DOE-HDBK-1122-2009 Chg Notice 2, Radiological Control Technician Training (Part 4 of 9)
Functional areas: Radiation, Radiological Control Technician, Training
This Handbook describes an implementation process for core training as recommended in chapter 14 to Implementation Guide G441.1-1C , Radiation Protection Programs for Use with Title 10, Code of Federal Regulations, Part 835, Occupational Radiation Protection, and as outlined in the DOE standard, Radiological Control (RCS). The Handbook is meant to assist those individuals within the Department of Energy, Managing and Operating contractors, and Managing and Integrating contractors identified as having responsibility for implementing core training recommended by the RCS
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- DOE-HDBK-1122-2009 Chg Notice 2Radiological Control Technician Training (Part 1 of 9, links to all Parts)
- DOE-HDBK-1122-2009 Chg Notice 2Radiological Control Technician Training (Part 2 of 9)
- DOE-HDBK-1122-2009 Chg Notice 2Radiological Control Technician Training (Part 3 of 9)
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Section 1
DOE-HDBK-1122-2009
Module 1.01 Basic Mathematics and Algebra Study Guide
Part 4 of 9
Radiological Control Technician Training
Fundamental Academic Training Study Guide Phase I
Coordinated and Conducted
for the
Office of Health, Safety and Security
U.S. Department of Energy
DOE-HDBK-1122-2009
Module 1.01 Basic Mathematics and Algebra Study Guide
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Module 1.01 Basic Mathematics and Algebra Study Guide
Table of Contents
Page
Module 1.01 Basic Mathematics and Algebra........................................................................1.01-1
Module 1.02 Unit Analysis and Conversion
Module 1.06 Radioactivity and Radioactive Decay .................................................................... 1.06-1
...........................................................................1.02-1
Module 1.03 Physical Sciences...............................................................................................1.03-1
Module 1.04 Nuclear Physics .................................................................................................1.04-1
Module 1.05 Sources of Radiation..........................................................................................1.05-1
Module 1.07 Interaction of Radiation with Matter .................................................................1.07-1
Module 1.08 Biological Effects of Radiation .........................................................................1.08-1
Module 1.09 Radiological Protection Standards ....................................................................1.09-1
Module 1.10 ALARA .............................................................................................................1.10-1
Module 1.11 External Exposure Control ................................................................................1.11-1
Module 1.12 Internal Exposure Control .................................................................................1.12-1
Module 1.13 Radiation Detector Theory ................................................................................1.13-1
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Module 1.01 Basic Mathematics and Algebra Study Guide
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DOE-HDBK-1122-2009
Module 1.01 Basic Mathematics and Algebra Study Guide
Course Title: Radiological Control Technician
Module Title: Basic Mathematics and Algebra
Module Number: 1.01
Objectives:
1.01.01 Add, subtract, multiply, and divide fractions.
1.01.02 Add, subtract, multiply, and divide decimals.
1.01.03 Convert fractions to decimals and decimals to fractions.
1.01.04 Convert percent to decimal and decimal to percent.
1.01.05 Add, subtract, multiply, and divide signed numbers.
1.01.06 Add, subtract, multiply, and divide numbers with exponents.
1.01.07 Find the square roots of numbers.
1.01.08 Convert between numbers expressed in standard form and in scientific notation.
1.01.09 Add, subtract, multiply, and divide numbers expressed in scientific notation.
1.01.10 Solve equations using the "Order of Mathematical Operations."
1.01.11 Perform algebraic functions.
1.01.12 Solve equations using common and/or natural logarithms.
Introduction
Radiological control operations frequently require the RCT to use arithmetic and algebra to
perform various calculations. These include scientific notation, unit analysis and conversion,
radioactive decay calculations, dose rate/distance calculations, shielding calculations, stay-
time calculations. A good foundation in mathematics and algebra is important to ensure that
the data obtained from calculations is accurate. Accurate data is crucial to the assignment of
proper radiological controls.
Section 2
References:
1. DOE-HDBK-1014/1-92 (June 1992) "Mathematics: Volume 1 of 2"; DOE Fundamentals
Handbook Series.
1.01-1
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Module 1.01 Basic Mathematics and Algebra Study Guide
SYMBOLS FOR BASIC OPERATIONS
The four basic mathematical operations are addition, subtraction, multiplication, and division.
Furthermore, it is often necessary to group numbers or operations using parentheses or brackets.
In writing problems in this course the following notation is used to denote the operation to be
performed on the numbers. If a and b represent numbers or variables, the operations will be
denoted as follows:
Table 1. Symbols for Basic Mathematical Operations
Operation Notation
Addition:
Subtraction
Multiplication
Division:
a + b
a - b
a × b
a ÷ b
a · b
a/b
a(b)
b
a
ab
ab
Grouping:
Equality:
Inequality:
Less than:
Greater than:
( ) [ ]
=
≠
< Less than or equal to:
> Greater than or equal to:
1.01.01 Add, subtract, multiply, and divide fractions.
FRACTIONS
Whole numbers consist of the normal counting numbers and zero, e.g.,
{0, 1, 2, 3, 4...}
A fraction is part of a whole number. It is simply an expression of a division of two whole
numbers. A fraction is written in the format:
a or a/b
b
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Module 1.01 Basic Mathematics and Algebra Study Guide
The number above the bar a is called the numerator and the number below the bar b is called the
denominator. A proper fraction is a fraction in which the number in the numerator is less than
the number in the denominator. If the numerator is greater than the denominator then it is an
7 25 15 61improper fraction. For example, ½ and ¼ are proper fractions, while , , , or or are
5 5 7 27
improper fractions.
Any whole number can be written as a fraction by letting the whole number be the numerator
and 1 be the denominator. For example:
5 2 05 = 2 = 0 =
1 1 1
Five can be written as 10/2, 15/3, 20/4, etc. Similarly, the fraction ¼ can be written as 2/8, 3/12,
4/16, etc. These are called equivalent fractions. An equivalent fraction is built up, per se, by
multiplying the numerator and the denominator by the same non-zero number. For example:
3 3 ⋅ 2 6 3 3 ⋅ 5 15
= = = =
4 4 ⋅ 2 8 4 4 ⋅ 5 20
A fraction is reduced by dividing the numerator and the denominator by the same nonzero
number. For example:
12 12 ÷ 2 6 6 6 ÷ 3 2
= = = =
18 18 ÷ 2 9 9 9 ÷ 3 3
A fraction is reduced to lowest terms when 1 is the only number that divides both numerator and
denominator evenly. This is done by finding the greatest common multiple between the
numerator and denominator. In the previous example, two successive reductions were performed.
For the fraction 12/18, the greatest common multiple would be 6, or (2 × 3), which results in a
reduction down to a denominator of 3.
A whole number written with a fraction is called a mixed number. Examples of mixed numbers
would be 1½, 3¼, 5¾, etc. A mixed number can be simplified to a single improper fraction using
the following steps:
1. Multiply the whole number by the denominator of the fraction.
2. Add the numerator of the fraction to the product in step 1.
3. Place the sum in step 2 as the numerator over the denominator.
1.01-3
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Module 1.01 Basic Mathematics and Algebra Study Guide
For example:
3 (5 ⋅ 4) + 3 235 = =
4 4 4
Adding and Subtracting Fractions
Fractions With the Same Denominator
To add two fractions which have the same denominator:
Section 3
1. Add the numerators.
2. Place the sum of step 1 over the common denominator.
3. Reduce fraction in step 2 to lowest terms (if necessary).
For example:
1 3 1 + 3 4
+ = =
5 5 5 5
Subtraction of two fractions with the same denominator is accomplished in the same
manner as addition. For example,
5 3 5 − 3 2 2 ÷ 2 1
− = = = =
8 8 8 8 8 ÷ 2 4
Fractions With Different Denominators
To add two fractions with different denominators requires that the fractions be built up so
that they have the same denominator. This is done by finding the lowest common
denominator. Once a common denominator is obtained, the rules given above for the
same denominator apply.
For example, 1/3 + 2/5. The fraction 1/3 could be built up to 2/6, 3/9, 4/12, 5/15, 6/18,
7/21, etc. The fraction 2/5 could be built up to 4/10, 6/15, 8/20, 10/25, etc. The lowest
common denominator for the two fractions would be 15. The problem would be solved as
follows:
1 2 1 ⋅ 5 2 ⋅ 3 5 6 5 + 6 11
+ = + = + = =
3 5 3 ⋅ 5 5 ⋅ 3 15 15 15 15
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Module 1.01 Basic Mathematics and Algebra Study Guide
Subtraction of fractions with different denominators is accomplished using the same steps
as for addition. For example:
3 2 3 ⋅ 3 2 ⋅ 4 9 8 9 − 8 1
− = − = − = =
4 3 4 ⋅ 3 3 ⋅ 4 12 12 12 12
Multiplying and Dividing Fractions
Multiplication of fractions is much easier than addition and subtraction, especially if the
numbers in the numerators and denominators are small. Fractions with larger numerators
and/or denominators may require additional steps. In either case, the product of the
multiplication will most likely need to be reduced in order to arrive at the final answer.
To multiply fractions:
1. Multiply the numerators.
2. Multiply the denominators.
3. Place product in step 1 over product in step 2.
4. Reduce fraction to lowest terms.
For example:
5 3 5 ⋅ 3 15 15 ÷ 3 5
⋅ = = = =
6 4 6 ⋅ 4 24 24 ÷ 3 8
A variation on the order of the steps to multiply fractions is to factor the numerators and
denominators first, reduce and cancel, and then multiply. For example:
3 20 3 2 ⋅ 2 ⋅ 5 3/ ⋅ 2/ ⋅ 2/ ⋅ 5 5 5
⋅ = ⋅ = = =
8 9 2 ⋅ 2 ⋅ 2 3 ⋅ 3 2 ⋅ 2/ ⋅ 2/ ⋅ 3/ ⋅ 3 2 ⋅ 3 6
Reciprocals
Two numbers whose product is 1 are called reciprocals, or multiplicative inverses. For
example:
a. 5 and 1 are reciprocals because 5 · 1 = 1.
5 5
4 5b. 4 and 5 are reciprocals because ⋅ = 1
5 4 5 4
c. 1 is its own reciprocal because 1 · 1 = 1.
d. 0 has no reciprocal because 0 times any number is 0 not 1.
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Module 1.01 Basic Mathematics and Algebra Study Guide
The symbol for the reciprocal, or multiplicative inverse, of a non-zero real number a is 1 .
a
Every real number except 0 has a reciprocal. Therefore, for every non-zero real number a,
there is a unique real number 1 such that:
a
1 a ⋅ = 1
a
Now, look at the following product:
⎛ 1 1 ⎞ ⎛ 1 ⎞⎛ 1 ⎞⎛ 1 ⎞( ) ⋅ = ⎜a ⋅ ⎜b b = 1 ⋅1 = 1ab ⎜ ⎟ ⎟ ⋅ ⎟⎜ ⋅ ⎟
⎝ a b ⎠ ⎝ a ⎠⎝ a ⎠⎝ b ⎠
Relationship of multiplication to division
The operation of division is really just inverted multiplication (reciprocals). Notice from
the above examples that the reciprocal of a fraction is merely "switching" the numerator
1and denominator. The number 5 is really 5 , and the reciprocal of 5 is .
1 5
3Likewise, the reciprocal of 2 is .
3 2
Fractions are a division by definition. Division of fractions is accomplished in two steps:
1. Invert the second fraction, i.e., change it to its reciprocal, and change the division to
multiplication.
Section 4
2. Multiply the two fractions using the steps stated above.
For example:
4 2 4 3 12 12 ÷ 2 6
÷ = ⋅ = = =
7 3 7 2 14 14 ÷ 2 7
1 2 2 3
= 1 ÷ = 1 ⋅ =
2 3 3 23
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Module 1.01 Basic Mathematics and Algebra Study Guide
Practice Problems
Solve the following problems involving fractions. Answers should be reduced to lowest
terms.
1. 1/3 + 2/3
2. 5/7 - 3/7
3. 5/9 + 2/3
4. 6/7 - 1/2
5. 2 - 1/3
6. 3/8 + 15/16
7. 25/32 - 3/4
8. 15/21 - 4/7
9. 13/20 - 2/5
10. 7/18 + 5/9
11. 2/3 × 1/5
12. 4/7 × 3/4
13. 1/2 × 2
14. 3/5 × 4
15. 4/9 ÷ 2/3
16. 8/13 × 2/3
17. 12/15 × 3/5
18. 20/25 ÷ 4/5
19. 7/8 × 2/5
20. 14/21 ÷ 2/7
1.01.02 Add, subtract, multiply and divide decimals.
DECIMALS
A decimal is another way of expressing a fraction or mixed number. It is simply the numerical
result of divison (and fractions are division). Recall that our number system is based on 10
("deci" in "decimal" means ten) and is a place-value system; that is, each digit {i.e., 0, 1, 2, 3, 4,
5, 6, 7, 8, 9} in a numeral has a particular value determined by its location or place in the
number. For a number in decimal notation, the numerals to the left of the decimal point
comprise the whole number, and the numerals to the right are the decimal fraction, (with the
denominator being a power of ten).
Figure 1. Decimal Place Value System
1.01-7
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Module 1.01 Basic Mathematics and Algebra Study Guide
For example, the numeral 125.378 (decimal notation) represents the expanded numeral
3 7 8100 + 20 + 5 + + +
10 100 1000
If this numeral were written as a mixed number, we would write it as:
378125
1000
Addition and Subtraction of Decimals
In order to add or subtract decimals use the following steps:
1. Arrange the numbers in a column so that the decimal points are aligned.
2. Add or subtract in columns from right to left. Additional zeros may need to be
added to the right of the subtrahend (a number that is to be subtracted from a
minuend).
3. Place the decimal point in the answer in line with the other decimal points.
For example:
21.3 654.200
+ 4.2 - 26.888
25.5 627.312
Multiplying Decimals
To multiply decimal numbers, do the following:
1. Multiply the numbers as if there were no decimal points.
2. Count the number of decimal places in each number and add them together.
3. Place the decimal point in the product so that it has the same number of decimal
places as the sum in step 2.
For example:
5.28 0.04
¯ 3.7 ¯ 0.957
3696 028
1584 020
19.536 036
000
0.03828
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Module 1.01 Basic Mathematics and Algebra Study Guide
Division of Decimals
The steps for division of decimals are as follows:
1. Move the decimal point of the divisor (the number by which a dividend is divided) to
the right until it becomes a whole number.
2. Move the decimal point of the dividend to the right the same number of places moved
in step 1.
3. Divide the numbers as if they were whole numbers.
For example: 7 ÷ 0.25
28
0.25 7.00
50
200
200
0
Decimal Forms
As we have learned, decimals are the result of division (or a fraction). When the
remainder of the division is zero, the resulting decimal is called a terminating or finite
decimal. For example, fractions like 2/5, 3/8, and 5/6 will all result in finite decimals.
These fractions and the resulting decimals are known as rational numbers.
Section 5
On the other hand, fractions like 1/3, 2/7, 5/11, and 7/13 result in a non-terminating or
infinite decimal. For example, 2/7 results in the decimal 0.285714286 . . . , the dots
meaning that the decimal continues without end. These numbers are known as irrational
numbers. Note that even though irrational numbers are non-terminating, (e.g., 1/3 and
5/11) are repeating or periodic decimals because the same digit or block of digits repeats
unendingly. For example:
1 5
= 0.3333... = 0.454545...
3 11
A bar is often used to indicate the block of digits that repeat, as shown below:
51 = 0.45= 0.3
3 11
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Module 1.01 Basic Mathematics and Algebra Study Guide
Practice Problems
Solve the following problems involving decimals.
1. 0.23 + 3.4 6. 2.3 × 3.2
2. 5.75 - 2.05 7. 0.007 × 2.18
3. 6.1 - 1.6 8. 5.2 ÷ 1.4
4. 0.018 + 0.045 9. 12.26 ÷ 0.04
5. 468.75 - 192.5 10. 4.0 × 0.25
1.01.03 Convert fractions to decimals and decimals to fractions.
FRACTION TO DECIMAL CONVERSION
To convert a fraction to a decimal we simply perform the operation of division that the
fraction represents. For example, the fraction 3/4 represents "3 divided by 4," and would
be converted as follows:
0 . 75
00.34
2 . 8
20
20
0
Practice Problems
Convert the following fractions to decimals.
1. 1/2 4. 12/25
2. 2/5 5. 13/39
3. 5/8 6. 7/16
Convert the following decimals to fractions. Reduce answers to lowest terms.
7. 0.125 9. 4.25
8. 0.6666 10. 0.2
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1.01.04 Convert percent to decimal and decimal to percent.
PERCENT
Percentage is a familiar and widely used concept for expressing common and decimal fractions.
Most people know the meaning of terms such as 100 percent and 50 percent. The word percent
actually means "out of a hundred." (Consider that there are 100 "cents" in a dollar, and that a
"century" is 100 years.) A percent is simply a fraction whose denominator is 100. Thus, 50
percent means 50/100, or 0.50, while 25 percent means 25/100, or 0.25.
Percent is abbreviated by the symbol %. So, 75 percent is written 75%.
Converting Decimal to Percent
A decimal fraction is changed to a percent by moving the decimal point two places to the
right and adding a percent sign. For example, 1/8 equals 0.125. Therefore:
1
= 0.125 = 12.5%
8 rr
A percent is changed to a common fraction by omitting the percent sign, placing the number
over 100, and reducing the resulting fraction if possible. For example, 32% equals 32/100
which reduces to 8/25. When the percent consists of a mixed decimal number with a percent
sign, the resulting fraction will contain a mixed decimal numerator. This can be changed to a
whole number by multiplying the numerator and the denominator by 10, 100, 1,000, etc. For
example:
40.25 40.25×100 4025 80540.25% = = = =
100 100×100 10,000 2000
Percentage is most frequently used to indicate a fractional part. Thus 20% of the total power
output for 75% of the employees refer to fractional parts of some total number.
To perform arithmetic operations with a percent, it is normally changed to a common or
decimal fraction. Usually, a decimal fraction is more convenient.
1.01-11
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Module 1.01 Basic Mathematics and Algebra Study Guide
Converting Percent to Decimal
A percent is changed to a decimal fraction by omitting the percent sign and moving the
decimal point two places to the left. For example:
48% = 0.48
Section 6
Thus, 92% equals 0.92, 8% equals 0.08, and so on.
Practice Problems
Convert the following decimals to percent.
1. 0.5 4. 0.06
2. 0.782 5. 0.049
3. 1.1 6. 0.0055
Convert the following percentages to decimals.
7. 65% 9. 300%
8. 0.25% 10. 0.09%
1.01.05 Add, subtract, multiply and divide signed numbers.
SIGNED NUMBERS
The numbers that are used to quantify the number of objects in a group, the "counting numbers",
are always positive numbers; that is, they are always greater than zero. However, there are many
occasions when negative numbers (numbers less than zero) must be used. These numbers arise
when we try to describe measurement in a direction opposite to the positive numbers. For
example, if we assign a value of +3 to a point which is 3 feet above the ground, what number
should be assigned to a point which is 3 feet below the ground? Perhaps the most familiar
example of the use of negative numbers is the measurement of temperature, where temperatures
below an arbitrary reference level are assigned negative values.
Every number has a sign associated with it. The plus (+) sign indicates a positive number,
whereas the minus ( - ) sign indicates a negative number. When no sign is given, a plus (+) sign
is implied. The fact that the plus and minus signs are also used for the arithmetic operations of
addition and subtraction should not be a cause for confusion, for we shall see that they have
equivalent meanings.
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Every number has an absolute value, regardless of its sign. The absolute value indicates the
distance from zero, without regard to direction. The number 5 is 5 units from zero, in the positive
direction. The number -5 is also 5 units from zero, but in the negative direction. The absolute
value of each of these numbers is 5. The absolute value of a number is indicated by a pair of
vertical lines enclosing the number: |5|.
Operations with Signed Numbers
The arithmetic operations of addition, subtraction, multiplication, and division of signed
numbers can be more easily visualized if the numbers are placed on a number line (see
Figure 2). The positive numbers are greater than zero, and they lie to the right of zero on the
number line. The negative numbers are less than zero, and lie to the left of zero on the
number line.
FIGURE 2. Number Line
The number line extends an infinite distance in each direction and therefore includes all
numbers. The process of addition can be considered as counting in one direction or the other
from a starting point on the number line. For example, let us add 1 + 2. We locate +1 on the
number line and then count 2 units to the right, since we are adding +2. The result will be +3.
To illustrate further, let us add +2 and -4. We first locate +2 on the number line and then
count 4 units to the left. We end up at -2.
The number line is useful for illustrating the principles of addition, but it clearly would be
inconvenient to use in the case of large numbers. Consequently, the following rules were
developed to govern the addition process:
Adding and Subtracting Signed Numbers.
