure
d. Environmental monitoring enables pathway data to be
collected and analyzed. This can help verify or reject
theoretical "transport mechanism" data used in
determining population exposure
7. Test Adequacy of Radiological Control Measures
a. Small amounts of non-routine radionuclides beginning
to show up in the environmental samples could indicate
problems at the site
b. Radiological Controls and operations at the site can
then be reviewed prior to any releases above the
prescribed limits
8. Study of Air and Water Mixing Patterns
a. To aid in the study of transport mechanisms, small
amounts of radioisotopes are sometimes released under
controlled conditions to determine air and water
pathways
b. This data is used in determining population dose
estimates
9. "Non-Industry" Applications
a. Atmospheric and oceanic circulation studies
DOE-HDBK-1122-2009
Module 2.09 Environmental Monitoring Instructor’s Guide
2.09-7
b. Monitoring of redistribution of radioactivity due to
man's use of radioactive materials, and man's extensive
modification of the earth's surface. Redistribution of
naturally-occurring radionuclides in the environment
can cause significant changes in the background
radiation levels in an area. Changes are made by:
1) bringing in topsoil from other areas
2) the use of fertilizers
3) plowing the ground
4) the addition of water to the ground
a) can serve to attenuate radiation
b) may also introduce new radionuclides
5) the presence of structures
a) attenuate radiation
b) may also introduce new radionuclides
6) industrial activities
a) can emit naturally occurring radionuclides to
the air or water
7) there are many other changes that individuals make
B. PRINCIPLES OF PROGRAM DESIGN
In order to meet regulatory requirements, environmental
monitoring programs must be operated at DOE facilities. One
of the main reasons to operate an environmental monitoring
program is to determine what increases in radioactivity in the
environment is due to the operation of the site.
1. Pre-operational Program Design
Prior to operating a site, an environmental monitoring
program will be run in order to:
Section 60
a. Locate Radiation Anomalies
This information helps to
identify critical nuclides and
critical pathways for the new
site.
DOE-HDBK-1122-2009
Module 2.09 Environmental Monitoring Instructor’s Guide
2.09-8
b. Document Ambient Levels
c. Identify Critical Pathways/Nuclides
d. Document Meteorology Patterns
2. Post-operational Program Design
Another phase of environmental monitoring is entered once
the site begins operations. Measurements are now made to
aid in dose assessment, for the determination of compliance
with allowed releases, and for the identification of any
changes in radioactivity in the environment due to the
operation of the site. In order to accomplish these goals,
we need:
a. A monitoring program with enough sensitivity to detect
environmental changes in radioactivity.
b. A monitoring program with enough selectivity to be
able to separate nuclides of interest from background
interference.
The post-operational program is commonly on a
smaller scale than the pre-operational program. Due to
the extensive monitoring done prior to start of
operations, attention to the post-operational program
can be focused primarily on the critical nuclides, and
the instrumentation on the critical pathways.
C. RADIOLOGICAL CONTROL RESPONSIBILITIES
1. Radiological Surveys are conducted to monitor radioactive
contamination
a. General Monitoring Requirements:
1) Ambient air in the immediate vicinity of active and
inactive sites
2) Surface water (rivers, estuaries, lakes and oceans)
and sediments are monitored for constituents
indicating the status of operational practices and
control
3) Soil and vegetation are monitored to detect
possible contamination from fallout and uptake.
4) Ground water wells are surveyed to ensure their
physical integrity
DOE-HDBK-1122-2009
Module 2.09 Environmental Monitoring Instructor’s Guide
2.09-9
5) Background dose rates are monitored near facilities
that may have elevated dose rates
6) Radiation surveys are performed to detect
contamination spread
2. Survey frequencies for particular sites are to be determined
by the technical judgement of Environmental Protection
and/or Radiological Control and may depend on the site
history, radiological status, use and general conditions.
3. Appropriate documentation must be completed for each
environmental survey.
4. Radiological Surveys:
(Insert site specific information here.)
a. Soil
b. Water
c. Air
5. Suspect Waste Site Investigations
a. A suspect waste site is any site that is thought for any
reason to contain dangerous waste, hazardous waste
and/or radioactive waste. This does not include sites
already identified
6. Suspect waste site identification
a. Any employee having any reason to believe that a site
contains dangerous waste, hazardous waste, and/or
radioactive waste should report this information to
management.
b. The following conditions should be looked for:
1) Soil discoloration is present
2) An unusual soil depression or disturbance exists
3) Pipes emerging from the ground (indicates a
possible crib, tank or other structure)
4) Plant stress
Objective 2.09.05
Objective 2.09.06
DOE-HDBK-1122-2009
Module 2.09 Environmental Monitoring Instructor’s Guide
2.09-10
5) The unusual absence of plant life
6) Vaults, chambers, concrete or steel structures,
drums, pipes, or munitions protruding from the
surface of a disturbed area
7) Holes, sinkholes, or collapsed structures (indicates
Section 61
the presence of man-made structures or voids
beneath the surface)
8) The presence of hazardous and/or radioactive
material in soil samples
9) Documentation or personnel interviews which
indicate the past existence of a waste disposal site
D. ANALYSIS OF ENVIRONMENTAL SAMPLES
1. Environmental sample types include:
a. Air samples
b. Soil samples
c. Vegetation samples
d. Animal samples
e. Surface water samples
f. Groundwater samples
g. Background radiation
h. Radiation surveys.
2. Methods of Monitoring
a. Environmental levels of external gamma radiation are
measured using film or thermoluminescent dosimeters
1) The lower detection level for film badges is
approximately 10 mrem/month
2) The lower detection level for TLDs is
approximately 1 mrem/month. Corrections must
be made, however, for fading of dosimeters, and
energy dependence
DOE-HDBK-1122-2009
Module 2.09 Environmental Monitoring Instructor’s Guide
2.09-11
b. Activity deposited on the ground (or "fallout") is
isotopically analyzed and quantified to determine
release point of origin and amount released. Generally,
gas-flow proportional counters are used for gross alpha
and beta determinations. Gamma spectrum are
obtained using Germanium semiconductor systems.
Alpha spectroscopy can also be used to isotopically
analyze and quantify environmental samples
1) Fallout simply means radioactive particles that
settle out onto the ground. The term does not
necessarily imply a nuclear detonation has occurred
2) "Flypaper" technique is used, which consists of an
adhesive covered piece of waterproof paper, which
is positioned in the environment to catch and hold
particulate matter which settles out. This technique
traps approximately 70% of the particles that fall
on it
3) Rain water is also collected and analyzed for
radioactivity that may have been washed from the
air
4) Grass and other broadleaf vegetation is also a good
collection media for "fallout." (Note how this may
be part of a critical pathway, e.g., cows graze on
contaminated pastures, and the general population
drinks the now contaminated milk)
c. Atmospheric sampling is accomplished by drawing air
through a filter at a known rate and then counting the
filter for particulate activity
1) Air sampling for particulates
a) Inertial separation is one method for
radioactive particulate air sampling. It is
especially effective in determining the size
distribution of particles. This information is
necessary for internal dose assessment
following inhalation of particulate
radionuclides. A Cascade Impactor is an
example of a sampler utilizing the inertial
separation method
DOE-HDBK-1122-2009
Module 2.09 Environmental Monitoring Instructor’s Guide
2.09-12
b) Filtration is another method for radioactive
particulate air sampling. This consists simply
of a pump which pulls air through a filter
matrix. The filter is then removed and counted
to determine airborne radioactive particulate
concentrations
(1) Dust loading is a factor in collection
efficiency. As the filter becomes plugged
up with dust, air flow generally decreases,
but the collection efficiency usually
increases
(2) The rate at which air (particles) is drawn
through the filter also is a factor in
collection efficiency.
(a) At low rates of air flow, efficiency is
relatively high due to diffusion of
particles in the filter media. In other
words, the air particles "drift" through
the filter media, and become trapped in
the dead air spaces in the filter
Section 62
(b) At high rates of air flow, efficiency is
also relatively high due to the
phenomena of impaction. This is an
increased collection of particles due to
the higher speed of the particles
causing them to "crash" into the filter
media, and bury themselves in the
fibers of the filter. It is necessary to
realize, however, that for gross beta
and especially gross alpha counting,
this method will introduce more self-
shielding in the counting process
2) Air sampling for gases
a) Continuous flow sampling for radioactive
gases is a common method of air concentration
determination. Air is pumped or exhausted
through a chamber housing a detector. The
detector, coupled with an air flow-rate meter,
can give real-time determination of airborne
radioactivity concentration. An example of a
system utilizing this method is a Stack Monitor.
DOE-HDBK-1122-2009
Module 2.09 Environmental Monitoring Instructor’s Guide
2.09-13
b) Grab sampling is another method of measuring
air activity concentration. This method uses an
evacuated chamber which is opened in the
environment to be sampled, then re-sealed.
The inside surfaces of the chamber are coated
with a scintillation phosphor, such that when
different types of radiation interact with the
phosphor, small flashes of light are produced.
When the chamber is placed in a light-tight
housing with a photomultiplier tube, these
flashes of light are measured and are indicative
of the activity concentration in the grab cell.
Another type of grab sampler is an evacuated
tube or chamber with a thin-walled G-M tube
mounted along it's central axis. For analysis,
then, the G-M is connected to a scaler, and a
gross count is made
c) Adsorption is the assimilation of gas, vapor or
dissolved matter by the surface of a solid or
liquid (the adsorbent). Gaseous air activity
concentration is measured by drawing the air to
be measured through the adsorbent, and then
counting the adsorbent. Common adsorbents
are activated charcoal, silver zeolite (AgZ), and
silica gel
d) Condensation is used in monitoring for
airborne tritium activity. Water vapor in the air
which may contain tritium components are
condensed by using a super-cooled strip of
metal in the ambient air. Water vapor will
condense and freeze on this strip. The ice is
then melted, and a liquid scintillation counter is
then used to count for tritium.
d. Aquatic samples may include sediments, bottom
organisms, vegetation, fin fish, or shell fish. Water
needs to be analyzed only if it is used for consumption
or irrigation. In most cases, samples of shell fish and
fin fish are saved to document the principal route of
human exposure. If waste is being discharged into a
flowing stream of potable water, a continuous sampler
should be used.
e. Food sampling is not necessary if proper regulations
are followed that restrict the discharge of liquid and
solid radioactive effluents (other than that which is
desirable for good relationships with the public). The
type of sampling will be determined by the isotope
released.
DOE-HDBK-1122-2009
Module 2.09 Environmental Monitoring Instructor’s Guide
2.09-14
1) Radionuclides such as Co-60 and Zn-65
concentrate in shellfish. Sampling should be done
if these radioactive fission products are discharged
into an estuary populated with shellfish.
2) If I-131 is released, cow pastures should be
sampled as well as the milk produced. I-131 will
appear in milk within 24 hours.
E. SITE ENVIRONMENTAL MONITORING METHODS
Section 63
(Insert site specific information here.)
F. TRANSPORT MECHANISMS
1. Atmospheric Transport
a. Airborne radioactive contaminants are carried
downwind and dispersed by normal atmospheric
mixing processes
b. Internal irradiation occurs if the radionuclides are
inhaled and incorporated in the body
c. External irradiation occurs by beta and gamma
irradiation from the plume
d. Material is removed from the plume by impaction of
the plume with the ground surface or by washout due to
rain
e. Deposition of the material from the plume leads to
further exposure pathways through:
1) Direct external exposure from contaminated
surfaces
2) Inhalation of re-suspended material
3) Ingestion of contaminated foodstuffs
f. Factors considered in determining the deposition of
radioactive material back to earth include:
1) Wind speed
2) Temperature
3) Stack height
4) Particle size
Objective 2.09.07
DOE-HDBK-1122-2009
Module 2.09 Environmental Monitoring Instructor’s Guide
2.09-15
5) Weather conditions
g. A reverse in the normal upward movement of hot air
can slow down the dilution of radioactive release. The
condition where hot air develops over cooler air is
called a temperature inversion. A temperature
inversion can occur when:
1) A warm front covers a cooler earth
2) A cool front is injected under warm air (sea breeze)
3) The normal cycle of a summer day when the earth
cools off faster than the air above
2. Surface Water Transport
a. Liquid effluents may be discharged into various types
of surface water bodies:
1) Rivers
2) Estuaries
3) Lakes
4) Oceans
b. In rivers, the rate of transport is slower than in the
atmosphere
c. Radionuclides may be absorbed by bottom sediments,
and may accumulate in the aquatic biota
d. Although these two processes involve only a small
fraction of the inventory, they may be significant with
respect to radiation exposure
e. Radioactive materials released in rivers eventually feed
into the ocean
1) In the ocean surface layer (75 m in depth and
located above the thermocline) the mixing time is
3-5 years
2) Below the thermocline in the deep ocean, the
mixing is much slower
f. Some aquatic mixing factors include
1) Depth of water
DOE-HDBK-1122-2009
Module 2.09 Environmental Monitoring Instructor’s Guide
2.09-16
2) Type of bottom
3) Shoreline configuration
4) Tidal factors
5) Wind
6) Temperature
7) Salinity
8) Solubility of radioactive material
9) Depth at which pollutant is introduced
3. Movement in the Ground
a. Radionuclide movement in the ground is generally the
slowest
b. Movement of most radionuclides depends upon
convective transport in water
c. In humid regions the rate of ground water movement
near the surface is on the order of 1 ft/day. In arid
areas, the rate is much slower
d. There is an abundance of solid material for absorption
of radionuclides and interaction with this geologic
media can reduce the rate of radionuclide movement to
a small fraction of underground water movement
III. SUMMARY
A. Review major topics
1. Environmental monitoring goals
2. Principles of program design
3. Radiological control responsibilities
4. Analysis of environmental samples
5. Site environmental monitoring methods
6. Transport mechanisms
B. Review learning objectives
DOE-HDBK-1122-2009
Module 2.09 Environmental Monitoring Instructor’s Guide
2.09-17
IV. EVALUATION
Section 64
Evaluation should consist of a written examination comprised of
multiple choice, fill-in the blank, matching and/or short answer
questions. 80% should be the minimum passing criteria for
examinations.
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DOE-HDBK-1122-2009
Module 2.10 Access Control and Work Area Setup Instructor’s Guide
2.10-1
Course Title: Radiological Control Technician
Module Title: Access Control and Work Area Setup
Module Number: 2.10
Objectives:
→ 2.10.01 State the purpose of and information found on a Radiological Work Permit
(RWP) including the different classifications at your site.
→ 2.10.02 State responsibilities in using or initiating a RWP.
→ 2.10.03 State the document that governs the ALARA program at your site.
→ 2.10.04 Describe how exposure/performance goals are established at your site.
→ 2.10.05 State the conditions under which a pre-job ALARA review is required at your site.
→ 2.10.06 State the conditions under which a post-job ALARA review is required at your
site.
2.10.07 State purpose of radiological postings, signs, labels, and barricades; and the RCTs
responsibilities for them.
→ 2.10.08 Identify the following radiological postings at your site, requirements for
posting/barriers, and requirements for entry:
a. Radiological Buffer Area
b. Radiation Area
c. High Radiation Area
d. Very High Radiation Area
e. Hot Spot
f. Contamination Area
g. High Contamination Area
h. Airborne Radioactivity Area
i. Fixed Surface Contamination
j. Soil Contamination
k. Radioactive Material Area
l. Underground Radioactive Material Area
2.10.09 Describe good practices, support equipment to use, and common discrepancies in
setting up radiological areas.
2.10.10 List discrepancies frequently observed in containment devices.
2.10.11 Describe good practices in setting up portable ventilation systems and count rate
meters.
→ 2.10.12 List the requirements individuals should follow while working in RBAs.
→ 2.10.13 State the requirements for removing or releasing materials from any radiological
area.
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References:
1. 10 CFR 835, “Occupational Radiation Protection” (2007).
2. DOE Radiological Control Standard, 2008.
Instructional Aids:
1. Overheads
2. Overhead projector/screen
3. Chalkboard/whiteboard
4. Lessons learned
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I. MODULE INTRODUCTION
A. Self Introduction
1. Name
2. Phone number
3. Background
4. Emergency procedure review
B. Motivation
This lesson presents instruction in Radiological Work Permits, various
types of postings used in radiological areas, setting up radiological areas,
access controls, and releasing of material from radiological areas. All of
these are fundamental duties of RCTs.
C. Overview of Lesson
1. General Overview - Area setup and access control
2. Points of importance
a. RWPs
b. Radiological postings
c. Setting up radiological areas
d. Good practices and discrepancies commonly observed in setup
of various portions of radiological areas.
e. Access control
f. Removing materials from radiological areas
D. Introduce Objectives
II. MODULE OUTLINE
A. RADIOLOGICAL WORK PERMITS (RWPs)
(Insert site specific information here)
O.H.: Objectives
See DOE RCS Art.
321-323
Objective 2.10.01
Section 65
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1. Structure of an RWP
a. Description of work
b. Work area/process radiological controls
c. Dosimetry requirements
d. Pre-job briefing requirements, as applicable
e. Training requirements for entry
f. Protective clothing and respiratory protection requirements
g. Radiological control coverage requirements and stay time
controls, as applicable
h. Limiting radiological conditions that may void the RWP
i. Special dose or contamination reduction considerations
j. Special personnel frisking considerations
k. Technical work document number, as applicable
l. Unique identifying number
m. Date of issue and expiration
n. Authorizing signature
2. RWPs should be used to control the following activities:
a. Entry into High and Very High Radiation Areas
b. Entry into High Contamination Areas
c. Entry into Airborne Radioactivity Areas
3. RWPs should be used to control the following activities:
a. Entry into Radiation Areas
b. Entry into Contamination Areas
c. Handling of materials with removable contamination that
exceeds the values in Table 2-2 of the Radiological Control
Standard
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4. Responsibilities when using an RWP
a. It is important for individuals to comply with the requirements of
the RWP to prevent personnel contamination or unnecessary
radiation exposure.
(Insert site specific information here)
B. ALARA CONSIDERATIONS FOR ACCESS CONTROL AND WORK
AREA SETUP
1. ALARA documentation
(Insert site specific information here)
2. Exposure/performance goals
(Insert site specific information here)
3. Pre-job ALARA Reviews
a. At a minimum, the pre-job briefing should include:
1. Scope of work to be performed
2. Radiological conditions of the workplace
3. Procedural and RWP requirements
4. Special radiological control requirements
5. Radiologically limiting conditions, such as contamination or
radiation levels that may void the RWP
6. Radiological Control Hold Points
7. Communications and coordination with other groups
8. Provisions for housekeeping and final cleanup
9. Emergency response provisions
b. Pre-job ALARA review requirements
(Insert site specific information here)
Objective 2.10.02
Objective 2.10.03
See DOE RCS Art. 131-
133 (or appropriate site
document)
Objective 2.10.04
DOE RCS Art. 324.2
Objective 2.10.05
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4. Post-job ALARA Reviews
a. Post-job meetings allow the opportunity to critique the work
performance. Although, they will not affect the dose already
received for a particular job, they can be effective in reducing the
doses received the next time that job is performed.
b. Information discussed at post-job meetings includes discussions
of what went wrong and what could have been done differently
to reduce the exposures received.
c. Post-job meetings rely heavily on the input of each radiation
worker for information on how best to reduce exposure the next
time that job is performed.
d. Typical questions asked could include:
1) Were there any problems performing the job in accordance
with the procedure?
2) Did you have the tools and equipment needed to perform the
work? Could special tools ease the job?
3) Were there any unexpected conditions noted during the
work? Could these conditions have been anticipated?
Section 66
4) Were there any unexpected delays in the performance of the
job? What was the cause of the delay?
5) Was temporary shielding used? Could the use of temporary
shielding reduce exposures received for this job?
6) What tools or work practices worked well that need to be
reused?
e. Post-job ALARA Review Requirements
(Insert site specific information here)
C. RADIOLOGICAL POSTINGS
1. Purpose of radiological postings, signs and labels is to:
a. Identify items or areas that have the potential for, or actually
contain, radiological hazards.
Objective 2.10.06
Objective 2.10.07
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2.10-7
b. Identify the radiological hazard(s) present in an area (e.g.
Radiation Area, Airborne Radioactivity area, Radiography Area).
c. And to prevent:
1) Workers from inadvertently entering radiologically
controlled area(s), and/or
2) Mishandling radioactive materials.
2. Each individual is responsible to read and comply with all the
information identified on radiological postings, signs and labels.
3. Since there may be more than one radiological hazard identified on a
posting, sign or label, it is important to read all of the information
and not just the first line.
4. All access points into an area must be posted to ensure workers are
adequately warned of the hazards in the area.
5. Postings and status boards (if applicable) should be promptly
updated after completion of a survey to reflect the corrected
conditions in the area.
6. If necessary the RWP should be amended to reflect any changes in
the area.
7. The information on status boards, RWPs, posting and survey maps
should be consistent. If there is a discrepancy it should be
immediately corrected. Workers could review erroneous data that
has not been updated and subsequently become contaminated or
receive some unnecessary radiation exposure.
a. Radiological Control Technicians should immediately update
postings after performing a survey. The RWP and any status
boards must also be updated.
b. If the posting was updated and the RWP was not, a worker may
consider the RWP correct and the posting wrong.
c. If a worker entered the area based on the incorrect RWP
information he could become contaminated or receive some
unnecessary radiation exposure.
8. Areas should be posted if there is a strong potential for the situation
to exist, even if it is not now present.
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a. Areas can be posted as Airborne Radioactivity Areas or Surface
Contamination Areas, if equipment in the area has been known
to leak and create airborne or contamination hazards. Posting
areas in such a situation will ensure that the proper protective
equipment is used and could prevent a personnel contamination
incident or a case of internal exposure.
b. If areas are posted only when the appropriate limits have been
reached, personnel can be subjected to hazards when the hazard
could have otherwise been minimized.
9. Disregarding any radiological posting, sign or label can lead to
unnecessary or excessive radiation exposure and/or personnel
contamination.
10. Unauthorized removal or relocation of radiological postings, signs
and labels may lead to disciplinary actions up to and including job
termination.
11. If any type of material used to identify radiological hazards is found
Section 67
outside a RBA, it should be reported to radiological control
personnel immediately. RCT shall perform a survey of the sign,
posting or label and conduct a survey of the area in which it was
found.
a. Any contamination or higher than expected radiation levels must
be promptly reported to the RCT supervisor.
D. TYPE OF RADIOLOGICAL POSTINGS, SIGNS AND LABELS
10 CFR 835 requires the following for posting and labeling:
1. §835.601 General Requirements
(a) Except as otherwise provided in this subpart, postings and labels
required by this subpart shall include the standard radiation
warning trefoil in black or magenta imposed upon a yellow
background.
(b) Signs required by this subpart shall be clearly and conspicuously
posted and may include radiological protection instructions.
(c) The posting and labeling requirements in this subpart may be
modified to reflect the special considerations of DOE activities
conducted at private residences or businesses. Such
modifications shall provide the same level of protection to
individuals as the existing provisions in this subpart.
Objective 2.10.08
NOTE: See also
§835.605
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2. §835.602 Controlled areas
(a) Each access point to a controlled area (as defined in §835.2)
shall be posted whenever radiological areas exist in the area.
Individuals who enter only the controlled area without entering
radiological areas are not expected to receive a total effective
dose of more than 100 mrem (0.001 sievert) in a year.
(b) Signs used for this purpose may be selected by the contractor to
avoid conflict with local security requirements.
3. §835.603 Radiological areas
Each access point to a radiological area (as defined in §835.2) shall
be posted with conspicuous signs bearing the wording provided in
this section.
(a) Radiation Area - any area, accessible to individuals, in which
radiation levels could result in an individual receiving an
equivalent dose to the whole body in excess of 0.005 rem (0.05
millisievert) in 1 hour at 30 centimeters from the source or from
any surface that the radiation penetrates.
The words “Caution, Radiation Area” shall be posted at each
radiation area.
(b) High Radiation Area - any area, accessible to individuals, in
which radiation levels could result in an individual receiving an
equivalent dose to the whole body in excess of 0.1 rem (0.001
sievert) in 1 hour at 30 centimeters from the radiation source or
from any surface that the radiation penetrates.
The words, “Caution, High Radiation Area” or “Danger, High
Radiation Area shall be posted at each high radiation area.
(c) Very High Radiation Area - any area, accessible to individuals,
in which radiation levels could result in an individual receiving
an absorbed dose in excess of 500 rads (5 grays) in one hour at 1
meter from a radiation source or from any surface that the
radiation penetrates. The words “Grave Danger, Very High
Radiation Area” shall be posted at each very high radiation area.
(d) Airborne Radioactivity Area - any area, accessible to individuals,
where (1) the concentration of airborne radioactivity, above
natural background, exceeds or is likely to exceed the DAC
values listed in Appendix A or Appendix C of 10 CFR 835; or
(2) an individual present in an area without respiratory protection
could receive an intake exceeding 12 DAC-hours in a week.
DOE-HDBK-1122-2009
Section 68
Module 2.10 Access Control and Work Area Setup Instructor’s Guide
2.10-10
The words “Caution, Airborne Radioactivity Area” or “Danger,
Airborne Radioactivity Area” shall be posted at each airborne
radioactivity area.
(e) Contamination Area means any area, accessible to individuals,
where removable surface contamination levels exceed or are
likely to exceed the removable surface contamination values
specified in Appendix D of this Part 835, but do not exceed 100
times those values. The words “Caution, Contamination Area”
shall be posted at each contamination area.
(f) High Contamination Area means any area, accessible to
individuals, where removable surface contamination levels
exceed or are likely to exceed 100 times the removable surface
contamination values specified in appendix D of Part 835. The
words “Caution, High Contamination Area” or “Danger, High
Contamination Area” shall be posted at each high contamination
area.
(g) Radioactive Material Area means any area within a controlled
area, accessible to individuals, in which items or containers of
radioactive material exist and the total activity of radioactive
material exceeds the applicable values provided in appendix E of
Part 835. The words “Caution, Radioactive Material(s)” shall be
posted at each radioactive material area.
4. §835.604 Exceptions to posting requirements
(a) Areas may be excepted from the posting requirements of
§835.603 for periods of less than 8 continuous hours when
placed under continuous observation and control of an individual
knowledgeable of, and empowered to implement, required
access and exposure control measures.
(b) The following areas may be excepted from the radioactive
material area posting requirements of §835.603(g):
(1) Areas posted in accordance with 835.603(a) through (f); and
(2) Areas in which each item or container of radioactive material
is clearly and adequately labeled in accordance with
§§835.605 and 835.606 such that individuals entering the
area are made aware of the hazard.
(c) Areas containing only packages received from radioactive
material transportation need not be posted in accordance with
§835.603 until the packages are surveyed in accordance with
§835.405.
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5. Area designations
(Insert site specific information here)
6. Requirements for posting/barriers
(Insert site specific information here)
3. Requirements for entry
(Insert site specific information here)
E. SETTING UP RADIOLOGICAL AREAS
1. Good practices to be considered whenever possible in setting up
Radiological Areas.
a. Establish walkways in low dose areas.
b. Do not store radioactive materials near walkways or where
personnel frequently work.
c. Place rope boundaries as close to the source of contamination as
possible to minimize the size of the contaminated area. Care
must be taken to ensure the area is not so limited that
contamination is easily spread across the boundaries.
d. Use appropriate containment devices to prevent the spread of
contamination.
e. Establish laydown areas for equipment to limit personnel safety
hazards and/or radiation exposure.
f. Set up SOPs upwind of contamination hazards.
g. Post all accessible sides and entrance(s) to areas containing
radiological hazards.
h. Use Personnel Contamination monitors along with portable
contamination survey instrumentation whenever possible. PCMs
are more likely to detect contamination on individuals because
personnel tend to survey too quickly.
Section 69
Review 10 CFR 835
definitions of areas.
See 10 CFR 835
NOTE: RMA posting
and labeling of
radioactive material
was covered in
Module 2.08.
Objective 2.10.09
If this happened with an
actual contamination
incident the employee
surveying quickly could
subsequently pass over the
contamination areas with
the portable contamination
survey instrumentation.