To add two numbers with the same signs, add their absolute values and attach the common
sign. For example:
(-3) + (-2) = -5
To add two numbers with opposite signs, find the difference of their absolute values, then
attach the sign of the original number which had the greater absolute value. For example:
(-2) + 3 = 1
1.01-13
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Section 7
Module 1.01 Basic Mathematics and Algebra Study Guide
Notice that -3 and +3 are the same distance but in opposite directions from 0 on the number
line. What happens when you add two numbers like 3 and -3?
3 + (-3) = 0
-7 + 7 = 0
If the sum of two signed numbers is 0, the numbers are called additive inverses or opposites.
For example:
7 - 3 = 4 is the same as: 7 + (-3) = 4
8 - 2 = 6 is the same as: 8 + (-2) = 6
It can be seen that subtracting a number is equivalent to adding its additive inverse or
opposite.
To subtract a signed number, add its opposite or additive inverse. In other words, change
the subtraction symbol to addition and change the sign of the second signed number. For
example:
5 - (-8) = 5 + (+8) ⇐ add +8 (Answer = 13)
6 - 11 = 6 + ( -11) ⇐ add -11 (Answer = -5)
-4 - ( -7) = -4 + (+7) ⇐ add +7 (Answer = 3)
Multiplying and Dividing Signed Numbers.
The product of two numbers with like signs is a positive number. The product of two
numbers with unlike signs is a negative number. In symbols:
(+) × (+) = (+) (+) × ( - ) = ( - )
( - ) × ( - ) = (+) ( - ) × (+) = ( - )
For example:
(-4) × (-3) = (+12)
(-4) × (+3) = (-12)
The division of numbers with like signs gives a positive quotient. The division of numbers
with unlike signs gives a negative quotient. In symbols:
(+)/(+) = (+) (+)/( - ) = ( - )
( - )/( - ) = (+) ( - )/(+) = ( - )
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Module 1.01 Basic Mathematics and Algebra Study Guide
For example:
(-24)/(-6) = (+4)
(-24)/(+6) = (-4)
Remember that multiplication is really a short form of addition. When we say +4 × ( - 3), we
are adding the number - 3 four times, that is, ( - 3) + ( - 3) + ( - 3) + ( - 3) = - 12. Also, since
division is a short form of subtraction, when we say - 24 ÷ ( - 6), we subtract the number - 6
from the number - 24 four times in order to reach 0, i.e., - 24 - ( - 6) - ( - 6) - ( - 6) - ( - 6) = 0.
Although we could repeat the process for the multiplication and division of any signed
numbers, usage of the two rules will produce equivalent results.
Practice Problems
Solve the following problems involving signed numbers.
1. (- 28) + ( - 51) 9. (- 4)(5)
2. (- 2) + ( - 5) 10. 6/(- 3)
3. 40 + ( - 21) 11. 4 ( - 5)
4. (- 87) + 50 12. (- 6)/(- 3)
5. 48 + ( - 27) 13. (- 6)/3
6. 56 - ( - 5) 14. (- 8)(- 5)
7. 81 - 4 15. (- 7)(6)
8. - 48 - ( - 2)
1.01.06 Add, subtract, multiply, and divide numbers with exponents.
EXPONENTS
An exponent is a small number placed to the right and a little above another number, called the
base; to show how many times the base is to be multiplied by itself. Thus, 34 (read "three to the
fourth power") means 3 used as a factor four times or 3 × 3 × 3 × 3. In this case, 4 is the
exponent, and 3 is the base.
In general, if b is any real number and n is any positive integer, the nth power of b is written bn
(where b is the base and n is the exponent) is read as "b to the nth power." This tells you that b is
used as a factor n times.
Thus, 52 is called "5 raised to the second power" (or 5 "squared"), and 23 is called "2 raised to the
third power" (or 2 "cubed"). When no exponent is shown for a number or no power is indicated,
the exponent or power is understood to be 1. Thus, 7 is the same as 71. Any number raised to the
power of zero equals one; e.g., 70 = 1. Normally, exponents of zero and one are not left as the
final value, but are changed to the simpler form of the base.
1.01-15
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Section 8
Module 1.01 Basic Mathematics and Algebra Study Guide
Exponents can be expressed as integers, as in the examples above, or as fractions or decimals
such as 91/2 or 103.2
. They may also be positive or negative.
Exponents and powers are particularly useful in mathematics not only because they shorten the
writing of mathematical expressions, but also because they simplify many mathematical
operations. However, there are several special rules which govern mathematical operations
involving numbers with exponents.
Addition and Subtraction
The addition or subtraction of numbers with exponents can be performed only if both the
bases and the exponents of the numbers are the same. When the bases of the exponents are
different, the multiplication indicated by the exponent must be performed and the numbers
then added or subtracted. Thus, 25 and 24 cannot be added directly because their exponents
are different. They can be added only by carrying out the indicated multiplication first. Thus,
25 equals 2 × 2 × 2 × 2 × 2 which equals 32, and 24 equals 2 × 2 × 2 × 2 which equals 16.
Therefore, 25 + 24 equals 32 + 16, which equals 48.
When the bases and the exponents are the same, the numbers can be added or subtracted
directly. For example:
35 + 35 = 2(35
) = 2(243) = 486
Multiplication
The multiplication of numbers with exponents of the same base is performed by adding the
exponents. The general form is as follows:
(am )(an ) = a(m+n)
It is important to remember that the bases of the numbers must be the same before they can
be multiplied by adding their exponents. The base of the product is the same as the base of
the two factors. Thus,
32 × 33 = 35 = 243
Division
The division of numbers with exponents of the same base is performed by subtracting the
exponent of the divisor (denominator) from the exponent of the dividend (numerator). The
general form is:
ma (m−n)= a
na
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Again, it is important to remember that the bases of the numbers must be the same before
they can be divided by subtracting their exponents. The base of the quotient is the same as
the base of the number divided. Thus,
52 (5−2) 3= 2 = 2 = 8
22
Division of numbers with exponents can be used to show why any number raised to the
power of zero equals one. We know that any fraction in which the numerator equals the
denominator can be reduced to 1; e.g., 2/2 = 1. Similarly:
32 (3−3) 0= 2 = 2 = 1
32
Exponent Raised to a Power
Raising a number with an exponent to a power is performed by multiplying the exponent by the
power. The general form is:
(am)n = amn
The base of the answer is the same as the base of the number raised to the power. Thus:
(52)3 = 5(2¯3) = 56 = 15,625
Product Raised to a Power
Raising a product of several numbers to a power is performed by raising each number to the
power. The general form is as follows:
n bn (ab)n = a
For example:
[(2)(3)(4)]2 = (22)(32)(42) = (4)(9)(16) = 576
This same result can also be obtained like this:
[(2)(3)(4)]2 = 242 = 576
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Mixed Product and Exponents Raised to a Power
The same rule can be used to raise a product of several numbers with exponents to a
power. The general form looks like this:
(Aa Bb Cc )n = A(a¯n) B(b¯n) C(c¯n)
For example:
[(2)4 (3)3 (4)2
]
2 = (24¯2) (33¯2) (42¯2) = (28) (36) (44) = (256) (729) (256)
Fraction Raised to a Power
Section 9
Raising a fraction to a power is performed by raising both numerator and denominator to the
power. It should be remembered that with a proper fraction (i.e., numerator is less than the
denominator) the resulting number must be less than one. Also, the resulting number will be
less than the value of the original fraction. Thus, (2/3)3 equals 23/33, which equals 8/27,
which is less than one and less than the original fraction, 2/3.
Negative Exponents and Powers
A negative exponent or power has a special meaning. Any number, except 0, with a negative
exponent equals the reciprocal of the same number with the same positive exponent. For
example:
The same rules for addition, subtraction, multiplication, division, and raising to a power
apply to negative exponents that apply to positive exponents. However, in adding,
subtracting, or multiplying the exponents, the rules for signed numbers must also be observed.
Fractional Exponents
Fractional exponents are used to represent roots (see next section). The general form of a
fractional exponent is a
m
n , which reads "the nth root of am ." For example, a
1
2 , means a the
2square root of a1 , or a. In other words, a
1
= a
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Calculator Method
To raise a number to a power using a scientific calculator, use the following steps:
1) Enter the number. (Fractions must first be converted to decimal form.)
2) Press the key. yx
3) Enter the power. (Fractions must first be converted to decimal form.)
4) Press the = key. The number displayed will be the number entered in step 1 raised to the
power entered in step 3.
Practice Problems
1. (32)(33) 4. (106)(10-4)
2. 75/73 5. 6-4/6-3
3. (105)(106) 6. 6-8/63
1.01.07 Find the square roots of numbers.
SQUARE ROOTS
To square a number means to multiply the number by itself, i.e., raise it to the second power.
(Consider that a square is two-dimensional.) For example, 2 squared is 4, since 2 × 2 = 4. The
square of 3 is 9, 4 squared is 16, and so on.
Just as subtraction "undoes" addition and division "undoes" multiplication, squaring a number
can be "undone" by finding the square root. The general definition is as follows:
If a2 = b, then a is a square root of b.
Be careful not to confuse the terms square and square root. For example, if 52 = 25, this indicates
that 25 is the square of 5, and 5 is the square root of 25. To be explicit, we say that it is a
perfect square because 5 times itself is 25.
All perfect squares other than 0 have two square roots, one positive and one negative. For
example, because 72 = 49 and (-7)2 = 49, both 7 and -7 are square roots of 49. The symbol ,
referred to as the radical, is used to write the principal, or positive, square root of a positive
number.
49 = 7 is read "The positive square root of 49 equals 7."
A negative square root is designated by the symbol − .
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49 = -7 is read "The negative square root of 49 equals -7."
It is often convenient to use plus-or-minus notation:
± 49 means the positive or negative square root of 49.
Therefore, the rule is that every positive real number a has two square roots: a and - a .
2It follows from the definition of square root that ( a ) = a, and that a 2 = a. Because the square
of every real number is either positive or zero, negative numbers do not have square roots in the
set of real numbers.
Section 10
Notice that 4 ⋅ 25 = 100 = 10 , and 4 ⋅ 25 = 2 ⋅5 = 10 . Therefore, 4 ⋅ 25 = 4 ⋅ 25
Therefore, in general, we can say:
For any nonnegative real numbers a and b: a ⋅b = a ⋅ b
a aIt also follows that =
b b
Calculator Method
To calculate the square root of any number using a scientific calculator, follow these steps:
1) Enter the number. (Fractions must first be converted to decimal form.)
2) Press the x key. The number displayed will be the square root of the number entered in
step 1. An alternate method is to press the yx key and then type 0.5. This raises the
number in step 1 to the power of 0.5, or ½.
Other roots
For informational purposes only, we mention the fact that other roots may be found for a
number. One of these is the cube root. To cube a number means to multiply the number by
itself three times, i.e., raise it to the third power. (Consider that a cube is three-dimensional.)
For example, 2 cubed is 8, since 2 × 2 × 2 = 8. The cube root (or third root) of a number, then,
is the number that, when raised to the third power (cubed), equals the first number. The
notation for a cube root is 3
a .
Note that any root may be taken from a number to "undo" an exponent, such as the fourth or
fifth root. The general definition for a root is:
If an = b, then a is the nth root of b.
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The notation for the nth root is n
a . These roots follow the same general rules as the square
root.
Practice Exercises
Find the indicated square roots.
1. 16
2. 144
3. 2)6(
4.
64
1
5.
36
81
6. 81−
7. 215
8. 400−
9. 499 ⋅
10. 625−
1.01.08 Convert between numbers expressed in standard form and in scientific
notation.
SCIENTIFIC NOTATION
The difficulty in writing very large or very small numbers in the usual manner is that a large
number of zeros are required to write these numbers. This difficulty is overcome by using
scientific notation, in which integral powers of ten are used instead of a large number of zeros to
indicate the position of the decimal point. In addition to simplifying the writing of very large or
very small numbers, scientific notation clearly identifies the number of significant digits in a
number and simplifies arithmetic calculations involving multiplication, division, or raising to a
power. For these reasons, it is good practice to write numbers in scientific notation when these
operations are involved.
The following demonstrates how the number 1 million can be represented by various factors of
10:
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Converting From Standard Form To Scientific Notation
There are two steps involved in writing a number in scientific notation.
1) Move the decimal point just to the right of the first significant digit. The first significant
digit is the first non-zero digit counting from the left.
2) Indicate multiplication of the resulting number by a power of ten that makes its value
equal to the original value. The power of ten is found by counting the number of places
the decimal point was moved from its original position. If counted to the left, the power is
positive; if counted to the right, it is negative. For example:
Suppose you want to express a number such as 700 in scientific notation.
Suppose you want to express 0.0014 in scientific notation.
Converting from Scientific Notation to Standard Form
To transform from scientific notation to standard form, follow the opposite procedure.
Section 11
1.96 × 105 = 196000
2.27 × 10-2 = 0.0227
There are two parts of a number written in scientific notation, the significant digits and the
power of ten. Thus, in the number 3.21 × 106, 3, 2, and 1 are the significant digits and106 is
the power of ten.
The ability to clearly see the number of significant digits can be helpful in performing
arithmetic calculations. For example, the number of significant digits which should be
reported in the product of two numbers can be readily determined if the two numbers are first
written in scientific notation.
When numbers are expressed in scientific notation, calculations can be more easily
visualized. This is because they involve only numbers between 1 and 10 and positive and
negative integral powers of ten which can be treated separately in the calculations using the
rules for numbers with exponents.
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1.01.09 Add, subtract, multiply, and divide numbers expressed in scientific notation.
Addition and Subtraction Using Scientific Notation
Addition and subtraction cannot normally be performed directly using scientific notation
because they require adding or subtracting digits of equal place value. Thus, when numbers
expressed in scientific notation are to be added or subtracted, they must first be converted to
forms having equal place value. This is commonly done by expressing them as numbers
which are multiplied by the same integral power of ten. The sum or difference of these
significant digits, multiplied by their common power of ten, is the sum or difference of the
original numbers. For example:
(3.54 × 105) + (2.51 × 104)
3.54 × 105 is first changed to 35.4 × 104
35.4 ¯ 104
+ 2.41 ¯ 104
37.91¯ 104 = 3.79 ¯ 105
Multiplication and Division Using Scientific Notation
Multiplication or division of numbers using scientific notation is performed by multiplying or
dividing the significant digits and the powers of ten separately. The significant digits are
multiplied or divided in the same manner as other mixed decimals. The powers of ten are
multiplied or divided by adding or subtracting their exponents using the rules for
multiplication and division of numbers with exponents. For example:
(2.7 × 102)(3.1 × 10-3) = (2.7)(3.1) × (102)(10-3) = 8.37 × 10-1
which should be rounded off to 8.4 × 10-1
One of the most useful applications of scientific notation is in arithmetic calculations which
involve a series of multiplications and divisions. The use of scientific notation permits
accurate location of the decimal point in the final answer. For example:
Perform the following calculation using scientific notation:
(219)(0.00204)
(21.2)(0.0312)
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1) Write each term in scientific notation:
(2.19 ×102)(2.04 ×10-3)
(2.12 ×101)(3.12 ×10-2)
2) Multiply and divide the significant digits:
(2.19)(2.04) −4.46
= = 0.675
(2.12)(3.12) 6.61
3) Multiply and divide the powers of ten by adding and subtracting exponents:
2 −3 −1(10 )(10 ) 10 −1+1 0= = 10 = 10
1 −2 −1(10 )(10 ) 10
4) Combine the results:
0.675 × 100 = 0.675 = 6.75 × 10-1
"E" Notation
An alternate method for annotating scientific notation is often used by pocket calculators,
computers, and some references. The method uses an E in place of the "× 10," and the
number written after the E is the exponent of 10. The standard and alternate methods for
scientific notation are equivalent and can be converted from one form to another without a
change in value. The examples below use both methods in equivalent expressions:
Section 12
3.79 ×105 = 3.79E5
4.02 ×10-6 = 4.02E-6
5.89 ×100 = 5.89E0
Using "E" Notation with a Calculator
Numbers in scientific notation are entered into a scientific calculator as follows:
1) Enter the significant digits.
2) Press the E or EXP key. (Actual key label may vary.)
3) Enter the power of 10. If the power is negative press the +/- key in conjunction with
entering the power.
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http:101)(3.12
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Practice Problems
1. (2 × 10-2 )(3 × 102)
2. (6 × 10-8)/(3 × 103)
3. (9 × 104)(- 1 × 10-2)
4. (3 × 10-7)(9 × 102)
5. (7E2)(6E4)
6. (5E - 3)/(5E - 2)
1.01.10 Solve equations using the "Order of Mathematical Operations.
ORDER OF MATHEMATICAL OPERATIONS
In solving any equation it is necessary to perform the operations in the equation in accordance
with a certain hierarchy or order of operations. Equations are solved by simplifying operations
of higher order first, according to group, left to right. The order for solving equations is as
follows:
1) Simplify expressions within grouping symbols, beginning with the innermost set if more
than one set is used.
2) Simplify all powers.
3) Perform all multiplications and divisions in order from left to right.
4) Perform all additions and subtractions in order from left to right.
For example: (3 + 1)2 × 3 - 14 ÷ 2
1) Simplify parentheses: (3 +1)2 ×3 −14 ÷ 2
123
2) Simplify powers: (4)2 ×3 −14 ÷ 2
4 2 41 4 4 3
3) Perform multiplication and 16×3 −14 ÷ 2 division left to right:123 123
4) Perform subtraction: 48 - 7 = 41 (final answer)
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Practice Problems
1. 5 + ( - 3) - ( - 2) - 6 6. 33 + 10 ÷ 5
2. 18 - [52 ÷ (7 + 6)] 7. (8 + 4 – 3)2
3. 19 - 7 + 12 - 2 ÷ 8 8. 7(42 - 10) ÷ (12 - ¾)
4. 23 - 20 ÷ 4 + 4 – 3 9. 7(6 – 22 )
5. 10 + 6(0.5)3 10. (57 – 25 )1/2
1.01.11 Perform algebraic functions.
ALGEBRA
Algebra is the branch of mathematics which deals with the manipulation of words and letters,
generically called symbols, which represent numbers. Two factors contribute to the widespread
use of algebra in scientific calculations. First, by using words and letters to represent the values
of physical quantities, physical relationships can be expressed in clear, concise, and completely
generalized form. Second, by using words and letters in place of numbers, combinations of
physical relationships may be simplified to yield results applicable to any set of numbers.
For example, the area of a rectangle equals the product of the length of the rectangle multiplied
by its width. In generalized terms, this statement can be written as:
Area = Length × Width.
This expression is a simple rule which tells the relationship between the area and the length and
width of a rectangle. It does not mean that words are multiplied together but rather that numbers
are inserted for the length and the width to obtain the area. For example, if the length is 4 feet
and the width is 2 feet, the area is 2 feet × 4 feet or 8 square feet. This expression can be further
simplified by using symbols or letters instead of words. For example, if area is designated by the
letter A, length designated by the letter l, and width designated by the letter w, the following
expression results:
A = l × w or A = lw
In algebraic expressions, when two or more letters representing numbers are written next to each
other without a symbol between them, multiplication is indicated.
Section 13
Variables vs. Numbers
When words or letters are used to represent numbers, they are called variables. Thus, when
letters like x, y, z, f, or k are used to represent the values of physical quantities, they are
called variables because their value varies with the actual numbers they may be chosen to
represent. In the area calculation above, A, l, and w are variables used to represent the
numerical values of area, length and width, respectively.
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Properties of Variables
Recall that every number has a sign and an exponent associated with it. Recall also that any
number can be written as a fraction by putting that number as the numerator and 1 as the
denominator, e.g., 5 = 5/1. These properties also apply to any symbols that we might use to
represent numbers. Additionally, a symbol by itself stands for one of whatever the variable
represents. That is to say, the symbol a by itself means "one of the variable represented by the
letter a", or 1a. Combining this with the other "invisible" properties mentioned, the symbol a is
understood to represent "positive one of the variable represented by the letter a to the power of
one, over 1," which would be expressed as:
+1a1
= a
1
An expression that is either a numeral, a variable or the product of a numeral and one or more
variables is called a monomial. A combination or sum of monomials is called a polynomial.
Examples of each are:
Monomials: 12 z br -4x3
Polynomials: 3x + 9 6a2 – 15
Equations
An equation is a statement that indicates how two quantities or expressions are equal.
The two quantities are written with an equal sign (=) between them. For example,
1 + 1 = 2 10 = 6 - ( - 4)
5 × 3 = 15 18 ÷ 2 = 9
are all equations because in each case the quantity on the left side is equal to the quantity on
the right side.
In algebra we use variables to represent numbers in equations. In this lesson we will
manipulate and solve equations involving more than one variable, but we will find the
solution, i.e., the final answer, to equations having only one variable.
Algebraic Manipulation
The basic principle, or axiom, used in solving any equation is: whatever operation is
performed on one side of an equation - be it addition, subtraction, multiplication, division,
raising to an exponent, taking a root - must also be performed on the other side if the
equation is to remain true. This principle MUST be adhered to in solving all types of equations.