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2. The following are commonly observed discrepancies that should be
avoided in the setup of Radiological Areas.
a. Posting information not updated or information otherwise
incorrect.
b. Boundaries not verified for contamination, radiation, and
airborne radioactivity hazards.
c. Survey instruments out of calibration or defective.
d. Step-off-pads not set up for efficient removal of protective
clothing. (Not enough room to prevent contaminating the SOPs.)
e. Laundry and waste receptacles not placed for efficient use or not
placed at all. Receptacles not properly labeled as to their
contents.
f. Boundaries of areas setup too far from the hazards interfering
with access to areas otherwise unaffected.
g. Portable contamination survey instruments not located close to
the step-off-pads.
h. Status boards do not reflect where SOPs and boundaries lie.
i. Status board not kept up-to-date. The information on status
boards, postings and RWPs should agree.
j. Tripping hazards exist from wires, hoses, or cables.
k. Background radiation in monitoring area too high for efficient
detection of low level contamination.
l. Instrumentation not set up for proper operation.
m. Protective clothing (gloves and booties) not readily available in a
personnel contamination event.
n. Phone or other communication devices not available near the
SOP or portable contamination survey instruments.
o. Not posting all accesses to the area.
p. Failure to post dress and undress procedures.
3. Since contamination or airborne radioactivity and radiation levels are
subject to change, it is essential to be able to quickly establish a
Radiological Area. To properly set up a Radiological Area, the
following support equipment should be readily available.
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4. Containment devices include glove boxes, glove ports, hot cells, huts,
and windbreaks. Common discrepancies observed in containment
devices include.
a. Holes/leaks in the containments, facilitating the spread of
contamination.
b. Liquids accumulating in hoses or main portions of the
containment.
c. Airlocks too small to remove protective clothing without
spreading contamination.
d. Ventilation exhaust not directed to the plant ventilation system.
e. Material allowed to accumulate inside containments, limiting
safe and/or efficient use.
f. Sharp objects used inside containments (not covered or taped).
g. Devices not tethered to prevent introduction into systems.
h. Transfer sleeves/ports are not used or are unavailable.
i. Containment not provided with a HEPA filter or ventilation
exhaust.
j. Containments not periodically surveyed inside and out.
k. No means of quickly verifying loss of ventilation.
l. Containment not decontaminated prior to dismantling.
m. Adequate access not provided for lines or hoses.
n. Containment not maintained at a negative pressure.
o. Containment not supported properly to minimize stress from
minor ventilation changes or not structurally supported to
maintain its configuration during use.
Section 70
p. Containments not inspected prior to use and periodically during
use.
q. Not using appropriate containment devices for leaks.
r. Not using a funnel to collect leakage, if appropriate.
s. Plastic components showing fatigue or wear.
Objective 2.10.10
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t. Funnel not positioned to collect all leaking fluid, if appropriate.
u. Drain lines kinked allowing the buildup of liquids.
v. Drain lines not secured properly to the collection device.
w. Containment device not labeled to indicate hazards that are
present.
5. Portable ventilation systems are frequently used to remove
contaminated air or filter contamination in the air. Radiological
control personnel should adhere to the following good practices in
setting up portable ventilation systems.
a. Use only HEPA (High Efficiency Particulate Air) filters with
pre-filters (roughing filters).
b. Perform radiation survey on filters periodically while in use.
c. Have radiological limits established for filter replacement.
d. Exhaust filter discharge to the plant ventilation system whenever
possible.
e. Ensure that there are no openings in the trunk or between the
blower and the filter.
f. Monitor the filter differential pressure (d/p) periodically.
g. Establish filter D/P at which the filter must be replaced.
h. Remove filters into plastic bags to prevent the release of activity.
i. Position streamers to signify the flow of ventilation through
doorways or through containment devices.
6. The proper setup and use of portable contamination survey
instruments and Personnel Contamination Monitors (PCMs) can
ensure that contamination is more likely to be detected on workers.
The following is a list of good practices for setting up portable
contamination survey instrumentation and PCMs.
a. They must be placed in low background area.
b. They need reliable power supply.
c. They should be positioned to facilitate easy access by workers.
d. Alarms should be set according to site administrative control
levels or DOE limits.
Objective 2.10.11
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e. Must ensure instrument is source checked and calibrated.
f. Extension cords must be checked for electrical safety.
g. Portable contamination survey instruments and PCMs should be
placed upwind of contaminated areas.
h. They should not be placed near radioactive material storage
areas or other areas where the background radiation can change.
i. Portable contamination survey instruments should have sources
provided to source check the instrument.
F. ACCESS CONTROL
10 CFR 835 requires the following:
1. §835.501 Radiological Areas
(a) Personnel entry control shall be maintained for each radiological
area.
(b) The degree of control shall be commensurate with existing and
potential radiological hazards within the area.
(c) One or more of the following methods shall be used to ensure
control:
(1) Signs and barricades;
(2) Control devices on entrances;
(3) Conspicuous visual and/or audible alarms;
(4) Locked entrance ways; or
(5) Administrative controls.
(d) Written authorizations shall be required to control entry into and
perform work within radiological areas. These authorizations
shall specify radiation protection measures commensurate with
the existing and potential hazards.
(e) No control(s) shall be installed at any radiological area exit that
Section 71
would prevent rapid evacuation of personnel under emergency
conditions.
Review 10 CFR 835
definitions
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2. §835.502 High and Very High Radiation Areas
(a) The following measures shall be implemented for each entry into
a high radiation area:
(1) The area shall be monitored as necessary during access to
determine the exposure rates to which the individuals are
exposed; and
(2) Each individual shall be monitored by a supplemental
dosimetry device or other means capable of providing an
immediate estimate of the individual's equivalent dose to the
whole body during the entry.
(b) Physical controls. One or more of the following controls shall be
used for each entrance or access point to a high radiation area
where radiation levels exist such that an individual could exceed
an equivalent dose to the whole body of 1 rem (0.01 sievert) in
any one hour at 30 centimeters from the source or from any
surface that the radiation penetrates:
(1) A control device that prevents entry to the area when high
radiation levels exist or that, upon entry, causes the radiation
level to be reduced below the level that defines a high
radiation area;
(2) A device that functions automatically to prevent use or
operation of the radiation source or field while individuals
are in the area;
(3) A control device that energizes a conspicuous visible or
audible alarm signal so that the individual entering the high
radiation area and the supervisor of the activity are made
aware of the entry;
(4) Entryways that are locked. During periods when access to
the area is required, positive control over each entry is
maintained;
(5) Continuous direct or electronic surveillance that is capable
of preventing unauthorized entry;
(6) A control device that will automatically generate audible and
visual alarm signals to alert personnel in the area before use
or operation of the radiation source and in sufficient time to
permit evacuation of the area or activation of a secondary
control device that will prevent use or operation of the
source.
DOE-HDBK-1122-2009
Module 2.10 Access Control and Work Area Setup Instructor’s Guide
2.10-17
(c) Very high radiation areas. In addition to the above requirements,
additional measures shall be implemented to ensure individuals
are not able to gain unauthorized or inadvertent access to very
high radiation areas.
(d) No control(s) shall be established in a high or very high radiation
area that would prevent rapid evacuation of personnel.
3. Besides meeting the requirements for entry into Radiological Areas
and RBAs, personnel must also ensure that they take appropriate
measures to maintain their exposures ALARA.
a. Workers who receive radiation exposures from other nuclear
facilities must report the exposure to radiological control and
their supervisor upon returning to the site.
b. Avoid contact with potentially contaminated surfaces.
c. Any management/supervision or RCT personnel should give
stop work or evacuation orders if unanticipated radiation or
contamination is encountered or if the appropriate RWP is not
being followed.
d. Wear dosimeter(s) in accordance with the RWP.
e. Maintain exposure ALARA.
f. Report all injuries.
g. Monitor clothing and exposed skin as required and report the
presence of radioactive contamination.
h. Place contaminated items and waste in approved radioactive
waste containers.
Section 72
i. Personnel should wash their hands when leaving the RBA and
prior to eating or using tobacco products.
j. Personnel who are not respirator qualified shall not enter areas
posted as "Respiratory Protection Required".
4. Hot Particles
a. Hot particles are small, discrete, highly radioactive particles
capable of causing extremely high doses to a localized area in a
short period of time. Hot particle contamination may be present
or be generated when contaminated systems are opened or when
operations such as machining, cutting, or grinding are performed
on highly radioactive materials.
Objective 2.10.12
See DOE RCS Art. 338
and Appendix 3D (or
appropriate site document)
DOE-HDBK-1122-2009
Module 2.10 Access Control and Work Area Setup Instructor’s Guide
2.10-18
b. The site-specific Radiological Controls Manuals usually define
hot particles. Typically they will be described as very small
discrete particles capable of producing an equivalent dose to the
skin greater than 100 mrem in one hour.
c. Special surveys in areas with the potential for hot particle
contamination.
d. Posting areas to specifically identify the presence of hot particles.
e. Controlling access to hot particle areas should be through a job-
specific RWP. The following controls should be considered for
inclusion on the RWP:
1) Periodic personnel monitoring during the work activity, at a
frequency based on the potential magnitude of skin exposure
2) Additional personal protective equipment and clothing
3) Direct radiological control coverage during work or
assistance during protective clothing removal
4) Use of sticky pads or multiple step-off pads
f. Personal protective equipment and clothing used in hot particle
areas should be segregated from other radiological protective
equipment and clothing during laundering and surveyed prior to
reuse
g. Response to hot particle skin contamination of personnel should
include the following:
1) Immediate removal and retention of the hot particle for
subsequent analysis
2) Analysis of the particle
3) Assessment of worker dose
4) Evaluation of work control adequacy
G. REMOVING MATERIALS FROM RADIOLOGICAL AREAS
Facility operations require that radioactive material and non-radioactive
material be removed from Radiological Areas, RBAs, and from the site.
Prior to allowing this material to leave, important steps outlined in the
procedures must be followed. 10 CFR 835 requires the following:
1. §835.1101 Control of material and equipment
Objective 2.10.13
DOE-HDBK-1122-2009
Module 2.10 Access Control and Work Area Setup Instructor’s Guide
2.10-19
(a) Except as provided below, material and equipment in
contamination areas, high contamination areas, and airborne
radioactivity areas shall not be released to a controlled area if:
(1) Removable contamination levels on accessible surfaces
exceed the removable surface contamination values specified
in Appendix D of 10 CFR 835; or
(2) Prior use suggests that the removable contamination levels
on inaccessible surfaces are likely to exceed the removable
surface contamination values specified in Appendix D of 10
CFR 835.
(b) Material and equipment exceeding the removable surface
contamination levels specified in Appendix D of 10 CFR 835
may be conditionally released for movement on-site from one
radiological area for immediate placement in another
radiological area only if appropriate monitoring is performed and
appropriate controls for the movement are established and
exercised.
Section 73
(c) Material and equipment with fixed contamination levels that
exceed the limits specified in Appendix D of 10 CFR 835 may
be released for use in controlled areas outside of the radiological
areas only under the following conditions:
(1) Removable surface contamination levels are below the
removable surface contamination values specified in
Appendix D of 10 CFR 835; and
(2) The material or equipment is routinely monitored and clearly
marked or labeled to alert personnel of the contaminated
status.
2. Release to Radiological Buffer Areas
(Insert site specific information here)
3. Release to Uncontrolled Areas
(Insert site specific information here)
DOE-HDBK-1122-2009
Module 2.10 Access Control and Work Area Setup Instructor’s Guide
2.10-20
III. SUMMARY
A. Review major topics
1. RWPs
2. Radiological postings
3. Setting up radiological areas
4. Good practices and discrepancies commonly observed in setup of
various portions of radiological areas.
5. Access control
6. Removing materials from radiological areas
B. Review learning objectives
IV. EVALUATION
Evaluation should consist of a written examination comprised of multiple
choice, fill-in the blank, matching and/or short answer questions. 80%
should be the minimum passing criteria for examinations.
DOE-HDBK-1122-2009
Module 2.11 Radiological Work Coverage Instructor’s Guide
2.11-1
Course Title: Radiological Control Technician
Module Title: Radiological Work Coverage
Module Number: 2.11
Objectives:
2.11.01 List four purposes of job coverage.
2.11.02 Explain the differences between continuous and intermittent job coverage.
2.11.03 Given example conditions, identify those that should require job coverage.
2.11.04 Identify items that should be considered in planning job coverage.
2.11.05 Identify examples of information that should be discussed with workers during
pre-job briefings.
2.11.06 Describe exposure control techniques that can be used to control worker and
technician radiation exposures.
→ 2.11.07 Describe the in-progress radiological surveys that should be performed, at your
site, under various radiological conditions.
→ 2.11.08 Describe site requirements for documentation of in-progress radiological surveys.
→ 2.11.09 Explain actions that should be taken if surveys show radiological conditions
significantly different from that expected.
2.11.10 Describe contamination control techniques that can be used to limit or prevent
personnel and area contamination and/or reduce radioactive waste generation.
2.11.11 Describe job coverage techniques that can be used to prevent or limit the spread
of airborne radioactive material.
2.11.12 Describe overall job control techniques in maintaining control of radiological
work.
2.11.13 State the reasons to stop radiological work activities in accordance with the DOE
RCS.
References:
1. DOE Radiological Control Standard (2008).
DOE-HDBK-1122-2009
Module 2.11 Radiological Work Coverage Instructor’s Guide
2.11-2
Instructional Aids:
1. Overheads
2. Overhead projector/screen
3. Chalkboard/whiteboard
4. Lessons learned
DOE-HDBK-1122-2009
Module 2.11 Radiological Work Coverage Instructor’s Guide
2.11-3
I. MODULE INTRODUCTION
A. Self Introduction
1. Name
2. Phone number
3. Background
4. Emergency procedure review
B. Motivation
The purpose of job coverage by RCTs is to assist workers in keeping
their radiation exposures ALARA.
C. Overview of Lesson
Section 74
1. Explanation of job coverage
2. Conditions requiring job coverage
3. Prerequisites for planning job coverage
4. Job coverage techniques
D. Introduce Objectives
II. LESSON OUTLINE
A. Explanation of Term "Job or Work Coverage"
1. Purposes
a. Radiation exposure control
1) Keep ALARA
2) Keep within limits
O.H.: Objectives
Ask students what is
meant by job or work
coverage.
Modify their answers
for correctness.
Objective 2.11.01
Ask students for the
purposes of job
coverage. Modify
their answers for
coverage and list on
blackboard.
DOE-HDBK-1122-2009
Module 2.11 Radiological Work Coverage Instructor’s Guide
2.11-4
b. Contamination control
1) Reduce creation
2) Reduce spread
c. Airborne radioactive material control
1) Reduce creation
2) Reduce spread
d. Radioactive waste
Reduce creation
2. Types
a. Continuous
Technician remains at the job site during entire job and covers
only that job
b. Intermittent
Coverage of more than one job or periodic checks for job
coverage
B. Conditions Requiring Job Coverage
1. Workers doses near limits
2. Radiation levels increase significantly
3. Entry to some high radiation levels
4. Spreading contamination or airborne
5. Contamination or airborne levels increase significantly
6. Questions regarding the adequacy of personnel dosimetry being
used
7. Inexperienced workers
Objective 2.11.02
Objective 2.11.03
Ask the students for
conditions that could
require job coverage.
Modify their answers and
write on the board. After
you write on the board,
give an example of each
condition.
DOE-HDBK-1122-2009
Module 2.11 Radiological Work Coverage Instructor’s Guide
2.11-5
C. Prerequisites for Planning Job Coverage
1. Detailed job description
2. Review past problem areas
a. Review surveys
b. Talk with technicians
c. Review applicable Post Job ALARA Reviews
3. Review system
a. Effects of opening
b. Effects of welding, cutting, grinding
4. Detailed survey
a. Job site
High and low dose rate areas
• Extremity dose rates
• Beta dose rates
• Hot Spots
• Other possible hazards
b. Pathways to site
c. Identify
1) Contamination levels
2) Airborne levels
Objective 2.11.04
Ask student what items
should be planned before
going on to the job site.
Modify their answers for
correctness. Write their
answers on the board.
Explain why each item
must be considered.
(See appropriate site
document)
Explain that by knowing
the dose rate, individuals
can avoid areas of highest
dose rate and wait in low
dose rate areas.
DOE-HDBK-1122-2009
Module 2.11 Radiological Work Coverage Instructor’s Guide
2.11-6
5. Record workers' allowable exposures
6. Communications with workers
a. Face-to-face
b. Hand signals
c. Remote headsets
d. Safety lines
e. Portable radios
7. Communications with lab
a. Transferring air samples
b. Results of surveys, samples
8. Equipment at job site
a. Dosimeters
b. Charger
c. Air sampler
d. Survey instrument(s)
e. Respirator (if needed)
f. Watch or clock
g. Emergency Actions and Emergency Exits
Explain that these limits
should be written down
and taken to the job site.
Do not trust memory.
Ask students how
communications can be
achieved. Write their
answers on the board.
Ask the students what
equipment should be
available at the job site.
List the equipment on
the board. Explain why
each could be needed.
DOE-HDBK-1122-2009
Module 2.11 Radiological Work Coverage Instructor’s Guide
2.11-7
Section 75
Consideration of Other Hazards
When evaluation the hazards for a job evolution, it is important to
consider non-radiological hazards as well. A framework aligned with
the principles and functions of Integrated Safety Management (ISM)
requires systematically integration of safety into management and work
practices at all levels so that missions are accomplished while protecting
the public, the worker, and the environment. This is accomplished
through effective integration of safety management into all facets of
work planning and execution. Under ISM, both DOE and DOE-
contractor line managers are charged with responsibility for integrating
safety measures into all facets of work planning and execution. Line
managers should use their site-specific radiological control manual as a
guide to integrating radiological control measures into work planning
and execution. Both the ISM and ALARA processes require hazard
controls to be tailored to the work being performed. In addition to
establishing basic radiological safety standards that must be observed,
10 CFR 835 establishes requirements that provide significant flexibility
so that individual activities may implement compliance measures in a
manner that is commensurate with specific hazards and work activities.
On December 2, 2002, the 107th Congress amended the Atomic Energy
Act by adding Section 234.C and on December 18, 2003, DOE
published a Notice of Proposed Rulemaking in the Federal Register,
entitled, “Worker Safety and Health Program.” The Rule became final
on February 9, 2006 as 10 CFR 851. This rule provides for a worker
health and safety program for DOE contractors and should be addressed
in hazard analysis evaluation for radiological operations.
DOE-HDBK-1122-2009
Module 2.11 Radiological Work Coverage Instructor’s Guide
2.11-8
9. Pre-job Briefings
a. Radiological conditions
b. Effect of job on conditions
c. Communications method
d. Special dosimetry
e. Special protective clothing
f. RCT functions
g. Importance of following the RWP and its specific directions
D. Job Coverage Techniques
1. Exposure Control
Objective 2.11.05
Explain that by keeping
the workers on the job
informed,
communications will be
improved. Ask the
students what information
should be given to the
workers. Write the
information on the board.
Objective 2.11.06
Explain that the exact
techniques used will vary
depending on the job,
radiological conditions,
and worker experience.
For each of the following
techniques, state the
technique and why it is
necessary. Teach as a
discussion.
Write "Exposure Control"
on the board. List the
techniques under this
heading. Leave these
techniques under this
heading. Leave these
techniques on the board.
Use the same method for
Sections 2-4, so that at the
end of the lecture all four
headings and the
respective techniques will
be on the board.
DOE-HDBK-1122-2009
Module 2.11 Radiological Work Coverage Instructor’s Guide
2.11-9
a. Perform frequent surveys during job performance
1) Purpose and types of surveys
2) Base on probability of conditions changing
3) Required by operational procedures
4) Document Surveys
a) Purpose
b) Requirement
5) Report unusual conditions to management
6) Verify dose rates remain as posted
b. Wait in low dose rate areas
1) Purpose
2) Identify from survey
3) Reduces time in radiation area
c. Check dosimeters
1) Purpose
Accumulated dose
2) Technician reads
3) Have workers read
Section 76
4) Reduce contamination of dosimeter
a) Remove outer glove
b) Use clean glove
For examples of when
surveys are required
during job
performances, refer to
site procedures.
Ask students how this can
reduce dose received.
Modify answers for
correctness.
DOE-HDBK-1122-2009
Module 2.11 Radiological Work Coverage Instructor’s Guide
2.11-10
d. Determine time allowed in areas
Time = Authorized Exposure/Dose Rate
e. Workers location vs. dose rate
1) Purpose
Determine dose received
2) Dose = Dose Rate x Time
f. Document workers' locations and times
Purpose
• Prevent reliance on memory
• Inaccurate dose estimates
g. Workers dosimetry location vs. dose rate
1) Purpose
Dose estimation
2) May require special dosimetry
a) Finger badges
b) Extremity
c) Head
h. Modify temporary shielding
1) Purpose
Prevent un-evaluated exposure rates
2) Must have Rad Con approval
i. Modify temporary shielding - Rad Con
Must evaluate before moving
Explain that not all of the
time can be allowed for
performing the job.
Workers may receive
significant exposure going
to and leaving the job.
Ask the students why this
is an important concept.
Use a drawing to illustrate
an example if necessary.
DOE-HDBK-1122-2009
Module 2.11 Radiological Work Coverage Instructor’s Guide
2.11-11
j. In-progress radiological surveys
(Insert site specific information here)
k. In-progress radiological survey documentation
(Insert site specific information here)
l. Unexpected radiological conditions
(Insert site specific information here)
2. Contamination Control
a. Watch workers
1) Purpose
Lessen personnel and area contamination
2) Look for
a) Hand to face movements
b) Dropping tools
c) Hammering
d) Scuffing feet
e) Wire brushing
b. Transferring material
1) Bagging
2) Plastic sheets
3) Floor cover for pathway
Objective 2.11.07
Objective 2.11.08
Objective 2.11.09
Objective 2.11.10
Write "Contamination
Control" beside
"Exposure Control." List
each technique beneath
Contamination Control.
Ask the Students what
actions they should be
looking for.
Thoroughly cover all of
the correct practices in
bagging tools, trash or
equipment.
DOE-HDBK-1122-2009
Module 2.11 Radiological Work Coverage Instructor’s Guide
2.11-12
c. Tools and equipment
Methods
• Taping
• Using previously contaminated tools
d. Equipment going from contaminated to clean areas
Examples
• Crane rigging
• Air and water hoses (secure hoses/lines)
e. Reduce radioactive waste
1) Purpose
a) Reduce contamination
b) Reduce costs
c) Reduce processing time
d) Reduce dose
2) Techniques
a) Remove packing material
b) Minimize water for decon
3. Airborne Radioactivity Control
Ask students what steps
can be taken to lessen the
probability of
contaminating tools and
equipment before use.
Ask the student for
examples of equipment
that may go from
contaminated to clean
areas.
Write "Airborne
Radioactivity Control" on
the board. List the
techniques beneath this
heading.
DOE-HDBK-1122-2009
Module 2.11 Radiological Work Coverage Instructor’s Guide
2.11-13
a. Actions creating airborne
1) Actions causing
a) Opening systems
b) Welding, grinding, cutting
c) Hammering
d) Wire brushing
e) Sweeping
f) Leaks and sprays
g) Air hose systems/tools
2) Corrective actions
b. Portable air samples
1) Purpose
Identify problem
2) Analyze in lab
Time delay
3) Corrective measures
c. Continuous air monitors (CAMs)
1) Purpose
Section 77
Identify problem
2) Immediate indication
Objective 2.11.11
Ask the students what
actions could create
airborne. Modify their
answers for correctness.
Ask students for a
disadvantage of analyzing
the sample in a lab.
Ask the students for an
advantage of CAMs vs.
portable air samples.
DOE-HDBK-1122-2009
Module 2.11 Radiological Work Coverage Instructor’s Guide
2.11-14
3) Corrective measures
d. Ventilate enclosed areas
1) Purpose
a) Remove airborne
b) Contain airborne
2) Installed ventilation
3) Temporary Ask students for examples of temporary
ventilation.
a) Fans with hose and HEPA filters
b) Hose from installed duct of HVAC
c) Tents
4. Overall Job Control Techniques
a. Establish worker trust and confidence
1) Purpose
Improve communications
2) Earned not given
3) Techniques
a) Reliable
b) Realistic
c) Credible
d) Consistent
Ask the students for
the disadvantages of
CAMs compared to
portable samplers.
Objective 2.11.12
Write "Overall Job
Control" on the board.
List the techniques
beneath this heading.
Ask students for
characteristics of people
they trust. Point out that
they should develop the
same characteristics to
earn worker trust.
DOE-HDBK-1122-2009
Module 2.11 Radiological Work Coverage Instructor’s Guide
2.11-15
b. Keep workers in sight
1) Purpose
a) Identify poor work habits
b) Correct poor work habits
2) Sometimes impossible
c. Keep contact with workers
1) Purpose
a) Improve rapport
b) Alleviate worker apprehension
2) Techniques
a) Face to face
b) Remote communications
d. Workers' Notification to RC
1) Purpose
Prevent un-evaluated radiological conditions
2) Before opening systems
3) Before changing work techniques
e. Correct poor work habits
1) Purpose
a) Prevent contamination of workers and area
b) Keep doses ALARA
Explain that most workers
are apprehensive when
using remote
communications. Staying
in contact alleviates their
concerns.
State that even though
RWP's usually require
workers to notify RC, the
technician should remind the
workers of the requirement
and explain the reasons why
to the workers.
DOE-HDBK-1122-2009
Module 2.11 Radiological Work Coverage Instructor’s Guide
2.11-16
2) Techniques
a) Offer as advice
b) Explain consequences
c) Explain proper method
f. Show a positive, helpful attitude toward co-workers
Purpose
• Improve communications
• Improve credibility
g. Don't overreact
1) Consequence
2) Remain calm
h. Stop Work Authority
1) Purpose
2) Maintain Control
3) Reevaluate situation
4) Correct problem before allowing work to continue
5) Stop work when:
a) Inadequate radiological controls
b) Radiological controls not being implemented
c) Radiological hold point not being satisfied
Objective 2.11.13
Teach as a discussion.
Present the students with
the problem area and ask
for the consequences of
the problem and how the
problem could be solved.
Note that more than one
answer could be correct.
Encourage student
participation by asking if
there are more ideas or if
they are all in agreement
with the solution.
DOE-HDBK-1122-2009
Module 2.11 Radiological Work Coverage Instructor’s Guide
2.11-17
d) Any workers dosimeter alarms or exhibits unexpected
readings
6) Example situation of when to use stop work authority
5. Common problem areas
a. Remaining in work area, not lower exposure area.
b. Leaning or sitting on high contact dose rate equipment.
c. Not using existing shielding to full advantage.
Section 78
d. Improperly handing item out of controlled area.
e. Not catching radioactive liquids (if applicable).
f. Creating unnecessary radwaste.
g. Improperly ventilating areas.
h. Removing high dose rate items from work areas.
i. Moving crane rigging in and out of contaminated areas.
j. Improperly controlling hot sparks and burning slag when
welding.
k. Remaining in high dose rate areas beyond time allowed.
l. Opening systems or containers before notifying RC.
m. Changing work methods before notifying RC.
DOE-HDBK-1122-2009
Module 2.11 Radiological Work Coverage Instructor’s Guide
2.11-18
III. SUMMARY
A. Review major points
1. Explanation of job coverage
2. Conditions requiring job coverage
3. Prerequisites for planning job coverage
4. Job coverage techniques
B. Review learning objectives
IV. EVALUATION
Evaluation should consist of a written examination comprised of multiple
choice, fill-in the blank, matching and/or short answer questions. 80%
should be the minimum passing criteria for examinations.
DOE-HDBK-1122-2009
Module 2.12 Shipment/Receipt of Radioactive Material Instructor’s Guide
2.12-1
Course Title: Radiological Control Technician
Module Title: Shipment/Receipt of Radioactive Material
Module Number: 2.12
Objectives:
2.12.01 List the applicable agencies which have regulations that govern the transport of
radioactive material.