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This axiom can be thought of by visualizing the balancing of a scale. If the scale is initially
balanced, it will remain balanced if the same weight is added to both sides, if the same weight is
removed from both sides, if the weights on both sides are increased by the same factor, or if the
weights on both sides are decreased by the same factor.
Here are the general forms for algebraic manipulation of equations. For the real numbers
a, b, c and n:
Manipulating and Solving Linear Equations
The addition or subtraction of the same quantity from both sides of an equation may be
accomplished by transposing a quantity from one side of the equation to the other.
Transposing is a shortened way of applying the addition or subtraction axioms. Any term
may be transposed or transferred from one side of an equation to the other if its sign is
changed. Thus, in the equation below the +4 can be transposed to the other side of the
equation by changing its sign:
Section 14
5x + 4 = 14
(5x + 4) - 4 = (14) - 4
5x = 14 - 4
5x = 10
Transposing also works with multiplication and division. Remembering that any number can
be expressed as a fraction we can rewrite the last line of the equation above. We can then
move the 5 in the numerator of the left side to the denominator of the right side:
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Some linear equations may contain multiple terms (monomials) involving the same variable.
In order to simplify the equation like terms must be combined. Don't forget those "invisible
properties of variables." Here's an example:
Quadratic Equations
In manipulating an equation involving multiple variables, the "variable of interest" (or the
variable to be solved for) must be moved to one side of the equal sign and all other variables
must be moved to the other side. In order to accomplish this, operations must be performed
on both sides of the equation that will result in a variable or group of variables, to be
canceled out from one side. This cancellation can only occur if the "opposite function" is
performed on a function that already exists on that side of the equation. This means that a
variable that is being multiplied can be canceled by dividing by the same variable. Addition
can be canceled with subtraction, multiplication with division, etc.
For example:
Another example:
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Do not forget that the order of operations must be observed when manipulating equations.
Otherwise a completely different solution may result. The key is to do the opposite function
in reverse order. Here is an example which shows how this is done.
Once the order of the arithmetic functions has been established, manipulation of the formula
can begin. In the example above, if the values for a, b, and c were known, the first step would
be to add b to a. The second step would be to divide by c. Therefore, in order to solve it, we
do the opposite functions in reverse order. So, we first multiply by c. Then, we would
subtract b. It is a good idea to rewrite the equation each time so that the operations can be
reevaluated before the next step.
Substitution
Linear equations are solved by combining like terms and reducing to find the solution.
Quadratic equations are solved by substituting given values into the equation for all but one
of the variables, thus making it a linear equation. The best approach is to first solve for the
variable of interest by algebraic manipulation. Then find the solution by substituting the
given values into the equation for the respective variables. The single, unknown variable, or
the variable of interest, will be left on one side, being set equal to the solution. For example:
Given the equation: 2x – y2 = 3a - b; where x = 5, y = (-4) and a = 3; solve for b:
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Practice Problems
Solve for the unknown variable:
Substitute the values given and simplify the expression.
1.01.12 Solve equations using common and/or natural logarithms.
LOGARITHMS
Section 15
In many cases, arithmetic operations can be performed much more quickly if the numbers
involved are numbers with exponents to the same base. For example, the multiplication or
division of numbers with exponents to the same base can be performed by merely adding or
subtracting the exponents. Raising to a power or taking a root can be performed by merely
multiplying or dividing the exponents by the power or root. It is this feature of numbers with
exponents which led to the development of logarithms. If all numbers could be readily written as
numbers with exponents to the same base, multiplication, division, raising to powers and taking
roots could be performed much more quickly.
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Any number can be expressed as a power of any other number. For example, 64 equals 26, 43, or
82. 64 also equals 72.137 or 101.806 . The use of logarithms involves expressing numbers as powers
of a common number, such as 10, so that arithmetic operations with these numbers can be
performed more quickly.
Simply put, a logarithm is an exponent. More explicitly, the logarithm of a number n is the
exponent x of a given base b that is required to produce that number. The symbol log is used to
denote taking a logarithm. The base is usually indicated by a small number written to the right
and slightly below the symbol log (e.g., logb). The general relationship and form are as follows:
If n = bx; where b > 0 and b ≠ 1, then: logb n = x.
For example:
1000 = 103 – log10 1000 = 3
This says that the base ten logarithm of 1000 is 3, which means that the base number, 10, must
be raised to the power of 3 to equal 1000.
Here are some additional examples:
Before the development of the scientific calculator, the use of logarithms saved considerable
computation time. For example, the evaluation of the following expression by hand would take a
very long time.
However, using logarithms the above expression could be evaluated in a matter of minutes.
Thus, logarithms, or logs, became one of the most useful tools in mathematics. In addition to
simplifying arithmetic calculations and shortening computation time, logs are also important in
engineering applications. The relationship between a number and its logarithm is used frequently
to assist in measuring physical quantities when they vary over a wide range. For example,
logarithmic scales are used to measure the neutron flux in nuclear reactors. Logarithms are also
used for scales on charts and meters.
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Properties of Logarithms
Since logarithms are exponents, the basic rules of exponents can be used to develop several
useful properties of logarithms. Suppose that a, x, and y are numbers, and a is a suitable base
for a logarithm (a > 0, a ≠ 1). The product rule for exponents says:
x y (x+ y)a ⋅ a = a
Let us say that: u = ax and v = ay
If we write each of these in logarithmic form we would have:
x = loga u and y = loga v
x y (x+ y)Then: u ⋅ v = a ⋅ a = a
If we write this in logarithmic form it would be:
log (u ⋅ v) = x + y
a
If we substitute the values for x and y from above we have:
log a (u ⋅v) = log u + log v
a a
This results in one of the rules for logarithms, the product rule. Using similar methods, we
could also prove the other two rules that have been developed for logarithms.
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Section 16
Base Ten Logarithms
Logs with the base of 10 are the most commonly used logarithms because of their relationship to
the place values in the decimal system. Because of their wide use, base ten logarithms are often
referred to as common logarithms. Observe the patterns in the number line and table below.
Notice the relationship between the power of ten and the logarithm.
Any number can be expressed as a power of ten. Thus, 10 equals 101, 1,000 equals 103,
64 equals 101.806 and 527.3 equals 102.7221. Once a number has been expressed as a power of ten,
the base ten logarithm of the number is known-it is the exponent of 10. Thus log10
10 equals 1, log10 1000 equals 3, log10 64 equals 1.806 and log10 527.3 equals 2.722.
Since base ten logarithms are so commonly used, the subscript 10 is often omitted after the
symbol log. Thus, log 27.3 means the logarithm of 27.3 to the base 10.
A common logarithm is most often a mixed number consisting of a whole number part and a
decimal fraction part. The whole number part is called the characteristic of the logarithm. The
decimal fraction part is called the mantissa. For example, in the logarithm of 527.3, which equals
2.7221, the characteristic is 2 and the mantissa is 0.7221. The mantissas of most logarithms are
rounded off to a specified number of significant digits, typically four.
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Log-Table Method
To find the common logarithm of a number using four-place log tables, use the following
steps:
1) Write the number in scientific notation with up to four significant digits.
2) Using the product rule for logarithms, write the log of the product as the sum of
the logs of the factors.
3) Determine the mantissa as follows:
a) Find the row in the table corresponding to the first two digits of the number,
then move over to the column corresponding to the third digit of the number.
b) Find the number under the proportional parts section corresponding to the
fourth digit of the number, and add it to the last digit of the decimal obtained
in step 3.a.
4) Determine the characteristic by using the power of 10 written in step 1 and write
the logs in the form of a sum.
NOTE: If the power of 10 is negative, the log may be left in this form.
5) Using the product rule, write the sum of the logs as the log of a product.
NOTE: If the power of 10 is negative, the mantissa will be changed because of the
subtraction of a whole number.
Example: log 45,830
1) Write the number in scientific notation. log (4.583 × 104 )
2) Use the product rule to write the product as the
sum of the logs.
log 4.583 + log 104
3) a) Find the 4.5 row of the log table. Move over to the 8
column to find the mantissa. 0.6609
log 4.583 + 4
b) Find the 3 column under the proportional parts
section of the log table. Add this to the last digit of
the mantissa in step 3.a.
+ 0.0003
0.6612
4) Write the mantissa and characteristic as a sum. 0.6612 + 4
5) Add the characteristic to the mantissa. 4.6612
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Example: log 0.004583
1) First, we write the number in scientific notation. log (4.583 × 10-3)
2) Next, we use the product rule to write the product as log 4.583 + log 10-3
Section 17
the sum of the logs.
log 4.583 + ( - 3)
3) The mantissa will be the same as in the previous
example because the significant digits are the same. 0.6612
4) Now, we write the mantissa and characteristic as a 0.6612 + ( - 3)
sum. Since the characteristic is negative we could
leave the logarithm in this form. 0.6612 - 3
5) Add the characteristic to the mantissa. Note that the - 2.3388
mantissa has changed. Also note that this is not the
same as - 3.6612.
As you may have observed, the mantissa of the base ten logarithm of a number depends only
on the succession of significant digits in the number. The position of the decimal point in the
number does not affect the mantissa. Of course, the characteristics are different for each of
these numbers.
Note that any time the logarithm of a number is rounded off it would be considered an
approximate answer since each digit is necessary to exactly duplicate the number when the
base is raised to that exponent. Since each significant digit of the logarithm affects the actual
value of the number, a standard of four significant digits should be maintained to ensure
appropriate accuracy in the answers.
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Calculator Method
Since hand-held scientific calculators are readily available today, it is impractical to use log
tables. To find the logarithm of a number with a calculator:
1. Enter the number.
2. Press the log key. The number displayed is the logarithm of the number entered in
step 1.
Natural Logarithms
A logarithm can be written to any base. For most practical computations, base ten logarithms
are used because of their relationship to the place values in the decimal system. However, in
many scientific and engineering problems, it is convenient to use another base, symbolized
by the letter e. e is an irrational number whose value is 2.71828 . . . The actual value of e is
the limiting value of (1 + 1/n)n as n gets larger and larger.
Although it is an irrational number, it can still be used as the base for logarithms in the same
way as 10 is used for base ten logarithms. e is the basis for many laws of nature, such as the
laws of growth and decay of physical quantities, including the decay of radioactive
substances and the growth and decay of neutron population in a nuclear reactor. Because of
the relationship of e to natural phenomena, logarithms to the base e are called natural
logarithms.
The natural logarithm of a number is the exponent to which e must be raised in order to get
that number. The symbol ln is used to denote a natural logarithm which is the same as saying
loge. The relationship is expressed as follows:
If ex = n then ln n = x
For example:
0.693147... = 2. ln 2 = 0.693147 . . . which means that e
2.302585... = 10ln 10 = 2.302585 . . . which means that e
ln e = 1 which means that e1 = e
Natural logarithms are not often used for computations. However, they appear frequently in
decay and shielding calculations problems because of the relationship of e to natural
phenomena. As a result, it is important to know how to determine the natural logarithms of
numbers.
Tables of natural logarithms are available in several standard handbooks. However, there are
several important differences between natural logarithms and base ten logarithms which must
be understood to use natural logarithms. A natural logarithm is not separated into a
characteristic and a mantissa. This is because the whole number part of a natural logarithm
Section 18
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ln
does not relate to the position of the decimal point. Therefore, tables of natural logarithms
give the entire logarithm, not just the decimal fraction part. Moreover, if a natural logarithm
is negative, the entire logarithm is negative and is shown as such in a table of natural
logarithms. Further, there is no part of the natural logarithm of a number which is not
affected by the position of the decimal point. For all these reasons, tables of natural
logarithms cannot be made concise.
To find the natural log of a number using a hand-held calculator:
1. Enter the number.
2. Press the key. The number displayed is the natural logarithm of the number entered
in step 1.
Antilogarithms
An antilogarithm, usually shortened to "antilog," is the opposite of a logarithm and is much
easier to do. The antilog of a given number is the value obtained by raising the base to that
number. Finding antilogs is an important part in the overall use of logarithms in
computations. If numbers are converted to logarithms to perform calculations, the answer
must be converted back from logarithms once the calculations have been performed. The
symbol log -1 is used in calculations to indicate the antilog is going to be taken. The base of
10 is assumed unless otherwise noted. The general form is:
log -1 x = n which means 10 x = n
For example:
log -1 3 which means 103 = 1000
To find the antilog of a number using log tables: log -1 2.7832
1) Write the number in log long form. log -1 (0.7832 + 2)
2) Find the mantissa in the table. Take the 6.0
value at the head of the row and attach to it 7
the value at the head of the column. 6.07
3) Write this value in scientific notation, 6.07 × 10 2
putting the characteristic of the original
number as the power of ten.
4) Write this number in standard form. 607
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On a scientific calculator the antilog of a number is obtained by raising the base (10) to that
number.
1) Enter the number.
2) Press the log-1 or 10 x key. The number displayed is the antilog of the number log of
entered in step 1. In other words, 10 raised to that power.
The symbol ln-1 is used to denote the inverse natural log, i.e. the antilog of base e.
xln-1 x = n which means e = n
For example:
0.693... = 2ln-1 0.693 . . . which means e
On a scientific calculator the inverse natural log of a number is obtained as follows:
1) Enter the number.
ln-1 x2) Press the or e key. The number displayed is the inverse natural log of the
number of entered in step 1. In other words, e raised to that power.
Solving for Variables as Exponents
One of the useful applications for logarithms is to solve algebraic equations with unknown
exponents. In the following example, for instance, if the exponent is not known, it would be
difficult to determine the correct value of x in order to make the statement (or equation) true.
2356 = 3x
With the use of logarithms, however, this type of problem can be easily solved. The steps for
solving an equation of this type are:
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1) Make sure the base raised to the unknown exponent is isolated on one side of the
equation (this may involve some manipulation of the formula in more complicated
equations).
2) Take the log of both sides of the equation:
Section 19
log 2356 = log 3x
3) The right side of the equation can be rewritten using the power rule:
log 2356 = x (log 3)
4) Divide both sides by log 3 which moves it to the right side of the equation:
log 2356 x(log 3)
=
log 3 log 3
5) Cancel terms and rewrite the equation:
log 2356
= x
log 3
6) Perform the operations and solve:
7) This answer can now be checked by substituting it back into the original equation to see
if it makes the statement true:
2356 = 37.068
Some problems may involve the base of the natural logarithm e raised to an unknown power.
This exponent can be determined by isolating e on one side of the equation and then taking
the natural log of both sides. This is done because the natural log of e is 1. For example:
n125 = 1000e
125 n= e
1000
125 nln = ln e
1000
ln 0.125 = (ln e)(n)
ln 0.125 = (1)(n)
-2.0794 = n
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Practice Problems
Perform the following operations:
1. log 6.40 5. ln 86
2. log 0.5 6. ln 0.5
3. log-1 16 7. ln-1 0.695
4. log-1 3.7846 8. ln-1 1
Use logarithms to solve for the unknown variable:
9. 5 = 4x 11. 9 = 22(3)y
10. 23 = 6t 12. 50 = 2000(½)n
SUMMARY
A good foundation in mathematics is essential for the RCT. Calculations of various types are
performed routinely in radiological control operations. The skills learned in this lesson will be
applied in many of the lessons that follow as well as in the workplace.
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ANSWERS TO PRACTICE PROBLEMS:
Fractions
1. 1/3 + 2/3 = 3/3 = 1
2. 5/7 _ 3/7 = 2/7
3. 5/9 + 2/3 = 5/9 + 6/9 = 11/9 = 1 2/9
4. 6/7 _ 1/2 = 12/14 _ 7/14 = 5/14
5. 2 _ 1/3 = 6/3 _ 1/3 = 5/3 = 1 2/3
6. 3/8 + 15/16 = 6/16 + 15/16 = 21/16 = 1 5/16
7. 25/32 _ 3/4 = 25/32 _ 24/32 = 1/32
8. 15/21 _ 4/7 = 5/7 _ 4/7 = 1/7
9. 13/20 _ 2/5 = 13/20 _ 8/20 = 5/20 = 1/4
10. 7/18 + 5/9 = 7/18 + 10/18 = 17/18
11. 2/3 × 1/5 = 2/15
12. 4/7 × 3/4 = 3/7
13. 1/2 × 2 = 1
14. 3/5 × 4 = 12/5 = 2 2/5
15. 4/9 ÷ 2/3 = 4/9 × 3/2 = 2/3
16. 8/13 × 2/3 = 16/39
17. 12/15 × 3/5 = 36/75
18. 20/25 ÷ 4/5 = 20/25 × 5/4 = 4/5 × 5/4 = 1
19. 7/8 × 2/5 = 7/4 × 1/5 = 7/20
20. 14/21 ÷ 2/7 = 14/21 × 7/2 = 2/3 × 7/2 = 7/3 = 2 1/3
Decimals
1. 0.23 + 3.4 = 3.63
2. 5.75 _ 2.05 = 3.7
3. 6.1 _ 1.6 = 4.5
4. 0.018 + 0.045 = 0.063
5. 468.75 _ 192.5 = 276.25
6. 2.3 × 3.2 = 7.36
7. 0.007 × 2.18 = 0.01526
8. 5.2 ÷ 1.4 = 3.7143
9. 12.26 ÷ 0.04 = 306.5
10. 4.0 × 0.25 = 1
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Fraction/Decimal Conversions
1. 1/2 = 0.5
2. 2/5 = 0.4
3. 5/8 = 0.625
4. 12/25 = 0.48
5. 13/39 = 0.¯3
6. 7/16 = 0.4375
7. 0.125 = 125/1000 = 1/8
8. 0.6666 = 2/3
9. 4.25 = 4 25/100 = 4¼
10. 0.2 = 2/10 =1/5
Percent
1. 0.5 = 50%
2. 0.782 = 78.2%
3. 1.1 = 110%
4. 0.06 = 6%
5. 0.049 = 4.9%
6. 0.0055 = 0.55%
7. 65% = 0.65
8. 0.25% = 0.0025
9. 300% = 3
10. 0.09% = 0.0009
Signed Numbers
1. (-28) + (-51) = -79
2. (-2) + (-5) = -7
3. 40 + (-21) = 19
4. -87 + 50 = -37
5. 48 + (-27) = 21
6. 56 - (-5) = 61
7. 81 - 4 = 77
8. -48 - (-2) = -46
9. -4(5) = -20
10. 6/(-3) = -2
11. 4 (-5) = -20
12. (-6)/(-3) = 2
13. (-6)/3 = -2
14. (-8)(-5) = 40
15. (-7)(6) = -42
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Exponents
1. (32)(33) = 35
2. 75/73 = 72
3. (105)(106) = 1011
4. (106)(10-4) = 102
5. 6-4/6-3 = 6-1
6. 6-8/63 = 6-11
Square Roots
1.
2.
3.
4.
5.
6.
7.
8.
416 =
981 = −−
Section 20
12144 =
15152 =
66)( 2 =
20400 = −−
8
1
64
1
=
739 49 22 ⋅=⋅ = 32 ⋅ 7 2 213 7 =⋅=
281 81 9 9 39. = = = =
2 6 236 36 6
210. − 625 = − 25 = −25
Scientific Notation
1. (2 × 10-2)(3 × 10-2) = 6 × 10-4
2. (6 × 10-8)/(3 × 103) = 2 × 10-11
3. (9 × 104)(-1 × 10-2) = -9 × 102
4. (3 × 10-7)(9 × 102) = 2.7 × 10-4
5. (7E2)(6E4) = 4.2E7
6. (5E-3)/(5E-2) = 1E-1
Order of Operations
1. 5 + (-3) - (-2) - 6 = 5 + 6 - 6 = 5
2. 18 - [52 ÷ (7 + 6)] = 18 - (52 ÷ 13) = 18 - 4 = 14
3. 19 - 7 + 12 - 2 ÷ 8 = 12 + 24 ÷ 8 = 12 + 3 + 15
4. 23 - 20 ÷ 4 + 4 - 3 = 8 - 5 + 12 = 3 + 12 = 15
5. 10 + 6(0.5)3 = 10 + 6(0.125) = 10 + 0.75 = 10.75
6. 33 + 10 ÷ 5 = 27 + 2 = 29
7. (8 + 4 - 3)2 = (8 + 12)2 = 202 = 400
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8. 7(42 - 10) ÷ (12 - ¾) = 7(16 - 10) ÷ 9 = 7(6) ÷ 9 = 42 ÷ 9 = 4.667
9. 7(6 - 22) = 7(6 - 4) = 7(2) = 14
10. (57 - 25)½ = (57 - 32)½ = 25½ = 5
Algebra
1. x + 3 = 10
x + 3 – 3 = 10 – 3
x = 7
2. 5 + z = 8
5 + z – 5 = 8 – 5
z = 3
y3. = 2
4
y4 ⋅ = 2 ⋅ 4
4
y = 8
4. r = 6
2
⋅
r2 = 6 ⋅ 2
2
r = 12
5. 5(j + 5) = 45
5(j + 5) = 45
5 5
j + 5 = 9
j + 5 – 5 = 9 – 5
j = 4
6. 5d = 25
5d 25
=
5 5
d = 5
7. 9n 2 = 81
29n 81
=
9 9
2n = 9
2n = 9
n = 3
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8. a + 6 − 6a = −14
6 − 5a = −14
6 − 5a − 6 = −14
−5a = −20
−5a −20
=
− 5 − 5
a = 4
9. a 2b = c 2 d
2 2a b c d
=
b b
2 c 2 d a =
b
2c d2a =
b
2c d a =
b
b c10. =
a d
b c a ⋅ = ⋅ a
a d
cab =
d
cad ⋅b = ⋅ d
d
db = ca
db ca
=
c c
db
= a
c
11. 3x +14 y − xy where x = 5, y = 2
3(5) + 14(2) – 5(2)
15 + 28 – 10
43-10
33
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4s +112. where s = -3, t = 10
6t + s
4(−3) +1
6(10) + (−3)
−12 +1
60 + (−3)
−11
57
16a + 5b13. where a = -1, b = 5
1− 4a
16(−1) + 5(5)
1− 4(−1)
−16 + 25
1+ 4
9
5
41
5
j14. 3i + = 0 where k = 2, j = -12, solve for i
1+ k
−123i + = 0
1+ 2
3i − 4 = 0
3i = 4
4i =
3
1
i = 1
3
15. 7(2m - ¾n) - l - 10 where m - ½ n - 8, solve for l
7[2(½) - ¾(8)] - l - 10
7(1 - 6) - l - 10
7(-5) - l - 10
-35 - l - 10
l - 45
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Logarithms
1. log 6.40 = 0.8062
2. log 0.5 = _0.301
3. log-1 16 = 1 × 1016
4. log-1 3.7846 = 6089.76
5. ln 86 = 4.45
6. ln 0.5 = _0.693
7. ln-1 0.695 = 2.004
8. ln-1 1 = e = 2.7182 . . .
9.
10.
11.
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12.
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Module 1.02 Unit Analysis & Conversion Study Guide
Course Title: Radiological Control Technician
Module Title: Unit Analysis & Conversion
Module Number: 1.02
Objectives :
1.02.01 Identify the commonly used unit systems of measurement and the base units
for mass, length, and time in each system.
1.02.02 Identify the values and abbreviations for SI prefixes.
1.02.03 Given a measurement and the appropriate conversion factor(s) or conversion
factor table, convert the measurement to the specified units.
1.02.04 Using the formula provided, convert a given temperature measurement to
specified units.
INTRODUCTION
Section 21
A working knowledge of the unit analysis and conversion process is necessary for the
Radiological Control Technician. It is useful for air and water sample activity
calculations, contamination calculations, and many other applications. This lesson will
introduce the International System of Units (SI), the prefixes used with SI units, and the
unit analysis and conversion process. Many calculations accomplished in radiological
control are actually unit conversions, not complex calculations involving formulas that
must be memorized.
REFERENCES:
1. "Health Physics and Radiological Health Handbook"; Shleien; 1992.
2. DOE-HDBK-1010-92 (June 1992) "Classical Physics" DOE Fundamental
Handbook; US Department of Energy.
3. "Chart of the Nuclides"; Sixteenth Edition, Knolls Atomic; 2003.
UNITS AND MEASUREMENTS
Units are used in expressing physical quantities or measurements, i.e., length, mass, etc.
All measurements are actually relative in the sense that they are comparisons with some
standard unit of measurement. Two items are necessary to express these physical
quantities: a number which expresses the magnitude and a unit which expresses the
dimension. A number and a unit must both be present to define a measurement.
Measurements are algebraic quantities and as such may be mathematically manipulated
subject to algebraic rules.
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Fundamental Quantities
All measurements or physical
quantities can be expressed in
terms of three fundamental
quantities. They are called
fundamental quantities because
they are dimensionally
independent. They are:
� Length (L)
� Mass (M) (not the same as
weight)
� Time (T)
Figure 1. Fundamental Units
Derived Quantities
Other quantities are derived from the fundamental quantities. These derived quantities
are formed by multiplication and/or division of fundamental quantities. For example:
� Area is the product of length times length (width), which is L × L, or L2.
� Volume is area times length, which is length times length times length, or L3.
� Velocity is expressed in length per unit time, or L/T.
� Density is expressed in mass per unit volume, or M/L3.
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1.02.01 Identify the commonly used unit systems of measurements and the base units
for mass, length, and time in each system.
SYSTEMS OF UNITS
The units by which physical quantities are measured are established in accordance with
an agreed standard. Measurements made are thereby based on the original standard
which the unit represents. The various units that are established, then, form a system by
which all measurements can be made.
English System
The system that has historically been used in the United States is the English System,
sometimes called the English Engineering System (EES). Though no longer used in
England, many of the units in this system have been used for centuries and were
originally based on common objects or human body parts, such as the foot or yard.
Though practical then, the standards for these units were variable as the standard varied
from object to object, or from person to person. The base units for length, mass, and time
in the English system are the foot, pound, and second, respectively.
Section 22
Even though fixed standards have since been established for these antiquated units, no
uniform correlation exists between units established for the same quantity. For example,
in measuring relatively small lengths there are inches, feet, and yards. There are twelve
inches in a foot, and yet there are only three feet in a yard. This lack of uniformity makes
conversion from one unit to another confusing as well as cumbersome. However, in the
U.S., this system is still the primary system used in business and commerce.
Table 1. English System Base Units
Physical
Quantity Unit Abbr.
Length: foot ft.
Mass: pound lb.
Time: second sec.
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International System of Units (SI)
Since the exchange of scientific information is world-wide today, international
committees have been set up to standardize the names and symbols for physical
quantities. In 1960, the International System of Units (abbreviated SI from the French
name Le Système Internationale d'Unites) was adopted by the 11th General Conference
of Weights and Measures (CGPM). The SI, or modernized metric system, is based on
the decimal (base 10) numbering system. First devised in France around the time of the
French Revolution, the metric system has since been refined and expanded so as to
establish a practical system of units of measurement suitable for adoption by all countries.
The SI system consists of a set of specifically defined units and prefixes that serve as an
internationally accepted system of measurement. Nearly all countries in the world use
metric or SI units for business and commerce as well as for scientific applications.
1.02.02 Identify the values and abbreviations for SI prefixes.
SI Prefixes
The SI system is completely decimalized and uses prefixes for the base units of meter (m)
and gram (g), as well as for derived units, such as the liter (l) which equals 1000 cm3.
SI prefixes are used with units for various magnitudes associated with the measurement
being made. Units with a prefix whose value is a positive power of ten are called
multiples. Units with a prefix whose value is a negative power of ten are called
submultiples.
For example, try using a yard stick to measure the size of a frame on film for a camera.
Instead you would use inches, because it is a more suitable unit. With the metric system,
in order to measure tiny lengths, such as film size, the prefix milli- can be attached to the
meter unit to make a millimeter, or 1/1000 of a meter. A millimeter is much smaller and
is ideal in this situation. On the other hand, we would use a prefix like kilo- for
measuring distances traveled in a car. A kilometer would be more suited for these large
distances than the meter.
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Table 2. SI Prefixes
PREFIX FACTOR SYMBOL PREFIX FACTOR SYMBOL
yotta 1024 Y deci 10-1 d
zetta 1021 Z centi 10-2 c
exa 1018 E milli 10-3 m
peta 1015 P micro 10-6 µ
tera 1012 T nano 10-9 n
giga 109 G pico 10-12 p
mega 106 M femto 10-15 f
kilo 103 k atto 10-18 a
hecto 102 h zepto 10-21 z
deka 101 da yocto 10-24 y
Prior to the adoption of the SI system, two groups of units were commonly used for the
quantities length, mass, and time: MKS (for meter-kilogram-second) and CGS (for
centimeter-gram-second).
Table 3. Metric Subsystems
Physical Quantity CGS MKS
Length: centimeter meter
Mass: gram kilogram
Time: second second
Section 23
SI Units
There are seven fundamental physical quantities in the SI system . These are length,
mass, time, temperature, electric charge, luminous intensity, and molecular quantity (or
amount of substance). In the SI system there is one SI unit for each physical quantity.
The SI system base units are those in the metric MKS system. Table 4 lists the seven
fundamental quantities and their associated SI unit. The units for these seven
fundamental quantities provide the base from which the units for other physical quantities
are derived.
For most applications the RCT will only be concerned with the first four quantities as
well as the quantities derived from them.
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Radiological Units
In the SI system, there are derived units for quantities used for radiological control.
These are the becquerel, the gray, and the sievert. The SI unit of activity is the becquerel,
which is the activity of a radionuclide decaying at the rate of one spontaneous nuclear
transition per second. The gray is the unit of absorbed dose, which is the energy per unit
mass imparted to matter by ionizing radiation, with the units of one joule per kilogram.
The unit for dose equivalence is the sievert, which has the units of joule per kilogram.
These quantities and their applications will be discussed in detail in Lesson 1.06.
Other units
There are several other SI derived units that are not listed in Table 4. It should be noted
that the SI system is evolving and that there will be changes from time to time. The
standards for some fundamental units have changed in recent years and may change again
as technology improves our ability to measure even more accurately.
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Table 4. International System (SI) Units
Physical Quantity Unit Symbol Dimensions
Base units
Length: meter m m
Mass: kilogram kg kg
Time: second s or sec. s
Temperature: kelvin K K or °K
Electric current: ampere A or amp A or (C/s)
Luminous intensity: candela cd cd
Molecular quantity: mole mol mol
Selected derived units
Volume: cubic meter m3 m3
Force: newton N kg·m/s2
Work/Energy: joule J N·m
Power: watt W J/s
Pressure: pascal Pa N/m2
Electric charge: coulomb C A·s
Electric potential: volt V J/C
Electric resistance: ohm Σ V/A
Frequency: hertz Hz s-1
Activity: becquerel Bq disintegration/s
Absorbed dose: gray Gy J/kg
Equivalent dose: sievert Sv Gy·WR
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Module 1.02 Unit Analysis & Conversion Study Guide
1.02.03 Given a measurement and the appropriate conversion factor(s) or conversion
factor table, convert the measurement to the specified units.
UNIT ANALYSIS AND CONVERSION PROCESS
Units and the Rules of Algebra
Remember that a measurement consists of a number and a unit. When working problems
with measurements, it should be noted that the measurement units are subject to the same
algebraic rules as the values. Some examples are provided below.
( ) ( )× cm = cm2cm
ft3
2= ft
ft
1
= yr−1
yr
As a result, measurements can be multiplied, divided, etc., in order to convert to a
different system of units. Obviously, in order to do this, the units must be the same. For
example, a square measures one foot in length and 18 inches in width. To find the area of
the square in square inches we must multiply the length by the width. However, when
the measurements are in different units, and cannot be multiplied directly.
Section 24
We can convert feet to inches. We know that there are 12 inches in one foot. We can use
this ratio to convert 1 foot to 12 inches. Then we can then calculate the area as 12 inches
× 18 inches, which equals 216 in2, which is a valid measurement.
Steps for Unit Analysis and Conversion
1) Determine given unit(s) and desired unit(s).
2) Build (or obtain) conversion factor(s) -- see Conversion Tables at end of lesson
A conversion factor is a ratio of two equivalent physical quantities expressed in different
units. When expressed as a fraction, the value of all conversion factors is 1. Because a
conversion factor equals 1, it does not matter which value is placed in the numerator or
denominator of the fraction.
Examples of conversion factors are:
1.02-8
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Module 1.02 Unit Analysis & Conversion Study Guide
365days 12inches 1foot 3
1year 1 foot 2.832E4cm 3
Building conversion factors involving the metric prefixes for the same unit can be tricky.
This involves the conversion of a base unit to, or from, a subunit or superunit.
To do this, use the following steps: Example: 1 gram to milligrams
a) Place the base unit in the numerator g
and the subunit/ superunit in the
mg
denominator (or vice versa):
b) Place a 1 in front of the g
subunit/superunit:
1mg
c) Place the value of the prefix on the m (milli-) = 10-3 or 1E
subunit/ superunit in front of the 1E − 3g
base unit:
1mg
Also remember that algebraic manipulation can be used when working with metric
prefixes and bases. For example, 1 centimeter = 10-2 meters. This means that 1 meter =
1/10-2 centimeters, or 100 cm. Therefore, the two conversion factors below are equal:
1E − 2m 1m
=
1cm 100 cm
3) Set up an equation by multiplying the given units by the conversion factor(s) to
obtain desired unit(s).
When a measurement is multiplied by a conversion factor, the unit(s) (and
probably the magnitude) will change; however, the actual measurement itself does
not change. For example, 1 ft and 12 inches are still the same length; only
different units are used to express the measurement.
1.02-9
DOE-HDBK-1122-2009
Module 1.02 Unit Analysis & Conversion Study Guide
By using a "ladder" or "train tracks," a series of conversions can be accomplished
in order to get to the desired unit(s). By properly arranging the numerator and
denominator of the conversion factor(s), given and intermediate units will cancel
out by multiplication or division, leaving the desired units. Some examples of the
unit analysis and conversion process follow:
EXAMPLE 1.
Convert 3 years to seconds.
Step 1 - Determine given and desired unit(s):
Given units: years
Desired units: seconds.
Step 2 - Build/obtain conversion factor(s):
We can use multiple conversion factors to accomplish this problem:
1 year = 365.25 days
1 day = 24 hours
1 hour = 60 minutes
1 minute = 60 seconds
Step 3 - Analyze and cancel given and intermediate units. Perform multiplication
and division of numbers:
⎛ 3years ⎞⎛ 365.25days ⎞⎛ 24hours ⎞⎛ 60minutes ⎞⎛ 60seconds ⎞ = 94,672,800sec. ⎜ ⎟⎜ ⎟⎜ ⎟⎜ ⎟⎜ ⎟
⎝ ⎠⎝ 1year ⎠⎝ 1day ⎠⎝ 1hour ⎠⎝ 1minute ⎠
1.02-10
DOE-HDBK-1122-2009
Module 1.02 Unit Analysis & Conversion Study Guide
Unit analysis and conversion process follow:
EXAMPLE 2.
μCi dpmWhat is the activity of a solution in if it has 2000 ?
ml gallon
Step 1 - Determine given and desired unit(s):
dpmGiven units:
gallon
μCi
Desired units:
ml
Step 2 - Build conversion factor(s):
Section 25
1 liter = 0.26418 gallons
1 dpm = 4.5 E-07 µCi
1 liter = 1000 ml
Step 3 - Analyze and cancel given and intermediate units. Perform multiplication and
division of numbers.
2000dpm ⎞ 4.5E − μCi ⎞⎛ 0.26418 ⎛ l⎛ ⎛ 7 gal ⎞ 1 ⎞ μCi
= 2.38E − 7⎜ ⎟⎜ ⎟⎜ ⎟⎜ ⎟
⎝ gal ⎠⎝ 1dpm ⎠⎝ 1l ⎠⎝1,000 ml ⎠ ml
Practical exercises and their solutions are provided at the end of this lesson.
1.02-11
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Module 1.02 Unit Analysis & Conversion Study Guide
1.02.04 Using the formula provided, convert a given temperature measurement to
specified units.
TEMPERATURE MEASUREMENTS AND CONVERSIONS
Temperature measurements are made to determine the amount of heat flow in an
environment. To measure temperature it is necessary to establish relative scales of
comparison. Three temperature scales are in common use today. The general
temperature measurements we use on a day-to-day basis in the United States are based on
the Fahrenheit scale. In science, the Celsius scale and the Kelvin scale are used. Figure
2 shows a comparison of the three scales.
The Fahrenheit scale, named for its developer, was devised in the early 1700's. This
scale was originally based on the temperatures of human blood and salt-water, and later
on the freezing and boiling points of water. Today, the Fahrenheit scale is a secondary
scale defined with reference to the other two scientific scales. The symbol °F is used to
represent a degree on the Fahrenheit scale.
About thirty years after the Fahrenheit scale was adopted, Anders Celsius, a Swedish
astronomer, suggested that it would be simpler to use a temperature scale divided into
one hundred degrees between the freezing and boiling points of water. For many years
his scale was called the centigrade scale. In 1948 an international conference of
scientists re-named it the Celsius scale in honor of its inventor. The Celsius degree, °C,
was defined as 1/100 of the temperature difference between the freezing point and boiling
point of water.
In the 19th century, an English scientist, Lord Kelvin, established a more fundamental
temperature scale that used the lowest possible temperature as a reference point for the
beginning of the scale. The lowest possible temperature, sometimes called absolute zero,
was established as 0 K (zero Kelvin). This temperature is 273.15°C below zero,
or -273.15°C. Accordingly, the Kelvin degree, K, was chosen to be the same as a Celsius
degree so that there would be a simple relationship between the two scales.
Note that the degree sign (°) is not used when stating a temperature on the Kelvin scale.
Temperature is stated simply as Kelvin (K). The Kelvin was adopted by the 10th
Conference of Weights and Measures in 1954, and is the SI unit of thermodynamic
temperature. Note that the degree Celsius (°C) is the SI unit for expressing Celsius
temperature and temperature intervals. The temperature interval one degree Celsius
equals one kelvin exactly. Thus, 0°C = 273.15 K by definition.
1.02-12
DOE-HDBK-1122-2009
Module 1.02 Unit Analysis & Conversion Study Guide
To convert from one unit system to another, the following formulas are used:
Table 5. Equations for Temperature Conversions
° −
C ( F 32) or ° =C (°F )⎛ ⎞5
° = − 32 ⎜ ⎟°F to °C 1.8 9⎝ ⎠
⎛ ⎞F 1.8 ° +C F ⎜ ⎟ ° + 32 ° = 32 or ° = C( ) 9 ( )°C to °F 5⎝ ⎠
1.02-13
DOE-HDBK-1122-2009
Module 1.02 Unit Analysis & Conversion Study Guide
K = C° + 273.15°C to K
EXAMPLE 3.
Convert 65° Fahrenheit to Celsius.
(65° − 32)F
C° =
1.8
Section 26
33
C° =
1.8
° =C 18.3°C
1.02-14
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Module 1.02 Unit Analysis & Conversion Study Guide
PRACTICAL EXERCISES:
Convert the following measurements:
1. 67 mm = __________ feet.
2. 1843 ounces = __________ kg.
3. 3500 microsieverts (µSv) = __________ millirem (mrem).
4. 0.007 years = __________ minutes.
5. 5000 disintegrations per minute (dpm) = __________ millicuries (mCi).
1.02-15
DOE-HDBK-1122-2009
Module 1.02 Unit Analysis & Conversion Study Guide
6. 2350 micrometer (µm) = __________ inches.
7. 2.5E-4 ergs = __________ keV.
8. 205 °F = __________ K.
9. 2E-3 rad = __________ milligray (mGy).
10. −25 °C = __________ °F.
1.02-16
DOE-HDBK-1122-2009
Module 1.02 Unit Analysis & Conversion Study Guide
Use unit analysis and conversion to solve the following problems.
11. Light travels at 186,000 miles per second. How many feet will light travel in one
minute?
12. A worker earns a monthly salary of $2500. If the worker gets paid every two weeks and
works no overtime, what will be the gross amount for a given pay period?
13. An air sampler has run for 18 hours, 15 minutes at 60 liters per minute. When collected
and analyzed the sample reads 7685 disintegrations per minute (dpm). What is the
concentration of the sample in microcuries/cm3?
1.02-17
DOE-HDBK-1122-2009
Module 1.02 Unit Analysis & Conversion Study Guide
PRACTICAL EXERCISE SOLUTIONS:
1. 67 mm = __________ feet.
⎛ 67mm ⎞⎛ 1m ⎞⎛ 3.2808 ft ⎞ = 0.22 ft⎜ ⎟⎜ ⎟⎜ ⎟
⎝ 1 ⎠⎝ 1 3 E mm ⎠⎝ 1m ⎠
2. 1843 ounces = __________ kg.
⎛1843oz ⎞⎛ 28.35g ⎞⎛ 1kg ⎞
oz = 52.25kg ⎜ ⎟⎜ ⎟⎜ ⎟
⎝ 1 ⎠⎝ 1 ⎠⎝ E g ⎠1 3
3. 3500 microsieverts (µSv) = __________ millirem (mrem).
3.5 3μ ⎞ 1Sv ⎞ 1 2rem ⎞⎛ 1 3 mrem ⎞⎛ E Sv ⎛ ⎛ E E
= 3.5E2mrem = 350mrem ⎜ ⎟⎜ ⎟⎜ ⎟⎜ ⎟
⎠⎝ E Sv 1⎝ 1 1 6μ ⎠⎝ Sv ⎠⎝ 1rem ⎠
4. 0.007 years = __________ minutes.
⎛ 0.007 year ⎞⎛ 365.25 ⎞⎛ 24hours ⎞⎛ 60minutes ⎞ = 3681.72minutes ⎜ ⎟⎜ ⎟⎜ ⎟⎜ ⎟
⎝ 1 ⎠⎝ 1year ⎠⎝ 1day ⎠⎝ 1hour ⎠
5. 5000 dis./min. = __________ millicuries (mCi).