2.12.02 Define terms used in DOT regulations.
2.12.03 Describe methods that may be used to determine the radionuclide contents of a
package.
2.12.04 Describe the necessary radiation and contamination surveys to be performed on
packages and state the applicable limits.
2.12.05 Describe the necessary radiation and contamination surveys to be performed on
exclusive use vehicles and state the applicable limits.
2.12.06 Identify the proper placement of placards on a transport vehicle.
→ 2.12.07 Identify inspection criteria that should be checked prior to releasing a shipment at
your site.
→ 2.12.08 Describe site procedures for receipt and shipment of radioactive material
shipments.
→ 2.12.09 List the actions required at your site if a shipment is received exceeding radiation
or contamination limits.
→ 2.12.10 Describe the proper step-by-step method for opening a package containing
radioactive material at your site.
REFERENCES
1. 10 CFR 835 (2007), “Occupational Radiation Protection”.
2. 49 CFR, Parts 100-177, “Transportation”.
3. DOE Order 460.1B (2003), “Packaging and Transportation Safety”.
4. DOE Order 460.2 A (2004), “Departmental Materials Transportation and Packaging
Management”.
DOE-HDBK-1122-2009
Module 2.12 Shipment/Receipt of Radioactive Material Instructor’s Guide
2.12-2
I. MODULE INTRODUCTION
A. Self Introduction
1. Name
2. Phone number
3. Background
4. Emergency procedure review
B. Motivation
The basis behind the regulations governing the packaging and shipping of
radioactive material is to keep radiation and radioactive material from affecting
the environment during transportation and to keep the environment from
affecting the integrity of the radioactive material.
The package itself is to be designed and constructed to be the effective barrier
between the environment and the radioactive material, thus most of the
regulatory restrictions apply to the package and the method of shipment used to
transport the package.
To reduce any potential hazard, the regulatory requirements become more
restrictive as the quantity, concentration, and potential hazard of the radioactive
material increases.
Section 79
C. Overview of Lesson
This unit will present an overview of shipping and transportation regulations
and methods for radioactive materials.
D. Introduce Objectives
II. MODULE OUTLINE
A. Regulatory Structure
Numerous governmental agencies have jurisdiction over the transfer and
shipment of radioactive material from nuclear facilities. The primary
organizations are:
• U.S. Department of Energy
• U.S. Nuclear Regulatory Commission
• U.S. Department of Transportation, Hazardous Material Bureau
• U.S. Coast Guard
• International Civil Aviation Organization or International Air Transport
Association
• State transportation departments or radiation health bureaus.
O.H.: Objectives
Objective 2.12.01
DOE-HDBK-1122-2009
Module 2.12 Shipment/Receipt of Radioactive Material Instructor’s Guide
2.12-3
B. U.S. Department of Energy
The U.S. DOE establishes regulations to protect the public health and safety
from undue risk from DOE activities. These regulations are in the form of 10
CFR 835 and DOE Orders. DOE requirements applicable to packaging and
transportation of radioactive material include:
1. 10 CFR 835
The Exclusion section of 10 CFR 835.1 states that occupational doses
received as a result of excluded activities and radioactive material
transportation shall be considered when determining compliance with
the occupational dose limits in §§835.202 and 835.207.
2. DOE O 460.1B
a. Establishes administrative procedures for the certification and use
of radioactive and other hazardous materials packaging by DOE.
b. Establishes standards and requirements for the packaging and
transportation of hazardous (including radioactive) materials,
substances and wastes. This Order requires that packages for
radioactive materials meet the NRC standards in 10 CFR 71 and
imposes additional restrictions.
3. DOE Order 460.2
Establishes DOE policies and procedures for the management of
materials transportation activities, including traffic management, for
other than intrabuilding and intrasite transfers. It contains general
requirements related to all transportation activities, not just hazardous
or radioactive materials.
DOE-HDBK-1122-2009
Module 2.12 Shipment/Receipt of Radioactive Material Instructor’s Guide
2.12-4
4. U.S. Department of Transportation
The U.S. DOT regulates transportation by air, water, rail, and highway.
The Materials Transportation Bureau has established rules governing
the packaging and transport of hazardous material, including
radioactive material.
These regulations are contained in 49 CFR 170 - 179 and are
applicable to any person who transports, or ships, a hazardous material.
Even though most of the requirements for shipping radioactive material
are located in Part 173, the other sections of DOT regulations must not
be overlooked.
C. Regulatory Compliance
There are many regulations and documents from several agencies that govern
the transfer and transport of radioactive material. Compliance with all
regulations, not just those from one agency, is required to transfer and
shipment of radioactive material. The number of regulations involved depends
upon the chosen mode of transport and the quantity of radioactive material.
Each individual or group assigned the responsibility of transferring and
shipping radioactive material must maintain a complete set of current
regulations from all applicable agencies as well as other supporting regulatory
guides, licenses and clarifying documents.
Section 80
Keep in mind that most regulations usually contain exemptions and may
contain more restrictive clauses. For example, the DOT may exempt some
shipments of low quantities and types of radioactive material from their
regulations. The DOT exemption, however, does not automatically exempt the
material from DOE requirements. It is best to be aware of the requirements
from all agencies to avoid citations for using one specific exemption that is not
recognized by the other agencies.
D. Definition of Terms
The following definitions are found in 49 CFR 173.403 (this is not a complete
listing of the §173.403 definitions):
1. A1. The maximum activity of special form radioactive material permitted
in a Type A package.
Objective 2.12.02
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2. A2. The maximum activity of radioactive material, other than special form,
Low Specific Activity, or Surface Contaminated Object, permitted in a
Type A package.
3. Radioactive Material. Any material having a specific activity greater than
70 Bq per gram (0.002 microcurie per gram). No other U.S. Department or
Agency uses this limit.
4. Exclusive Use (also referred to as “sole use” of “full load”). Sole use by a
single consignor of a conveyance for which all intial, intermediate, and
final loading and unloading are carried out in accordance with the direction
of the consignor or the consignee. The consignor and the carrier must
ensure that any loading or unloading is performed by personnel having
radiological training and resources appropriate for safe handling of the
consignment. The consignor must issue specific instructions in writing, for
maintenance of exclusive use shipment controls, and include them with the
shipping paper information provided to the carrier by the consignor.
5. Limited Quantity. A quantity of radioactive material not exceeding the
materials packaging limits specified in §173.425 and conforming with
requirements specified in §173.421.
6. Low Specific Activity (LSA). Radioactive material with limited specific
activity which satisfies the descriptions and limits set forth below.
Shielding materials surrounding LSA material may not be considered in
determining the estimated average specific activity of the package contents.
LSA material must be in one of three groups:
1) LSA-I
i) Ores containing only naturally occurring radionuclides (e.g.,
uranium, thorium) and uranium or thorium concentrates of ores; or
ii) Solid unirradiated natural uranium or depleted uranium or natural
thorium or their solid or liquid compounds or mixtures; or
iii) Radioactive material, other than fissile material, for which the A2
value is unlimited; or
iv) Mill tailings, contaminated earth, concrete, rubble, other debris,
and activated material in which the radioactive material is
essentially uniformly distributed and the average specific activity
does not exceed 10-6A2/g.
2) LSA-II
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i) Water with tritium concentration up to 0.8 Tbq/liter (20
Ci/liter); or
ii) Material in which the radioactive material is distributed
throughout and the average specific activity does not exceed
10-4A2/g for solids and gases, and 10-5A2/g for liquids.
3) LSA-III: Solids (e.g., consolidated wastes, activated materials) that
meet the requirements of §173.468 and which:
Section 81
i) The radioactive material is distributed throughout a solid or a
collection of solid objects, or is essentially uniformly
distributed in a solid compact binding agent (such as concrete,
bitumin, ceramic, etc.); and
ii) The radioactive material is relatively insoluble, or it is
intrinsically contained in an insoluble material, so that even
under loss of packaging, the loss of radioactive material per
package by leaching when placed in water for seven days
would not exceed 0.1 A2; and
iii) The average specific activity of the solid does not exceed
2x10-3A2/g.
7. Normal Form. Radioactive material which has not been demonstrated to
qualify as Special Form radioactive material. In other words, this includes
most radioactive material shipped, except encapsulated sources with the
"Special Form" certification.
8. Package. The packaging together with its radioactive contents as presented
for transport.
1) Excepted Package means a packaging together with its excepted
radioactive materials as specified in §§173.421-173.426 and 173.428.
2) Type A Package means a packaging that, together with its radioactive
contents limited to A1 or A2 as appropriate, meets the requirements of
§§173.410 and 173.412 and is designed to retain the integrity of
containment and shielding required by Part 173 under normal
conditions of transport as demonstrated by the tests set forth in
§173.465 or §173.466, as appropriate.
3) Type B Package means a packaging that, together with its radioactive
contents, is designed to retain the integrity of containment and
shielding required by Part 173 when subjected to the normal conditions
of transport and hypothetical accident test conditions set forth in 10
CFR 71. There are specific
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Type B packages, which include Type B(U) and Type B(M) packages.
Their requirements are specified in §173.403.
4) Industrial Packaging means a packaging that, together with its Low
Specific Activity material or Surface Contaminated Object contents,
meets the requirements of §§173.410 and 173.411. Industrial
Packaging is further categorized in §173.411 as Type 1, Type 2, or
Type 3.
9. Packaging. The assembly of components necessary to ensure compliance
with the packaging requirements of Part 173, Subpart I. It may consist of
one or more receptacles, absorbent materials, spacing structures, thermal
insulation, radiation shielding, service equipment for filling, emptying,
venting and pressure relief, and devices for cooling or absorbing
mechanical shocks. The conveyance, tie-down system, and auxiliary
equipment may sometimes be designated as part of the packaging.
10. Special Form. Radioactive material which satisfies the following
conditions:
1) It is either a single solid piece or is contained in a sealed capsule that
can be opened only by destroying the capsule;
2) The piece or capsule has at least one dimension not less than 5
millimeters (0.2 inch); and
3) It satisfies the test requirements of §173.469. There are other specific
special form encapsulation design exceptions found elsewhere in Part
173.
11. Surface Contaminated Object (SCO). A solid object which is not itself
radioactive but which has radioactive material distributed on any of its
surfaces. SCO must be in one of two groups with surface activity not
exceeding the following limits:
1) SCO-I: A solid object on which:
Section 82
i) The non-fixed contamination on the accessible surface
averaged over 300 cm2 (or the area of the surface if less than
300 cm2) does not exceed 4 Bq/cm2 (10-4 microcurie/cm2) for
beta and gamma and low toxicity alpha emitters, or 0.4 Bq/cm2
(10-5 microcurie/cm2) for all other alpha emitters;
ii) The fixed contamination on the accessible surface averaged
over 300 cm2 (or the area of the surface if less than 300 cm2)
does not exceed 4x104 Bq/cm2 (1.0 microcurie/cm2) for beta
and gamma and low toxicity alpha emitters, or 4x103 Bq/cm2
(0.1 microcurie/cm2) for all other alpha emitters.
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iii) The non-fixed contamination plus the fixed contamination on
the accessible surface averaged over 300 cm2 (or the area of
the surface if less than 300 cm2) does not exceed 4x104 Bq/cm2
(1.0 microcurie/cm2) for beta and gamma and low toxicity
alpha emitters, or 4x103 Bq/cm2 (0.1 microcurie/cm2) for all
other alpha emitters.
2) SCO-II: A solid object on which the limits for SCO-I are exceeded and
on which:
i) The non-fixed contamination on the accessible surface
averaged over 300 cm2 (or the area of the surface if less than
300 cm2) does not exceed 400 Bq/cm2 (10-2 microcurie/cm2)
for beta and gamma and low toxicity alpha emitters, or 40
Bq/cm2 (10-3 microcurie/cm2) for all other alpha emitters;
ii) The fixed contamination on the accessible surface averaged
over 300 cm2 (or the area of the surface if less than 300 cm2)
does not exceed 8x105 Bq/cm2 (20 microcurie/cm2) for beta
and gamma and low toxicity alpha emitters, or 8x104 Bq/cm2
(2 microcurie/cm2) for all other alpha emitters; and
iii) The non-fixed contamination plus the fixed contamination on
the accessible surface averaged over 300 cm2 (or the area of
the surface if less than 300 cm2) does not exceed 8x105 Bq/cm2
(20 microcurie/cm2) for beta and gamma and low toxicity
alpha emitters, or 8x104 Bq/cm2 (2 microcurie/cm2) for all
other alpha emitters.
12. Transport Index. The dimensionless number (rounded up to the next
tenth) placed on the label of a package to designate the degree of
control to be exercised by the carrier during transportation.
13. Type A Quantity. A quantity of radioactive material, the aggregate
radioactivity of which does not exceed A1 for special form radioactive
material or A2 for normal form radioactive material.
14. Type B Quantity. A quantity of radioactive material greater than a
Type A quantity.
E. Application of Regulatory Requirements
1. Radioactive Contents
Objective 2.12.03
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In order to determine packaging, labeling and other requirements for
shipping radioactive material, the radionuclide content of the material
must be known. This includes the identity and quantity of each isotope.
There are four basic methods which are considered acceptable for
radionuclide identification.
a. materials accountability - primarily applicable to wastes and
involves determining the quantity of radioactive material contained
within a volume by comparing the amount of radioactive material
entering and exiting a given process.
b. classification by source - determining the radionuclide content
through knowledge and control of the source of the material.
c. gross radioactivity measurements - acceptable, provided that:
Section 83
i. the gross radioactivity measurements are correlated to the
actual radionuclides in the material
ii. the gross measurement is initially correlated to actual
radionuclide content and periodically verified
d. direct measurement of individual radionuclides - individual
gamma emitting radionuclides are directly measured using gamma
spectroscopy.
F. Package Radiation Surveys and Limits
Except as provided in paragraph (b) of §173.441, each package of
radioactive materials offered for transportation must be designed and
prepared for shipment, so that under conditions normally incident to
transportation, the radiation level does not exceed 2 mSv/hour (200
mrem/hour) at any point on the external surface of the package, and the
transport index does not exceed 10.
A package which exceeds 2 mSv/hour (200 mrem/hour) or a transport
index of 10 must be transported by exclusive use shipment, and the
radiation levels for such shipment may not exceed the following during
transportation:
1. 2 mSv/h (200 mrem/h) on the external surface of the package unless
the following conditions are met, in which case the limit is 10 mSv/h
(1000 mrem/h):
a. The shipment is made in a closed transport vehicle;
Objective 2.12.04
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2.12-10
b. The package is secured within the vehicle so that its position
remains fixed during transportation; and
c. There are no loading or unloading operations between the
beginning and end of the transportation;
2. 2 mSv/h (200 mrem/h) at any point on the outer surfaces of the vehicle,
including the top and underside of the vehicle; or in the case of a
flat-bed style vehicle, at any point on the vertical planes projected from
the outer edges of the vehicle, on the upper surface of the load or
enclosure if used, and on the lower external surface of the vehicle;
3. 0.1 mSv/h (10 mrem/h) at any point 2 meters (6.6 feet) from the outer
lateral surfaces of the vehicle (excluding the top and underside of the
vehicle); or in the case of a flat-bed style vehicle, at any point 2 meters
(6.6 feet) from the vertical planes projected by the outer edges of the
vehicle (excluding the top and underside of the vehicle); and
4. 0.02 mSv/h (2mrem/h) in any normally occupied space, except that this
provision does not apply to carriers if they operate under the provisions
of a State or federally regulated radiation protection program and if
personnel under their control who are in such an occupied space wear
radiation dosimetry devices.
For shipments made under the exclusive use provisions, the offeror shall
provide specific written instructions for maintenance of the exclusive use
shipment controls to the carrier. The instructions must be included with the
shipping paper information. The instructions must be sufficient so that,
when followed, they will cause the carrier to avoid actions that will
unnecessarily delay delivery or unnecessarily result in increased radiation
levels or radiation exposures to transport workers or members of the
general public.
Packages exceeding 2 mSv/hour (200 mrem/hour) or a transport index of
10 may not be transported by aircraft.
G. Contamination Surveys and Limits (Off-site shipments via non-DOE
conveyance)
The level of non-fixed (removable) radioactive contamination on the
external surfaces of each package offered for transport must be kept as low
as reasonably achievable. The level of non-fixed radioactive contamination
may not exceed the limits set forth in Table 11 of §173.443 and must be
determined by either:
Section 84
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1. Wiping an area of 300 square centimeters of the surface concerned
with an absorbent material, using moderate pressure, and measuring
the activity on the wiping material. Sufficient measurements must be
taken in the most appropriate locations to yield a representative
assessment of the non-fixed contamination levels. The amount of
radioactivity measured on any single wiping material, when averaged
over the surface wiped, may not exceed the limits set forth in Table 11
of §173.443 at any time during transport; or
2. Using other methods of assessment of equal or greater efficiency, in
which case the efficiency of the method used must be taken into
account and the non-fixed contamination on the external surfaces of
the package may not exceed ten times the limits set forth in Table 11 of
§173.443, as follows:
Table 1 - DOT Contamination Limits (Table 11 of §173.443)
Maximum Permissible Limits Contaminant
Bq/cm2 µCi/cm2 dpm/cm2
Beta and gamma emitters and low
toxicity alpha emitters 0.4 10-5 22
All other alpha emitting
radionuclides 0.04 10-6 2.2
§173.428 states that a packaging which previously contained
radioactive materials and has been emptied of contents as far as
practical, is excepted from the shipping paper and certification,
marking and labeling requirements of this Part 173, provided that
a. The packaging meets the requirements of Sec. 173.421(a) (2), (3),
and (5) of this §173 Subpart I;
b. The packaging is in unimpaired condition and is securely closed so
that there will be no leakage of radioactive material under
conditions normally incident to transportation;
c. Internal contamination does not exceed 100 times the limits in
§173.443(a);
d. Any labels previously applied in conformance with Subpart E of
§172 are removed, obliterated, or covered and the ``Empty'' label
prescribed in §172.450 is affixed to the packaging; and
e. The packaging is prepared for shipment as specified in §173.422.
H. Contamination Surveys and Limits (On-site and off-site shipments by DOE
conveyance)
Objective 2.12.05
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2.12-12
49 CFR 172 through 173 describe requirements for inspecting and
surveying packages, containers and transport conveyances prior to off-site
transport. The 49 CFR 173 contamination values shall be used as
controlling limits for off-site shipments transported by DOE and non-DOE
conveyances. These limits also apply to on-site transfers of shipments by
non-DOE conveyances received from or destined to off-site locations.
On-site shipments by DOE conveyances may use alternative DOE limits
for contamination, radiation, packaging, etc., provided the alternative is
approved.
DOE Radiological Control Standard, Table 2-2, contamination values may
be used as controlling limits for on-site and off-site transportation when
using a DOE conveyance. When a shipment is received from an off-site
destination, in or on a non-DOE conveyance, the 49 CFR contamination
values shall be used when transfers are made in a DOE conveyance from
the on-site receiving location to the ultimate on-site destination.
I. Package Marking, Sealing and Labeling.
Section 85
§173.427 states that for LSA material and SCO required to be consigned as
exclusive use for domestic transportation only, packages are excepted from
the marking and labeling requirements of this subchapter. However, the
exterior of each nonbulk package must be stenciled or otherwise marked
``Radioactive--LSA'' or ``Radioactive--SCO'', as appropriate, and nonbulk
packages that contain a hazardous substance must also be stenciled or
otherwise marked with the letters ``RQ'' in association with the above
description.
Except as provided above, LSA material and SCO must be packaged as
follows:
1. In an industrial package;
2. For domestic transportation only, in a Type A package. The
requirements of §173.412 (a), (b), (c) and (k) do not apply;
3. For domestic transportation only, in a strong, tight package that
prevents leakage of the radioactive content under normal conditions of
transport. In addition to the requirements of paragraph (a) of §173.427,
the following requirements must be met:
a. The shipment must be exclusive use;
b. The quantity of radioactive material in each packaging may not
exceed an A2 quantity;
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4. For domestic transportation only, in a packaging that complies with the
provisions of 10 CFR 71.52, and is transported in exclusive use; or
5. Any Type B, B(U) or B(M) packaging authorized pursuant to §173.416.
J. Type A Packages
In addition to meeting the general design requirements prescribed in
§173.410, each Type A packaging must be designed so that
1. The outside of the packaging incorporates a feature, such as a seal, that
is not readily breakable, and that, while intact, is evidence that the
package has not been opened. In the case of packages shipped in closed
transport vehicles in exclusive use, the cargo compartment, instead of
the individual packages, may be sealed.
2. The smallest external dimension of the package is not less than 10
centimeters (4 inches).
K Type B Packages
Type B package labeling and marking must meet the following
requirements:
1. Follow the same requirements as those described for Type A packages.
2. Follow any additional sealing, labeling, and marking requirements
contained in the NRC Certificate of Compliance for the package or site
transport plan.
L. Surveys of Transport Vehicle
Radiation and contamination surveys should be performed when an
Exclusive Use transport vehicle arrives at the site to ensure that the vehicle
is not exceeding applicable DOT limits. If found to be above these limits,
the vehicle should not be loaded until properly decontaminated and the
owner of the transport vehicle and the site packaging and transportation
department informed. During loading, exclusive use transport vehicles
should be frequently surveyed to avoid the problem of rearranging the load
after it is discovered that the radiation levels are above limits.
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M. Vehicle Radiation Surveys
Radiation surveys should be performed at the appropriate locations to
ensure that the radiation level limits are not exceeded.
N Outgoing Vehicle Contamination Surveys
Section 86
DOT regulations do not specify contamination limits for transport vehicles
other than those designated exclusive use. It is assumed that if packages
loaded onto vehicles are kept within their contamination limits, the vehicle
will be within the package contamination limits. Contamination surveys of
the packages should be conducted at the time of loading to ensure that they
have not become contaminated in storage or through handling.
Even though DOT regulations do not specifically require contamination
surveys for non-exclusive use vehicles, it is good radiological control
practice to perform such surveys to ensure that no contamination is spread
to off site areas. Prior to releasing a radioactive material shipment vehicle,
survey the bed of the truck, floor, seat, and door handles of the cab,
controls in cab, tires, and other areas which could have become
contaminated during loading.
O. Proper Placarding of Transport Vehicle
1. Do not over-label or placard a vehicle unnecessarily. Application of
such placard when the hazard does not exist is a violation of
regulations.
2. Description of Placard. The radioactive placard is diamond shaped
with "Radioactive" in black centered across it on a white background.
The upper portion of the sign has a black radiation symbol on a yellow
background (49 CFR 172.556). The placard must be fastened to all
four sides of the vehicle (49 CFR 172.504(a)).
3. Location of Placards on Transport Vehicle. Placards must be on all
four sides of the vehicle. If a tractor is disconnected from the trailer,
placards must be on all four sides of the trailer otherwise the front
placard can be on the tractor. After the shipment has been officially
received on the receivers property, it is usually posted in accordance
with regular posting (Radiation Area, High Radiation Area,
Contamination Area, etc.)
P. Inspection Prior to Release of Shipment
(Insert site specific information here)
Objective 2.12.06
Objective 2.12.07
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2.12-15
Q. Documentation
For all shipments, the shipping papers must adhere to the requirements of
49 CFR 172.200 through 172.204.
R. Verification of Receiving Facility's Authorization to Receive the Material
10 CFR 30.41 and 10 CFR 70.42 require that before transferring
byproduct and/or special nuclear material, respectively, the shipper
must verify that the receiving facility has a license that authorizes the
receipt of the material being shipped.
Although these restrictions only apply to NRC licensees, it is good
practice to perform the same verification prior to shipping radioactive
material to other DOE facilities. Some DOE facilities that normally
use only a few isotopes may not have the proper training or
instruments to safely receive and control the material. It must also not
be assumed that other government agencies are exempt from NRC
regulations and license restrictions.
S. Violations of Regulations
Frequent violations of DOT regulations include:
• Leaking packages
• Contaminated packages and vehicles
• Radiation levels exceeding limits in vehicle cabs, underneath vehicles,
and other limits
• Load not securely fastened
• Mechanical deficiencies in the vehicles
• Instructions not provided to carrier for maintaining "exclusive use" of
vehicle
• Improper package closure
• Improper packagings for the type or quantity of radioactive material
• Improper or missing markings, labels or placards
• Incomplete and incorrect information on shipping papers.
Section 87
T. Receipt of Radioactive Material
10 CFR 835 requires the following:
1. §835.405 Receipt of radioactive packages.
a. If packages containing quantities of radioactive material in excess
of a Type A quantity (as defined in 10 CFR 71.4) are expected to
be received from radioactive material transportation, arrangements
shall be made to either:
Objective 2.12.08
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2.12-16
i. Take possession of the package when the carrier offers it for
delivery; or
ii. Receive notification as soon as practicable after arrival of the
package at the carrier’s terminal and to take possession of the
package expeditiously after receiving such notification.
b. Upon receipt from radioactive material transportation, external
surfaces of packages known to contain radioactive material shall
be monitored if the package:
i. Is labeled with a Radioactive White I, Yellow II, or Yellow III
label (as specified in 49 CFR 172.403 and 172.436-440); or
ii. Has been transported as low specific activity material on an
exclusive use vehicle (as these terms are defined in 10 CFR
71.4); or
iii. Has evidence of degradation, such as packages that are crushed,
wet, or damaged.
c. The monitoring required by paragraph (b) shall include:
1. Measurements of removable contamination levels, unless the
package contains only special form (as defined at 10 CFR
71.4) or gaseous radioactive material; and
2. Measurements of the radiation levels, unless the package
contains a Type B quantity (as defined in 10 CFR 71.4) of
radioactive material.
d. The monitoring required by paragraph (b) of this section shall be
completed as soon as practicable following receipt of the package,
but not later than 8 hours after the beginning of the working day
following receipt of the package.
e. Monitoring per § 835.405(b) is not required for packages
transported on a DOE site which have remained under the
continuous observation and control of an individual who is
knowledgeable of and implements required exposure
control measures.
(Insert site specific information here)
U. Shipment of Radioactive Material
(Insert site specific information here)
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V. Shipment Exceeding Limits
If it is known, assumed, or suspected that the delivering vehicle or
packages are contaminated, the delivering carrier, all intermediate carriers
and the shipper must be notified immediately so that potentially
contaminated vehicles can be withdrawn from service and checked.
Loading docks and terminals through which the package passed in transit
must also be surveyed. If any contamination is found on package surfaces,
it is important to check any areas, equipment or personnel who may have
become contaminated handling the package. Depending on the extent of
contamination, the incident may also require notification to DOE
Headquarters under the Unusual Occurrence Reporting system and could
result in activation of the Radiological Assistance Plan. If a package was
received from an NRC licensee, the director of the NRC Inspection and
Enforcement Regional Office should also be notified.
(Insert site specific information here)
V. OPENING PACKAGES OF RADIOACTIVE MATERIAL
It is good radiological control practice to establish, maintain, and follow
procedures for opening packages containing radioactive material.
Section 88
(Insert site specific information here)
III. SUMMARY
Radioactive material which is to be transported from one location to another must
be properly packaged, surveyed, labeled and documented. Currently there are
approximately 50,000 weekly shipments of radioactive material in the U.S. Strict
adherence to shipping requirements is requisite to maintain high levels of safety.
IV. EVALUATION
Evaluation should consist of a written examination comprised of multiple choice,
fill-in-the-blank, matching, and/or short answer questions. 80% should be the
minimum passing criteria for examinations.
Objective 2.12.09
Objective 2.12.10
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DOE-HDBK-1122-2009
Module 2.13 Radiological Incidents and Emergencies Instructor’s Guide
2.13-1
Course Title: Radiological Control Technician
Module Title: Radiological Incidents and Emergencies
Module Number: 2.13
Objectives:
2.13.01 Describe the general response and responsibilities of an RCT during any incident.
→ 2.13.02 Identify any emergency equipment and facilities that are available, including the
location and contents of emergency equipment kits.
→ 2.13.03 Describe the RCT response to a Continuous Air Monitor (CAM) alarm.
→ 2.13.04 Describe the RCT response to a personnel contamination monitor alarm.