⎛ ⎞
⎛ 5 3E dis ⎞⎜ 1Ci ⎟⎛ 1 3 E mCi ⎞
= 2.25E − 6mCi ⎜ ⎟⎜ ⎟⎜ ⎟
⎝ min ⎠ dis ⎝ 1ci ⎠⎜ 2.22 12 ⎟E
⎝ min ⎠
1.02-18
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Module 1.02 Unit Analysis & Conversion Study Guide
6. 2350 micrometer (µm) = __________ inch.
⎛ 2350μ ⎞⎛ 3.937E − 5inches ⎞
= 0.0925inches = 9.25E − 2inch ⎜ ⎟⎜ ⎟1 1μ⎝ ⎠⎝ ⎠
7. 2.5E-4 ergs = __________ keV.
⎛ 2.5E − 4ergs ⎞⎛ E ⎛ 1 ⎞6.2148 11 ⎞ keV
=1.55 5E keV ⎜ ⎟⎜ ⎟⎜ ⎟
⎝ 1 ⎠⎝ 1erg ⎠⎝1 3 ⎠E eV
8. 205 ΕF = __________ K.
(205° − 32)F
° =C = 96.1°C
1.8
K = 96.1 C 273.16 = 369.27K
° +
9. 2E-3 rad = __________ milligray (mGy).
⎛ 2E − 3rad ⎞⎛ 0.01Gy ⎞⎛1 3 ⎞E mGys
⎜ ⎟⎜ ⎟⎜ ⎟ = 2E − 2mGy = 0.02mGy
⎝ 1 ⎠⎝ 1rad ⎠⎝ 1Gy ⎠
10. −25 °C = __________ °F.
° = ( 25 C )1.8 + 32 = 13 F − ° − °F
1.02-19
DOE-HDBK-1122-2009
Module 1.02 Unit Analysis & Conversion Study Guide
Use unit analysis and conversion to solve the following:
11. Light travels at 186,000 miles per second. How many feet will light travel in one
minute?
⎛186,000 miles ⎞⎛ 5280 ft ⎞⎛ 60sec ⎞ ft
= 5.89 10 E⎜ ⎟⎜ ⎟⎜ ⎟
⎝ sec ⎠⎝ 1mile ⎠⎝ 1minute ⎠ min
12. A worker earns a monthly salary of $2500. If the worker gets paid every two weeks and
works no overtime, what will be the gross amount for a given pay period?
⎛ 2500dollars ⎞⎛12months ⎞⎛ 1year ⎞⎛ 2weeks ⎞ dollars
= 1153.85⎜ ⎟⎜ ⎟⎜ ⎟⎜ ⎟
⎝ months ⎠⎝ 1year ⎠⎝ 52 weeks ⎠⎝ payperiod ⎠ payperiod
Section 27
13. An air sampler has run for 18 hours, 15 minutes at 60 liters per minute. When collected
and analyzed the sample reads 7685 dis./min. What is the concentration of the sample in
microcuries/cm3?
⎛15minutes ⎞⎛ 1hour ⎞ = 0.25hour⎜ ⎟⎜ ⎟
⎝ 1 ⎠⎝ 60 minutes ⎠
18 hours + 0.25 hours = 18.25 hours
⎛18.25hours ⎞⎛ 60minutes ⎞⎛ 60l ⎞ = 65,700 l⎜ ⎟⎜ ⎟⎜ ⎟
⎝ 1 ⎠⎝ 1hour ⎠⎝ 1minute ⎠
⎛ 7685dpm ⎞⎛ 1Ci ⎞⎛1 6E μCi ⎞⎛ 1l ⎞⎛ 0.99997 ml ⎞ μCi
= 5.26E −11⎜ ⎟⎜ ⎟⎜ ⎟⎜ ⎟⎜ ⎟E ⎠⎝ 1 E ml cc ⎝ 6.57E4l ⎠⎝ 2.22 12 dpm Ci ⎠⎝ 1 3 ⎠⎝ 1 ⎠ cc
1.02-20
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Module 1.02 Unit Analysis & Conversion Study Guide
INSTRUCTIONS FOR USING CONVERSION FACTOR TABLES
The tables that follow include conversion factors that are useful to the RCT. They are
useful in making a single conversion from one unit to another by using the guide arrows
at the top of the page in accordance with the direction of the conversion. However, when
using the tables to develop equivalent fractions for use in unit analysis equations, a better
understanding of how to read the conversion factors given in the table is required.
The conversions in the table have been arranged by section in the order of fundamental
units, followed by derived units:
Length
Mass
Time
Area
Volume
Density
Radiological
Energy
Fission
Miscellaneous (Temperature, etc.)
The easiest way to read a conversion from the table is done as follows. Reading left to
right, "one (1) of the units in the left column is equal to the number in the center column
of the unit in the right column." For example, look at the first conversion listed under
Length. This conversion would be read from left to right as "1 angstrom is equal to E-8
centimeters," or
Another conversion would be read from left to right as "1 millimeter (mm) is equal to
1E-1 centimeters," or 1 mm = 0.1 cm. This method can be applied to any of the
conversions listed in these tables when reading left to right.
If reading right to left, the conversion should be read as "one (1) of the unit in the right
column is equal to the inverse of (1 over) the number in the center column of the unit in
the left column." For example, using the conversion shown previously, the conversion
reading right to left would be "1 inch is equal to the inverse of 3.937E-5 (1/3.937E-5)
micrometers," or
11inch = = 2.54 E4 μm
3.937E − 5μm
1.02-21
DOE-HDBK-1122-2009
Module 1.01 Basic Mathematics and Algebra Study Guide
Multiply # of by to obtain # of
to obtain # of by Divide # of
Length
angstroms (Å) 10-8 Cm
10-10Å M
micrometer (µm) 10-3 Mm
µm 10-4 Cm
µm 10-6 M
µm 3.937 × 10-5 in.
mm 10-1 Cm
cm 0.3937 in.
cm 3.2808 × 10-2 Ft
cm 10-2 M
m 39.370 in.
m 3.2808 Ft
m 1.0936 Yd
m 10-3 Km
m 6.2137 × 10-4 Miles
km 0.62137 Miles
mils 10-3 in.
mils 2.540 × 10-3 Cm
in. 103 Mils
in. 2.5400 Cm
ft 30.480 Cm
rods 5.500 Yd
miles 5280 Ft
miles 1760 Yd
miles 1.6094 Km
1.02-23
DOE-HDBK-1122-2009
Module 1.02 Unit Analysis & Conversion Study Guide
Multiply # of by to obtain # of
to obtain # of by Divide # of
Mass
mg 10-3 G
mg 3.527 × 10-5 oz avdp
mg 1.543 × 10-2 Grains
g 3.527 × 10-2 oz avdp
g 10-3 Kg
g 980.7 Dynes
g 2.205 × 10-3 Lb
kg 2.205 Lb
kg 0.0685 Slugs
kg 9.807 × 105 Dynes
lb 4.448 × 105 Dynes
lb 453.592 G
lb 0.4536 Kg
lb 16 oz avdp
lb 0.0311 Slugs
dynes 1.020 × 10-3 G
dynes 2.248 × 10-6 Lb
u (unified--12C scale) 1.66043 × 10-27 Kg
amu (physical--160 scale) 1.65980 × 10-27 Kg
oz 28.35 G
oz 6.25 × 10-2 Lb
Note: Mass to energy conversions under miscellaneous
Section 28
1.02-24
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Module 1.02 Unit Analysis & Conversion Study Guide
Multiply # of by to obtain # of
to obtain # of by Divide # of
Time
days 86,400 Sec
days 1440 Min
days 24 Hours
years 3.15576 × 107 Sec
years 525,960 Min
years 8766 Hr
years 365.25 Days
Area
10-24 2barns cm
circular mils 7.854 × 10-7 in.2
cm2 1024 Barns
cm2 0.1550 in.2
cm2 1.076 × 10-3 ft2
cm2 10-4 m2
ft2 929.0 cm2
ft2 144 in2
ft2 9.290 × 10-2 m2
in.2 6.452 cm2
in.2 6.944 × 10-3 ft2
in.2 6.452 × 10-4 m2
m2 1550 in.2
m2 10.76 ft2
m2 1.196 yd2
m2 3.861 × 10-7 sq mi
1.02-25
DOE-HDBK-1122-2009
Module 1.02 Unit Analysis & Conversion Study Guide
Multiply # of by to obtain # of
to obtain # of by Divide # of
Volume
cm3 (cc) 0.99997 Ml
cm3 6.1023 × 10-2 in.3
cm3 10-6 m3
cm3 9.9997 × 10-4 Liters
cm3 3.5314 × 10-5 ft3
m3 35.314 ft3
m3 2.642 × 102 Gal
m3 9.9997 × 102 Liters
in.3 16.387 cm3
in.3 5.787 × 10-4 ft3
in.3 1.639 × 10-2 Liters
in.3 4.329 × 10-3 Gal
ft3 2.832 × 10-2 m3
ft3 7.481 Gal
ft3 28.32 Liters
ft3 1728 in.3
gal (U.S.) 231.0 in.3
gal 0.13368 ft3
liters 33.8147 fluid oz
liters 1.05671 Quarts
liters 0.26418 Gal
gm moles (gas) 22.4 liters (s.t.p.)
1.02-26
DOE-HDBK-1122-2009
Module 1.02 Unit Analysis & Conversion Study Guide
Multiply # of
to obtain # of
cm3/g
ft3/lb
g/cm3
lb/ft3
lb/in.3
lb/gal
becquerel
curies
curies
curies
curies
curies
curies
curies
dis/min
dis/min
dis/sec
dis/sec
kilocuries
microcuries
microcuries
millicuries
millicuries
R
R
R
by
by
Density
1.602 × 10-2
62.43
62.43
1.602 × 10-2
27.68
0.1198
Radiological Units
2.703 × 10-11
3.700 × 1010
2.220 × 1012
103
106
1012
10-3
3.700 × 1010
4.505 × 10-10
4.505 × 10-7
2.703 × 10-8
2.703 × 10-5
103
3.700 × 104
2.220 × 106
3.700 × 107
2.220 × 109
2.58 × 10-4
1
2.082 × 109
to obtain # of
Divide # of
ft3/lb
cm3/g
lb/ft3
g/cm3
g/cm3
g/cm3
Curies
dis/sec
dis/min
Millicuries
Microcuries
Picocuries
Kilocuries
Becquerel
Millicuries
Microcuries
Millicuries
Microcuries
Curies
dis/sec
dis/min
dis/sec
dis/min
C/kg of air
esu/cm3 of air (s.t.p.)
ion prs/cm3 of air
(s.t.p.)
1.02-27
DOE-HDBK-1122-2009
Module 1.02 Unit Analysis & Conversion Study Guide
Multiply # of
to obtain # of
R
R (33.7 eV/ion pr.)
R (33.7 eV/ion pr.)
R (33.7 eV/ion pr.)
R (33.7 eV/ion pr.)
R (33.7 eV/ion pr.)
rads
rads
rads
rads
rads
rads
rads (33.7 eV/ion pr.)
gray
rem
sievert
µCi/3 (µCi/ml)
µCi/cm3
dpm/m3
Btu
Btu
Btu
Btu
Btu/lb
eV
by
by
Radiological Units (continued)
1.610 × 1012
7.02 × 104
5.43 × 107
86.9
2.08 × 10-6
.98
0.01
0.01
100
8.071 × 104
6.242 × 107
10-5
2.39 × 109
100
0.01
100
2.22 × 1012
2.22 × 109
0.4505
Energy
1.0548 × 103
0.25198
1.0548 × 1010
2.930 × 10-4
0.556
1.6021 × 10-12
to obtain # of
Divide # of
ion prs/g of air
MeV/cm3 of air (s.t.p.)
MeV/g of air
ergs/g of air
g-cal/g of air
ergs/g of soft tissue
Gray
J/kg
ergs/g
MeV/cm3 or air (s.t.p.)
MeV/g
watt-sec/g
ion prs/cm3 of air
(s.t.p.)
Rad
Sievert
Rem
dpm/m3
dpm/liter
pCi/m3
joules (absolute)
kg-cal
Ergs
kW-hr
g-cal/g
Ergs
1.02-28
DOE-HDBK-1122-2009
Module 1.02 Unit Analysis & Conversion Study Guide
Multiply # of by to obtain # of
to obtain # of by Divide # of
Energy (continued)
eV 1.6021 × 10-19 joules (abs)
eV 10-3 keV
eV 10-6 MeV
ergs 10-7 joules (abs)
ergs 6.2418 × 105 MeV
ergs 6.2418 × 1011 eV
ergs 1.0 dyne-cm
ergs 9.480 × 10-11 Btu
ergs 7.375 × 10-8 ft-lb
ergs 2.390 × 10-8 g-cal
ergs 1.020 × 10-3 g-cm
gm-calories 3.968 × 10-3 Btu
gm-calories 4.186 × 107 Ergs
joules (abs) 107 Ergs
joules (abs) 0.7376 ft-lb
joules (abs) 9.480 × 10-4 Btu
g-cal/g 1.8 Btu/lb
kg-cal 3.968 Btu
kg-cal 3.087 × 103 ft-lb
ft-lb 1.356 joules (abs)
ft-lb 3.239 × 10-4 kg-cal
kW-hr 2.247 × 1019 MeV
kW-hr 3.60 × 1013 Ergs
MeV 1.6021 × 10-6 Ergs
Section 29
Note: Mass to energy conversions under miscellaneous
1.02-29
DOE-HDBK-1122-2009
Module 1.02 Unit Analysis & Conversion Study Guide
Multiply # of by to obtain # of
to obtain # of by Divide # of
Fission
Btu 1.28 × 10-8 grams 235U fissionedb
Btu 1.53 × 10-8 grams 235U destroyedb,c
Btu 3.29 × 1013 Fissions
fission of 1 g 235U 1 megawatt-days
fissions 8.9058 × 10-18 kilowatt-hours
fissionsb 3.204 × 10-4 Ergs
kilowatt-hours 2.7865 × 1017 235U fission neutrons
average thermal
kilowatts per kilogram 235U 2.43 × 1010 neutron flu× in fuelb,d
megawatt-days per ton U 1.174 × 10-4 % U atoms fissionede
average thermal
megawatts per ton U 2.68 × 1010/Ef neutron flu× in fuelb
neutrons per kilobarn 1 × 1021 neutrons/cm2
watts 3.121 × 1010 fissions/sec
1.02-30
DOE-HDBK-1122-2009
Module 1.02 Unit Analysis & Conversion Study Guide
Multiply # of by to obtain # of
to obtain # of by Divide # of
Miscellaneous
radians 57.296 Degrees
eV 1.78258 × 10-33 Grams
eV 1.07356 × 10-9 U
erg 1.11265 × 10-21 Grams
proton masses 938.256 MeV
neutron masses 939.550 MeV
electron masses 511.006 keV
u (amu on 12C scale) 931.478 MeV
Temperature
F 32) 5(° − ⎛ ⎞C C ( F 32 ⎜ ⎟° = ° = ° − )
1.8 9⎝ ⎠
F ° ⎛ ⎞ C
° =1.8( )C + 32 9F ⎜ ⎟ ° + 32° = ( )
5⎝ ⎠
K C 273.16° = ° +
Wavelength to Energy Conversion
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Module 1.03Physical Sciences
Course Title: Radiological Control Technician
Module Title: Physical Sciences
Module Number: 1.03
Objectives :
1.03.01 Define the following terms as they relate to physics:
a. Work
b. Force
c. Energy
1.03.02 Identify and describe four forms of energy.
1.03.03 State the Law of Conservation of Energy.
1.03.04 Distinguish between a solid, a liquid, and a gas in terms of shape and volume.
1.03.05 Identify the basic structure of the atom, including the characteristics of subatomic
particles.
1.03.06 Define the following terms:
a. Atomic number
b. Mass number
c. Atomic mass
d. Atomic weight
1.03.07 Identify what each symbol represents in the X notation.
1.03.08 State the mode of arrangement of the elements in the Periodic Table.
1.03.09 Identify periods and groups in the Periodic Table in terms of their layout.
1.03.10 Define the terms as they relate to atomic structure:
a. Valence shell
b. Valence electron
INTRODUCTION
This lesson introduces the RCT to the concepts of energy, work, and the physical states of
matter. Knowledge of these topics is important to the RCT as he or she works in
environments where materials can undergo changes in state, resulting in changes in the work
environment.
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References:
1. "Chart of the Nuclides"; Sixteenth Edition, Knolls Atomic; 2003.
2. "Modern Physics"; Holt, Rinehart and Winston, Publishers; 1976.
3. "Chemistry: An Investigative Approach"; Houghton Mifflin Co., Boston; 1976.
4. "Chemical Principles with Qualitative Analysis"; Sixth ed.; Saunders College
Pub.; 1986.
5. "Introduction to Chemistry" sixth ed., Dickson, T. R., John Wiley & Sons, Inc.;
1991.
6. "Matter"; Lapp, Ralph E., Life Science Library, Time Life Books; 1965.
7. "Physics"; Giancoli, Douglas C., second ed., Prentice Hall, Inc.; 1985.
8. DOE/HDBK-1015 "Chemistry: Volume 1 of 2"; DOE Fundamentals Handbook
Series; January 1993.
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1.03.01 Define the following terms as they relate to physics:
a. Work
b. Force
c. Energy
Section 30
WORK & FORCE
Physics is the branch of science that describes the properties, changes, and interactions of
energy and matter. This unit will serve as a brief introduction to some of the concepts of
physics as they apply to the situations that may be encountered by RCTs. Energy can be
understood by relating it to another physical concept - work.
The word work has a variety of meanings in everyday language. In physics, however, work is
specifically defined as a force acting through a distance. Simply put, a force is a push or a pull.
A more technical definition of force is any action on an object that can cause the object to
change speed or direction.
Units
Force is derived as the product of mass and acceleration (see equation below). The SI
derived unit of force is the newton (N). It is defined as the force which, when applied to
a body having a mass of one kilogram, gives it an acceleration of one meter per second
squared; that is:
kg × mN = 2s
As we said before, work is what is accomplished by the action of a force when it makes
an object move through a distance. Mathematically, work is expressed as the product of
a displacement and the force in the direction of the displacement; that is:
W = Fd
where: W = Work
F = Force (newtons)
d = Distance (meters)
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For example, a horse works by exerting a physical force (muscle movement) to move a
carriage. As the horse pulls, the carriage moves forward in the direction that the horse is
pulling. Work is also done by an outside force (energy) to remove an electron from its
orbit around the nucleus of an atom.
The SI derived unit of work is the joule (J). One joule of work is performed when a force
of one newton is exerted through a distance of one meter. Thus:
J N m= ×
By this definition, work can only be performed when the force causes an object to be
moved. This means that if the distance is zero then no work has been performed, even
though a force has been applied. For example, if you stand at rest holding a bag of
groceries in your hands, you do no work on it; your arms may become tired (and indeed
energy is being expended by your muscles), but because the bag is not moved through a
distance (d = 0), no work is performed (W = 0).
ENERGY
Energy (E) is defined as the ability to do work. Energy and work are closely related, but
they are not the same thing. The relationship is that it takes energy to do work, and work can
generate energy. This energy will be found in various forms.
1.03.02 Identify and describe four forms of energy.
Kinetic Energy
Kinetic energy describes the energy of motion an object possesses. For example, a
moving airplane possesses kinetic energy.
1 2EK = mv
2
where: m = mass
v = velocity
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Potential Energy
Potential energy (gravitational) indicates how much energy is stored as a result of the
position or the configuration of an object. For example, water at the top of a waterfall
possesses potential energy.
EP = mgh
where: m = mass
g = free fall acceleration
h = vertical distance
Thermal Energy
Thermal energy, or heat, describes the energy that results from the random motion of
molecules. (Molecules are groups of atoms held together by strong forces called
chemical bonds.) For example, steam possesses thermal energy.
Chemical Energy
Section 31
Chemical energy describes the energy that is derived from atomic and molecular
interactions in which new substances are produced. For example, the substances in a
dry cell provide energy when they react.
Other Forms of Energy
Other forms of energy, such as electrical and nuclear, will be described in later lessons. Energy
may also appear as acoustical (sound) or radiant (light) energy.
1.03.03 State the Law of Conservation of Energy.
Law of Conservation of Energy
The Law of Conservation of Energy states that the total amount of energy in a closed
system remains unchanged. Stated in other terms, as long as no energy enters or leaves
the system, the amount of energy in the system will always be the same, although it can
be converted from one form to another.
For example, suppose a boulder lies at the bottom of a hill and bulldozer is used to push it
to the top. If the dozer puts a certain continuous force on the boulder to keep it moving
up the slope and moves it a distance, work has been done. The dozer is able to do this
work because its engine burns gasoline, creates heat. The heat is converted into the
kinetic energy of the moving bulldozer and the boulder in front of it. Some of this energy
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is converted into heat and noise. Some is converted into the potential energy that the
dozer and the boulder have gained in going to the top of the hill. If the boulder is allowed
to roll
back down the hill again, its potential energy will be converted partly into kinetic energy
and partly into heat. The heat is produced by friction as the boulder rolls. Eventually the
boulder will come to a stop, when all of its kinetic energy has been converted into heat.
It leaves a trail of heat that is soaked up in the surroundings.
Gasoline contains chemical energy that is released in the form of heat when a chemical
reaction (burning) with oxygen occurs. This energy comes from the breaking and making
of bonds between atoms. New products, carbon dioxide and water, are formed as the
gasoline combines with oxygen. The energy of the burning gasoline produces heat
energy which causes the gaseous combustion products to do work on the pistons in the
engine. The work results in the bulldozer moving, giving it kinetic energy.
Units of Energy
Energy is expressed in the same units as work, that is, joules (J). The joule is the SI unit
of energy. However, because energy can take on many different forms, it is sometimes
measured in other units which can be converted to joules. Some of these units are
mentioned below.
Thermal Energy
Thermal energy is often measured in units of calories (CGS) or British Thermal
Units or BTUs (English).
• A calorie is the amount of heat needed to raise the temperature of 1 gram
of water by 1 °C. One calorie is equal to 4.18605 joules.
• A BTU is the amount of heat needed to raise the temperature of 1 pound
of water by 1 °F. One BTU is equal to 1.055E3 joules.
Electrical Energy
Electrical energy is sometimes expressed in units of kilowatt-hours. One kw-hr is
equal to 3.6E6 joules
A very small unit used to describe the energy of atomic and subatomic size particles is
the electron volt (eV). One electron volt is the amount of energy acquired by an
electron when it moves through a potential of one volt. For example, it takes about
15.8 eV of energy to remove an electron from an argon atom. Superunits such as
kiloelectron volt (keV) and megaelectron volt (MeV) are used to indicate the energies of
various ionizing radiations.
Section 32
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Work-Energy Relationship
When work is done by a system or object, it expends energy. For example, when the
gaseous combustion products in an automobile engine push against the pistons, the gas
loses energy. The chemical energy stored in the gasoline is used to do work so that the
car will move.
When work is done on a system or object, it acquires energy. The work done on the car
by the combustion of the gasoline causes the car to move, giving it more kinetic energy.
When energy is converted to work or changed into another form of energy, the total
amount of energy remains constant. Although it may appear that an energy loss has
occurred, all of the original energy can be accounted for.
Consider again the automobile engine. The energy stored in the gasoline is converted to
heat energy, some of which is eventually converted to kinetic energy. The remainder of
the heat energy is removed by the engine's cooling system. The motion of the engine
parts creates friction, heat energy, which is also removed by the engine's cooling system.
As the car travels, it encounters resistance with the air. If no acceleration occurs, the car
will slow down as the kinetic energy is converted to friction or heat energy. The contact
of the tires on the road converts some of the available kinetic energy to heat energy
(friction), slowing down the car. A significant amount of the energy stored in the
gasoline is dissipated as wasted heat energy.
Energy-mass relationship
Energy can also be converted into mass and mass converted into energy. This will be
discussed further in section 1.04 "Nuclear Sciences."
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1.03.03 Distinguish between a solid, a liquid, and a gas in terms of shape and volume.
ENERGY AND CHANGE OF STATE
Matter is anything that has mass and takes up space. All matter is made up of atoms and
molecules which are the building blocks used to form all kinds of different substances. These
atoms and molecules are in constant random motion. Because of this motion they have
thermal energy. The amount of energy depends on the temperature and determines the state or
phase of the substance. There are three states of matter, solid, liquid and gas.
Any substance can exist in any of the three states, but there is generally one state which
predominates under normal conditions (temperature and pressure). Take water, for example.
At normal temperatures, water is in the liquid state. In the solid state, water is called ice. The
gaseous state of water is called steam or water vapor. It's all still water, just in different states.
Table 1 provides a summary of these three states in terms of shape and volume.
Table 1. States of Matter Compared
State Shape Volume
Solid
Liquid
Gas
definite
indefinite
indefinite
definite
definite
indefinite
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Solid State
A solid has definite shape and volume. The solid state differs from the liquid and
gaseous states in that:
• The molecules or ions of a solid are held in place by strong attractive forces.
• The molecules have thermal energy, but the energy is not sufficient to overcome
the attractive forces.
• The molecules of a solid are arranged in an orderly, fixed pattern.
The rigid arrangement of molecules causes the solid to have a definite shape and a
definite volume.
Section 33
Liquid State
When heat is added to a substance, the molecules acquire more energy, which causes
them to break free of their fixed crystalline arrangement. As a solid is heated, its
temperature rises until the change of state from solid to liquid occurs.
The volume of a liquid is definite since the molecules are very close to each other, with
almost no space in between. Consequently, liquids can undergo a negligible amount of
compression. However, the attractive forces between the molecules are not strong
enough to hold the liquid in a definite shape. For this reason a liquid takes the shape of
its container.
High energy molecules near the surface of a liquid can overcome the attractive forces of
other molecules. These molecules transfer from the liquid state to the gaseous state. If
energy (heat) is removed from the liquid, the kinetic energy of the molecules decreases
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and the attractive forces can hold the molecules in fixed positions. When compared with
the kinetic energy, the attractive forces are not strong enough to hold the molecules in
fixed positions, forming a solid.
Gaseous State
If the temperature of a liquid is increased sufficiently, it boils, that is, molecules change
to the gaseous state and escape from the surface. Eventually, all of the liquid will
become a gas. A gas has both indefinite shape and indefinite volume. A large space
exists between gas molecules because of their high thermal energy. This allows for even
more compression of a substance in the gaseous state.
1.03.03 Identify the basic structure of the atom, including the characteristics of
subatomic particles.
THE ATOM
The Bohr Model
As stated previously, the fundamental
building block of matter is the atom. The
basic atomic model, as described by Ernest
Rutherford and Niels Bohr in 1911, consists
of a positively charged core surrounded by
negatively-charged shells. The central core,
called the nucleus, contains protons and
neutrons. Nuclear forces hold the nucleus
together. The shells are formed by electrons
which exist in structured orbits around the
nucleus. Below is a summary of the three
primary subatomic particles which are the
constituent parts of the atom.
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Protons
• Positively charged (+1)
• Mass: 1.6726E-24 gm or 1.007276470 amu
• Each element is determined by the number of protons in its nucleus. All atoms of the
same element have the same number of protons.
Neutrons
• Neutrally charged (0)
• Mass: 1.6749E-24 gm or 1.008665012 amu
• The number of neutrons determines the isotope of an element. Isotopes are atoms which
have the same number of protons (therefore, of the same element) but different number of
neutrons. This does not affect the chemical properties of the element.
Electrons
• Negatively charged (-1)
• Small mass: 9.1085E-28 gm or 0.00054858026 amu (1/1840 of a proton)
Because the mass of an electron is so small as compared to that of a proton or neutron,
virtually the entire mass of an atom is furnished by the nucleus.
• The number of electrons is normally equal to the number of protons. Therefore, the atom
is electrically neutral.
• The number of electrons in the outermost shell determines the chemical behavior or
properties of the atom.
THE ELEMENTS
Section 34
Even though all atoms have the same basic structure, not all atoms are the same. There are
over a hundred different types of atoms. These different types of atoms are known as elements.
The atoms of a given element are alike but have different properties than the atoms of other
elements.
Elements are the simplest forms of matter. They can exist alone or in various combinations.
Different elements can chemically combine to form molecules or molecular compounds. For
example, water is a compound, consisting of water molecules. These molecules can be
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decomposed into the elements hydrogen and oxygen. The elements hydrogen and oxygen are
fundamental forms of matter. They cannot be further separated into simpler chemicals.
Chemical Names
Currently, there are over 110 named elements. Table 2 lists the elements and their
symbols. Some have been known for many centuries, while others have only been
discovered in the last 15 or 20 years. Each element has a unique name. The names of the
elements have a variety of origins. Some elements were named for their color or other
physical characteristics. Others were named after persons, places, planets or
mythological figures.
For example, the name chromium comes from the Greek word chroma, which means
"color." Chromium is found naturally in compounds used as pigments. The elements
curium, einsteinium, and fermium were named after famous nuclear physicists.
Germanium, polonium and americium, were named after countries. Uranium, neptunium
and plutonium are named in sequence for the three celestial bodies Uranus, Neptune and
Pluto.
Chemical Symbols
For convenience, elements have a symbol which is used as a shorthand for writing the
names of elements. The symbol for an element is either one or two letters taken from the
name of the element (see Table 2). Note that some have symbols that are based on the
historical name of the element. For example, the symbols for silver and gold are Ag and
Au respectively. These come from the old Latin names argentum and aurum. The
symbol for mercury, Hg, comes from the Greek hydrargyros which means "liquid silver."
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Element Symbol Z Element Symbol Z Element Symbol Z
Actinium Ac 89 Hafnium Hf 72 Promethium Pm 61
Aluminum Al 13 Hassium Hs 108 Protactinium Pa 91
Americium Am 95 Helium He 2 Radium Ra 88
Antimony Sb 51 Holmium Ho 67 Radon Rn 86
Argon Ar 18 Hydrogen H 1 Rhenium Re 75
Arsenic As 33 Indium In 49 Rhodium Rh 45
Astatine At 85 Iodine I 53 Rubidium Rb 37
Barium Ba 56 Iridium Ir 77 Ruthenium Ru 44
Berkelium Bk 97 Iron Fe 26 Rutherfordium Rf 104
Beryllium Be 4 Krypton Kr 36 Samarium Sm 62
Bismuth Bi 83 Lanthanum La 57 Scandium Sc 21
Bohrium Bh 107 Lawrencium Lw 103 Seaborgium Sg 106
Boron B 5 Lead Pb 82 Selenium Se 34
Bromine Br 35 Lithium Li 3 Silicon Si 14
Cadmium Cd 48 Lutetium Lu 71 Silver Ag 47
Calcium Ca 20 Magnesium Mg 12 Sodium Na 11
Californium Cf 98 Manganese Mn 25 Strontium Sr 38
Carbon C 6 Meitnerium Mt 109 Sulfur S 16
Cerium Ce 58 Mendelevium Md 101 Tantalum Ta 73
Cesium Cs 55 Mercury Hg 80 Technetium Tc 43
Chlorine Cl 17 Molybdenum Mo 42 Tellurium Te 52
Chromium Cr 24 Neodymium Nd 60 Terbium Tb 65
Cobalt Co 27 Neon Ne 10 Thallium Tl 81
Copper Cu 29 Neptunium Np 93 Thorium Th 90
Curium Cm 96 Nickel Ni 28 Thulium Tm 69
Dubnium Db 105 Niobium Nb 41 Tin Sn 50
Dysprosium Dy 66 Nitrogen N 7 Titanium Ti 22
Einsteinium Es 99 Nobelium No 102 Tungsten W 74
Erbium Er 68 Osmium Os 76 Uranium U 92
Europium Eu 63 Oxygen O 8 Vanadium V 23
Fermium Fm 100 Palladium Pd 46 Xenon Xe 54
Fluorine F 9 Phosphorus P 15 Ytterbium Yb 70
Francium Fr 87 Platinum Pt 78 Yttrium Y 39
Gadolinium Gd 64 Plutonium Pu 94 Zinc Zn 30
Gallium Ga 31 Polonium Po 84 Zirconium Zr 40
Germanium Ge 32 Potassium K 19
Gold Au 79 Praseodymium Pr 59
Section 35
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1.03.03 Define the following terms:
a) Atomic number
b) Mass number
c) Atomic mass
d) Atomic weight
Atomic Number
The number of protons in the nucleus of an element is called the atomic number. All
atoms of a particular element have the same atomic number. Atomic numbers are
integers. For example, a hydrogen atom has one proton in the nucleus. Therefore, the
atomic number of hydrogen is 1. A helium atom has two protons in the nucleus, which
means that its atomic number is 2. Uranium has 92 protons in the nucleus and, therefore,
has an atomic number of 92. Atomic number is often represented by the symbol Z.
Mass Number
The total number of protons plus neutrons in the nucleus of a particular isotope of an
element is called the mass number. It is the integer nearest to the mass of the atom of
concern. Since a proton has a mass of 1.0073 amu, we will give a proton a mass number
of 1. The mass number of a neutron would also be 1, since its mass is 1.0087 amu. So,
by adding the number of protons and the number of neutrons we can determine the mass
number of the atom of concern.
For example, a normal hydrogen atom has 1 proton, but no neutrons. Therefore, its mass
number is 1. A helium atom has 2 protons and 2 neutrons, which means that it has a
mass number of 4. If a uranium isotope has 146 neutrons then it has a mass number of
238 (92 + 146), while if it only has 143 neutrons its mass number would be 235.
The mass number can be used with the name of the element to identify which isotope of
an element we are referring to. If we are referring to the isotope of uranium that has a
mass number of 238, we can write it as Uranium-238. If we are referring to the isotope
of mass number 235, we write it as Uranium-235. Often, this expression is shortened by
using the chemical symbol instead of the full name of the element, as in U-238 or U-235.
Atomic Mass
The actual mass of an atom of a particular isotope is called its atomic mass. The units
are expressed in Atomic Mass Units (AMU). AMUs are based on 1/12 of the mass of a
Carbon-12 atom (1.660E-24 gm). In other words, the mass of one C-12 atom is exactly
12 amu.
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For example, the mass of a hydrogen atom is 1.007825 amu (1 proton + 1 electron =
1.00727647 + 0.00054858026) . The mass of a Uranium-238 atom in amu is 238.0508,
while the mass of a U-235 atom is only 235.0439. Notice that atomic masses are very
accurate and are written as decimals.
Atomic Weight
The weighted average of the isotopic masses of an element, based on the percent
abundance of its naturally occurring isotopes, is called the atomic weight. The atomic
weight is expressed in AMU and is used mainly in calculations of chemical reactions.
Since AMUs are based on Carbon-12, one may wonder why the Periodic Table (see
Figure 5) shows the atomic weight of Carbon as 12.011, and not exactly 12. The
explanation is simple and will help to clarify the difference between the atomic weight of
an element and the atomic mass of an isotope of that element.
Carbon, as it occurs in nature, is a mixture of two isotopes: about 98.9% of all carbon
atoms are C-12, while the abundance of C-13 atoms is 1.1% (a total of 100%). The
presence of these heavier Carbon atoms explains why the atomic weight of carbon is
slightly more than 12. The atomic weight of an element is a "weighted average" (no pun
intended). This average is determined by finding the sum of the mass of each isotope
multiplied by its percent abundance. If the atomic mass of C-12 is 12.00, and the atomic
mass of C-13 is 13.00, we can determine the atomic weight of carbon:
Section 36
12.00(0.989) + 13.00(0.011) = 11.868 + 0.143 = 12.011 amu
With the understanding of these concepts, we can discuss the Periodic Table of the
Elements and the information it provides.
1.03.07 Identify what each symbol represents in the Z
AX notation.
NUCLIDE NOTATION
The format for representing a specific combination of protons and neutrons is to use its
nuclear symbol. This is done by using the standard chemical symbol, with the atomic
number written as a subscript at the lower left of the symbol, and the mass number written as
a superscript at the upper left of the symbol:
A
Z X
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where: X = Symbol for element
Z = Atomic number: number of protons
A = Mass number: number of protons (Z) plus number of neutrons
(N); therefore: A = Z + N
For example, the notation for Uranium-238 would be 238
92 U .
1.03.08 State the mode of arrangement of the elements in the Periodic Table.
1.03.09 Identify periods and groups in the Periodic Table in terms of their layout.
MODERN PERIODIC TABLE
The modern Periodic Table (see Figure 5) is an arrangement of the elements in order of
increasing atomic number. A comparison of the properties for selected elements will
illustrate that there is a predictable, recurring pattern, or periodicity. This observation is
summarized in the Periodic Law, which states that the properties of the elements are repetitive
or recurring functions of their atomic numbers.
Data about each element in the Periodic Table are presented in a column and row format. The
rows or horizontal sections in the Periodic Table are called periods. The columns or
vertical sections are called groups or families because they "behave" chemically similar; that
is they have similar chemical properties.
Since the number of electrons is equal to the number of protons, the structure of the Periodic
Table directly relates to the number and arrangement of electrons in the atom (see Table
3). Figure 4 below gives a simple illustration of the electron shells described in the Bohr
model of the atom.
Electrons orbit around the nucleus in structured shells, designated sequentially as 1 through 7
(K through Q) from inside out. Shells represent groups of energy states called orbitals. The
higher the energy of the orbital the greater the distance from the nucleus. The lowest energy
state is in the innermost shell (K).
The number of orbitals in a shell is the square of the shell number (n). The maximum number
of electrons which can occupy an orbital is 2. Therefore, each shell can hold a maximum of
2n2 electrons. For example, for the L shell the maximum number of electrons would be 8:
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L-shell: n = 2 →→→→ 2(22) = 8
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Z Element K L M N O Z Element K L M N O P Q
1 Hydrogen 1 55 Cesium 2 8 18 18 8 1
2 Helium 2 56 Barium 2 8 18 18 8 2
3 Lithium 2 1 57 Lanthanum 2 8 18 18 9 2
4 Beryllium 2 2 58 Cerium 2 8 18 20 8 2
5 Boron 2 3 59 Praseodymium 2 8 18 21 8 2
6 Carbon 2 4 60 Neodymium 2 8 18 22 8 2
7 Nitrogen 2 5 61 Promethium 2 8 18 23 8 2
8 Oxygen 2 6 62 Samarium 2 8 18 24 8 2
9 Fluorine 2 7 63 Europium 2 8 18 25 8 2
Section 37
10 Neon 2 8 64 Gadolinium 2 8 18 25 9 2
11 Sodium 2 8 1 65 Terbium 2 8 18 27 8 2
12 Magnesium 2 8 2 66 Dysprosium 2 8 18 28 8 2
13 Aluminum 2 8 3 67 Holmium 2 8 18 29 8 2
14 Silicon 2 8 4 68 Erbium 2 8 18 30 8 2
15 Phosphorus 2 8 5 69 Thulium 2 8 18 31 8 2
16 Sulfur 2 8 6 70 Ytterbium 2 8 18 32 8 2
17 Chlorine 2 8 7 71 Lutetium 2 8 18 32 9 2
18 Argon 2 8 8 72 Hafnium 2 8 18 32 10 2
19 Potassium 2 8 8 1 73 Tantalum 2 8 18 32 11 2
20 Calcium 2 8 8 2 74 Tungsten 2 8 18 32 12 2
21 Scandium 2 8 9 2 75 Rhenium 2 8 18 32 13 2
22 Titanium 2 8 10 2 76 Osmium 2 8 18 32 14 2
23 Vanadium 2 8 11 2 77 Iridium 2 8 18 32 15 2
24 Chromium 2 8 13 1 78 Platinum 2 8 18 32 16 2
25 Manganese 2 8 13 2 79 Gold 2 8 18 32 18 1
26 Iron 2 8 14 2 80 Mercury 2 8 18 32 18 2
27 Cobalt 2 8 15 2 81 Thallium 2 8 18 32 18 3
28 Nickel 2 8 16 2 82 Lead 2 8 18 32 18 4
29 Copper 2 8 18 1 83 Bismuth 2 8 18 32 18 5
30 Zinc 2 8 18 2 84 Polonium 2 8 18 32 18 6
31 Gallium 2 8 18 3 85 Astatine 2 8 18 32 18 7
32 Germanium 2 8 18 4 86 Radon 2 8 18 32 18 8
33 Arsenic 2 8 18 5 87 Francium 2 8 18 32 18 8 1
34 Selenium 2 8 18 6 88 Radium 2 8 18 32 18 8 2
35 Bromine 2 8 18 7 89 Actinium 2 8 18 32 18 9 2
36 Krypton 2 8 18 8 90 Thorium 2 8 18 32 18 10 2
37 Rubidium 2 8 18 8 1 91 Protactinium 2 8 18 32 20 9 2
38 Strontium 2 8 18 8 2 92 Uranium 2 8 18 32 21 9 2
39 Yttrium 2 8 18 9 2 93 Neptunium 2 8 18 32 22 9 2
40 Zirconium 2 8 18 10 2 94 Plutonium 2 8 18 32 24 8 2
41 Niobium 2 8 18 12 1 95 Americium 2 8 18 32 25 8 2
42 Molybdenum 2 8 18 13 1 96 Curium 2 8 18 32 25 9 2
43 Technetium 2 8 18 13 2 97 Berkelium 2 8 18 32 27 8 2
44 Ruthenium 2 8 18 15 1 98 Californium 2 8 18 32 28 8 2
45 Rhodium 2 8 18 16 1 99 Einsteinium 2 8 18 32 29 8 2
46 Palladium 2 8 18 18 0 100 Fermium 2 8 18 32 30 8 2
47 Silver 2 8 18 18 1 101 Mendelevium 2 8 18 32 31 8 2
48 Cadmium 2 8 18 18 2 102 Nobelium 2 8 18 32 32 8 2
49 Indium 2 8 18 18 3 103 Lawrencium 2 8 18 32 32 9 2
50 Tin 2 8 18 18 4 104 Rutherfordium 2 8 18 32 32 10 2
51 Antimony 2 8 18 18 5 105 Dubnium 2 8 18 32 32 11 2
52 Tellurium 2 8 18 18 6 106 Seaborgium 2 8 18 32 32 12 2
53 Iodine 2 8 18 18 7 107 Bohrium 2 8 18 32 32 13 2
54 Xenon 2 8 18 18 8 109 Meitnerium 2 8 18 32 32 15 2
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Module 1.03 Physical Sciences Study Guide
1.03.10 Define the terms as they relate to atomic structure:
a) Valence shell
b) Valence electron
The highest occupied energy level in a ground-state atom is called its valence shell. Therefore,
the electrons contained in it are called valence electrons. The rows or periods in the Periodic
Table correspond to the electron shells. The elements contained in first period have their
valence electrons in the first energy level or K-shell. The elements contained in the second
period have their outer or valence shell electrons in the second energy level or L-shell, and so
on. The pattern continues down the table.