→ 2.13.05 Describe the RCT response to off scale or lost dosimetry.
→ 2.13.06 Describe the RCT response to rapidly increasing, unanticipated radiation levels or
an area radiation monitor alarm.
→ 2.13.07 Describe the RCT response to a dry or liquid radioactive material spill.
→ 2.13.08 Describe the RCT response to a fire in a radiological area or involving radioactive
materials.
→ 2.13.09 Describe the RCT response to other specific site incidents (as applicable).
→ 2.13.10 Describe the response levels associated with radiological emergencies.
→ 2.13.11 Describe site specific procedures for documenting radiological incidents.
→ 2.13.12 Identify the structure of the emergency response organization at your site.
→ 2.13.13 Identify the available offsite incident support groups and explain the assistance that
each group can provide.
→ 2.13.14 Discuss radiological incidents at the plant or other plants, including cause,
prevention, and recommended incident response.
References:
1. Title 10 CFR Part 835 (2007), "Occupational Radiation Protection" Subpart N.
2. DOE Order 151.1C (2005), "Comprehensive Emergency Management Systems".
3. (Site specific emergency preparedness manuals).
DOE-HDBK-1122-2009
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2.13-2
Instructional Aides:
1. Overheads
2. Overhead projector/screen
3. Whiteboard/chalkboard
4. Lessons learned
DOE-HDBK-1122-2009
Module 2.13 Radiological Incidents and Emergencies Instructor’s Guide
2.13-3
I. MODULE INTRODUCTION
A. Self Introduction
1. Name
2. Phone number
3. Background
4. Emergency procedure review
B. Motivation
State that most people have an attitude that "it can't happen here" and
don't take incident response planning seriously. Explain that
incidents do occur, and experience has shown that best response
comes from workers who have prepared themselves with a plan for
dealing with incidents. Relate to a car skidding on ice. If the driver
has thought about corrective actions for skidding, he will be less
likely to panic. State that no plan can give an exact solution to every
problem, but that a step-by-step approach to responding to any
problem can be used.
Section 89
C. Overview of Lesson
1. Radiological incidents
2. Response to incidents
3. Response to emergencies or potential emergencies
4. Radiological emergency planning and organizations
D. Introduce Objectives
II. MODULE OUTLINE
NOTE: This lesson plan should be developed using site specific
information and regulatory documents. The following is a
recommended format of material.
A. Radiological Incidents and Emergencies
1. Definition
Show O.H.:
Objectives
Ask the student to
explain the difference
between an
emergency and
incident and define
each one. Modify
their answer and
write the correct
definition on the
board.
DOE-HDBK-1122-2009
Module 2.13 Radiological Incidents and Emergencies Instructor’s Guide
2.13-4
a. Incident
1) Unplanned event involving radiation or radioactive
materials (part of an emergency)
2) Response governed by normal procedures
b. Emergencies are classified as either an Alert, Site Area
Emergency, or General Emergency, in order of increasing
severity, when events occur that represent a specific threat to
workers and the public due to the release or potential release
of significant quantities of radiological and non-radiological
hazardous materials. Classification aids in the rapid
communication of critical information and the initiation of
appropriate time-urgent emergency response actions.
c. Operational Emergencies are major unplanned or abnormal
events or conditions that: involve or affect DOE/NNSA
facilities and activities by causing or having the potential to
cause serious health and safety or environmental impacts;
require resources from outside the immediate/affected area
or local event scene to supplement the initial response; and,
require time-urgent notifications to initiate response
activities at locations beyond the event scene. In general, to
be considered an Operational Emergency, an event or
condition involving the uncontrolled release of a hazardous
material must: immediately threaten or endanger personnel
who are in close proximity of the event; have the potential
for dispersal beyond the immediate vicinity of the release in
quantities that threaten the health and safety of onsite
personnel or the public in collocated facilities, activities,
and/or offsite; and have a potential rate of dispersal
sufficient to require a time-urgent response to implement
protective actions for workers and the public. Each
DOE/NNSA site/facility must classify Operational
Emergencies as either an Alert, Site Area Emergency, or
General Emergency, in order of increasing severity, when
events occur that represent a specific threat to workers and
the public due to the release or potential release of
significant quantities of hazardous materials from
DOE/NNSA facilities/activities/operations. Classification
aids in the rapid communication of critical information and
the initiation of appropriate time-urgent emergency response
actions.
2. Causes
a. Ignorance
b. Forgetfulness
DOE-HDBK-1122-2009
Module 2.13 Radiological Incidents and Emergencies Instructor’s Guide
2.13-5
c. Oversight
d. Unforeseen circumstances
e. Communications failures
f. Mechanical failures
g. Human error
h. Natural disasters
3. Examples
(Insert site specific information here)
Ask the student for
causes of incidents.
List these on the
board.
Ask the student for
examples of potential
incidents at the site.
List these on the
board and relate to
causes.
Ensure that all of the
basic incident types
described in the site
accident analysis are
included in the
discussion.
Section 90
DOE-HDBK-1122-2009
Module 2.13 Radiological Incidents and Emergencies Instructor’s Guide
2.13-6
a. Ignorance - Inexperienced operator not knowing correct
procedure and opens the wrong valve. For each general type
of incident:
b. Oversight - Misreading an indicator and allowing a valve to
be opened.
• Discuss expected radiation levels and/or types and
quantities of isotopes released
c. Mechanical Failure - Instrument line ruptures causing spread
of contamination.
• Discuss on site consequences
• Discuss off site consequences
• Ask the student for examples of how human error or
violating procedures could result in the
consequences of the incident being greater than
presented in the site accident analysis.
4. Non-radiological risks
B. General Response to Emergencies
1. Although radiological control personnel respond to an
emergency using basic guidelines, an area or site may have
specific procedures which have priority over these guidelines.
2. Radiological control personnel must be familiar with the
emergency procedures applicable to each site and the types of
equipment to which they are assigned. The basic guidelines can
then be used in conjunction with the specific procedures. In
addition, the order or necessity of some actions may change
depending on whether one is the first responder, one of many
responders, or a backup person.
3. The basic emergency response guidelines are:
Explain that
immediate threats to
life and health, such
as fire, may require
disregarding normal
procedures, but that
ALARA can always
be applied if not
following normal
procedures.
Objective 2.13.01
DOE-HDBK-1122-2009
Module 2.13 Radiological Incidents and Emergencies Instructor’s Guide
2.13-7
a. Define and assess the problem. Typically personnel at the
scene are a good source of information, however remote
instrumentation and other resources should not be
overlooked. Depending on the nature of the incident, do not
delay or over analyze the situation. Assess only what is
needed for action.
b. Attempt to stop the cause of the emergency. No undue risks
should be taken.
c. Notify site management and safety.
d. Warn personnel in the area of the emergency. This keeps
unnecessary personnel away from the event site, minimizing
their exposure.
e. Isolate the area. Install barriers as quickly as possible to
establish an exclusion area. The exclusion area may be very
large initially. In determining the size of the exclusion area,
consider internal and external exposure rates, potential for
criticality, possible spread of radioactive contamination or
other hazardous materials, weather conditions, non-
radiological hazards, and security (site security may assist in
establishing boundaries). Outside the exclusion area normal
operations may continue. Even if there is no radiological
risk, an RCT may help others provide access control.
f. Minimize personnel exposure. During initial response
remember to use ALARA concepts, as practical. Plan
supplementary operations as necessary to assure personnel
exposure is minimized. All planned exposures above the
occupational limits (5 rem) is voluntary. The following
guidelines for control of emergency exposures are
1) Up to 10 rem for protecting major property and where
lower dose limit is not practicable
Whether or not to
activate a site
emergency response
program (such as
dialing 911) is
determined by the
nature of the incident.
Activation usually
automatically fulfills
this requirement.
When a situation is
confusing, not fully
understood, or may
not be controllable;
over reacting is better
than under reacting.
Section 91
DOE-HDBK-1122-2009
Module 2.13 Radiological Incidents and Emergencies Instructor’s Guide
2.13-8
2) Up to 25 rem for lifesaving or protection of large
populations where lower dose limit is not practicable
3) Above 25 rem for lifesaving or protection of large
populations. Only on a voluntary basis to personnel
fully aware of the risks involved
g. Secure ventilation. Close entrances, windows, and the
supply ventilation systems as necessary. Unless one is
certain that ventilation is contributing to the incident, this
may involve no more than just ensuring that conditions are
correct for normal designed ventilation.
h. Perform surveys. Radiological control personnel are trained
to perform emergency surveys. Types of surveys will vary
with the nature of the emergency. Performing good surveys
may require significant time but must be done before
recovery can be initiated.
i. Initiate the recovery. This includes clean-up operations,
decontamination and moving the exclusion area barricade
inward.
C. Facilities and Equipment
1. Facilities
RCTs should have a thorough knowledge and understanding of
processes and hazards of their assigned facility. This should
include a knowledge of the Site Emergency Response Plan.
These plans usually contain information concerning evacuation
routes, staging areas, handling of contaminated personnel, and
information concerning off-site support organizations.
2. Equipment
Typically, facilities maintain "emergency kits/cabinets" which
contain supplies used in responding to emergencies. These
kits/cabinets usually contain smears, gloves, bags, supplies for
posting, dosimetry, respiratory equipment, and a copy of facility
emergency procedures.
(Insert site specific information here)
Objective 2.13.02
RCTs should always
know the resources
and equipment
available to them in
the area where they
are working. For
each site or area,
discuss the location,
security and
habitability
provisions,
equipment and
communications
available.
DOE-HDBK-1122-2009
Module 2.13 Radiological Incidents and Emergencies Instructor’s Guide
2.13-9
D. Response to Continuous Air Monitor (Cam) Alarm
Airborne radioactivity may be caused by a breach in a system, or
resuspension of particulate radioactivity due to work evolutions such a
welding, grinding, or other heavy work. Indications that an airborne
contamination event is occurring include CAM alarms, air samples
exceeding limits, and increasing radiation levels.
1. Initial Response
a) Stop operations that may be causing airborne radioactivity
b) Warn others to evacuate
c) Secure unfiltered ventilation
d) Contact line or facility management for support
2. Supplementary Actions (re-entry)
a) Upon re-entry, don respiratory equipment and protective clothing
based on conditions of the event
b) Evaluate the affected area by taking an air sample, measuring
radiation levels, and checking for CAM malfunction
c) Obtain additional air samples as necessary to determine
boundaries and maintain access control
d) Identify isotope(s) to help determine problem source and
protective measures
e) Consider additional ventilation to minimize personnel exposure
and reduce the need for respiratory equipment (HEPA)
f) Measure and control surface contamination to minimize the
spread of contamination
g) Survey exhaust systems, ventilation filters, and ducts. Have
decontamination performed as necessary to minimize
contamination spread
Section 92
h) Evaluate the potential for internal exposure and contact facility
dosimetrist for proper internal dosimetry protocol
i) Personnel should be interviewed for information on any off-
normal event which could have caused the alarm
j) Take air samples, once operations resume, to verify that the
cause of airborne activity has been corrected
Objective 2.13.03
DOE-HDBK-1122-2009
Module 2.13 Radiological Incidents and Emergencies Instructor’s Guide
2.13-10
(Insert site specific information here)
E. Response to Personnel Contamination Monitor Alarm
1. Initial Response
a. Instruct affected worker to remain in area (standfast)
b. Report to the scene with at least portable instruments for
direct surveys and smear media
c. Perform whole body surveys (frisk) for the appropriate type
of radiation (alpha and/or beta-gamma). The RCT should be
careful not to contaminate self and instrumentation
d. Take actions to minimize cross-contamination, such as
covering or placing a glove over a contaminated hand
2. Supplemental Actions
a. Survey affected area to characterize the extent of
contamination
b. Suspect an up-take if contamination is verified and survey
facial area for contamination, taking nasal smears or nose
blows. If positive, contact RCT supervision and refer to
your facility specific procedures
c. If contaminated, follow-up actions include saving any
radioactive material pertaining to the contamination event, as
this may help characterize the event at a later time.
d. Refer to facility specific procedures if contamination persists
e. Document all surveys and estimate skin dose on proper
forms Do not unduly delay any decontamination efforts by
taking too long in documenting contamination for skin dose
estimates. Remember that dose is being incurred all the time
that the skin is contaminated. Think ALARA especially in
the case of high energy beta emitters.
f. Report all confirmed skin contaminations to RCT
supervision and refer to your facility specific procedures if
transporting to a medical facility.
g. Gather appropriate information for follow-up surveys.
Explain the basis for
and significance of
the alarm setpoints
for CAMs at your
site
Objective 2.13.04
DOE-HDBK-1122-2009
Module 2.13 Radiological Incidents and Emergencies Instructor’s Guide
2.13-11
3. Follow-up actions shall be in accordance with the site procedure.
These typically include:
a. Removal of contaminated clothing or decontamination of
minor skin contamination. Decontaminate skin using mild
non-abrasive soap and tepid water or decon toweletts.
Continue decon as long as significant reduction in activity is
occurring after each decon. Do not irritate the skin.
b. Verification that personnel monitoring equipment is working
properly. Equipment should not be returned to service until
all problems are resolved. Alarms can be caused by a
variety of equipment failures or by "nuisance" non-work
related situations such as environmental radon resulting from
local conditions.
(Insert site specific information here)
F. Response to Off-scale or Lost Dosimetry
1. For Off-scale self reading dosimeters, typical actions include:
a. Assure that the worker is placed in as safe an area as
possible (low dose area) and that the work has been left in a
safe condition where possible.
b. Alert others working in the area (for off-scale response).
c. Evaluate the situation. All dose indicated by the dosimeter is
Section 93
assumed to have been received by the individual until it can
be clearly demonstrated otherwise.
d. Gather data for dose estimate. Data typically includes work
area dose rates, work activities, worker position, co-worker
dose readings, and travel path conditions. For High
exposures, the official permanent dosimetry (TLD or film
badge) should be retrieved for processing.
2. For lost dosimetry, typical actions include:
a. Individual(s) must leave the area if dosimetry is required.
b. Contact RCT supervision for reissue of dosimetry.
NOTE: Alarms and
alarm set points
should not be
tampered with. If
alarm cannot be
silenced by the
acknowledge button,
take out of service.
Objective 2.13.05
DOE-HDBK-1122-2009
Module 2.13 Radiological Incidents and Emergencies Instructor’s Guide
2.13-12
3. Supplemental action
a. Notify workers supervision
b. Restrict additional entries until a dose assessment can be
completed
c. Consider suspending further work on the RWP until issues are
resolved
(Insert site specific information here)
G. Response to Rapidly Increasing, Unanticipated Radiation Levels or an
Area Radiation Monitor Alarm.
1. Initial Response
a. Evacuate personnel as quickly as possible to a safe area (low
dose area).
b. Measure radiation levels in affected area.
c. Notify line/facility management. Whether or not to activate a
site emergency response program (such as dialing 911) is
determined by the nature of the incident. Activation usually
automatically fulfills this requirement. When a situation is
confusing, not fully understood, or may not be controllable; over
reacting is better than under reacting.
d. Evaluate the situation. The best contact is people at the scene.
e. Verify postings and boundaries are adequate.
2. Supplemental Actions
a. Verify personnel staging area dose rates are acceptable and
check individual exposures. Notify RCT supervision of results.
b. Re-occupy area upon approval of line/facility management.
c. Document all surveys using appropriate forms.
(Insert site specific information here)
H. Response to Dry or Liquid Radioactive Spill of Known Material and
Origin Requiring SWIMS
1. STOP the spill.
a. Take appropriate precautions, dependent on situation, all are
different.
Objective 2.13.06
Objective 2.13.07
DOE-HDBK-1122-2009
Module 2.13 Radiological Incidents and Emergencies Instructor’s Guide
2.13-13
b. Correct immediately, if possible without undue risks.
ALARA should be practiced at all times. If a major spill can
be averted with minimal risk, then some action may be
warranted; otherwise, try to contain the spill as it presents
itself.
2. WARN other personnel.
a. Let people in the affected area know what is going on.
b. If situation warrants, evacuate the area.
c. Notify your supervisor, site management, and emergency
response network if appropriate. As before, whether or not
to activate a site emergency response program (such as
dialing 911) is determined by the nature of the incident.
Activation usually automatically fulfills this requirement.
When a situation is confusing, not fully understood, or may
not be controllable; over reacting is better than under
reacting.
3. ISOLATE the area. Use banners or whatever materials available
to isolate the area. Recruit whatever personnel are at hand to
assist.
• Establish boundaries and post the area for exposure and
contamination control.
Section 94
4. MINIMIZE exposure. Use all protective gear available. Do not
risk uptakes by not using respiratory protection or anti-
contamination clothing.
a. To yourself as well as others.
b. Practice ALARA principles.
5. SECURE Ventilation
• Control HVAC (heating, ventilation, air conditioning).
6. Supplemental actions
a. Survey as necessary including air sampling.
b. Decontaminate as necessary.
c. Verify boundaries.
d. Complete all documentation surveys and logs.
Unless one is certain
that ventilation is
contributing to the
incident, this may
involve no more than
just ensuring that
conditions are correct
for normal designed
ventilation.
Major spills may
very likely involve
many people and
require Radiation
Work Permits and
ALARA reviews of
activities. Do not try
to clean up a major
spill by yourself, just
keep it contained and
isolated until the
entire clean up
operation is
formulated.
DOE-HDBK-1122-2009
Module 2.13 Radiological Incidents and Emergencies Instructor’s Guide
2.13-14
(Insert site specific information here)
7. If you cannot contain the spill or are unaware of the spill’s nature,
use WIN
a. Warn others
b. Isolate the area
c. Notify
I. Response to a Fire in a Radiological Area or Involving Radioactive
Materials
Typically Radiological Control will supply support to the Fire
Department and will be represented at the Command Post.
Additional actions could include the following.
1. Assist in evacuation of personnel.
2. Perform air samples, radiation, and contamination surveys.
3. Establish radiological boundaries.
(Insert site specific information here)
J. Response to Other Site Specific Incidents
(Insert site specific information here)
K. Response Levels
1. ALERT. An Alert shall be declared when events are predicted,
are in progress, or have occurred that result in actual or potential
substantial degradation in:
a) Level of control over hazardous materials
b) Safety or security of a nuclear weapon, component, or test
device that would not pose an immediate threat to workers or
the public
c) Safety or security of a facility or process that could, with
further degradation, produce a Site Area Emergency or
General Emergency
2. Site Area Emergency. A Site Area Emergency shall be declared
when events are predicted, in progress, or have occurred that
result in actual or potential situations that could include one or
more of the following:
Objective 2.13.09
Objective 2.13.10
DOE-HDBK-1122-2009
Module 2.13 Radiological Incidents and Emergencies Instructor’s Guide
2.13-15
a) Major failure of functions necessary for the protection of
workers or the public
b) Threat to the integrity of a nuclear weapon, component, or
test device that may adversely impact the health safety of
workers in the immediate area, but not the public
c) Major degradation in level of safety or security of a facility
or process that could, with further degradation, produce a
General Emergency
3. General Emergency. A General Emergency shall be declared
when events are predicted, in progress, or have occurred that
result in actual or likely situations that could result in one or
more of the following:
a) Catastrophic reduction of facility safety or security systems
with potential for the release of large quantities of hazardous
materials to the environment
b) Catastrophic failures in safety or security systems
threatening the integrity of a nuclear weapon, component, or
test device that may adversely impact the health and safety
of workers and the public
Section 95
(Insert site specific information here)
L. Documentation of Radiological Incidents and Event Categorizations
(Insert site specific information here)
Event Categorizations
Significance Category 1. Occurrences in this category are those that are
not Operational Emergencies and that have a significant impact on safe
facility operations, worker or public safety and health, regulatory
compliance, or public/business interests.
Significance Category R. Occurrences in this category are those identified
as recurring, as determined from the periodic performance analysis of
occurrences across a site.
Significance Category 2. Occurrences in this category are those that are
not Operational Emergencies and that have a moderate impact on safe
facility operations, worker or public safety and health, regulatory
compliance, or public/business interests.
Objective 2.13.11
DOE-HDBK-1122-2009
Module 2.13 Radiological Incidents and Emergencies Instructor’s Guide
2.13-16
Significance Category 3. Occurrences in this category are those that are
not Operational Emergencies and that have a minor impact on safe facility
operations, worker or public safety and health, regulatory compliance, or
public/business interests
Significance Category 4. Occurrences in this category are those that are
not Operational Emergencies and that have some impact on safe facility
operations, worker or public safety and health, public/business interests.
M. Emergency Response Organization
(Insert site specific information here)
Emergency organization and responsibilities may include:
1. Site specific teams
2. Crisis Manager
3. Crisis Management Team
4. Operational Assistance Team
5. Emergency Response Team
6. First Line Initial Response Team
N. Offsite Support Groups
(Insert site specific information here)
1. Purpose is to overcome the limitations of the lack of training and
insufficient equipment/personnel.
2. May include:
a. Firefighting
b. Medical
c. Law enforcement
d. Radiological Assistance Program (RAP) Team
O. Site Specific Lessons Learned
(Insert site specific information here)
Discuss reporting and
authority
relationships, persons
normally assigned to
each team, and where
they are located.
Emphasize the
responsibilities of
RCT when assigned
to applicable teams.
Objective 2.13.13
For each offsite
support group,
discuss the training
and qualifications,
number of personnel,
and equipment
resources available.
Explain that local
offsite response
groups may have
different dose
guidelines that they
have to follow.
Emphasize that the
most restrictive
guideline must be
followed for these
personnel.
Objective 2.13.14
DOE-HDBK-1122-2009
Module 2.13 Radiological Incidents and Emergencies Instructor’s Guide
2.13-17
Ensure that all of
the basic incident
types at the site are
included in the
discussion. For
each of the
following incidents,
refer the students to
the applicable site
procedures listed
and discuss each
step. Emphasize
the rationale for the
actions instead of
just listing them.
Include each of the
following under the
discussion of each
incident type as
applicable:
• Additional ways
in which each
could be
discovered, such
as routine
surveys or
observation of
unusual
conditions.
• Who is in charge
of response
• Radiation
Control
responsibilities
• Immediate
actions
• Corrective
actions
• Recovery
• Documentation
Read the accident
reports and analysis
and then:
• Discuss the
Section 96
radiation levels
and/or types and
DOE-HDBK-1122-2009
Module 2.13 Radiological Incidents and Emergencies Instructor’s Guide
2.13-18
III. SUMMARY
A. Review major points
1. Radiological incidents
2. Response to incidents
3. Response to emergencies or potential emergencies
4. Radiological emergencies planning and organizations
B. Review learning objectives
IV.EVALUATION
Evaluation should consist of a written examination comprised of multiple
choice, fill-in the blank, matching and/or short answer questions. 80%
should be the minimum passing criteria for examinations.
• quantities of
isotopes released.
• Discuss on site
consequences.
Discuss off site
consequences.
Conduct summary by
asking questions
which will show that
the student objectives
have been met.
Modify answers for
completeness,
correctness and
clarity. Use the
student objectives to
formulate your
questions. Base your
selection of questions
on the areas that the
students have
demonstrated some
weakness or
misconceptions.
DOE-HDBK-1122-2009
Module 2.14 Personnel Decontamination Instructor’s Guide
2.14-1
Course Title: Radiological Control Technician
Module Title: Personnel Decontamination
Module Number: 2.14
Objectives:
2.14.01 List the three factors which determine the actions taken in decontamination of personnel.
→ 2.14.02 List the preliminary actions and notifications required by the RCT for an individual
suspected to be contaminated.
→ 2.14.03 List the actions to be taken by the RCT when contamination of clothing is confirmed.
→ 2.14.04 List the actions to be taken by the RCT when skin contamination is confirmed.
→ 2.14.05 List the steps for using decontamination reagents to decontaminate personnel.
References: (Site Specific).
Instructional Aids:
1. Overheads
2. Overhead projector/screen
3. Chalkboard/whiteboard
4. Lessons learned
DOE-HDBK-1122-2009
Module 2.14 Personnel Decontamination Instructor’s Guide
2.14-2
I. MODULE INTRODUCTION
A. Self Introduction
1. Name
2. Phone number
3. Background
4. Emergency procedure review
B. Motivation
In our work environment, one of the major concerns of radiological
protection is the prevention of personnel contamination. When personnel
contamination has been identified, it is the responsibility of RCTs to
control or oversee the decontamination of the individual using the best
method available.
C. Overview of Lesson
1. Personnel decontamination
2. Basic factors
3. Suspected personnel contamination
4. Contaminated clothing
5. Skin contamination
6. Documentation
7. Decontamination reagents
D. Introduce Objectives
II. MODULE OUTLINE
A. Personnel Contamination
1. Monitoring
The potential for personnel contamination, either external or internal, is
normally identified through one of five monitoring methods:
Show O.H.: Objectives
DOE-HDBK-1122-2009
Module 2.14 Personnel Decontamination Instructor’s Guide
2.14-3
a. Hand Held Count Rate Meters: external
b. Personnel Contamination Monitors: external
c. Partial Body Monitors: external
d. Whole Body Counts: internal (In-Vivo)
e. Excreta Analysis: internal (In-Vitro)
2. Work conditions
In some cases the presence of contamination is assumed prior to
personnel monitoring
a. Exposure of individual to known contaminated liquid
b. Exposure of individual to airborne contamination without proper
protection devices
c. Improper work practices within contamination area
Section 97
1) Improper removal of protective clothing or devices
2) Improper work practices with contaminated material
3) Failure to follow the radiological control requirements set for
work performed
4) Unknowingly working with material discovered to be
contaminated
B. Basic Factors
Once Health Physics has knowledge of potential contamination to an
individual, the actions taken by the RCT will be controlled by three basic
radiological control factors.
1. Physical condition of worker
2. Location of contamination on worker
3. Activity of nuclide(s) present
1. Physical condition
The primary concern is the physical condition of the individual. All actions
will be determined by the present condition of the individual.
Objective 2.14.01
DOE-HDBK-1122-2009
Module 2.14 Personnel Decontamination Instructor’s Guide
2.14-4
a. Is the individual free from any known injury?
b. If an injury has occurred, identify conditions.
2. Location of contamination
Once the physical condition of the individual has been identified, the
location of the contamination must be determined
a. Is the contamination localized on the general skin surface?
b. Is the contamination located at body orifice or is a body orifice in
close proximity?
c. Is the contamination located in or around a break in the skin
structure of the individual?
1) Abrasions
2) Punctures
3) Lacerations
d. Is there any type of skin condition present in the vicinity of the
contamination?
e. Is the contamination on the clothing of the individual?
3. Activity and type of nuclides
The activity of the contamination must be determined as well as the
type of nuclides present
a. What is the beta-gamma activity of the nuclides present?
b. What is the alpha activity of the nuclides present?
C. Preliminary RCT Actions for Personnel with Suspected Contamination
Upon notification of a potential personnel contamination, the initial actions
taken are established by procedure.
(Insert site specific material here)
Typical actions include:
1. Obtain instruments and proceed to location.
Objective 2.14.02
See DOE RCS Art. 541
DOE-HDBK-1122-2009
Module 2.14 Personnel Decontamination Instructor’s Guide
2.14-5
2. Assess conditions
a. Make necessary notifications in case of injury.
b. Survey for quick indication of contamination levels and location.
c. Ask questions about potential contamination event.
d. Assess need to notify RC to request support.
e. Remove levels of contamination immediately on skin or clothing.
Retain removed contamination for dose assessment by Dosimetry.
3. Perform a detailed, whole body survey of exposed surfaces (PCs,
personal clothing and/or skin), for both alpha and beta-gamma
contamination. Starting at the head and proceeding to the feet, pay
particular attention to the following areas:
− contaminated area (if known)
− nose and mouth
− hands
− skin folds
− buttocks
− knees
− feet
a. Verify that the instrument is in service (e.g., turn the monitor on,
check the battery, source response, and calibration) set it to the
proper scale and adjust the audio output so it can be heard during
the survey.
b. Hold the probe less than 1/2 inch from the surface being surveyed
for beta and gamma contamination, approximately 1/4 inch for
alpha contamination. Do not touch the area being surveyed with
the probe to preclude contaminating the probe.
c. Move the probe slowly (approximately 2 inches per second) over
the surface.