The number of electrons in the valence shell determines the chemical properties or "behavior"
of the atom. The valence shell can have a maximum of eight electrons, except for the K-shell
which can only have two. Atoms are chemically stable when the valence shell has no
vacancies; that is, they "prefer" to have a full valence shell. Atoms of elements toward the
right of the Periodic Table seem to lack only one or two electrons. These will "look" for ways
to gain electrons in order to fill their valence shell. Atoms of elements on the left side of the
table seem to have an excess of one or two electrons. These will tend to find ways to lose these
excess electrons so that the full lower shell will be the valence shell.
Section 38
The outcome is that certain atoms will combine with other atoms in order to fill their valence
shells. This combination that occurs is called a chemical bond, and results in the formation of
a molecule. The bond is accomplished by "sharing" or "giving up" valence electrons, thus
forming a molecule whose chemical properties are different than those of the individual
element atoms.
A good example is table salt. Salt is a 1:1 combination of sodium and chlorine; that is, a salt
molecule is formed when one sodium atom bonds with one chlorine atom. If we look at Table
3, we can see that sodium (Na) has 1 electron in its outermost shell. Chlorine (Cl) needs one
electron to complete its valence shell. The sodium atom "gives up" its extra electron to the
chlorine atom who then "thinks" that its valence shell is full. Because the sodium atom has one
less electron, the atom now has a net positive charge; that is, it has one less electron than it has
protons. The chlorine atom now has a net negative charge because it has one more electron
than it has protons. The opposite charges of the two ions attract and form an ionic bond. The
bond results in a sodium chloride molecule (NaCl). However, this is just one type of chemical
bond between atoms. There are several other types of chemical bonds that can occur, but
which are beyond the scope of this lesson.
Note the rightmost column in the Periodic Table. These elements are known as the noble or
inert gases because they all have a full valence shell (see also the underlined elements in Table
3). This means that they "feel" no need to bond with other atoms. Noble gases are thus
considered chemically inert and very rarely interact with other elements.
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The Quantum Mechanical Model
Over the years, the Bohr model of the atom was found to be inadequate as the principles
of quantum mechanics evolved. A newer model, known as the quantum mechanical
model, describes the electrons arranged in energy levels corresponding to the "electron
shells" of the Bohr model. In the quantum mechanical model the electron is not viewed as
particle in a specific orbit, but rather as an electron cloud in which the negative charge of
the electron is spread out within the cloud. These energy levels are referred to as orbitals
to emphasize that these are not circular "orbits" like those of the Bohr model but rather
electron clouds. An electron cloud is a representation of the volume about the nucleus in
which an electron of a specific energy is likely to be found.
The quantum mechanical model further states that the energy levels are subdivided into
sublevels, referred to by the letters s, p, d, f, etc. An energy level can contain one or more
sublevels or orbitals, and a maximum of two electrons can reside in each sublevel. For
example, the first energy level contains one s sublevel which can accommodate a
maximum of two electrons.
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DOE-HDBK-1122-2009
Module 1.04 Nuclear Physics Study Guide
Course Title: Radiological Control Technician
Module Title: Nuclear Physics
Module Number: 1.04
Objectives :
1.04.01 Identify the definitions of the following terms:
a. Nucleon
b. Nuclide
c. Isotope
1.04.02 Identify the basic principles of the mass-energy equivalence concept.
1.04.03 Identify the definitions of the following terms:
a. Mass defect
b. Binding energy
c. Binding energy per nucleon
Section 39
1.04.04 Identify the definitions of the following terms:
a. Fission
b. Criticality
c. Fusion
INTRODUCTION
Nuclear power is made possible by the process of nuclear fission. Fission is but one of a
large number of nuclear reactions which can take place. Many reactions other than fission
are quite important because they affect the way we deal with all aspects of handling and
storing nuclear materials. These reactions include radioactive decay, scattering, and
radiative capture. This lesson is designed to provide an understanding of the forces
present within an atom.
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References:
1. "Basic Radiation Protection Technology"; Gollnick, Daniel; 5th ed.; Pacific
Radiation Corporation; 2008.
2. "Introduction to Health Physics"; Cember, Herman; 4nd ed.; McGraw-Hill
Medical; 2008.
3. ANL-88-26 (1988) "Operational Health Physics Training"; Moe, Harold; Argonne
National Laboratory, Chicago
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1.04.01 Identify the definitions of the following terms:
a. Nucleon
b. Nuclide
c. Isotope
NUCLEAR TERMINOLOGY
There are several terms used in the field of nuclear physics that an RCT must understand.
Nucleon
Neutrons and protons are found in the nucleus of an atom, and for this reason are
collectively referred to as nucleons. A nucleon is defined as a constituent particle of the
atomic nucleus, either a neutron or a proton.
Nuclide
A species of atom characterized by the constitution of its nucleus, which is specified by its
atomic mass and atomic number (Z), or by its number of protons (Z), number of neutrons
(N), and energy content. A listing of all nuclides can be found on the "Chart of the
Nuclides," which will be introduced in a later lesson.
Isotope
This term was mentioned in Lesson 1.03 when we discussed the concepts of atomic mass
and atomic weight. Isotopes are defined as nuclides which have the same number of
protons but different numbers of neutrons. Therefore, any nuclides which have the
same atomic number (i.e. the same element) but different atomic mass numbers are
isotopes.
For example, hydrogen has three isotopes, known as Protium, Deuterium and Tritium.
Since hydrogen has one proton, any hydrogen atom will have an atomic number of 1.
However, the atomic mass numbers of the three isotopes are different: Protium (1H) has
an mass number of 1 (1 proton, no neutrons), deuterium (D or 2H) has a mass number of 2
(1 proton, 1 neutron), and tritium (T or 3H) has a mass number of 3 (1 proton, 2 neutrons).
1.04.02 Identify the basic principles of the mass-energy equivalence concept.
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MASS-ENERGY EQUIVALENCE
Of fundamental concern in nuclear reactions is the question of whether a given reaction is
possible and, if so, how much energy is required to initiate the reaction or is released
when the reaction occurs. The key to these questions lies in the relationship between the
mass and energy of an object.
The theory that relates the two was proposed by Albert Einstein in 1905. Einstein's special
theory of relativity culminated in the famous equation:
E = mc2
where: E = Energy
m = mass
c = speed of light
This equation expresses the equivalence of mass and energy, meaning that mass may be
transformed to energy and vice versa. Because of this equivalence the two are often
referred to collectively as mass-energy.
Section 40
The mass-energy equivalence theory implies that mass and energy are interchangeable.
The theory further states that the mass of an object depends on its speed. Thus, all
matter contains energy by virtue of its mass. It is this energy source that is tapped to
obtain nuclear energy.
The Law of Conservation of Energy applies to mass as well as energy, since the two are
equivalent. Therefore, in any nuclear reaction the total mass-energy is conserved i.e.
mass-energy cannot be created or destroyed. This is of importance when it becomes
necessary to calculate the energies of the various types of radiation which accompany the
radioactive decay of nuclei.
Pair Annihilation: An Example of Mass to Energy Conversion
An interaction which occurs is pair annihilation, where two particles with mass,
specifically a positron and an electron (negatron), collide and are transformed into two
rays (photons) of electromagnetic energy. A positron is essentially an anti-electron,
having a positive charge. When a positron collides with an electron, both particles are
annihilated and their mass is converted completely to electromagnetic energy. (This
interaction will be discussed in Lesson 1.07 "Interactions of Radiation with Matter.")
If the mass of an electron/positron is 0.00054858026 amu, the resulting annihilation
energy (radiation) resulting from the collision would be:
2 0.0005485026 ( amu) 931.478MeV
× = 1.022MeV
1 amu
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1.04.03 Identify the definitions of the following terms:
a. Mass defect
b. Binding energy
c. Binding energy per nucleon
MASS DEFECT AND BINDING ENERGY
With an understanding of the equivalence of mass and energy, we can now examine the
principles which lie at the foundation of nuclear power.
Mass Defect
As we said earlier, the mass of an atom comes almost entirely from the nucleus. If a
nucleus could be disassembled to its constituent parts, i.e., protons and neutrons, it would
be found that the total mass of the atom is less than the sum of the masses of the
individual protons and neutrons. This is illustrated in Figure 1 below.
Figure 1. Atomic Scale
This slight difference in mass is known as the mass defect, ∗ (pronounced "delta"), and can be
computed for each nuclide, using the following equation.
∗ = (Z)(Mp) + (Z)(Me) + (A-Z)(Mn) - Ma
where: ∗ = mass defect
Z = atomic number
Mp = mass of a proton (1.00728 amu)
Me = mass of a electron (0.000548 amu)
A = mass number
Mn = mass of a neutron (1.00867 amu)
Ma = atomic mass (from Chart of the Nuclides)
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For example, consider an isotope of Lithium, Li:
A = 7
Z = 3
M = 7.01600 amu (per Chart of the Nuclides)
Therefore:
∗ = (3)(1.00728) + (3)(0.000548) + (7-3)(1.00867) - (7.01600)
∗ = (3.02184) + (0.001644) + (4.03468) - (7.01600)
∗ = (7.058164) - (7.01600)
∗ = 0.042164 amu
Binding Energy
The mass defect of 2
3Li is 0.042164 amu. This is the mass that is apparently "missing",
but, in fact, has been converted to energy, the energy that binds the lithium atom nucleus
together, or its binding energy. Binding energy is the energy equivalent of mass defect.
Note from the Lesson 1.02 Conversion Tables that:
1 amu = 931.478 MeV
So, if we multiply the mass defect by this number we can calculate the binding energy.
⎛ 0.042164amu ⎞⎛ 931.478MeV ⎞BE = = 39.27MeV ⎜ ⎟⎜ ⎟
⎝ 1 ⎠⎝ amu ⎠
Section 41
From this we have determined the energy converted from mass in the formation of the
nucleus. We will see that it is also the energy that must be applied to the nucleus in order
to break it apart.
Another important calculation is that of the binding energy of a neutron. This calculation
is of significance when the energetics of the fission process are considered. For example,
when 235U absorbs a neutron, the compound nucleus 236U is formed (see NUCLEAR
FISSION later in this lesson). The change in mass (Δm) is calculated and then converted
to its energy equivalent:
Δm = (mn + mU235) - mU236
Δm = (1.00867 + 235.0439) - 236.0456
Δm = 0.0070 amu
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0.0070 amu × 931.5 MeV/amu = 6.52 MeV
Thus, the nucleus possesses an excitation energy of 6.52 MeV when 235U absorbs a
neutron.
Binding Energy per Nucleon
If the total binding energy of a nucleus is divided by the total number of nucleons in the
nucleus, the binding energy per nucleon is obtained. This represents the average energy
which must be supplied in order to remove a nucleon from the nucleus. For example,
using the Li atom as before, the binding energy per nucleon would be calculated as
follows:
39.27MeV
= 5.61MeVpernucleon
7nucleons
If the binding energy per nucleon is plotted as a function of mass number (total number of
nucleons) for each element, a curve is obtained (see Figure 2). The binding energy per
nucleon peaks at about 8.5 MeV for mass numbers 40 - 120 and decreases to about 7.6
MeV per nucleon for uranium.
The binding energy per nucleon decreases with increasing mass number above mass 56
because as more protons are added, the proton-proton repulsion increases faster than the
nuclear attraction. Since the repulsive forces are increasing, less energy must be supplied,
on the average, to remove a nucleon. That is why there are no stable nuclides with mass
numbers beyond that of 208.
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NUCLEAR TRANSFORMATION EQUATIONS
Using the X format, equations can be written which depict a transformation that has
occurred in a nucleus or nuclei. Since it is an equation, both sides must be equal.
Therefore, the total mass-energy on the left must be equal to the total mass-energy on the
right. Keeping in mind that mass and energy are equivalent, any difference in total mass
is accounted for as energy released in the transformation. This energy release is called the
Q value. For example, the alpha decay of Radium-226 would be depicted as:
226 222 4Ra ⎯⎯→ Rn + α + Q88 86 2
The energy release, represented by Q in this case, is manifest as the kinetic energy of the
high-speed alpha particle, as well as the recoil of the Radon-222 atom.
1.04.04 Identify the definitions of the following terms:
a. Fission
b. Criticality
c. Fusion
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NUCLEAR FISSION
As we have shown, the nucleus of a single atom could be the source of considerable
energy. If the nucleus could be split so as to release this energy it could be used to
generate power. Therefore, if the energy from millions of atoms were released it would
be a great source of power. This thinking is the basis for nuclear power.
Section 42
When a free neutron strikes a nucleus, one of the processes which may occur is the
absorption of the neutron by the nucleus. It has been shown that the absorption of a
neutron by a nucleus raises the energy of the system by an amount equal to the binding
energy of the neutron. Under some circumstances, this absorption may result in the
splitting of the nucleus into at least two smaller nuclei with an accompanying release
of energy. This process is called fission. Two or three neutrons are usually released
during this type of transformation.
In order to account for how this process is possible, use is made of the liquid drop model
of the nucleus. This model is based on the observation that the nucleus, in many ways,
resembles a drop of liquid. The liquid drop is held together by cohesive forces between
molecules, and when the drop is deformed the cohesive forces may be insufficient to
restore the drop to its original shape. Splitting may occur, although in this case, there
would be no release of energy. Figure 3 illustrates this model.
The absorption of a neutron raises the energy of the system by an amount equal to the
binding energy of the neutron. This energy input causes deformation of the nucleus, but if
it is not of sufficient magnitude, the nucleon-nucleon attractive forces will act to return the
nucleus to its original shape. If the energy input is sufficiently large, the nucleus may
reach a point of separation, and a fission has occurred. The energy required to drive the
nucleus to the point of separation is called the critical energy for fission, Ec. The values
of Ec for various nuclei can be calculated, based on a knowledge of the forces which act to
hold the nucleus together.
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An example of a fission is shown below, involving neutron absorption by 235U:
235 1 236 138 95 1U + n ⎯⎯ U* ⎯⎯ ( ) + Q → → Ba + Kr + 3 n92 0 92 56 36 0
On the average, approximately 200 MeV of energy is released per fission.
The fission process can be "energetically" explained by comparing the critical energy for
fission with the amount of energy input, i.e., the neutron binding energy. For 238U and
232Th, the critical energy for fission is greater than the neutron binding energy. Therefore,
an additional amount of energy must be supplied in order for fission to occur in these
nuclei. This additional energy is in the form of neutron kinetic energy, and confirms the
observation that fission occurs in these fissionable nuclei only when the neutron has
approximately 1 MeV of kinetic energy.
The situation is quite different for 235U, 233U, and 239Pu. In these cases, the neutron
binding energy exceeds the critical energy for fission. Thus, these nuclei may be
fissioned by thermal, or very low energy, (0.025 eV) neutrons.
As mentioned earlier, the new elements which are formed as a result of the fissioning of
an atom are unstable because their N/P ratios are too high. To attain stability, the fission
fragments will undergo various transformations depending on the degree of instability.
Along with the neutrons immediately released during fission, a highly unstable element
may give off several neutrons to try to regain stability. This, of course, makes more
neutrons available to cause more fissions and is the basis for the chain reaction used to
produce nuclear power. The excited fission product nuclei will also give off other forms
of radiation in an attempt to achieve a stable status. These include beta and gamma
radiation.
Section 43
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Criticality
Criticality is the condition in which the neutrons produced by fission are equal to the
number of neutrons in the previous generation. This means that the neutrons in one
generation go on to produce an equal number of fission events, which events in turn
produce neutrons that produce another generation of fissions, and so forth. This
continuation results in the self-sustained chain reaction mentioned above. Figure 5 gives
a simple illustration of the chain reaction that occurs in a criticality.
As one can discern, this reaction requires control. If the population of neutrons remains
constant, the chain reaction will be sustained. The system is thus said to be critical.
However, if too many neutrons escape from the system or are absorbed but do not
produce a fission, then the system is said to be subcritical and the chain reaction will
eventually stop.
On the other hand, if the two or three neutrons produced in one fission each go on to
produce another fission, the number of fissions and the production of neutrons will
increase exponentially. In this case the chain reaction is said to be supercritical.
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In nuclear reactors this concept is expressed as the effective multiplication constant or Keff.
Keff is defined as the ratio of the number of neutrons in the reactor in one generation to the
number of neutrons in the previous generation. On the average, 2.5 neutrons are emitted
per uranium fission. If Keff has a value of greater than 1, the neutron flux is increasing,
and conversely, if it has a value of less than 1, the flux is decreasing with time. Table 1
illustrates the reactor condition for various values of the multiplication constant.
Table 1 - The Effective Multiplication Constant
Keff = Effective Multiplication Constant
Keff <1 = Subcritical Condition
Keff = 1 = Critical Condition
Keff >1 = Supercritical Condition
In a subcritical reactor, the neutron flux and power output will die off in time. When
critical, the reactor operates at a steady neutron and power output. A reactor must be
supercritical to increase the neutron flux and power level.
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Therefore, the population of neutrons must be controlled in order to control the number of
fissions that occur. Otherwise, the results could be devastating.
Fusion
Another reaction between nuclei which can be the source of power is fusion. Fusion is
the act of combining or "fusing" two or more atomic nuclei. Fusion thus builds atoms.
The process of fusing nuclei into a larger nucleus with an accompanying release of energy
is called fusion.
Fusion occurs naturally in the sun and is the source of its energy. The reaction is initiated
under the extremely high temperatures and pressure in the sun whereby H interacts with
12
6C . Hydrogen is then converted to helium and energy is liberated in the form of heat.
1 4 2+ +4( H) ⎯⎯ 2 ( ) + 24.7MeV 1 → He + 2 e
What occurs in the above equation is the combination of 4 hydrogen atoms, giving a total
of 4 protons and 4 electrons. 2 protons combine with 2 electrons to form 2 neutrons,
which combined with the remaining 2 protons forms a helium nucleus, leaving 2 electrons
and a release of energy.
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1.04-14
Section 44
DOE-HDBK-1122-2009
Module 1.05 Sources of Radiation Study Guide
Course Title: Radiological Control Technician
Module Title: Sources of Radiation
Module Number: 1.05
Objectives :
1.05.01 Identify the following four sources of natural background radiation including the
origin, radionuclides, variables, and contribution to exposure.
a. Terrestrial
b. Cosmic
c. Internal Emitters
d. Radon
1.05.02 Identify the following four sources of artificially produced radiation and the
magnitude of dose received from each.
a. Nuclear Fallout
b. Medical Exposures
c. Consumer Products
d. Nuclear Facilities
INTRODUCTION
Apart from the amount of radiation a worker may receive while performing work, they
will also be exposed to radiation because of the very nature of our environment. All
individuals are subject to some irradiation even though they may not work with
radioactive substances. This natural source of exposure is often referred to as
background radiation.
Studies of the nature and origin of this source of exposure to man have revealed three
main components: terrestrial radiation (which includes the radioactivities of the earth's
surface, air and water), cosmic radiation, and the naturally occurring radionuclides of the
human body. One might add that man-made sources influence the contribution from
some of these sources. The amount which each of these factors contributes varies with
the locale.
The study of these factors throughout the world is of value for a number of reasons.
Foremost among these is that the use of such data provides a basis or standard from which
allowable exposure limits for radiation workers may be developed. In areas where the
levels are much higher because of larger concentrations of natural radioactive materials,
knowledge may be gained about human hereditary effects at these increased levels. Such
data are also needed in assessing the impact on, or contribution of a nuclear facility to the
existing concentrations in a given area. In the design of buildings and/or shielding for
low-level work, it is of value to know the radioactive contents of the substances used.
Often the levels inside a building are higher than those outside of the building because this
factor has been neglected.