Section 98
d. If the count rate increases during the survey, pause for 5 to 10
seconds over the area to provide adequate time for instrument
response.
DOE-HDBK-1122-2009
Module 2.14 Personnel Decontamination Instructor’s Guide
2.14-6
e. If the count rate increases to a value greater than a pre-established
contamination limit or the instrument alarms, presence of
contamination is confirmed. If contamination is confirmed, remain
in the area and notify radiological control personnel.
f. The whole body survey should take several minutes. Do not hurry
the survey and survey all areas that could be contaminated.
4. If the following conditions exist, contact RC supervision and Medical
personnel as appropriate:
a. Extensive whole body contamination
b. An uptake is possible because facial contamination is present
5. If the contaminated individual must be moved to another location (e.g.
hospital or decontamination facility), contain the contamination as
much as possible before allowing the person to move by:
a. Removing and bagging shoes and/or covering feet with plastic
shoe covers/booties.
b. Covering the hands of the individual with gloves, preferably
"Surgical" gloves.
c. Donning a clean set of Anti-C's over contaminated clothes or
merely wrapping the individual with any covering.
D. Contaminated Clothing
When the clothing of an individual is found contaminated, advise the
individual to refrain from moving around or touching the contaminated
area and follow the specified procedures for decontamination.
(Insert site specific material here)
Typical actions include:
1. Contain and remove areas of gross contamination including hot
particles by pulling off with tape or cutting out the area and securely
bagging the contamination.
Objective 2.14.03
Note: Clothing contamination
should be treated just as
seriously as skin
contamination until the
clothing has been removed
and it has been verified that
no skin contamination is
present.
DOE-HDBK-1122-2009
Module 2.14 Personnel Decontamination Instructor’s Guide
2.14-7
2. Carefully remove and securely bag all contaminated clothing. Properly
store and save the contaminated clothing worn by the individual for
analysis by dosimetry if there is skin contamination or a possible
uptake of radioactive material.
3. Perform a personnel whole body survey after removal of contaminated
clothing to determine that the individual is not recontaminated.
a. If contamination persists consider moving to a decontamination
facility.
b. Assess potential for internal deposition (airborne, puncture) by
surveying outside and inside of masks, surveying facial area, and
taking mouth or nasal smears.
E. Skin Decontamination
When the skin of an individual is found contaminated, follow the specified
procedures for decontamination.
(Insert site specific material here)
Typical actions include:
1. Immediately remove hot particles and other high levels of
contamination. The time spent to determine the activity and area of
contamination should be minimized when high doses are possible.
2. Notify the RC supervisor or designated facility contact.
3. Determine the condition of the skin (cuts, sores, abrasions, irritations,
etc.) and decontaminate if appropriate.
a. Treatment of contaminated skin with skin conditions (including
wounds) is usually reserved for medical personnel. Flushing minor
wounds with plain tepid water may be permitted.
b. Whole skin can be decontaminated by wiping with moist towlettes,
Section 99
flushing with plain tepid water, or washing with mild non abrasive
soap and tepid water. Tape should only be used in areas where
there is minimal hair and hair can only be trimmed with permission
of the individual.
c. Retain particles or other samples of contamination for analysis and
dose assessment by Dosimetry.
Objective 2.14.04
Note: Stop the
decontamination effort if the
skin becomes irritated or the
individual complains of
discomfort.
DOE-HDBK-1122-2009
Module 2.14 Personnel Decontamination Instructor’s Guide
2.14-8
d. Assess potential for internal deposition (airborne, puncture) by
surveying outside and inside of masks, surveying facial area, and
taking mouth or nasal smears.
F. Documentation
After decontamination has been completed, it is essential that the proper
documentation is completed for proper records.
(Insert site specific material here)
Typical documentation includes:
1. An estimate of skin area and location affected and the activity involved.
2. The decontamination process including levels and iterations.
G. Decontamination Reagents
(Insert site specific material here)
Typical steps in the use of decontamination techniques are:
1. Washing with mild non-abrasive soaps, flushing with plain tepid water,
and sweating techniques should be used for initial decontamination.
Always begin with the least irritating agents before proceeding to
stronger agents. These techniques may be employed by RCTs in the
field.
Sticky tapes may also be used initially as long as the potential for skin
irritation is kept in mind.
2. Stronger and more abrasive soaps (Tide, Clorox, or cornmeal) may
dislodge the contamination but are generally used by medical
personnel because of their potential for damaging the skin.
3. Stronger chemical techniques such as those using Potassium
Permanganate (KMnO4), Sodium Bisulfite (NaHSO3), DTPA (as a
wash), or CaDTPA (as a wash) are not often needed, but when they
are, they should be used only by trained medical personnel.
Objective 2.14.05
Note: Stop the
decontamination effort if the
skin becomes irritated or the
individual complains of
discomfort.
DOE-HDBK-1122-2009
Module 2.14 Personnel Decontamination Instructor’s Guide
2.14-9
III. SUMMARY
A. Review major points
1. Personnel decontamination
2. Basic factors
3. Suspected personnel contamination
4. Contaminated clothing
5. Skin contamination
6. Documentation
7. Decontamination reagents
B. Review learning objectives
IV. EVALUATION
Evaluation should consist of a written examination comprised of multiple
choice, fill-in the blank, matching and/or short answer questions. 80% should
be the minimum passing criteria for examinations.
DOE-HDBK-1122-2009
Module 2.14 Personnel Decontamination Instructor’s Guide
2.14-10
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DOE-HDBK-1122-2009
Module 2.15 Radiological Considerations for First Aid Instructor’s Guide
2.15-1
Course Number: Radiological Control Technicians
Module Title: Radiological Considerations for First Aid
Module Number: 2.15
Objectives:
2.15.01 List the proper steps for the treatment of minor injuries occurring in various radiological
areas.
2.15.02 List the requirements for responding to major injuries or illnesses in radiological areas.
2.15.03 State the RCT's responsibility at the scene of a major injury in a radiological area after
medical personnel have arrived at the scene.
Section 100
→ 2.15.04 List the requirements for treatment and transport of contaminated injured personnel at
your facility.
.:
1. "Basic Radiation Protection Technology"; Gollnick, Daniel; 5th ed.; Pacific Radiation
Corporation; 2008.
2. Operational Health Physics Training - H. J. Moe
Instructional Aids:
1. Overheads
2. Overhead projector/screen
3. Whiteboard/chalkboard
4. Lessons learned
DOE-HDBK-1122-2009
Module 2.15 Radiological Considerations for First Aid Instructor’s Guide
2.15-2
I. MODULE INTRODUCTION
A. Self Introduction
1. Name
2. Phone number
3. Background
4. Emergency procedure review
B. Motivation
Injuries occurring in radiological areas, particularly in contaminated,
airborne, or areas with high radiation dose rates require special
considerations above and beyond standard first aid. The RCT may often
be the first person or one of the first, to arrive at the scene of an injury.
Because of this, the RCT must know how first aid requirements and
radiological control requirements may conflict and on what basis to
establish priorities. This lesson will introduce the special considerations
for injuries in radiological areas.
There is no way possible to prepare and train for all possible injuries and
radiological condition combinations. It is incumbent on the RCT to use
his or her knowledge and training to make judgement calls based on
available facts and conditions. Often there is more than one "right way"
to handle the situation, with many alternatives which may all work
equally well.
C. Overview of Lesson
1. Minor injuries occurring in radiological areas
2. Major injuries occurring in radiological areas
3. Interface of RCT with medical personnel
4. RCT responsibilities in the treatment and transport of contaminated
personnel
D. Introduce Objectives
II. MODULE OUTLINE
A. First Aid
Standard first aid is applied prior to contamination control whenever it is
considered to have life-saving value, or is important to the patient for
relief of pain or prevention of disability. It is the obligation of all who
Show O.H.: Objectives
DOE-HDBK-1122-2009
Module 2.15 Radiological Considerations for First Aid Instructor’s Guide
2.15-3
assist a patient to render such aid within the limits of their training and
qualifications.
B. Minor Injuries Occurring in Radiological Areas
1. Render first aid as needed
2. Survey for contamination (clothing, skin, wounds).
a. Radiological Protection is responsible for determining whether
wounds are contaminated, and then advise Medical.
3. Decontaminate as necessary, including area(s) around the wound(s).
Do not attempt to decontaminate the wound(s).
4. Inform Medical - This information is of use in determining
appropriate treatment.
a. Injured's name
b. Injured's condition
c. Location
d. Contamination levels
5. Get Medical Aid
a. If the person is not contaminated, the person may be escorted to
the nearest First Aid Station for treatment.
b. If the person is contaminated, contain the contamination if
possible by covering the area, and transport to the nearest
personnel decon station as necessary, and medical assistance
should be requested at that location
Objective 2.15.01
Decontamination of
wounds or broken skin
by RCT's is generally
limited to flushing with
tepid water. Complete
decontamination of
wounds or broken skin is
generally done by
Medical personnel.
Depending on the minor
injury and local
procedures, activation of
an emergency response
may be appropriate and
this would provide
medical aid.
Section 101
DOE-HDBK-1122-2009
Module 2.15 Radiological Considerations for First Aid Instructor’s Guide
2.15-4
C. Major Injuries Occurring in Radiological Areas
1. If first to arrive on the scene:
a. administer first aid
b. get help to the scene
c. survey injured person(s)
d. assist Medical personnel
2. Administer first aid. The first consideration is getting appropriate
medical treatment to the patient, either in the radiological area or
through evacuation from the radiological area. This should be
considered prior to first aid measures only if leaving the person in
the area for a short time would further endanger the injured's and
rescuer's health and safety.
a. Contamination levels would almost never be cause for
immediately evacuating, or delaying first aid to, a seriously
injured person from an area prior to first aid.
1) A contaminated live person is, in every case, preferable to a
clean deceased person.
2) If the person administering first aid becomes contaminated,
remember that the rescuer can be decontaminated much
easier than the injured person can be brought back to life if
first aid was delayed to enable the rescuer to avoid becoming
contaminated.
b. Airborne radioactivity would almost never be cause for
immediately evacuating, or delaying first aid to, a seriously
injured person from an area prior to first aid.
1) Remember that a live patient with some internal
contamination is always preferable to a deceased person with
no internal contamination.
c. Radiation levels could require evacuation to be the first
consideration.
Objective 2.15.02
Ask students: "What
contamination level, if any,
would require evacuation
prior to treatment?"
Ask students: "What if
person needs CPR and has
facial contamination?"
Ask students: "Would there
ever by an airborne level
high enough to warrant
evacuation prior to first
aid?"
Ask students what radiation
levels they think would
require movement prior to
first aid.
DOE-HDBK-1122-2009
Module 2.15 Radiological Considerations for First Aid Instructor’s Guide
2.15-5
1) Consideration must be given to both the injured and the
rescuer(s) in this instance.
2) If treating the person in the location would expose them or
the rescuer(s) to a hazardous radiation dose, movement out
of the area would then be done first.
3) This is a judgement call, depending upon the nature of the
injuries, the radiological conditions, the location of the
injured, etc. There is no "magic number" for a dose rate that
would require immediate movement regardless of injury.
3. Get help to the scene. The timing and method of doing this will
depend on the extent of the injuries, the location, how many people
are present, etc.
4. Survey the injured person(s). This should include the clothing,
exposed skin, and any wounds.
a. If the injured is in an area with high radiation levels, the RCT
must be able to provide an estimated equivalent dose to Medical.
Even if the levels are not high enough to warrant immediate
evacuation, the total dose to the injured individual may dictate
what medical treatment is given. This would require a
knowledge of the radiation dose rates in the area, and
determination (or estimate) of the length of time that the person
was exposed to these levels.
5. Assist Medical personnel with treatment, transportation, and
decontamination.
a. For a seriously injured and contaminated person, transportation
would be by ambulance.
b. For transport of contaminated person(s), the RCT would
Section 102
accompany the injured in the ambulance.
1) Necessary measures should be taken to reduce or eliminate
the spread of contamination on the way.
e.g., A person has an
injury with severe
bleeding in a very high
radiation area, receives
treatment and recovers,
but received in excess of
400 rems whole body
radiation. What is the
primary long term
medical concern?
Decontamination or even
the purchase of a new
ambulance is far easier
and cheaper than
bringing someone back to
life.
DOE-HDBK-1122-2009
Module 2.15 Radiological Considerations for First Aid Instructor’s Guide
2.15-6
2) If the patient has gross transferable contamination,
consideration should be given to wrapping the injured person
in a blanket to contain the contamination. Since this could
prevent or delay treatment, or in some cases aggravate the
injuries, it would only be done with the concurrence of
Medical personnel.
c. Control movement of personnel between rooms at the medical
facility to prevent the spread of contamination.
d. Provide containers and instruct patients regarding the collection
of bioassay samples. Collect specimens of any blood, excised
tissue, etc.
e. Survey all clothing, equipment and instruments used in the
transport vehicle, recommend decontamination or disposal of
items as necessary.
f. Some typical problems and concerns arising in hospital
situations:
1) Portable X-ray machines, as soon as the X-ray has been
taken, the hospital staff will usually want to remove the
machine from the room ASAP.
2) Waste and contaminated materials removed from the patient
may begin to pose a radiation hazard if allowed to
concentrate or remain in the immediate vicinity. Also will
increase background levels.
D. Interface of RCT and Medical Personnel
1. After the initial response and first aid, the primary duty of the RCT
will be with radiological concerns. The primary concern of Medical
personnel will be the patients' medical condition and treatment.
These two concerns must be balanced against one another keeping
the best interest of the patient in mind. RCTs are not doctors;
doctors and nurses are usually not qualified RCT personnel.
2. The RCT must be careful not to make medical decisions or
judgments that he/she is not qualified to make. The RCT will be
primarily responsible for decisions involving radiological concerns.
Examples:
a. A person has a piece of metal sticking out of her arm. The
bleeding has been slowed so that it is not life threatening.
Objective 2.15.03
Encourage a discussion
of this scenario with the
class and illustrate the
range of opinions.
DOE-HDBK-1122-2009
Module 2.15 Radiological Considerations for First Aid Instructor’s Guide
2.15-7
The piece of metal has contact radiation levels of 10 rad/hr B and 5
R/hr gamma. The medical personnel arriving at the scene ask you
"Should we remove the piece of metal prior to transporting the
patient?" What do you tell them?
b. A person has fallen off of a ladder and is unconscious. There are
no outward signs of serious injury. The person is breathing and
has a pulse. The immediate area has a neutron whole body
radiation level of 15 rems/hr. You had a medical person arrive at
the scene at the same time. Upon learning of the radiation level,
the medical person asks if he should immediately move the
person prior to the arrival at the scene of a stretcher or more
personnel. How do you respond?
3. The RCT should advise medical personnel of radiological conditions
Section 103
and precautions and make decisions concerning the radiological
protection of personnel on the scene.
E. Requirements for the Treatment and Transport of Contaminated Injured
Personnel
(Insert site specific material here.)
III. SUMMARY
A. Review major topics
1. Minor injuries occurring in radiological areas
2. Major injuries occurring in radiological areas
3. Interface of RCT with medical personnel
4. RCT responsibilities in the treatment and transport of contaminated
personnel
B. Review learning objectives
IV. EVALUATION
Evaluation should consist of a written examination comprised of multiple
choice, fill-in the blank, matching and/or short answer questions. 80%
should be the minimum passing criteria for examinations.
Encourage classroom
discussion of this
scenario, emphasizing
that there are an infinite
number of possible
injury/radiological
scenario combinations.
Objective 2.15.04
DOE-HDBK-1122-2009
Module 2.15 Radiological Considerations for First Aid Instructor’s Guide
2.15-8
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DOE-HDBK-1122-2009
Module 2.16 Radiation Survey Instrumentation Instructor’s Guide
2.16-1
Course Title: Radiological Control Technician
Module Title: Radiation Survey Instrumentation
Module Number: 2.16
Objectives:
2.16.01 List the factors which affect an RCT's selection of a portable radiation survey instrument,
and identify appropriate instruments for external radiation surveys.
→ 2.16.02 Identify the following features and specifications for ion chamber instruments used at
your facility:
a. Detector type
b. Instrument operating range
c. Detector shielding
d. Detector window
e. Types of radiation detected/measured
f. Operator-adjustable controls
g. Markings for detector effective center
h. Specific limitations/characteristics.
→ 2.16.03 Identify the following features and specifications for high range instruments used at your
facility:
a. Detector type
b. Instrument operating range
c. Detector shielding
d. Detector window
e. Types of radiation detected/measured
f. Operator-adjustable controls
g. Markings for detector effective center
h. Specific limitations/characteristics.
→ 2.16.04 Identify the following features and specifications for neutron detection and measurement
instruments used at your facility:
a. Detector type
b. Instrument operating range
c. Types of radiation detected/measured
d. Energy response
e. Operator-adjustable controls
f. Specific limitations/characteristics.
References:
1. Radiation Detection and Measurement, Glenn F. Knoll.
2. “Basic Radiation Protection Technology"; Gollnick, Daniel; 5th ed.; Pacific Radiation
Corporation; 2008.
3. Operational Health Physics, Harold J. Moe.
4. ANSI N323A.
5. (Various Manufacturers Technical Manuals).
DOE-HDBK-1122-2009
Module 2.16 Radiation Survey Instrumentation Instructor’s Guide
2.16-2
Instructional Aids:
1. Overheads
2. Overhead projector and screen
3. Chalkboard/markerboard
4. Lessons learned
DOE-HDBK-1122-2009
Module 2.16 Radiation Survey Instrumentation Instructor’s Guide
2.16-3
I. MODULE INTRODUCTION
A. Self Introduction
1. Name
2. Phone number
3. Background
4. Emergency procedure review
B. Motivation
External exposure controls used to minimize the equivalent dose to
personnel are based on the data taken with portable radiation survey
instruments. An understanding of these instruments is important to ensure
the data obtained is accurate and appropriate for the source of radiation.
This lesson contains information about widely used portable radiation
survey instruments.
Section 104
C. Overview of Lesson
1. General discussion
2. Factors affecting instrument selection
3. Eberline RO-2 series
4. Bicron RSO-50 and RSO-500
5. Victoreen 450B
6. Eberline Teletector
7. Eberline RO-7
8. Eberline PNR-4 with NRD sphere
9. Eberline ASP-1 with NRD sphere
D. Introduce Objectives
Show O.H.: Objectives
NOTE: The text is
provided for some
commonly used
instruments. The facility
must adjust text as
necessary for instruments
used at each site. Text
added for specific
instruments used at the
facility must, at a
minimum, cover
material required by
the objectives.
DOE-HDBK-1122-2009
Module 2.16 Radiation Survey Instrumentation Instructor’s Guide
2.16-4
II. MODULE OUTLINE
A. General Discussion
1. Measurements using portable radiation survey instruments provide the
basis for assignment of practical external exposure controls. In order
to establish the proper controls, radiation measurements must be an
accurate representation of the actual conditions.
2. Many factors can affect how well the measurement reflects the actual
conditions, such as:
a. Selection of the appropriate instrument based on type and energy
of radiation, radiation intensity, and other factors.
b. Correct operation of the instrument based on the instrument
operating characteristics and limitations.
c. Calibration of the instrument to a known radiation field similar in
type, energy and intensity to the radiation field to be measured.
d. Other radiological and non-radiological factors that affect the
instrument response, such as radioactive gases, mixed radiation
fields, humidity and temperature.
B. Factors Affecting Instrument Selection
1. As discussed, the selection of the proper instrument is critical to ensure
the data obtained are accurate and appropriate.
2. The instrument is selected based on the characteristics and
specifications for that instrument as compared to the required
measurements.
3. Several factors should be considered when selecting the instrument.
a. Type of data required:
Distinguish clearly between external radiation surveys (lesson
2.16) and contamination monitoring (lesson 2.17). External
radiation surveys require an instrument that reads R/hr, rem/hr, etc,
rather than cpm, etc.
Objective 2.16.01
DOE-HDBK-1122-2009
Module 2.16 Radiation Survey Instrumentation Instructor’s Guide
2.16-5
b. Measurement of the true equivalent dose:
Ion chambers (which read current instead of counting pulses) have
the flattest energy response. Ion chambers are closest to being
tissue equivalent. Generally the best choice for external beta-
gamma surveys is an ion chamber.
c. The type of radiation to be measured:
Ion chambers measure beta and gamma. For neutrons, choose a
rem ball (NRD). Alphas are not measured in an external radiation
survey, since they do not penetrate the skin (7 mg/cm2).
d. The intensity of the radiation (exposure or dose rate):
For high radiation fields (> 5 R/hr) use an extendible instrument
(Teletector) if this is "reasonably achievable" (ALARA).
e. The energy of the radiation to be measured:
low energy radiation will not penetrate either the skin, or the
window of most external radiation instruments;
GM detectors over-respond to low energy gammas;
most instruments under-respond to high energy neutrons.
f. Environmental factors:
ion chambers are usually vented to air, so radioactive gases or high
humidity affect the instrument response
g. Procedural requirements
4. Pre-operational check.
Section 105
Once the proper type of instrument has been identified, a pre-
operational check is essential and must be performed in accordance
with appropriate procedures.
a. Physical damage
Perform a physical inspection of the instrument by checking for
obvious physical defects or damage, especially of the probe, and
replace the probe or cable if necessary.
b. Calibration
Verify the instrument is calibrated and has not exceeded the calibration
due date.
DOE-HDBK-1122-2009
Module 2.16 Radiation Survey Instrumentation Instructor’s Guide
2.16-6
c. Battery
Perform a battery check to verify the battery condition is within the
acceptable range. Change the batteries if necessary.
d. Zero
Perform a zero adjustment for the meter needle, if applicable.
e. Source check
Perform a source response check as required by procedures.
5. To ensure the proper selection and operation of instruments, the
instrument operator must understand the operating characteristics and
limitations of each instrument available for use.
The following general principles apply to each of the specific
instruments described in later sections.
a. Detector type.
Ion chambers have the flattest energy response. Ion chambers are
closest to being tissue equivalent.
GM detectors over-respond to low energy gammas.
Special detectors are used for neutrons.
b. Operating range.
External radiation measuring instruments read in R/hr, rad/hr, or
rem/hr. In contrast, instruments designed for measuring
contamination read in cpm.
Extendible instruments are generally appropriate for high radiation
fields.
c. Detector shielding.
Large amounts of shielding are not practical with a portable
instrument, but some probes incorporate a small amount of
shielding to reduce background.
Many external radiation survey instruments incorporate a sliding "beta
shield". Note that this also shields low energy gammas.
DOE-HDBK-1122-2009
Module 2.16 Radiation Survey Instrumentation Instructor’s Guide
2.16-7
d. Detector window.
External radiation instruments generally have windows that are
about as thick as human skin (7 mg/cm2). The reason for this is: if
the radiation does not penetrate this window then it does not
penetrate skin, and so it does not contribute any external dose.
In contrast, contamination monitoring instruments have thinner
windows.
e. Types of radiation detected/measured.
Ion chambers have a flat energy response for gammas. Ion
chambers are closest to being tissue equivalent. They are also
good for betas, but a correction factor may be needed.
Tube shaped GM detectors are designed so that the walls are close
to the detector gas. Gamma interactions in the walls are important.
A well designed detector wall can partially compensate for the
over-response to low energy gammas. They are designed primarily
for gammas, and also measure betas if the window is not too thick.
Pancake shaped GM detectors have side walls separated from the
gas. They are good for betas, but have a low efficiency for gammas
because very few gammas hit the side walls.
Gas proportional detectors distinguish between alphas and betas.
They often discriminate against (reject) betas and gammas.
ZnS scintillation detectors only detect alphas.
NaI scintillation detectors are generally used for gammas.
Neutron detectors are very specialized.
f. Operator adjustable controls.
Portable instruments generally have a battery check.
Ion chambers generally have a zero adjustment.
Section 106
g. Markings for effective detector center.
External radiation surveys are generally taken at 30 cm (except for
transportation, see lesson 2.12) It is not always obvious what point
on the detector should be 30 cm from the source, so most detectors
mark the effective center.
DOE-HDBK-1122-2009
Module 2.16 Radiation Survey Instrumentation Instructor’s Guide
2.16-8
1) The effective center of the detector, as defined in ANSI N323,
is the point within the detector that produces, for a given set of
irradiation conditions, an instrument response equivalent to
that which would be produced if the entire detector were
located at that point.
2) The effective center can be thought of as the point in the
detector where the measurement of the radiation intensity is
taken.
3) Portable radiation survey instruments are calibrated in a
uniform field of radiation larger than the volume of the
detector, so that the same radiation intensity is seen throughout
the detector.
4) Therefore, the reading "taken" at the effective center represents
the rate value in all portions of the detector.
5) If the radiation field over the whole detector is not uniform
(such as from surface contamination, radiation streaming, or
from a small point source) the exposure rate will not be
uniform over the entire detector volume.
6) For non-uniformly irradiated detectors, the displayed value, as
"taken" at the effective center, will not reflect the actual
exposure rate value and a correction factor may be needed.
C. Eberline RO-2 Series Instruments
1. The Eberline RO-2, RO3 series of instruments are portable, air-vented
ion chamber instruments used to detect and measure gamma, X-ray,
and beta radiation.
Technical specifications for the RO-3 are similar to the RO-2.
2. Detector
a. Operated as an ionization chamber
b. A phenolic, or plastic, cylinder of 3 in. diameter and 12.7 in3 (208
cm3 volume with one end open but covered by a Mylar window)
c. Fill gas - air (vented to atmosphere through a desiccant pack)
d. The ion chamber detector is closer to tissue-equivalent than most
types, allowing the instrument to accurately access the exposure
rate to human tissue.
Objective 2.16.02
Show actual
instruments
Show actual detector
with desiccant pack
DOE-HDBK-1122-2009
Module 2.16 Radiation Survey Instrumentation Instructor’s Guide
2.16-9
1. The detector is approximately tissue equivalent because the
materials used for construction have an effective atomic
number Z close to that of tissue at 7.5.
2. Tissue equivalent implies that the detector responds the same
as human soft tissue (muscle) would if placed at the same point
in the radiation field.
No detector is perfectly "tissue equivalent", but a well-
designed Ion chamber is close enough for most work.
e. Although the detector is not as sensitive as a GM, it is the detector
of choice for accessing exposure because of its close correlation to
the energy deposited in human tissue by radiation.
3. The RO-2 series instruments are operated in the current mode, or the
mode that averages the individual pulse heights per unit time.
a. Individual pulse information is lost; therefore, the electrical signal
will not supply information about the type and energy of the
individual radiation interactions.
b. However, small pulses, which would be lost in the pulse mode, are
averaged along with the other interactions.
4. The instrument range of the Model RO-2 is 0 to 5000 mR/hr.
Section 107
The readings are expressed in R since the measurement is made in air.
The settings are as follows:
RO-2 Ranges:
0-5 mR/hr
0-50 mR/hr
0-500 mR/hr
0-5,000 mR/hr
5. The sliding beta shield is made of phenolic as follows:
• RO-2 shield: 400 mg/cm2 (1/8 inch) mounted on case.
• The active volume of the detector is shielded from the side by the
detector wall and the instrument case, and from the bottom by the
movable beta shield and two layers of windows.
• Detector wall is 200 mg/cm2 and the 0.13 cm aluminum case is
about 345 mg/cm2.
Review the concept of
density-thickness if
necessary
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6. The materials and density-thickness value of the two windows, one on
the case and one on the detector, for the Model RO-2 and RO3 are as
follows:
• RO-2 windows: 7 mg/cm2 total, two Mylar windows of 3.5 mg/cm2
each.
• RO-3 windows: 3.5 mg/cm2 total, one window of 1 mil Mylar.
7. The Model RO-2 instrument is designed to measure gamma, x-ray, and
beta radiation but will detect (not measure) fast neutron radiation.
a. The instruments will read approximately 10%, in mR/hr, of the
true neutron field, in mrem/hr.
b. Although an ionization chamber would respond to alpha radiation,
the Mylar windows and the air gap between the two windows
eliminates any possibility of an alpha response.
8. The energy response for the Model RO-2 is as follows:
a. Measures photon radiation within +20% for photon energies from
12 keV to 7 MeV (beta shield open). The minimum energy
increases to 25 keV if the shield is closed, and to about 40 keV
through the side of the instrument. Because of the thinner window,
the RO3 measures photons from 8 keV.
b. Measures beta radiation >70 keV with the beta shield open. A beta
factor may be appropriate for some situations.
9. Operator-adjustable controls
a. RO-2 range switch with OFF, ZERO, and BATT checking
positions.
1) Switch ranges labeled as 5, 50, 500, and 5,000
2) ZERO position works in conjunction with ZERO knob to
electronically zero the meter.
3) BAT1 and BAT2 positions check the two batteries used to
power the instrument circuitry.
4) OFF position turns the instrument off.
Show controls on the
instrument
NOTE: Mechanical
zero is adjusted using
screw on meter face
when the instrument is
off and should have
been adjusted at the
last calibration.
NOTE: The third
battery in the
instrument supplies the
detector bias, which is
minimal and does not
have a battery check
position.
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10. The effective center markings on the RO-2 are the "dimples" or
depressions on the sides and front of the instrument case.
11. Specific limitations/characteristics
a. The response time for the RO-2 series of instruments is 5 seconds
to reach 90% of the full value.
b. Geotropism, or the effect of gravity on the instrument, causes no
greater than a +2% of full scale change from the actual value.
c. Correction factors may be needed when the radiation field is not
uniform over the entire detector.
d. High humidity or moisture can cause leakage currents in the
detector and cause erratic meter readings.
1) The detector is vented through a silica gel desiccant, or drying
medium, contained in a plastic box.
2) The desiccant can become saturated and will need replacement
if the crystals start to turn clear or pink instead of the normal
blue color.
Section 108
e. The detector is vented to atmosphere; therefore, any change in
atmospheric density changes the air density in the detector.
1) An increase in temperature will lower the air density in the
detector and cause a lower response.
2) An increase in atmospheric pressure will cause an increase in
air density in the detector and cause a higher response.
3) Tables are provided in the technical manuals for correcting the
instrument response due to changes in pressure or temperature.
4) A change in response of about 10% will occur if the instrument
was calibrated at room temperature and used in an
environment that is different by about 50 ΕF.
f. Because the detector is vented to atmosphere, radioactive gases can
enter the detector and cause a reading.
D. Bicron RSO-50 and RSO-500 Instruments
1. The Bicron RSO-50 and RSO-500 instruments are portable air-vented
ion chamber instruments used to detect and measure gamma, x-ray,
and beta radiation.
Show markings on the
instrument
Show instruments.
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2. The Bicron RSO series of instruments are very similar in design and
construction to the Eberline RO-2 series of instruments.
3. Detector (identical for both models)
a. Operated as an ionization chamber
b. A phenolic, or plastic, cylinder of 3 in. diameter and 12.7 in3 (208
cm3) volume with one end open but covered by a Mylar window.
c. Fill gas - air (vented to atmosphere through a silica gel desiccant
pack)
4. The Bicron RSO series instruments are operated in the current mode,
or the mode that averages the individual pulse heights per unit time.
5. The instrument ranges of the two models are as follows:
a. RSO-500 Ranges:
0-0.5 R/hr
0-5 R/hr
0-50 R/hr
0-500 R/hr
b. RSO-50 Ranges:
0-50 mR/hr
0-500 mR/hr
0-5 R/hr
0-50 R/hr
6. The active volume of the detector is shielded from the side by the
detector wall and the instrument case and from the bottom by the
movable beta shield and two layers of windows.
a. Detector wall is 200 mg/cm2 and the 0.13 cm aluminum case is
about 345 mg/cm2.
b. The materials and density-thickness value of the two windows, one
on the case and one on the detector, are the same for both models.
1) RSO windows - 7 mg/cm2 total, both windows are Mylar of
3.5 mg/cm2 each
c. The sliding beta shield is made of phenolic and the density-
thickness value is the same for both models.
1) RSO shield - 400 mg/cm2 (1/8 in. thick) and is mounted
externally on the case
Show instrument
windows.
Show instrument
sliding shield.
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7. The Bicron RSO series of instruments are designed to measure gamma, x-
ray and beta radiation but will detect (not measure) fast neutron radiation.
a. The instruments will read approximately 10%, in mR/hr, of the
true neutron field, in mrem/hr.
b. Like the Eberline RO-2, the Bicron RSO series instruments will
not respond to alpha radiation because the alpha particles are
shielded before they reach the detector.
8. The energy response of the two models is identical.
a. Both models measure photon radiation within +20% for photon
energies from 12 keV to 7 MeV (beta shield open).
b. The minimum energy increases to 25 keV if the shield is closed,
and to about 40 keV through the side of the instrument.
c. Both models measure beta radiation >70 keV.
9. Operator-adjustable controls
Section 109
a. RSO-500 range switch with OFF, ZERO, and BATT checking
positions.
1) Switch ranges labeled as 0.5, 5, 50, and 500 R/hr
2) ZERO position works in conjunction with ZERO knob to
electronically zero the meter.
3) BAT position checks the two batteries used to power the
instrument circuitry and detector bias.
4) OFF position turns the instrument off.
b. RSO-50 range switch is the same but is labeled 50 and 500 mR/hr
and 5 and 50 R/hr.
10. The effective center markings on both Bicron models are the stamped
circles with a plus sign in the circle and are located on the sides and
front of the instrument case.
If the radiation field over the whole detector is not uniform (e.g. from
surface contamination, radiation streaming, or from a small point
source) the displayed value may need to be corrected.
11. Specific limitations/characteristics
a. The response time varies between the two models of Bicron
instruments available.
Show markings on
instrument.
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1) RSO-500 - approximately 10 seconds from 0-90% of the final
reading.
2) RSO-50 - approximately 5 seconds from 0-90% of the final
reading.
b. Correction factors may be needed when the radiation field is not
uniform over the entire detector.
c. High humidity or moisture can cause leakage currents in the
detector and cause erratic meter readings.
1) The detector is vented through a desiccant, or drying medium,
contained in a plastic box.
2) The desiccant can become saturated and will need replacement
if the crystals start to turn clear or pink.
d. Like the Eberline RO-2, the detector is vented to atmosphere;
therefore, any change in atmospheric density changes the air
density in the detector.
1) An increase in temperature will lower the air density in the
detector and cause a lower response.
2) An increase in atmospheric pressure will cause an increase in
air density in the detector and cause a higher response.
3) Tables are provided in the technical manuals for correcting the
instrument response due to changes in pressure or temperature.
4) A change in response of about 10% will occur if the instrument
was calibrated at room temperature and used in an
environment that is different by about 50oF.
e. Because the detector is vented to atmosphere, radioactive gases can
enter the detector and cause a reading.
E. Victoreen Model 450B
1. The Victoreen 450B is a portable, general purpose, ion chamber survey
instrument which uses microprocessor and LCD (liquid crystal display)
technology.
2. Detector
a. Operated as an ionization chamber
b. A Bakelite, or plastic, cylinder of 200 cm3 volume with one end
open but covered by a Mylar window
Show instrument.
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c. Fill gas - air (vented to atmosphere through a desiccant pack)
d. The ion chamber detector is designed as tissue-equivalent,
allowing the instrument to accurately access the exposure rate to
human tissue.
3. The Victoreen 450B is operated in the current mode as are most ion
chambers.
4. Instrument operating range
a. Overall range is 0-50 R/hr.
b. The instrument is auto-ranging, or automatically changes scales as
required for the instrument reading, and has the following scales:
1) 0-5 mR/hr
2) 0-50 mR/hr
3) 0-500 mR/hr
4) 0-5 R/hr
5) 0-50 R/hr
5. The active volume of the detector is shielded from the side by the
Section 110
detector wall and the instrument case and from the bottom by the
movable beta shield and windows.
a. Detector wall is 200 mg/cm2.
b. The sliding beta shield is made of Bakelite, which is a type of
plastic and the density-thickness value is 440 mg/cm2.
c. The two detector windows, one on the detector and one on the case,
are made of 1.7 mil Mylar for a total of 3.4 mg/cm2.
6. The 450B instrument is designed to measure gamma, x-ray, beta and
alpha radiation but will detect (not measure) fast neutron radiation.
a. The instruments will read approximately 10%, in mR/hr, of the
true neutron field, in mrem/hr.
7. Energy response
a. Photon energy response (+20%) is about 20 keV for slide open, 40
keV for slide closed, and 50 keV from the side.
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b. Beta energies >32 keV can be measured. Tech manual states 100 keV;
however, the minimum possible energy is 32 keV.
c. The alpha response is limited to energies >4 MeV and only if the
detector to source distance is less than the alpha range in air.
Recall that a 4 MeV alpha travels ~2.5 cm in air.
8. Operator-adjustable controls
a. Only three external controls are available on the 450B: the
ON/OFF switch, the MODE switch, and the meter light button.
b. The Mode switch is used during calibration and is not enabled for
operator use.
c. The ON/OFF switch turns the instrument on and off.
1) The instrument is auto-ranging and will change the bar graph,
digital value, and scale markings as appropriate for the
exposure rate value.
2) The instrument has an "auto-zero" feature that eliminates any
need for an external zero control.
3) If the batteries are low, then the instrument will display a
LOW BAT message.
d. A button switch is provided in the handle for turning the meter face
light on and off.
9. The effective center markings on the 450B are the painted-white
depressions in the plastic case and are located in the front and on the
sides.
10. Specific limitations/characteristics
a. The response times to 90% of the final value for the 450B
instrument are as follows, assuming that a step increase or decrease
in the rate does not cause a range change:
1) 0-5 mR/hr - 8 sec
2) 0-50 mR/hr - 5 sec
3) 0-500 mR/hr - 2 sec
4) 0-5 R/hr - 2 sec
Show markings.
NOTE: The response
times may be greater
for a step change from
background to a rate
value (e.g., background
to 4 mR/hr - 9.3 sec).
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5) 0-50 R/hr - 2 sec
b. Geotropism, or the effect of gravity on the instrument, causes no
greater than a +1% of full scale change from the actual value.
c. Correction factors may be needed when the radiation field is not
uniform over the entire detector, such as for surface contamination
beta dose rates.
d. High humidity or moisture could cause leakage currents in the
detector and cause erratic meter readings.
1) The detector is vented through a desiccant, or drying medium,
contained in a plastic cylinder.
2) The desiccant could become saturated and will need
replacement if the crystals start to turn clear or pink.
3) The atmospheric vent on the case has a rubber bladder to allow
for changes in temperature and pressure but prevents the free
flow of air into and out of the detector casing.
4) The rubber bladder minimizes the effects of high humidity
environments and radioactive gases.
Section 111
e. The detector is vented to atmosphere; therefore, any change in
atmospheric density changes the air density in the detector.
1) An increase in temperature will lower the air density in the
detector and cause a lower response.
2) An increase in atmospheric pressure will cause an increase in
air density in the detector and cause a higher response.
3) The value of the changes due to temperature and pressure are
similar to those of other air-vented ion chambers.
F. Eberline Teletector
1. The Eberline Teletector is an extendable, telescoping-rod instrument
designed with two Geiger-Mueller detectors for the measurement of
photon exposure rates and detection of beta radiation.
2. Detectors
Objective 2.16.03
Show instrument.
NOTE: Manufactured
in W. Germany and
distributed in U.S. by
Eberline
Detector window Show
window and rubber cap.
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a. Both detectors are sealed GM tubes with halogen-quenched
argon fill gas contained in an energy compensating case.
1) Energy compensation is required in GM detectors to
reduce the over-response to low energy photons.
b. The low range detector is the largest of the two detectors and is
located at the end of the detector housing.
1) The low range detector is used for the three lowest ranges
on the instrument.
c. The high range detector is the small cylinder located on the
offset circuit board in the detector housing.
1) The high range detector is used for the upper two scales.
d. The GM detectors are very sensitive; however, they lack the
direct correlation to energy deposited and are not as useful as
ion chamber instruments for assessing exposure or exposure
rates.
3. The Teletector instrument is operated in the pulse mode, or the
mode that counts each individual pulse.
a. Since any ionization in a GM tube causes the same large pulse,
any radiation interaction in the detector will be counted.
b. All the pulses are of the same large size regardless of the
energy or type of radiation; therefore, all information on the
type and energy of the radiation is lost.
4. The instrument range is 0 - 1000 R/hr.
The analog Teletector has five operating ranges, each with its own
meter face. The three lower ranges utilize the large GM detector
and the two upper ranges utilize the smaller GM detector.
a. 0-2 mR/hr
b. 0-50 mR/hr
c. 0-2 R/hr
d. 0-50 R/hr
e. 0-1000 R/hr
5. Detector shielding
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a. The two detectors are shielded by layers of lead and fiber to
reduce the low-energy photon response.
b. The low-range detector has a 30 mg/cm2 mica window and a
rubber cap to protect the window.
6. The Eberline Teletector will measure x-ray and gamma radiation
and can detect (but not measure) beta radiation.
a. Beta response is not accurate and should be used for detection
purposes only as stated in the manufacturer's instructions.
b. Alpha response is eliminated by the thicker window and casing.
c. Neutron response is insignificant due to the lower probability
of interaction in the small detectors.
7. Energy response
a. The energy response for photon radiation is 80 keV to 3 MeV
(+10%). If the detector is not pulled out of the telescoping rod
housing, the minimum photon energy will be higher.
b. Beta particles >160 keV can be detected but not measured.
8. Operator-adjustable controls
Section 112
a. The only control is the range switch with OFF and B (battery
check) positions.
b. Changing the range at the switch also changes the rotating
meter face to the appropriate meter face for that range.
9. Detector effective center markings
a. The effective center of both detectors is indicated by the
machined grooves in the detector housing, with the groove
closest to the beta window indicating the low-range detector.
b. The high range detector is mounted on a circuit board and is
not centered in the detector housing.
1) The offset is indicated by the machined groove in the
housing retaining ring at the back end of the detector
housing.
Mica is used on GM
detectors, because
Mylar would react with
the halogen quench gas.
Show instrument.
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2) Any contact readings taken using the high range detector
should align the offset indicator so that it points to the
source of radiation. Failure to do so will result in
inconsistent readings.
10. Specific limitations/characteristics
a. Response time for the instrument is approximately 1 second to
90% of full scale.
b. The sealed detectors do not require correction factors for
temperature or pressure.
c. The sealed detectors do not experience problems with
humidity or radioactive gases entering the detector.
d. Since beta radiation is only detected and not measured, no
correction factors are applied for beta radiation.
e. The 13 ft telescoping rod is durable but can be damaged if
twisted or bent.
f. Audible indication is available only through the speaker jack;
no internal speaker is installed.
g. The Eberline Teletector is non-saturating on the high ranges up
to 30,000 R/hr.
1) For GM detectors, the possibility exists that the detectors
become saturated in very high radiation fields. Some GM
detector instruments will read zero if the detector becomes
saturated.
G. Eberline RO-7
1. The RO-7 series instrument provides remote monitoring in high
range beta and gamma radiation fields.
a. The RO-7 consists of a basic digital readout instrument, three
interchangeable detectors, and various interconnecting devices.
b. The detectors may be interconnected to the instrument by flexible
cables of different lengths, by rigid extensions of different lengths
or by use of an underwater housing.
2. Detectors
a. All three detectors are air-vented ion chambers contained in a
plastic-lined (phenolic) aluminum housing. The detector fill gas is
air.
Objective 2.16.03
Show instrument.
Show detectors.
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b. The detector housing also contains other electronics, such as an
operational amplifier and detector identification circuitry.
c. The three available detectors are as follows:
1) The RO-7-LD is a low-range, gamma-only detector with an
active volume of about 50 cm3 and dimensions of 2.5 cm
diameter and 10.2 cm long.
2) The RO-7-BM is a mid-range, beta/gamma detector, with beta
window, that has an active volume of about 7 cm3 and
dimensions of 2.5 cm diameter and 1.5 cm long.
3) The RO-7-BH is a high-range, beta/gamma detector, with beta
window, that has an active volume of about 7 cm3 and
dimensions of 2.5 cm diameter and 1.5 cm long.
d. Each detector is labeled at the connector end of the detector.
NOTE: Two small screws on the label are marked ZERO and
CAL. These should only be adjusted at calibration and must not be
adjusted by the operator.
Section 113
3. The RO-7 instrument is operated in the current mode of operation.
4. The operating range of the instrument is dependent on the detector that
is connected to the instrument.
a. The range of the RO-7-LD detector is 0-2 R/hr.
b. The range of the RO-7-BM detector is 0-200 R/hr.
c. The range of the RO-7-BH detector is 0-20 kR/hr (20,000 R/hr).
5. Detector shielding
All three detectors have the phenolic liner and aluminum housing.
a. The RO-7-BM and RO-7-BH detectors each have a 7 mg/cm2
Mylar window.
b. The Lucite cap for the beta window is 100 mg/cm2. Show cap.
6. Types of radiation detected/measured
a. As previously mentioned, the RO-7-LD detector measures only
gamma and x-ray radiation.
Detector window
Show window.
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1) Both beta and alpha radiation are shielded by the detector
housing.
2) Neutron radiation response is insignificant due to the small
size of the detector.
b. The actual detectors in the RO-7-BM and RO-7-BH detector
assemblies are identical.
1) Both detect and measure gamma, x-ray, and beta radiation.
2) Alpha response is eliminated by the 7 mg/cm2 window (same
density thickness as the dead layer of skin).
3) Neutron radiation response is even smaller than the RO-7-LD
due to the smaller detector volume.
7. The energy response for the three detectors is as follows:
a. The RO-7-LD responds to photon radiation between 50 keV and
1.3 MeV (+20%).
b. The RO-7-BM and RO-7-BH detectors respond to photon radiation
differently depending on orientation and whether the Lucite cover
is in place.
1) Lucite cover off - 10 keV to 1.3 MeV (+20%)
2) Lucite over on - 25 keV to 1.3 MeV (+20%)
3) Shield on, from the side - 50 keV to 1.3 MeV (+20%)
c. The beta response for the RO-7-BM and RO-7-BH detectors is for
beta energies >70 keV.
8. Operator-adjustable controls
a. The ON/OFF switch is the only range control because the
instrument identifies the detector model and adjusts the readout
accordingly.
1) A low battery condition is indicated by a "colon" under the
battery mark on the meter.
b. The ZERO knob will zero the LCD readout.
c. A meter face light is turned on/off by the small switch in front of
the pistol grip.
9. No markings are provided for the detector effective center.
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10. Specific limitations/characteristics
a. The response time of the basic instrument is 2.5 seconds to 90% of
the final reading.
b. The correction factor for the true beta measurement is 1.5 as
recommended by the manufacturer.
c. Since the detector is air-vented, atmospheric temperature and
pressure changes affect the instrument reading.
1) The instrument response will remain within +10% for the
temperature range of -20 to 160 oF.
2) A correction table is available in the technical manual for
pressure changes.
d. The detectors are air-vented but do not have a desiccant pack. The
detector should be kept dry and out of high humidity environments
to prevent leakage currents.
e. Each detector has associated electronics designed for that
particular range. Over-ranging a detector may cause damage to the
detector electronics.
f. If the instrument is not calibrated with the underwater housing and
the housing is used, the response will be about 5% low. The
instrument reading should be multiplied by 1.05 to obtain the
corrected response.
Section 114
g. Interconnecting devices from the detector to the instrument that are
available from the manufacturer are the:
1) 15 ft flexible cable
2) 60 ft flexible cable
3) 2 ft rigid extension
4) 5 ft rigid extension
5) Stainless-steel underwater housing with 60 ft of cable
H. Eberline NRD Neutron Sphere
1. The Eberline NRD sphere is a portable instrument for the detection and
measurement of the equivalent dose rate from neutron radiation.
2. Detector
Objective 2.16.04
Show instrument.
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a. The detector is the Eberline NRD (neutron radiation detector)
sphere, which may be connected to the PNR-4 or to an ESP
instrument by a coaxial cable.
b. The NRD sphere is a 9 in. diameter, cadmium loaded, polyethylene
sphere with a BF3 proportional tube in the center of the sphere.
c. The BF3 (boron trifluoride) detector design allows the detection of
only thermal neutrons because of the low probability of absorption
by boron for other energy neutrons.
1) The thermal neutron capture reaction with the 10B results in gas
ionization pulses caused by the alpha particle product of the
reaction.
1 10 2 4
0 5 3 2n+ B- Li+ He
or
( )10 2
5 3B n,α Li
2) Detector shielding must be employed if the detector is used for
measurement of neutron energies other than thermal.
3. Detector shielding (no window)
a. A polyethylene sphere is used to allow assessment of the dose
from fast and intermediate energy neutrons.
1) The polyethylene has a high percentage of hydrogen which
thermalizes the fast and intermediate energy neutrons.
2) Those neutrons that are thermalized in the sphere can be
detected in the BF3 tube.
3) The diameter of the sphere is chosen during design for the
neutron energy spectrum expected to be measured.
b. The cadmium loading is a thin, perforated sheet of cadmium
surrounding the active volume of the detector and is designed to
reduce the over-response of the detector to certain energy neutrons.
May over-respond by 100-300% for intermediate neutrons without
Cd shield.
Show detector.
Recall thermal
neutrons are defined as
those neutrons with
kinetic energy in
thermal equilibrium
with their surroundings,
or 0.025 eV at STP.
A less prominent
reaction is:
B10(n, 2α)He3
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4. Operating range
a. The PNR-4 has an overall range of 0-5,000 mrem/hr.
b. PNR-4 has a LIN-LOG meter which means the meter face is a
combination of linear and logarithmic scales.
1) The auto-ranging meter uses two meter needles and covers
four decades (logarithmic portion).
2) Within each decade of the range, the meter divisions are
equally spaced (linear portion).
3) The first needle covers the first two decades of 0-5 mrem/hr
and 5-50 mrem/hr.
4) The second needle covers the last two decades of 50-500
mrem/hr and 500-5,000 mrem/hr.
5. Types of radiation detected and measured
a. The instrument is designed for detection and measurement of fast
and intermediate energy neutron radiation.
b. Alpha and beta radiation are not detected because they do not
penetrate the detector shielding.
c. Gamma radiation passes through the detector shielding but can be
rejected by the instrument circuitry up to 500 R/hr (dependent on
high voltage setting and desired rejection level). At low rates,
photon pulses are rejected. At high rates, pulse pile-up causes a
gamma response.
Section 115
d. Since the detector is operated in the proportional region, the pulses
from the alpha particles are larger than pulses from other
interactions and trigger a pulse height discriminator in the
instrument circuitry.
e. The mode of operation for the instrument is the pulse mode so that
individual pulses can be discriminated and counted.
6. Energy response for measured radiation
a. The instrument manufacturer states the instrument response closely
follows the theoretical dose equivalent from neutrons over a range
of 0.025 eV to about 10 MeV.
b. The instrument over-responds to intermediate energy neutrons and
under-responds to relativistic neutrons.
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7. Operator-adjustable controls
a. The only operator-adjustable control on the PNR4 is the
OFF/ON/BAT switch which turns the instrument on and off and
allows a check of the battery.
8. Specific limitations/characteristics
a. The response time depends on which decade of the scale is
appropriate.
1) First decade - 12 seconds
2) Second decade - 6 seconds
3) Third decade - 1.5 seconds
4) Fourth decade - 0.3 seconds
b. No correction factors are necessary.
c. The detector is a sealed pressurized cylinder and is not affected by
changes in humidity, radioactive gases or changes in atmospheric
density.
I. Eberline ASP-1 with NRD Sphere
1. The Eberline ASP-1 with the NRD sphere is a microcomputer-based,
analog-display, portable neutron radiation survey instrument.
2. The detector (Eberline NRD sphere) is identical to the detector used
with the PNR-4 neutron instrument.
3. The mode of operation is the pulse mode.
4. Instrument operating ranges
a. The overall range is 0-100 rem/hr and has a useable range of 1
mrem/hr - 60 rem/hr per HP procedure.
1) 0-1 mrem/hr
2) 0-10 mrem/hr
Show instrument.
NOTE: The operating
ranges are established
by the calibrating
facility based on the
detector used and
intended purpose by
using interchangeable
switch labels.
DOE-HDBK-1122-2009
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2.16-27
3) 0-100 mrem/hr
4) 0-1,000 mrem/hr
5) 0-10,000 mrem/hr
6) 0-100,000 mrem/hr
5. Detector shielding is the same as previously mentioned for the NRD
sphere.
6. The energy response is the same as previously mentioned for the NRD
sphere.
7. Operator-adjustable controls
a. The OFF/BAT/HV/range switch has the following functions:
1) The OFF position turns the instrument off.
2) The BAT position checks the instrument battery power supply.
3) The HV position checks the applied high voltage to the
detector and should match the value listed on the special label
on the instrument case.
4) The range markings are X1, X10, X100, X1K, X10K, and
X100K with a meter scale of 0-1.0.
b. The INTEGRATE/FAST/SLOW switch is a three position toggle
switch with the following functions:
1) In the INTEGRATE position, the instrument will show the
total dose accumulated since the last time the instrument was
reset to zero or turned off.
2) In the FAST position, the response time selected by the
microcomputer is for typical survey work.
3) In the SLOW position, the response is slower but with greater
accuracy than the FAST position.
c. The LIGHT/RESET switch is a three-position, spring-loaded
toggle switch with the following functions:
1) The LIGHT position illuminates the meter face.
Section 116
2) The RESET position will zero the meter reading for the current
mode (INTEGRATE/FAST/SLOW) setting of the instrument.
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3) The RESET switch will cause the "standard current" value to
be displayed if held for 5 seconds while in the FAST or SLOW
mode.
d. The SPEAKER is a two-position toggle switch for turning the
external speaker on and off.
e. Acoustic (airline-type) head phones can be plugged into the
speaker cover on the top of the instrument.
8. As previously mentioned, the NRD sphere has no effective center
markings.
9. Specific limitations/characteristics
a. The response time of the instrument is controlled by the
microcomputer and is based on the input count rate and whether
the mode switch is in FAST or SLOW.
1) In the FAST position, the instrument response time varies
between one and ten seconds.
2) In the SLOW position, the instrument response time will vary
up to a maximum of 29 seconds.
b. No correction factors are required to correct the displayed value.
c. The sealed detector is not affected by changes in atmospheric
density, humidity or radioactive gases.
d. The instrument has a microcomputer controlled "over-range"
indication.
1) When the radiation rate exceeds the useful range of the
detector, the computer will cause an over-range alarm.
2) When the instrument alarms, the meter needle will sweep back
and forth and an interrupted tone will sweep in the speaker.
J. Portable Instrument Specification Chart
1. The specifications for the instruments discussed can be summarized in
a chart that shows:
a. manufacturer
b. model
c. detector type
This is utilized as a
calibration check when
compared to
predetermined value.
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d. operating ranges
e. detector shield
f. detector window
g. radiation measured
h. radiation detected (but not measured)
i. response times.
III. SUMMARY
A. Review major points
1. General discussion
2. Factors affecting instrument selection
3. Eberline RO-2 series
4. Bicron RSO-50 and RSO-500
5. Victoreen 450B
6. Eberline Teletector
7. Eberline RO-7
8. Eberline PNR-4 with NRD sphere
9. Eberline ASP-1 with NRD sphere
B. Review learning objectives
IV. EVALUATION
Evaluation should consist of a written examination comprised of multiple
choice, fill-in the blank, matching and/or short answer questions. 80% should
be the minimum passing criteria for examinations.
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DOE-HDBK-1122-2009
Module 2.17 Contamination Monitoring Instrumentation Instructor’s Guide
2.17-1
Course Title: Radiological Control Technician
Module Title: Contamination Monitoring Instrumentation
Module Number: 2.17
Objectives:
2.17.01 List the factors which affects an RCT's selection of a portable contamination monitoring
instrument.
→ 2.17.02 Describe the following features and specifications for commonly used count rate meter
probes used at your site for beta/gamma and/or alpha surveys:
a. Detector type
b. Detector shielding and window
c. Types of radiation detected/measured
d. Energy response for measured radiation
e. Specific limitations/characteristics
→ 2.17.03 Describe the following features and specifications for commonly used count rate
Section 117
instruments used at your site:
a. Types of detectors available for use
b. Operator-adjustable controls
c. Specific limitations/characteristics
→ 2.17.04 Describe the following features and specifications for commonly used personnel
contamination monitors at your site:
a. Detector type
b. Detector shielding and window
c. Types of radiation detected/measured
d. Energy response for measured radiation
e. Operator-adjustable controls
f. Specific limitations/characteristics
→ 2.17.05 Describe the following features and specifications for commonly used contamination
monitors used at your site (Tool, bag, laundry monitors).
a. Detector type
b. Detector shielding and window
c. Types of radiation detected/measured
d. Energy response for measured radiation
e. Specific limitations/characteristics
References:
1. Radiation Detection and Measurement, Glenn F. Knoll.
2. "Basic Radiation Protection Technology"; Gollnick, Daniel; 5th ed.; Pacific Radiation
Corporation; 2008.
3. Operational Health Physics, Harold J. Moe.
4. ANSI N323A.
5. (Various Manufacturers Technical Manuals).
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Instructional Aids:
1. Overheads
2. Overhead projector/screen
3. Chalkboard/whiteboard
4. Lessons learned
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I. MODULE INTRODUCTION
A. Self-Introduction
1. Name
2. Phone number
3. Background
4. Emergency procedure review
B. Motivation
Environmental monitoring plays a large role in the field of radiological
control. Environmental monitoring is used to estimate human population
doses, determine the impact a site has on the environment, monitor for
unplanned releases as well as quantifying planned releases, and gives us
data useful in determining pathway data.
C. Overview of Lesson
1. Environmental monitoring goals
2. Principles of program design
3. Radiological control responsibilities
4. Analysis of environmental samples
5. Site environmental monitoring methods
6. Transport mechanisms
D. Introduce objectives
II. MODULE OUTLINE
NOTE: The text is provided for some commonly used instruments. The site
must adjust text as necessary for instruments used at each site. Text
added for specific instruments used at the site must, at a minimum,
cover material required by the objectives.
A. General Discussion
1. Measurements using portable contamination monitoring (count rate)
instruments provide the basis for assignment of practical
contamination and internal exposure controls.
O.H.: Objectives
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2. To establish the proper controls, the contamination measurements
must be an accurate representation of the actual conditions.
3. Measurements using non-portable contamination monitors, such as an
Eberline PCM-1B or PM-6 are used to identify personnel
contamination prior to exiting controlled areas or facilities. Hand and
shoe monitors are used by some sites.
4. Measurements using counter scalers to determine the levels of
transferrable contamination on specific location samples are the basis
for contamination postings and material releases from controlled
areas.
5. Many factors can affect how well the measurement reflects the actual
conditions, such as:
a. Selection of the appropriate instrument based on type and energy
of radiation, radiation intensity, and other factors.
Section 118
b. Correct operation of the instrument based on the instrument
operating characteristics and limitations.
c. Calibration of the instrument to a known radiation field similar in
type, energy and intensity to the radiation field to be measured.
d. Other radiological and non-radiological factors that affect the
instrument response, such as radioactive gases, mixed radiation
fields, humidity and temperature.
B. Factors Affecting Instrument Selection
1. The selection of the proper instrument is critical to ensure the data
obtained is accurate and appropriate.
2. Instrument selection is based on the characteristics and specifications
for that instrument as compared to the required measurements.
3. Several factors should be considered when selecting the instrument.
a. The type of radiation to be measured
b. The energy of the radiation to be measured
c. The intensity of the radiation (dose rate or activity levels)
Objective 2.17.01
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d. Interference from a mixed radiation field
e. Background radiation conditions
f. Environmental factors, such as radioactive gases or temperature,
affecting instrument response
g. Procedural requirements
4. To ensure the proper selection and operation of instruments, the
instrument operator must understand the operating characteristics and
limitations of each instrument available for use.
C. Count Rate Meter Hand Probes
1. EBERLINE MODEL HP-210 AND VICTOREEN MODEL 110C
a. Models like the Eberline Model HP-210 or Victoreen Model
110C hand probes are sensitive beta detectors using a thin
window "pancake" Geiger-Muller (GM) detector. These
detectors are designed for contamination surveys of personnel,
table tops, floors, equipment, etc.
1) Detector responds to alpha, beta, gamma and x-ray radiation
of minimum energies.
a) alpha >3 MeV
Detector must be close enough to the source of alpha
particles to prevent alpha particle attenuation in the air
between the source and the detector.
b) beta >40 keV
This precludes the detection of low energy beta particles,
such as the beta particle from the decay of tritium
(Emax= 18.6 keV.)
c) gamma >6 keV
Photon radiation, such as gamma or x-ray, can interact in
the detector walls and the fill gas to create a pulse.
However, the probability of interaction is small due to the
shallow depth of the detector and therefore the efficiency
for photon radiation is small.
Objective 2.17.02
Density determines
minimum energy
response
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2). GM tube has mica window of 1.4 to 2.0 mg/cm2 density.
3) Gamma sensitivity is approximately 3,600 counts per minute
(cpm) per mR/hr for Cs137.
4) Available with either high-density tungsten or aluminum
housings.
a) HP-210AL - aluminum housing with a low shielding
factor for low background use.
b) HP-210T - tungsten shield covering the top and sides of
the detector allows use in high background area.
c) Victoreen 110C - aluminum housing with a low shielding
factor for low background use.
5) Victoreen 110C series hand probes are almost identical to the
Eberline model HP-210AL.
b. Detector type
1) The detector is sealed Geiger-Mueller (GM) "pancake"
detector. A "pancake" detector has a radius or width that is
much larger than the depth of the detector.
Section 119
2) The shielded hand probe contains the GM detector which has
the mica window protected by a wire or stainless-steel etched
screen.
3) The fill gas in the GM tube is halogen-quenched argon.
4) The operating voltage for the GM detector is 900V + 50V.
5) Detector has 50 µs resolving time which is defined as the
minimum time that must elapse after the measurement of an
ionizing particle before a second particle can be measured.
c. Detector window and shielding
1) The thin detector window is 1.4 - 2.0 mg/cm2 mica and is
protected by the screen which is 79% open.
Weight of 1.5 lbs.
Weight of 4.5 lbs.
Halogen absorbs the
UV photons from the
excited positive ions
without ionizing.
About midway of the
voltage plateau
Dead time + recovery
time = resolving time
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May vary with detector type
a) Mica windows must be used instead of Mylar, because the
Mylar will react with the halogen quench gas.
b) The window has an effective surface area of 2.4 in2
(15.5 cm2).
d. Efficiencies for the detector are dependent on the type and energy
of the radiation.
1) The detector is designed, calibrated and used to measure beta
radiation.
a) 22% for 137Cs
b) 16% for 60Co
c) 32% for 90Sr-90Y
d) 15% for 99Tc
e) 6% for 14C
2) Typically, a conservative beta efficiency of 10% is assigned
for these types of problems. Therefore, to convert the cpm
reading to a dpm value, the meter reading is multiplied by ten.
(dpm = cpm X 10)
3) Efficiencies for alpha and photon radiation are not typically
quoted because the probes are not calibrated for either type of
radiation. However, gamma efficiencies are low, about 1-2%,
because of the shallow detector depth. Alpha efficiencies are
highly dependent on the particle energy and distance from the
source, but can be as high as 20%.
e. Specific limitations and characteristics
1) Generally, environmental conditions, such as humidity and
temperature, do not affect the response of the detector
because it is sealed at a pressure slightly less than
atmospheric pressure.
2) Use of the hand probe at proper frisking speeds and distances
is extremely important to ensure accurate results. The probe
should be used at a distance of no more than 1/2" and at a
speed of about 1" per second.
The numbers vary with
probe
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3) The mica window is extremely fragile and sufficient care
must be taken to prevent any punctures which will ruin the
detector.
4) The detector probe is not calibrated for alpha radiation;
however, it may be used for indication of alpha emission
from contamination, if used properly.
2. Victoreen Model 489-4 Detector Probe (THYAC)
a. The Model 489-4 detector probe is a cylindrical GM detector
with a sliding beta shield and can be used for high count rate
applications of contamination monitoring.
b. Detector
1) The detector is a sealed Geiger-Mueller (GM) cylindrical
detector.
2) The shielded probe contains the cylindrical GM tube which
has a stainless steel wall surrounding the entire detector
volume.
3) The fill gas in the GM tube is halogen-quenched argon.
4) The operating voltage for the GM detector is 900V + 50V.
c. Detector window and shielding
1) The detector "window" is the 30 mg/cm2 stainless steel wall
of the detector.
2) Shielding provided by a 360Ε sliding steel shield.
Section 120
d. The GM detector will detect any radiation that interacts within
the sensitive volume of the detector.
1) Charged particle radiation must pass through the detector
wall before an interaction can take place; therefore, the
minimum sensitivity for charged particle radiation is based
on the wall thickness and distance from the detector.
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a) The minimum sensitivity for beta particles is about
200 keV with the shield retracted, which precludes the
measurement of most average- energy, fission-product
beta particles. The detector will not detect beta radiation
with the shield in place.
b) Alpha particles can not be detected because all alpha
particles would be stopped in the detector wall.
2) Photon radiation, such as gamma or x-ray, can interact in the
detector walls and the fill gas to create a pulse. The
minimum sensitivity for photon radiation is about 6 keV with
the shield retracted and about 70 keV with the shield in place.
e. Efficiencies for the detector are dependent on the type and energy
of the radiation but are not typically quoted because the
instrument ranges are adjusted to read the irradiation field value
for the gamma-emitting isotope used during calibration.
f. Specific limitations and characteristics
1) Generally, environmental conditions, such as humidity and
temperature, do not affect the response of the detector
because it is sealed at a pressure slightly less than
atmospheric pressure.
2) When used with a count rate meter, the meter reading (cpm)
is converted to a dpm value by multiplying by thirty (dpm =
cpm X 30).
3) The detector probe is not calibrated and is not recommended
for measurement of beta radiation due to the thickness of the
detector wall.
3. Eberline Model AC-3 Alpha Hand Probe
a. The Model AC-3 is an alpha scintillation detector used to identify
alpha-emitting contamination.
b. Detector
1) Scintillation detector using ZnS (Ag) powder embedded in
tape.
Detector is not
calibrated for beta
radiation.
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2) Active detector area is 9.1 inch2 (59 cm2) within a 5 3/4 x 2
inch sampling area.
3) Low gamma sensitivity.
c. Detector window and shielding
1) Window is 1.5 mg/cm² aluminized plastic film.
2) Total probe assembly is 11½ inches long x 2 3/4 inches wide
x 3¼ inches.
3) Clear plastic probe cover is supplied for protecting the
detector window.
4) Weight of probe is 1 pound 6 ounces.
d. Efficiency
1) From a 1-inch diameter source or from 50 cm² of a large-area
distributed Pu-239 source, 2 pi geometry.
a) Minimum efficiency is 28%.
b) Typical efficiency is 31%.
c) Sensitivity to Pu-239 source is typically 2 x 107 cpm per
microcurie/cm2.
e. Specific limitations and characteristics
1) Probe is sensitive to gamma radiation.
a) Not used in areas where gamma interference in mR/hr
will indicate >300 cpm alpha.
b) The mr/hr value is affixed to each instrument during
routine calibration.
2) Detector window is very fragile. Puncture or damage to
covering will cause detector to become sensitive to light. All
detector windows must be checked for holes or damage.
3) Erratic meter movement can be due to electrical short in
probe connection cable. Check for damage by rotating probe
in a circular motion. If erratic reading is noted, instrument is
to be returned to calibration group.
Section 121
Standard PM tube is
replaced with less
sensitive one
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4) Detector is to be held 0.5 cm from the surface and moved at
approximately 1-2 inches per second.
D. Count Rate Instruments
1. Victoreen Model 496
a. Victoreen Model 496 is an analog GM count rate meter.
1) Used in conjunction with GM probe assembles to measure
beta and gamma radiation.
a) Victoreen 489-4
b) Victoreen 110-C
c) Eberline HP-210
2) Three operating ranges of 0-800, 0-8,000, and 0-80,000 cpm.
3) Response time of 10 seconds or less to 90% of the final
reading.
4) Accuracy of + 10% normally.
5) Weight of 4 pounds.
b. Operation
1) Meter face readout of 0-800.
2) Rotary switch for power and range functions.
a) off - setting for non-operation
b) batt - initial selection for testing of battery strength,
needle will identify battery strength.
c) x1 - establishes meter reading times 1 as the activity in
cpm (0-800 range).
d) x10 - identifies meter reading times 10 as the activity in
cpm (0-8,000 range).
Objective 2.17.03
Only detector with
which meter is
calibrated can be used.
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e) x100 - identifies meter reading times 100 as the activity
in cpm (0-80,000 range).
3) Volume control rotary switch
a) Audible indication of count rate by independently
controlled speaker.
b) Functions of off and on to control speaker.
4) Correction factors for beta/gamma cpm to dpm reading based
on type of detector attached.
a) Thyac 489-4 - meter reading x30.
b) Pancake probes - meter reading x10.
2. Ludlum Model 12
a. The Model 12 is an analog count rate meter
b. Electronic circuitry has potential for use of proportional,
scintillation, and GM detectors
c. Available in three different detector configurations. Detector
characteristics discussed earlier.
1) Eberline HP-210 detector -used for beta-gamma
measurement.
2) Victoreen 110C - used for beta-gamma measurement.
3) Eberline AC-3-7 Probe - used for alpha measurement.
d. Operating ranges of 0-500, 0-5,000, 0-50,000, and 0-500,000 cpm.
e. Fast-Slow toggle switch provides for meter response time
selection.
1) Slow - response time of 22 seconds for 90% of final reading.
2) Fast - response time of 4 seconds for 90% of final
f. Operation
1) Meter face readout of 0-500.
Only detector with
which calibrated can be
used.
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2) Range multiplier selector switch is a six-position switch.
a) OFF
b) BAT
c) x 1,000
d) x 100
e) x 10
f) x 1
3) Audio on-off switch for operation of count rate speaker.
4) Fast-Slow toggle switch to establish response time of
4 seconds (fast) or 22 seconds (slow).
5) RES button provides a rapid means to reset the meter to zero.
6) HV Test Button displays the detector voltage on the meter
when depressed.
7) Operates on two standard "D" cell batteries or rechargeable
cells.
8) Weight of 3.0 pounds, less detector and batteries.
3. LUDLUM MODEL 3-6
a. The Model 3-6 is an analog survey instrument
b. Electronic circuitry has potential for use of proportional,
scintillation, and GM detectors.
c. Operating ranges of 0-500, 0-5,000, 0-50,000, and 0-500,000 cpm.
d. Fast-Slow toggle switch provides for meter response time
selection.
Section 122
1) Fast - response time of 5 seconds for 90% of the final reading.
2) Slow- response time of 25 seconds for 90% of the final
reading.
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e. Operation
1) Meter face readout of 0-5,000.
2) Range multiplier selector switch is a six-position switch.
a) OFF
b) BAT
c) x 100
d) x 10
e) x 1
f) x 0.1
3) Audio on-off switch for operation of count rate speaker.
4) Fast-Slow toggle switch to establish response time of
5 seconds (fast) or 25 seconds (slow).
5) RES button provides a rapid means to reset the meter to zero.
6) Operates on two standard "D" cell batteries or rechargeable
cells.
7) Weight of 3.5 pounds, less detector.
4. Ludlum Model 177-2 Count Rate Meter
a. Placed at specific locations for personnel contamination
monitoring
b. Electronic circuitry has potential for use of scintillation, and GM
detectors.
c. Available in conjunction with alpha, beta-gamma, and alpha-
beta-gamma detection probes.
d. Operating ranges of 0-500, 0-5,000, 0-50,000, and 0-500,000 cpm.
e. Fast-Slow toggle switch provides for meter response time
selection.
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1) Slow - response time of 22 seconds for 90% of final reading.
2) Fast - response time of 2.2 seconds for 90% of final reading.
f. Operation
1) Meter face readout of 0-500.
2) Range multiplier selector switch is a six-position switch.
a) OFF
b) x 1
c) x 10
d) x 100
e) x 1,000
3) Audible click per radiation incident volume control
adjustment.
4) Operates on 115 V AC only and does not contain battery
pack.
5) RES Button provide a rapid means to reset the meter to zero.
6) Alarm Set Selector Switch is 11 position switch used to select
a predetermined alarm threshold (0.5 to 500) at 100 cpm over
background. Audible alarm setting of 1,000 Hz preset.
7) Weight of 4.2 pounds, less detector.
E. Personnel Contamination Monitor PCM-1B
1. Eberline Personnel Contamination Monitor, Model PCM-1B is a
microprocessor-based radiation detection system.
2. Performs quick indication of beta-gamma contamination, with option
of alpha capabilities.
a. PCM-1B has fifteen (15) independent gas-flow proportional
detectors.
Objective 2.17.04
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b. Control processing unit (CPU) includes an Intel 8085
microprocessor, memory, and input-output lines.
c. Performs two-part personnel whole body survey by performing a
right side then left side personnel body survey.
3. Operation mode
a. Monitor measure and stores background values for all detectors.
1) Checks for high background alarm levels.
2) Checks for low or high count failures.
3) Checks for low gas pressure conditions.
b. Ultrasonic motion sensor detects movement of person toward
monitor.
1) Background check is suspended.
2) Display reads - "STEP UP - INSERT RIGHT ARM"Red
LED flashing light while counting.
c. Placement of arm in arm cavity initiates personnel monitoring
routine.
1) Display reads - "COUNTING RIGHT SIDE"
2) Counting continues for duration of specific counting time.
a) If no alarm levels detected, unit beeps and displays
clearance.
b) Display reads - "RIGHT SIDE OK -- INSERT LEFT
ARM"
d. Placement of left arm in cavity initiates monitoring.
1) Display reads - "COUNTING LEFT SIDE"
Section 123
2) Counting continues for duration of specific counting time.
a) If no alarm levels detected, unit beeps and displays
clearance.
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b) Display reads - "COUNT COMPLETE, YOU MAY
PASS"
c) Display accompanied by chime and the LED extinguishes.
4. Alarm modes
a. Premature arm withdrawal.
Arm withdrawn prior to preset count time completion.
1) Alarm alert sounds.
2) Display read -"COUNT INCOMPLETE **RECOUNT**"
3) Reinsertion of arm restarts count.
b. Contamination detection
Activity in excess of alarm levels detected in either right or left
side count.
1) Alarm alert sounds at end of count time.
2) Appropriate display appears - "ALARM: ZONE 1 - ZONE 2
- ZONE 3," etc.
3) Alarm and display continue for specified alarm hold time.
4) Alarm stops and display read - "CONTAMINATED --
PLEASE STEP OUT."
5. Trouble Shooting
a. PCM-1B message display will illuminate the trouble or
diagnostic lights to identify various monitor malfunctions.
Description of basic malfunction conditions listed below.
b. High background - Background count rate in any zone(s) has
increased above selected limit.
1) Alarm light, high background light, Sonalert, and "Channel
Designation (i.e. 'Zone 1'): High Background" message are
activated.
Explain dead zones
and sum zone
readouts that may
identify these.
Sonalert - audible
alarm.
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2) Area should be checked for radioactive sources and/or
detector checked for dirt, moisture or radioactive
contamination.
c. High count fail –
1) Alarm light, trouble light, Sonalert, and channel designation
message are activated.
2) Count capacity in any zone has been exceeded and PM Group
to be contacted for troubleshooting.
d. Low count fail or low sensitivity fail
1) Alarm light, trouble light, Sonalert, and channel designation
message are activated.
2) May be result of component failure or decrease/loss of
decrease/loss of counting gas. Detector identified should be
checked for leak in mylar.
3) Leak in mylar can be sealed with scotch tape.
e. Contaminated detector -
1) Contaminated detector light is activated along with
contaminated detector message. Operation will continue with
detector light on.
2) Detector to be checked for contamination and decon around
detector performed with masslin cloth. Detector area can be
vacuumed.
f. Loss of gas pressure -
1) Two cylinders used but cylinder No. 1 used until empty.
When empty, "Bottle No. 1 Empty" light activated and No. 2
put in use automatically.
2) If both cylinders fail (empty) the trouble light, "Bottle No. 2
Empty," and display with indicate "Failure**Out of Gas"
message will be activated. Total loss of gas, PCM should be
turned off and upon gas replacement a 4 hour purge before
re-energizing of unit.
6. PCM-1B must not be used to monitor personnel with any
Detector can be
vacuumed for cleaning.
64k count capacity has
been exceeded, likely
by electronic surge.
Detectors in train need
to be checked.
Note: Monitor should
not be used until
contamination light has
been cleared.
DOE-HDBK-1122-2009
Module 2.17 Contamination Monitoring Instrumentation Instructor’s Guide
2.17-19
trouble light illuminated. Monitor placed in "out of Service" mode
until cause corrected.
F. Eberline PM-6
Section 124
1. Microprocessor-based radiation monitor using gas-flow proportional
detectors for whole body contamination scans.
2. Two basic types of PM-6s are typically used
a. PM-6A
1) Uses eleven gas-flow counters to detect beta-gamma
contamination.
2) Same basic operating characteristics as PCM-1B.
3) Source checked daily using beta-gamma source.
b. PM-6A-2
1) Uses fifteen gas-flow counters to detect alpha or beta-gamma
contamination.
2) Four additional detectors used in hand pods to increase ability
to detect hand contamination.
3) Hand and foot detectors sensitive to alpha as well as beta-
gamma contamination.
4) Source checked daily using alpha and beta-gamma sources for
both hand and foot detectors. Beta-gamma source is used on
body detectors.
3. Source checks and troubleshooting PM-6 is same as PCM-1B.
G. Specialty Contamination Monitors - (tool, bag, laundry monitors)
NOTE: Site must add materials based on other contamination monitors
used at the site. Text added must cover, at a minimum, the
material required by the objective.
1. Detector type
2. Detector shielding and window
3. Types of radiation detected/measured
Objective 2.17.05
DOE-HDBK-1122-2009
Module 2.17 Contamination Monitoring Instrumentation Instructor’s Guide
2.17-20
4. Energy response for measured radiation
5. Specific limitations/characteristics
III. SUMMARY
A. Review major topics
1. General discussion/instrument selection
2. Count rate meter probes
3. Count rate meters
4. Personnel contamination monitors
5. Specialty contamination monitors
B. Review learning objectives
IV. EVALUATION:
Evaluation should consist of a written examination comprised of multiple
choice, fill-in the blank, matching and/or short answer questions. 80% should
be the minimum passing criteria for examinations.
DOE-HDBK-1122-2009
Module 2.18 Air Sampling Equipment Instructor’s Guide
2.18-1
Course Title: Radiological Control Technician
Module Title: Air Sampling Equipment
Module Number: 2.18
Objectives:
2.18.01 Identify the factors that affect the operator's selection of a portable air sampler.
→ 2.18.02 Identify the physical and operating characteristics and the limitation(s) of the
Staplex and Radeco portable air samplers.
→ 2.18.03 Identify the physical and operating characteristics and the limitation(s) of Motor
air pumps.
→ 2.18.04 List the steps for a preoperational checkout of a portable air sampler.
→ 2.18.05 Identify the physical and operational characteristics and the limitation(s) of beta-
gamma constant air monitors (CAM's).
→ 2.18.06 Identify the physical and operating characteristics and the limitation(s) of alpha
constant air monitors (CAM's).
References:
1. "Basic Radiation Protection Technology"; Gollnick, Daniel; 5th ed.; Pacific Radiation
Corporation; 2008.
2. Operational Health Physics, Harold J. Moe.
3. ANSI N323A.
4. (Various Manufacturers Technical Manuals).
Instructional Aids:
1. Overheads
2. Overhead projector/screen
3. Chalkboard/whiteboard
4. Lessons learned
DOE-HDBK-1122-2009
Module 2.18 Air Sampling Equipment Instructor’s Guide
2.18-1
I. MODULE INTRODUCTION
A. Self-Introduction
1. Name
2. Phone number
3. Background
4. Emergency procedure review
B. Motivation
Before the proper internal exposure control methods can be determined
for personnel, an estimate of the airborne radioactivity concentration must
be obtained. Airborne radioactivity measurements are necessary to
ensure that the control measures are effective and continue to be effective.
This lesson contains information about widely used air sampling
equipment.
Section 125
C. Overview of Lesson
1. Selection of portable air samplers
2. Physical and operating characteristics and limitations
3. Preoperational checkout of portable air samplers
4. Beta-gamma constant air monitors
D. Introduce objectives
II. MODULE OUTLINE
NOTE: The text is provided for some commonly used instruments. The site
must adjust text as necessary for instruments used at each site. Text
added for specific instruments used at the site must, at a minimum,
cover material required by the objectives.
A. Factors Affecting the Selection of Portable Air Samplers
1. Type of radiation emitted by airborne contaminant in question
2. Physical state of airborne contaminant
3. Type and duration of job being performed
O.H.: Objectives
Objective 2.18.01
Objective 2.18.02
DOE-HDBK-1122-2009
Module 2.18 Air Sampling Equipment Instructor’s Guide
2.18-2
B. Physical and Operating Characteristics and Limitations
1. Staplex
a. Operational characteristics
1) Centrifugal force is the method used to induce air movement
a) Centrifugal force produces kinetic energy
b) Resultant velocity pressure converted to suction for
moving sampled air
2) Self-cooling
a) Inappropriate for long-term continuous sampling
3) Variable orifice flowmeter calibrated 0-70 cfm
a) Flow rate sticker on side is specific for appropriate
collection method
b) Typical flow rate(s): 7-28 cfm
b. Physical characteristics
1) 110-V fan motor with on-off switch
a) Requires external power source
2) 4-inch filter holder assembly with intake screen
a) MSA charcoal adaptor available
3) Portable: 10 pounds
c. Limitations
1) Inappropriate for long-term continuous sampling
2) May create an airborne area due to exhaust
3) Potential "crawler" while in operation due to the high torque
generated by the fan
4) DO NOT use in explosive atmospheres
d. Methods of sampling
DOE-HDBK-1122-2009
Module 2.18 Air Sampling Equipment Instructor’s Guide
2.18-3
1) Filtration
2) Absorption, if charcoal is used
3) Impaction, if impactor head is installed
e. Placement for surveys
1) Avoid creating airborne activity through stirring up dust with
sampler exhaust air
2) Tripods available
3) May be hung on chain for optimum positioning
f. Annular Kinetic Impactor Head
1) Inertial Collector-Head collects large airborne particles such
as plutonium without collecting coexisting particles
containing radon and thoron
2) Principle: Air to be sampled enters annular space at rear,
makes a 180-degree turn at greased planchet, and out the
center tube
3) Operational characteristics
a) Size of particles collected can be varied by adjusting slit
width and air flow velocity
4) Physical characteristics.
a) Head replaces Staplex screened intake orifice
b) Lightly greased planchet placed on head intake
2. Radeco (H809-VI)
a. Operational characteristics
1) Equipped with rotameter air flow indicator
a) Rotameter consists of
(1) A "float" which is free to move up and down
(2) A vertical tapered tube, which is larger at top than
bottom and contains the float
b) Operates using air pressure
Objective 2.18.02
DOE-HDBK-1122-2009
Module 2.18 Air Sampling Equipment Instructor’s Guide
2.18-4
(1) Air flows up the tube
(2) Causes float to rise
(3) Height to which float rises is proportional to air flow
rate
c) Many different types of floats
d) Rotameters are conventionally read at the highest point of
maximum diameter, unless otherwise indicated
Section 126
e) If in doubt about how to read a particular rotameter, check
with supervision or Works Engineering Mechanic
2) Flow rate adjustable from 1 to 8 cfm
3) 110-125 VAC
b. Physical characteristics
1) Equipped with a two-stage turbine blower and one horsepower
self-cooling universal type motor
2) Sample head uses 2 in. or 47 mm particulate and iodine filters
3) Instrument panel
a) Three-position switch - HIGH/OFF/VARIABLE
b) Control knob for FLOW ADJUST
c) Fuse holder
d) Rotameter
4) Weight: 10 lbs
c. Limitations
1) Cannot be used in explosive atmospheres
2) Inappropriate for long-term continuous sampling
DOE-HDBK-1122-2009
Module 2.18 Air Sampling Equipment Instructor’s Guide
2.18-5
d. Methods of sampling employed
1) Filtration
2) Adsorption, if charcoal is used
C. Motor Air Pumps
1. Types of motor air pumps.
a. MotoAir
b. ITT
c. Eberline
2. These units normally used to sample for extended periods of time at
low flow rates
3. Operational characteristics of typical motor air pumps.
a. Flow rate maintained relatively constant by regulator
b. Requires 110 V power supply
4. Physical characteristics of typical motor air pumps
a. Sample heads used designed to accept 2 in. diameter (47 mm)
media for both particulates and iodine
b. Common components
1) Carbon vane pump
2) Constant flow air regulator
3) Flow meter
c. Grounded three wire power cord is provided
5. Typical features - Eberline RAS-1
a. Operational characteristics.
1) Rotameter type flow meter
2) Flow rate range 0.5 to 3.5 cfm
Objective 2.18.03
DOE-HDBK-1122-2009
Module 2.18 Air Sampling Equipment Instructor’s Guide
2.18-6
3) Power requirement 5 amps
b. Physical characteristics
1) "Screw in" type particulate filter holder
2) "Clamshell" type iodine filter holder
3) ON/OFF power switch
4) Weight: 30 pounds
6. Sampling considerations
a. Filter paper must cover intake screen
b. Charcoal cartridge holder must have good seal
c. Check flow rate after turning on and before turning off
7. Reading a rotameter
a. Rotameter consists of
1) A "float" which is free to move up and down
2) A vertical tapered tube, which is larger at top than bottom
and contains the float
b. It operates using air pressure
1) Air flows up the tube
2) Causes float to rise
3) Height to which float rises is proportional to air flow rate
c. Rotameters are conventionally read at the highest point of
maximum diameter, unless otherwise indicated.
D. Preoperational Checkout of Portable Air Samplers
1. Current Calibration Sticker
2. Physical Damage
a. Power cord in good condition
Objective 2.18.04
DOE-HDBK-1122-2009
Module 2.18 Air Sampling Equipment Instructor’s Guide
2.18-7
b. All gaskets in place
c. General physical condition
1) Housing
2) Controls
3. Working Condition
a. Operates properly
1) Sound - no unusual noises
2) Sight - no smoke, no excessive sparking from motor brushes
3) Smell - no burning
4) Feel - no unusual vibration, not overly hot to touch
b. Appropriate air flow
c. Controls on sampler are operable
d. Ensure filters and cartridges are loaded in proper orientation to air
flow prior to sampling
E. Beta-gamma Constant Air Monitors (CAM's)
1. General Characteristics
a. Function
1) Continuously monitor quality of particulate beta-gamma
airborne activity in selected area
b. Physical characteristics
1) GM detector(s) - usually pancake type
a) Some utilize one GM detector to measure activity on
filter
Section 127
b) Other utilize two GM detectors
• One GM detector to measure activity on filter
Objective 2.18.05
DOE-HDBK-1122-2009
Module 2.18 Air Sampling Equipment Instructor’s Guide
2.18-8
• Other GM detector to measures ambient background
for background subtraction
2) Filter paper holder assembly in lead shield
3) Strip chart recorder
4) Mounted on enclosed, portable cart
5) Photohelic air flow meter
6) Alarm lights
a) High Activity alarm
b) Low air flow alarm
c. Limitations of CAM's
1) Low air flow
a) Must be placed near or downwind suspected source
2) Poor response to low energy beta
3) Lead shield ineffective for high gamma energies
a) CAM must be in low background
4) Responds to radon, thoron, and daughters
a) Produces fluctuating background on recorder
5) Not very portable
a) Approximate weight 500 pounds
d. Method of sampling - filtration
e. Operation and use
1) Initial startup
a) Check all switches in off position
• Master switch
DOE-HDBK-1122-2009
Module 2.18 Air Sampling Equipment Instructor’s Guide
2.18-9
• HV switch
b) Plug in power cord (110 V)
• Air blower will start
• Reset any alarms that activate
c) Ensure sufficient filter paper
d) Turn master switch on and allow two minute warmup
e) Turn HV switch on and allow 30 second warmup
f) E & I to adjust the following settings
• HV level
• High and low level alarm settings
• Scale switch overlap setting
g) Set recorder speed selector switch
• 3/4 in. per minute to ascertain chart moves
• 3/4 in. per hour, routine operation
h) CAM operating if slow buildup noted on recorder chart
F. Alpha Constant Air Monitors (CAM'S)
Continuously monitor quality of particulate alpha airborne activity in
selected areas
1. Operating characteristics
a. Air pumping system pulls air through impactor head
b. Count rate meter monitors planchet which will activate high
activity alarm horn and light at preset points
2. Physical characteristics
a. External cabinet features
1) Power Supply
Objective 2.18.06
DOE-HDBK-1122-2009
Module 2.18 Air Sampling Equipment Instructor’s Guide
2.18-10
2) Magnehelic gauge
3) Count rate meter (CRM)
4) Recorder chart
5) Power switches
6) Outlets
7) Photohelic air flow meter
8) Alarm lights
a) Radiation alarm
b) Low flow alarm
b. Internal cabinet features
1) Annular Kinetic Impactor sample head
2) Blower
3) Planchet (greased with ZnS and Silicone)
4) Photomultiplier (PM)
3. Limitation(s)
a. Does not give extremely accurate quantitative alpha measurement
1) Gives warning of increase activity
2) Possible to make estimates
b. Dust buildup and radon-thoron activity affect efficiency
4. Method of sampling - Impaction
5. Operation and Use
a. Initial startup
1) Place new "Alpha Tak" planchet on impactor head
a) Open light tight box door
DOE-HDBK-1122-2009
Module 2.18 Air Sampling Equipment Instructor’s Guide
2.18-11
b) Move PM tube housing from impactor head
c) Remove any used planchet
d) Place new planchet on impactor head
e) Move PM tube housing back into position
f) Close door
g) Indicate action on recorder chart.(date, time, etc.)
h) Take any used planchets to RC office for processing
2) Plug in power cord ensuring all switches are off prior to
plugging power cord in
3) Turn on switches in following order
a) Outlet switch
b) CRM power switch
4) Set CRM to x 1 scale
5) Set alarm to desired level
6) Set CRM PHA/GROSS switch to GROSS
Section 128
7) Notify instrumentation group (e.g., I&C) and/or supervisor of
any malfunctions
III. SUMMARY
A. Review major topics
1. Selection of portable air samplers
2. Physical and operating characteristics and limitations
3. Preoperational checkout of portable air samplers
4. Beta-gamma constant air monitors
B. Review learning objectives
DOE-HDBK-1122-2009
Module 2.18 Air Sampling Equipment Instructor’s Guide
2.18-12
IV. EVALUATION
Evaluation should consist of a written examination comprised of multiple choice,
fill-in the blank, matching and/or short answer questions. 80% should be the
minimum passing criteria for examinations.
DOE-HDBK-1122-2009
Module 2.19 Counting Room Equipment Instructor’s Guide
2.19-1
Course Title: Radiological Control Technician
Module Title: Counting Room Equipment
Module Number: 2.19
Objectives:
→ 2.19.01 Describe the following features and specifications for commonly used
laboratory counter or scalers:
a. Detector type
b. Detector shielding
c. Detector window
d. Types of radiation detected and measured
e. Operator-adjustable controls
f. Source check
g. Procedure for sample counting
→ 2.19.02 Describe the following features and specifications for low-background
automatic counting systems:
a. Detector type
b. Detector shielding
c. Detector window
d. Types of radiation detected and measured
e. Operator-adjustable controls
d. Source check
e. Procedures for sample counting
→ 2.19.03 Describe the following features and specifications for commonly used
gamma/alpha spectroscopy systems used at your facility:
a. Detector type
b. Detector shielding
c. Detector window
d. Types of radiation measured
d. Procedures
References:
1. Radiation Detection and Measurement, Glenn F. Knoll.
2. "Basic Radiation Protection Technology"; Gollnick, Daniel; 5th ed.; Pacific Radiation
Corporation; 2008.
3. Operational Health Physics, Harold J. Moe.
4. ANSI N323A.
5. (Various Manufacturers Technical Manuals).
Instructional Aids:
1. Overheads
2. Overhead projector/screen
3. Chalkboard/whiteboard
4. Lessons learned
DOE-HDBK-1122-2009
Module 2.19 Counting Room Equipment Instructor’s Guide
2.19-2
I. MODULE INTRODUCTION
A. Self-Introduction
1. Name
2. Phone number
3. Background
4. Emergency procedure review
B. Motivation
In this lesson, we will cover counting room equipment in relation to types
used, purpose for, radiation monitored, operational requirements, and
specific limitations and characteristics. The RCT uses information from
these counting instruments to identify and assess the hazards presented
by contamination and airborne radioactivity and establish protective
requirements for work performed in radiological areas.
C. Overview of Lesson
1. General principles
2. Laboratory counters or scalers
3. Low-background automatic systems
4. Gamma Spectroscopy
D. Introduce objectives
II. MODULE OUTLINE
A. Introduction
1. An overview of counters, scalers and associated equipment will
describe the basic functions of counting equipment used to detect
radiation activity.
2. The RCT uses information from these counting instruments to:
a. identify and assess the hazards presented by contamination and
airborne radioactivity and;
O.H.: Objectives
DOE-HDBK-1122-2009
Module 2.19 Counting Room Equipment Instructor’s Guide
2.19-3
b. establish protective requirements for work performed in
radiological areas.
Section 129
3. Stand-alone counters or scalers measure gross activity while
spectroscopy systems perform spectrum analysis to identify and
quantify activity from specific nuclides.
4. The common uses of counting room equipment in various facilities
will be discussed.
5. A variety of counting equipment is used, both manual and automated.
a. Shielded equipment to measure radioactivity just above
background levels.
b. Equipment to measure gross counts of alpha, beta and gamma to
determine if surface contamination limits are met.
c. Equipment to measure the energy spectrum for alpha and gamma
radiation so that individual isotopes can be identified and
quantified (e.g. to determine if an alpha emitter is a plutonium
isotope, a uranium isotope or a radon daughter).
6. The counting systems use various types of detectors, including:
a. gas proportional counters for alpha and beta radiation;
b. sodium iodide, scintillation detectors for gamma spectroscopy;
c. zinc sulfide (ZnS) scintillation detectors for alpha radiation;
d. liquid scintillation for tritium and carbon 14;
e. surface barrier (semiconductor) detectors for alpha spectroscopy,
f. lithium drifted germanium (GeLi semiconductor) detectors for
gamma spectroscopy,
g. high purity, germanium (HPGe semiconductor) detectors for
gamma spectroscopy.
DOE-HDBK-1122-2009
Module 2.19 Counting Room Equipment Instructor’s Guide
2.19-4
7. The most common uses of the equipment are to count:
a. Smears and swipes
b. Air filters
8. Nose swipes are also counted as one way to test if an individual has
been exposed to airborne radioactive contamination.
9. Both workplace and stack emission air filters are counted to measure
the concentration of specific radionuclides (e.g. plutonium, and
uranium) and classes of radionuclides (e.g. mixed fission products).
B. General Principles
A variety of counting room systems are used. The principles of these
systems will be discussed in general and then specific systems will be
described.
1. Detector Type
a. When looking for low levels of radioactivity from alpha emitters
(e.g. U, Pu, etc.) it is important to minimize the background count
rate from betas and gammas.
b. The principle used to accomplish this is pulse height
discrimination.
c. Betas have a range that is about 100 times greater than alphas, so
alphas will deposit about 100 times as much energy in a thin
detector, producing a larger pulse than betas. Therefore alpha
detectors are thin (typically 1 mg/cm2) and use pulse height
discrimination to distinguish alphas from betas.
d. Alpha detectors are generally either gas proportional counters,
ZnS scintillators, or silicon semiconductors.
e. Gamma spectroscopy requires good resolution to distinguish the
different energy peaks. GeLi or HPGe semiconductors give the
best resolution, though NaI scintillators are also used.
2. Detector Shielding
a. To reduce the background, shielding is often used.
DOE-HDBK-1122-2009
Module 2.19 Counting Room Equipment Instructor’s Guide
2.19-5
b. Betas can be shielded with aluminum or plastic.
c. Typical gamma shielding is a few inches of lead.
3. Detector Window
a. Since alphas have a short range the windows are thin, typically 1
mg/cm2 (or 0.25 mil plastic).
b. Some detectors have no window between the sample and the
detector; in this case there is a gas purge system for gas
proportional counters, or a light tight housing for scintillators.
Section 130
c. The alpha range is so short that self-shielding is often significant,
e.g. an alpha emitter buried in a filter may be shielded from the
detector by the fibers.
4. Types of Radiation
a. Some of the detectors discussed in objectives 1 and 2 are
designed for alphas, some for betas, and some will count both.
b. Gamma spectroscopy is discussed in objective 3.
c. Most nuclides emit more than one type of radiation, but beware
of exceptions (like Be-7 or C-14).
d. Beta background is greater than alpha, so alpha detectors use
pulse-height discrimination to differentiate between alphas and
betas.
e. Some gammas will generally be detected in these detectors, but
thin detectors have low gamma efficiency, and lead shielding
helps to reduce the gamma background still further.
5. Operator Adjustable Controls
a. Counting room systems have a timer to allow the operator to
measure the number of counts per minute (cpm).
b. The most common count time is 1 minute, but the count time can
be selected by the operator.
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Module 2.19 Counting Room Equipment Instructor’s Guide
2.19-6
6. Sources
a. National Institute of Standards and Technology (NIST) standard
sources are used to check the systems.
b. Common sources are:
1) Pu-239 for alpha
2) Sr-90 for beta
7. Procedures
a. Procedures generally include:
1) background count
2) source check
3) sample count
4) background subtraction
5) divide by time to get cpm
6) correct for 4 pi efficiency to get dpm
7) record the data
B. Laboratory Counters or Scalers
In this section, specific laboratory counters or scaler systems are
discussed, illustrating the general principles discussed above.
1. Sample Holder SH-4 with HP210 and ESP
a. The simplest system for counting smears is the portable
contamination survey instrument, the Eberline smart portable
ESP with hand probe HP210. ESP means Eberline Smart
Portable. HP means Hand Probe.
b. Recall from lesson 2.17 that the HP-210 probe is a pancake GM
detector with a thin (1.4 to 2 mg/cm2) window, suitable for
detecting beta contamination, and alphas above 3 MeV. Window
is thicker than most alpha detectors, so probe must be < 1/4 inch
from source of alphas.
Objective 2.19.01
DOE-HDBK-1122-2009
Module 2.19 Counting Room Equipment Instructor’s Guide
2.19-7
1) The HP210T is shielded with tungsten to reduce gamma
background.
2) The HP210AL is shielded with aluminum to reduce beta
background.
c. The problem with using the HP210 for quantitative measurements
(e.g. to satisfy release criteria) is one of ensuring a precise
geometry.
d. The SH-4 sample holder solves this problem by holding the
sample in a fixed position directly under the HP210 detector.
2. Eberline Scintillation Alpha Counter SAC-4
a. The Eberline SAC-4 is a scintillation alpha counter. S.A.C. is an
acronym
1) The scintillation phosphor is ZnS powder on a plastic light
pipe.
2) The system is a self contained unit with the detector and
associated electronics housed in a single unshielded box.
3) The detector and sample are both in a light tight can, so no
window is required between the ZnS detector and the sample.
b. The system will accept samples up to 2 inches in diameter by 3/8
inches thick. (Self shielding would be a major problem with
samples this thick.)
1) The sample holder in the slide drawer is adjustable. It can be
moved closer to the detector for thin samples.
Section 131
2) The SAC-4 is calibrated with the sample holder in a certain
position, so if the sample holder is moved, the calibration is
no longer valid.
c. The electronic package consists of the high voltage power supply
used to power the photomultiplier tube and determine its
amplification, and a linear amplifier. Amplifier output is 0 to 10
V
1) Only pulses with amplitudes above the discriminator level
will be counted. Discriminator level is 1.25 V
Shield gammas with
high Z material.
Shield betas with
low Z material.
See lesson 2.03
DOE-HDBK-1122-2009
Module 2.19 Counting Room Equipment Instructor’s Guide
2.19-8
2) This will discriminate against betas because they will
produce smaller pulses.
d. The output from the discriminator is counted by a six decade light
emitting diode (LED) readout.
1) The timing circuit is synchronized to the line frequency (60
Hz) and provides preset counting times from 0.1 to 50
minutes controlled by front panel switches.
2) This scaler can also be operated in a manual mode which will
continue to count until reset by the operator.
e. A Pu-239 source is used to check the system prior to each
operating shift.
1) Background counts are conducted as a part of the
performance check and to check for detector contamination.
2) The detector and sample drawer are easily removed for
decontamination if required.
f. The gross count rate is obtained by dividing total counts by the
time in minutes.
1) Background counts (typically 0.3 cpm) are subtracted from
gross counts to obtain net counts per minute (cpm).
2) The net count rate (cpm) is corrected for efficiency to
convert cpm to disintegrations per minute (dpm).
g. This counting system is used to obtain total activity and the
procedures are followed as described in the SAC-4 manual. Each
background, source count, and sample count is documented and
kept on file.
3. NMC PC-5 and PC-55
a. The PC-5 and PC-55 systems use gas flow proportional counters
as the detectors.
1) The gas used is P-10 (90% argon and 10% methane).
See lesson 2.03
Nuclear Measurement
Corporation
DOE-HDBK-1122-2009
Module 2.19 Counting Room Equipment Instructor’s Guide
2.19-9
2) The systems are self-contained units with the detector and
associated electronics housed in the same box.
3) The PC-55 is used to count both alpha and beta.
4) The PC-5 may be manually adjusted to count either alpha or
beta. It is normally set to count alpha only.
5) The determination of an alpha count or a beta count is
accomplished by pulse height discrimination.
b. No external shielding is used.
1) Typical background for the unshielded detector is 2 cpm for
alphas, and 60 to 100 cpm for betas.
c. The PC-5 and PC-55 have identical detectors, 2.25 inch in
diameter.
1) They may be installed with thin plastic windows with a
thickness of 0.25 mil (0.00025 inch, 1 mg/cm2) or they may
be installed with no window.
2) If there is no window, the operator must purge with P-10 gas
after inserting a sample and closing the gas tight door.
d. Front panel controls allow for pre-set gas purge times of 12, 36
and 144 seconds.
1) If the detector is installed with a thin plastic window, the
normal procedure is to flow the gas continually.
e. The sample to be counted is placed in a 2 inch diameter planchet
and placed in the sample drawer.
1) The sample drawer then slides the sample under the detector.
2) Should the detector drawer or sample holder become
Section 132
contaminated during counting, it is a simple task to remove
the detector and drawer for decontamination.
f. The high voltage supply has a dual operating range of 300 - 1300
volts and 1300 - 2300 volts controlled from a front panel voltage
potentiometer. RCTs do not normally adjust this.
Window is optional
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1) The high voltage determines the optimum setting to
discriminate alphas from betas.
g. The count time is also set by front panel switches providing pre-
set counting times in 0.1 minute increments up to 1000 minutes.
1) In the automatic mode, the counter will count to the pre-set
time interval.
2) In the manual mode, the counter will continue to count until
manually reset.
h. Two sources are used to check the system for proper operation.
1) The alpha source is Pu-239 electroplated on a nickel disc.
2) The beta source is 90Sr/90Y (Strontium-90 and its daughter,
Yttrium-90).
3) These sources are traceable to NIST (National Institute of
Standards and Technology).
C. Low-background Automatic Systems
1. In this section, several automatic counting systems are discussed.
a. The principles are the same as in section 1 (objective 1).
b. The essential differences between the systems in sections 1 and 2
are:
1) Complexity of electronics
2) number of detectors or automated sample changing
3) shielding to reduce background
2. Canberra 2400
a. The Canberra 2400 is a low background automatic counting
system.
1) The primary detector is a gas flow proportional counter with
a 2.25 inch diameter thin window, used
Objective 2.19.02
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to count both alpha and beta activity. Proportional counters
use pulse height discrimination.
2) A second larger proportional counter, the guard detector, is
used to count background.
3) The gas used is P-10 (90% argon and 10% methane).
4) The system may also incorporate a NaI scintillation detector,
an option with the Canberra 2400 systems, to simultaneously
count gamma rays.
b. The sample detectors are surrounded by 4 inches of lead shielding
to reduce background.
1) Typical background is 0.1 to 1 cpm alpha, 1 to 5 cpm beta, and
100 to 400 cpm gamma.
c. Canberra 2400 systems are used principally to count smears and
filters.
1) Gross counts for each sample are processed in the computer
and converted to dpm.
2) Smear counts above preset limits are highlighted and printed
on a separate report.
d. Performance checks are performed daily or prior to system use.
NIST traceable sources of:
1) Pu-239 (Plutonium),
2) Sr-90 (Strontium), and
3) Tc-99 (Technetium) are used.
e. The system has an automatic sample changer with a dual stack
that can handle up to 100 samples.
1) One stack holds the samples to be counted and the other stack
stores the samples that have been counted.
3. Berthold LB770
a. The Berthold LB770 counting system is a low background semi-
automatic counting system.
1) The system uses eleven P-10 gas flow proportional detectors;
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2) ten detectors are used to count 10 radioactive samples
simultaneously,
3) the other detector is used to count background radiation.
b. Each detector has a 2.25 inch diameter by 0.25 mil (0.00025 inch)
mylar window.
1) The detector bay is shielded with 4 inches of epoxy coated
Section 133
lead.
2) Typical backgrounds are 0.1 cpm alpha and 1 or 2 cpm beta.
3) Typical counting efficiencies are 27% alpha and 42% beta.
4) The planchet is 0.25 inch deep, but a 0.25 inch thick sample
would cause major self-shielding problems. Self shielding:
see lesson 2.03.
c. The Berthold systems are used primarily to count smears or filters.
1) Both alphas and betas are counted simultaneously in each
detector.
2) Determination of alpha or beta activity is accomplished by
pulse height discrimination.
3) The scalers in the Berthold systems are similar to those used
in the PC-55 but with more sophisticated electronics that
provide improved pulse shaping from the linear amplifier and
better discrimination of both pulse amplitude and pulse shape.
d. Plutonium-239 sources are used to check the system for alpha and
90Sr/90Y sources are used to check for beta. Yttrium-90 is the
daughter of Strontium-90.
1) These sources are traceable to NIST
e. The Berthold system is controlled by a computer.
1) Both alpha and beta counts received from each sample are
corrected for background and reported in one of three
categories, to alert the operator.
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2) If the count rate is below the minimum detectable activity
(MDA, see lesson 2.03) it falls into category 1.
3) A count rate that falls within predetermined limits, usually
above MDA but below the limit for release to a controlled
area (RadCon table 2.2) is category 2. MDA stands for
Minimum Detectable Activity, see lesson 2.03.
4) A count rate that is higher than the upper limit is category 3.
f. Background and efficiency data are collected for each detector,
stored and used for corrections.
1) Pre-set count times are determined by the operator and put
into the computer.
2) The count rate data from each detector is corrected and
converted to dpm for output to the printer.
4. Liquid Scintillation Counters, LSC
a. Tritium and C-14 emit such low energy betas that even a thin
layer of air would stop the betas.
1) To detect this radiation, the sample must be in intimate
contact with the detection medium.
2) This is achieved with a liquid scintillation system.
b. A liquid scintillation counting system uses a "cocktail" that
immerses the sample in the counting medium to maximize the
detection efficiency for low energy beta emitters.
1) This cocktail includes a liquid scintillator to convert the
energy deposited by low energy betas into light photons,
which are then counted using photomultipliers.
c. The sample chamber, containing the sample vial and
photomultiplier tubes, is light tight.
1) Since stray electrons can be spontaneously emitted from the
photocathode, or by the dynodes in the photomultiplier tube,
two tubes are used with
e.g. Packard 2550
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coincidence circuitry to reduce this source of noise called
"dark current".
2) Typical background for beta is 20 cpm.
d. The LSC system is typically used to count tritium samples from
swipes, water samples, and oil samples (vacuum pumps).
1) Tritium is also collected by drawing air samples through
silica-gel traps or glycol bubblers.
e. To calibrate the system, a series of cocktails with known amounts
of tritium are prepared.
1) These sources are loaded into the first sample holder (a tray
of 10 sample vials).
Section 134
2) The computer program calculates the detector efficiency for
each calibration source.
D. Gamma Spectroscopy
1. The instruments discussed in objectives 1 and 2 are designed to detect
alphas and/or betas, and make a gross count of total alpha and beta
activity.
a. In order to identify specific radionuclides, the unique spectrum of
energies particular to each radionuclide is used.
b. This technique is known as spectroscopy.
2. Alpha emitters (e.g. Th, U, Pu, Am and their daughters) have
characteristic alpha energies, but alpha spectroscopy, detecting the
alphas directly, is not optimal, because the energy loss of alpha
particles between the sample and the detector smears the energy
spectrum.
3. Gamma spectroscopy usually uses germanium detectors (GeLi or
HPGe) because the good resolution obtained with these detectors
enables gammas with nearly the same energy to be distinguished or
resolved.
4. EG&G Ortec Gamma X
a. The Gamma X Spectroscopy system uses an HPGe coaxial
photon detector to perform gamma and x-ray spectroscopy in the
energy range from 3 keV to 10 MeV.
Objective 2.19.03
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b. Detector Type
1) The detector is made of n-type high purity germanium
semiconductor (HPGe).
2) A 30 liter dewar of liquid nitrogen is used to cool the detector.
c. Detector Shielding
1) The detector is shielded by 4 inches of pre World War II steel.
2) This steel is used when a low background is desired as it was
manufactured before radioactive fallout from nuclear
weapons appeared in trace quantities.
3) A sample holder inside the shield allows the sample to be
positioned at distances from less than 1 cm up to 40 cm from
the detector end cap. Artificial radioactivity is discussed in
Lesson 1.06.
d. Detector Window
1) The detector window is 0.5 mm thick beryllium.
e. Types of Radiation Measured
1) The gamma spectrometer is designed to detect gammas and
x-rays from alpha emitting nuclides, and sort the data in a
multi channel analyzer to produce a spectrum that is
characteristic of the nuclide.
2) The peaks in the spectrum are close together, so excellent
resolution is required to distinguish the peaks.
3) Typical resolution from a germanium semiconductor detector
(HPGe or GeLi) is better than 1%, which means that if the
photon energy is 100 keV, the width of the peak is less than 1
keV.
4) Photons from two different nuclides that are 1 keV apart will
be seen as two distinct peaks.
f. Procedures
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1) Energy and efficiency calibrations are obtained using two
different sources that are NIST standards.
2) These are mixed sources that contain several gamma emitting
nuclides.
3) One source contains isotopes of Americium (Am), Antimony
(Sb), and Europium (Eu).
4) The second mixed source contains isotopes of Cadmium (Cd),
Cerium (Ce), Cobalt (Co), Strontium (Sr), Tin (Sn), Cesium
(Cs), and Yttrium (Y). These sources provide several
calibration energies.
5) The energy and efficiency calibration values are then used by
the analysis software.
6) Specific procedures are written to direct the operator through
the sample and computer setup, and the computer analysis.
7) The original copy of the results is kept on file for 1 year and
then archived for 75 years.
III. SUMMARY
A. Review major points
1. General principles
2. Laboratory counters or scalers
3. Low-background automatic systems
4. Gamma Spectroscopy
B. Review learning objectives
IV. EVALUATION
Evaluation should consist of a written examination comprised of multiple
choice, fill-in the blank, matching and/or short answer questions. 80% should
be the minimum passing criteria for examinations.