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Because of these needs, much data about background levels in many areas has been
acquired. This section is devoted to the discussion of these background factors and the
relative contribution of man-made radiation.
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. NCRP Report No. 45 "Natural Background Radiation in the United States".
4. NCRP Report No. 56 "Radiation Exposure from Consumer Product Miscellaneous
Sources".
5. NCRP Report No. 93 "Ionizing Radiation Exposure of the Population of the United
States".
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NATURAL BACKGROUND RADIATION SOURCES
1.05.01 Identify the following four sources of natural background radiation including
the origin, radionuclides, variables and contribution to exposure.
a. Terrestrial
Terrestrial Radiation
Radioactivity of the Earth
Section 45
The presence of certain small amounts of radioactivity in the soil adds to the
background levels to which man is exposed. The amount of radioactive materials
found in soil and rocks varies widely with the locale. The main contribution to the
background is the gamma ray dose from radioactive elements chiefly of the
uranium and thorium series and lesser amounts from radioactive K-40 and Rb-87.
Due to the high concentration of monazite, a thorium mineral, some regions in the
world have an extremely high background level. The majority of the population of
the Kerala region in India receive an annual dose greater than 500 mrem. A small
percentage of the inhabitants receive over 2,000 mrem per year and the highest
recorded value has been 5,865 mrem in one year. It is interesting to note that this
value is more than what is allowed for a DOE radiation worker. The Minas Garais
state in Brazil has an average terrestrial background dose rate of 1,160 mrem per
year. Their maximum recorded dose rate has been 12,000 mrem per year. In the
United States on the average, a square mile of soil, one foot deep, contains one ton
of K-40, three tons of U-238 and six tons of Th-232.
The amount of exposure one is subjected to depends upon the concentration in the
soil and the type of soil. In the U.S., three broad areas have been found. These
are: the coastal region along the Atlantic Ocean and the Gulf of Mexico, the
Colorado Plateau region, and the remainder of the country. The yearly whole
body dose equivalent rates in these areas range from 15-35 mrem, 75-140 mrem,
and 35-75 mrem, respectively. When absorbed dose rate measurements are
weighted by population, and averaged over the entire U.S., the yearly average is
estimated at 28 mrem (280 µSv) in NCRP Report No. 93.
Radioactivity of Water
Depending upon the type of water supply one is talking about, a number of
products may turn up. For example, sea water contains a large amount of K-40.
On the other hand, many natural springs show amounts of uranium, thorium, and
radium. Almost all water should be expected to contain certain amounts of
radioactivity. Since rain water will pick up radioactive substances from air, and
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ground water will pick up activity present in rocks or soil, one would expect to
find some radioactivity in water throughout the world.
The U.S. average of alpha emitters in water is <1 pCi/l. Some regions contain
significantly higher levels of naturally occurring alpha emitters: 40-50 pCi/l may
be found in Colorado; and 200 pCi/l may be found in bottled water from Brazil.
The chief source of dose rate from this background factor occurs as the result of
uptake of these waters by ingestion. This leads to an internal exposure. Any
estimate of the dose rate from this source is thus included in the estimate of the
dose rate from radioactivity in the human body. The transfer of radioactive
substances to the body seems to be mainly by food intake except in cases of very
high water concentrations.
1.05.01 Identify the following four sources of natural background radiation including
the origin, radionuclides, variables and contribution to exposure.
b. Cosmic
Cosmic Radiation
Section 46
Much work has been carried out in the study of cosmic radiation. This factor in
background levels was discovered during attempts to reduce background. Though
detection devices showed a response even in the absence of any known sources, it was
assumed this background was due entirely to traces of radioactive substances in the air
and ground. Thus, if a detector was elevated to a greater height above the earth's surface,
the background should be greatly reduced. The use of balloons carrying ion chambers to
great heights yielded data which showed the effect increased, rather than decreased.
These and other data showed that radiation was really coming from outer space. The
name cosmic rays was given to this high energy.
Further study has shown that cosmic radiation consists of two parts: primary and
secondary. The primary component may be further divided into galactic,
geomagnetically trapped radiation, and solar.
Primary
The galactic cosmic rays come from outside the solar system and are composed
mostly of positively charged particles. Studies have shown that outside the earth's
atmosphere, cosmic rays consist of 87% protons, of 11% alpha particles, and about
1% each of other heavier nuclei and electrons at latitudes above 55 degrees. These
particles may have energies in the range of about 1 GeV and higher.
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As a charged particle approaches the earth, it is acted upon by the earth's magnetic
field. In order to pass on through to the earth, the particle must have a certain
momentum. Otherwise, it may be trapped by the earth's magnetic field. This
gives rise to the second type of primary cosmic rays, the geomagnetically
trapped radiation.
Solar cosmic rays are produced following severe solar flares on the surface of the
sun. These rays consist of protons. The events are classed as high energy or low
energy. The high energy events can be observed by ground-level neutron devices.
The low energy events are more frequent but must be detected at high altitude.
Since these events produce radiation throughout the solar system, they are of great
importance in shielding design for manned space missions.
Secondary
Secondary cosmic rays result from interactions which occur when the primary rays
reach the earth's atmosphere. When the high energy particles collide with atoms
of the atmosphere, many products are emitted: pions, muons, electrons, photons,
protons, and neutrons. These, in turn, produce other secondaries as they collide
with elements or decay on the way toward the earth's surface. Thus, a
multiplication or shower occurs in which as many as 108 secondaries may result
from a single primary.
Most of the primary rays are absorbed in the upper 1/10 of the atmosphere. At
about 20 km and below, cosmic rays are almost wholly secondary in nature. The
total intensity of cosmic rays shows an increase from the top of the atmosphere
down to a height of 20 km. Although the primary intensity decreases, the total
effect increases because of the rapid rise in the number of the secondaries. Below
20 km, the total intensity shows a decrease with height because of attenuation of
the secondaries without further increase in their number due to primaries. At less
than 6 km of altitude, the highly penetrating muons, and the electrons they produce,
are the dominant components.
Section 47
At the earth's surface, the secondary cosmic rays consist mainly of muons (hard
component), electrons and photons (soft components), and neutrons and protons
(nucleonic component). At sea level about 3/4 of the cosmic ray intensity is due to
the hard component.
Because of the earth's magnetic field, cosmic ray intensity also varies with latitude.
The energy which is needed for a charged particle to reach the earth's atmosphere
at the geomagnetic equator is larger than that needed at other latitudes. The effect
is greatest for latitudes between 15 and 50 degrees. Above 50 degrees, the
intensity remains almost constant. Thus, the lowest value of the intensity occurs at
the geomagnetic equator, and the effect is expressed as the percentage increase at
55 degrees over that at the equator. At sea level, the effect is small for the ionizing
component (10%) but is larger for the neutron component.
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The dose rate produced by this source of background may be divided into two
parts. The portion caused by the ionizing component is estimated from ion
chamber readings. The portion caused by the neutron component is hard to
measure because the dose rate depends so much on the energy spectrum of the
neutrons. For the neutron dose estimates one must rely on calculations.
At sea level and high latitudes, the ionization rate, is about 2.1 x 106 ion pairs per
cubic meter. Using a neutron calculation, the sea level dose would be increased by
about 5%. Taking into account the dose variation with altitude, and the population
distribution with altitude, the average yearly dose equivalent rate to the
U.S. population from cosmic radiation is estimated to be 27 mrem (270 µSv).
This dose equivalent rate would be expected to decrease slightly with latitude and
increase with altitude. For example at Denver, the yearly dose would be about 50
mrem (500 µSv).
1.05.01 Identify the following four sources of natural background radiation including
the origin, radionuclides, variables and contribution to exposure.
c. Internal Emitters
Internal Emitters (Radioactivity of the Human Body)
Since small amounts of radioactive substances are found throughout the world in soil and
water, some of this activity is transferred to man by way of the food chain cycle. A
number of studies have been made to try to find a correlation between the amounts in soil
and that in man. Results have not shown a clear-cut relationship as yet.
In the human body, K-40, Rb-87, Ra-226, U-238, Po-210, and C-14 are the main
radionuclides of concern. Of these, K-40 is the most abundant substance in man. The
amount in food varies greatly, so that intake is quite dependent on diet. However,
variations in diet seem to have little effect on the body content. The content of K-40 in
body organs of man varies widely. Based on an average content of 0.2% by weight in soft
tissue, 0.05% in bone, the yearly dose equivalent rate to the gonads is estimated to be 19
mrem (190 µSv); 15 mrem (150 µSv) to bone surfaces; and 15 mrem (150 µSv) to bone
marrow. Rb-87 contributes only a few percent of these values.
Most of the Ra-226 which is taken into the body will be found in the skeleton. Much data
has been gathered on the concentration in humans, and the present assumed average
skeletal concentration is taken as about 0.29 Bq/kg. The skeletal content of Ra-228 is
taken as 0.14 Bq/kg. The yearly dose rate produced by these components is estimated to
be .5 mrem (5 µSv) to the gonads, 14.6 mrem (146 µSv) to bone surfaces and 2.2 mrem
(22 µSv) to bone marrow.
Section 48
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Based upon an average concentration of U-238 of 0.26 Bq/kg in bone, the estimated doses
in man are 4.8 mrem (48 µSv) to bone surfaces and 0.9 mrem (9 µSv) to the marrow.
From the estimated content in the gonads, the annual dose equivalent is estimated to be
about 1 mrem (10 µSv).
Similarly, the Po-210 decay chain contribution is taken as 2.22 Bq/kg, yielding annual
dose equivalents of 24 mrem (240 µSv) to bone surfaces and 4.9 mrem (49 µSv) to bone
marrow. The soft tissue concentration is taken as 0.111 Bq/kg, but is about twice that in
the gonads. This gives an annual gonad dose equivalent of 6 mrem (60 µSv).
The average whole body content of carbon is taken as 23%. However, C-14 is present in
normal carbon only to a very small extent (C-14/C-12 ~10-12), so that only a small amount
of C-14 is present. The annual average dose equivalent turns out to be about 1 mrem (10
µSv) total body. In soft tissue, the annual dose is 0.7 mrem (7 µSv). The annual dose to
the bone surfaces is 0.8 mrem (8 µSv), and to the bone marrow, 0.7 mrem (7 µSv).
The U.S. annual average dose equivalent for all internal emitters (food chain) in the
body is 39 mrem (390 µSv) as listed by the NCRP Report No. 93.
1.05.01 Identify the following four sources of natural background radiation including
the origin, radionuclides, variables and contribution to exposure.
d. Radon
Inhaled Radionuclides (Radioactivity of the Air)
The background which is found in air is due mainly to the presence of radon and thoron
gas, formed as daughter products of elements of the uranium and thorium series. The
decay of U-238 proceeds to Ra-226. When Ra-226 emits an alpha as it decays, the gas
Rn-222 is formed, which is called radon. In the thorium chain, the decay of Ra-224
results in the gaseous product Rn-220, which is called thoron.
Since uranium and thorium are present to some extent throughout the crust of the earth,
these products are being formed all the time. Since they are gases, they tend to diffuse up
through the earth's surface to become airborne. In turn, the decay products of these gases
attach themselves to dust in the air.
The amount of these gases in the air depends upon the uranium and thorium content of a
certain area. In any given area, the weather conditions will greatly affect the
concentrations of these gases. It is also common to find that the levels indoors are higher
than those outdoors. This is a function of the material of the building and the ventilation
rate. In mines and other underground caverns, the concentrations have been found to be
quite high.
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Some homes in Grand Junction and Durango, Colorado, have been found to have high
radon levels. This was traced to the use of uranium mill tailings, residues rich in radium,
as backfill. This discovery has led to radon measurements in homes in other areas of the
country. Some homes in Pennsylvania are situated on land with naturally elevated radium
concentrations, giving rise to increased indoor radon levels. Investigations have been
made of radon levels in homes in the Chicago area. Their results indicated that 6% of the
homes studied had radon concentrations comparable to those found at Grand Junction.
Because of the potential population dose from this source, much more work on defining
this potential problem is being carried out.
Section 49
The major source of exposure from radon in air occurs when the daughter products attach
themselves to aerosols and are inhaled. This leads to an internal dose to the lungs. As for
external exposure, the external gamma dose rate from Rn-222 and Rn-220 is estimated to
be less than 5% of the total external terrestrial dose rate. The contribution of inhaled
radon gas to the annual average effective dose equivalent is included as an inhaled
radionuclide.
Among other radioactive products which are found in air in measurable amounts are C-14,
H-3, Na-22, and Be-7. These are called cosmogenic radionuclides, since they are
produced in the atmosphere by cosmic rays. None of these products add a significant
amount to the background dose rate.
The U.S. annual average dose equivalent for various inhaled radionuclides (primarily
radon) is estimated at 200 mrem (2,000 µSv) by the NCRP Report No. 93.
MAN-MADE BACKGROUND RADIATION SOURCES
1.05.02 Identify the following four sources of artificially produced radiation and the
magnitude of dose received from each.
a. Nuclear Fallout
Nuclear Fallout
The term fallout has been applied to debris which settles to the earth as the result of a
nuclear blast. This debris is radioactive and thus a source of potential radiation exposure
to man. Radioactive fallout is not considered naturally occurring but is definitely a
contributor to background radiation sources.
Because of the intense heat produced in a nuclear explosion during a very short time,
matter which is in the vicinity of the bomb is quickly vaporized. This includes fission
products formed in the fission process, unused bomb fuel, the bomb casing and parts, and,
in short, any and all substances which happen to be around. These are caught in the
fireball which expands and rises very quickly. As the fireball cools and condensation
occurs, a mushroom-shaped cloud is formed, containing small solid particles of debris as
well as small drops of water. The cloud continues to rise to a height which is a function
of the bomb yield and the meteorological factors of the area. For yields in the megaton
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range (1 megaton equals an energy release equivalent to one million tons of TNT), the
cloud top may reach a height of 25 miles.
The fallout which occurs may be described as local or world-wide. The portion of debris
which becomes local fallout varies from none (in the case of a high-altitude air burst) to
about half (in the case of a contact surface burst). The height at which the bomb goes off
is thus quite important in the case of local fallout. If the fireball touches the surface of the
earth, it will carry aloft large amounts of surface matter. Also, because of the vacuum
effect created by the rapid rise of the fireball, other matter may be taken up into the rising
fireball. This leads to the formation of larger particles in the cloud that tend to settle out
quickly. If the width is not too great, the fallout pattern will be roughly a circle around
ground zero. Ground zero is the point on the surface directly under, at, or above the burst.
Other bits of matter will fall out at various stages. the distance from ground zero at which
they strike the surface and the time it takes depend upon the height from which they fall,
their size, and the wind patterns at all altitudes. This results in a cigar-shaped pattern
downwind of the burst point. Local fallout usually occurs within the first 24 hours after
the blast.
Section 50
If the height of the burst is such that the fireball does not touch the surface, then the debris
is carried aloft and dispersed into the atmosphere. This matter then descends to earth at a
later time and is called world-wide fallout.
The residence time of this debris is a function of the bomb yield. For yields in the kiloton
range, the debris is not projected into the stratosphere. It is limited to a region called the
troposphere, between about 9,000 and 17,000 meters. In this region, there is quite a bit of
turbulence as well as precipitation. The debris is removed rather quickly; from about one
day to one month.
If the burst is in the megaton range, the debris is carried into the stratosphere. In this
region little mixing will occur, and the absence of rain or snow prevents this matter from
being washed down. The time that it takes for this debris to return to the troposphere and
be washed down varies. It is a function of both the height in the stratosphere to which the
debris is lifted and the locale at which the burst occurs. It may take up to 5 years or more
for this debris to return to earth. On the other hand, for bursts in the northern hemisphere
in which the debris is confined to only the lower part of the stratosphere, the half-
residence time is thought to be less than one year. Half-residence time is the time for one-
half of the debris to be removed from the stratosphere.
In all, there are more than 200 fission products which result from a nuclear blast. The
half-life of each of these products covers the range from a fraction of a second to millions
of years. Local fallout will contain most of these products. Because of the time delay in
the appearance of world-wide fallout, only a few of these products are important from that
standpoint. Since local fallout is confined to a relatively small area, its effect on the
human population can be negated by proper choice of test sites, weather conditions, and
type of burst. The fallout of interest from the standpoint of possible effects on man due to
testing is the world-wide fallout.
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A number of factors must be considered when one attempts to assess the hazard from
world-wide fallout. Because of the associated time delay before world-wide fallout shows
up, many fission products and activation products decay out in transit. Others, because
they are produced in such small amounts, are diluted so that they do not produce much of
an effect. Also, once the fallout does arrive, to be of importance internally, there must be
a transfer to the body and absorption into the body organs. All these factors combine to
limit the number of fission products which may have an effect on man. The main
contribution comes from Sr-90, Cs-137, I-131, C-14, H-3 with minor contributions from
Kr-85, Fe-55, and Pu-239. Although the U.S. ceased atmospheric testing in 1962, the
inventory of fission products from previous bursts has committed man to future doses.
NCRP Report No. 93 lists the annual average effective dose equivalent from nuclear
fallout exposure at less than 1 mrem (10 µSv). However the total dose commitment, to be
delivered over many generations, is 140 mrem (1400 µSv).
1.05.02 Identify the following four sources of artificially produced radiation and the
magnitude of dose received from each.
b. Medical Exposures
Medical Exposures
Section 51
The exposure to the U.S. population from X-rays used in medical and dental procedures is the
largest source of man-made radiation. It is estimated that more than 300,000 X-ray units are in
use in the U.S., and that about 2/3 of the U.S. population is exposed. In 1970, the estimated
annual average bone marrow dose equivalent from dental and medical X-rays to the U.S.
population was about 78 mrem (780 µSv). In addition to the exposure from X-rays, nuclear
medicine programs use radiopharmaceuticals for diagnostic purposes. Radiologists also use
radionuclides for therapy treatment. It has been estimated that more than 10 million doses are
administered each year. NCRP Report No. 160 gives the dose equivalent for medical
radionuclides as ~ 300 mrem/yr
1)
2)
3)
computed tomography (total average dose ~ 150 mrem/yr)
nuclear medicine (total average dose ~ 75 mrem/yr)
radiography/fluroscopy (total average dose ~ 75 mrem/yr)
Diagnostic X-Rays
There are many different types and styles of X-ray machines used in the medical
field. An X-ray machine generally consists of the X-ray tube, an electrical source
of high voltage, a type of filament, and radiation shielding to collimate the beam to
some limited size and shape. A diagnostic X-ray machine is used to obtain an
image of some part of the body on some type of storage material. There are three
general types of diagnostic X-ray equipment: radiographic, fluoroscopic, and
photofluorographic.
Radiography involves the use of an X-ray tube and a photographic plate. The
patient is placed between the two and an image is produced on the film of the area
exposed. A common "chest X-ray" is an example of a radiographic X-ray.
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In a fluoroscopic X-ray machine the film cassette is substituted with an imaging
device (image intensifier). This enables the radiologist to observe the part of the
body exposed live on a video monitor. A blocking agent, such as barium, is often
swallowed by the patient to allow the medical staff to observe internal processes in
action. A fluoroscopic examination can be used to locate ulcers in a "GI series."
The photofluorographic process utilizes an X-ray tube, a fluorescent screen and a
camera. This practice is similar to radiographic X-rays, with the substitution of a
fluorescent screen for the film. The radiologist can take several pictures on one
roll of film of the image on the fluorescent screen. Photofluorography is used for
screening large numbers of individuals such as in the military or prison.
As science gradually became more aware of the potential hazards associated with
radiation exposures, the doses received from diagnostic X-rays have been closely
examined. Medical diagnostic exposures contribute more than 50% of the dose to
the U.S. population from artificial sources. The U.S. Public Health Services has
been tasked with tracking medical X-ray procedures at ten year intervals. Surveys
were conducted in 1961, 1970, and 1980. Due to budget cut backs, the 1980
survey does not contain as much useful data as the one produced in 1970. The
concept of "Genetically Significant Dose" (GSD) is used in most publications
covering background radiation. The GSD includes only the fraction of the
radiation which actually deposits energy in the gonads (ovaries and testes) of
persons of childbearing potential. Dose rates that produce a small exposure over a
years time cannot be expected to produce any acute somatic radiation injury. Late
effects from this exposure are almost negligible at these low dose rates. Genetic
mutations are transmitted on to our offspring who will then be exposed during
their lifetimes. The cumulative effect on genetic mutations over several
generations might show a very slight increase due to background radiation.
Section 52
Medical Radionuclides
Radionuclides are used in medicine by two general classifications: Nuclear
Medicine for diagnostic procedures and Radiation Oncology for radiation therapy.
Because this science is utilized by a limited portion of the U.S. population, its
contribution to the average U.S. dose is not significant.
Radionuclides are used to determine the extent of a medical problem in a patient.
The radionuclide is "attached" to a pharmaceutical which is administered to the
patient. The drug has the properties to deposit the radioisotope in the organ of
concern. Then using external radiation detectors, the medical staff can determine
abnormalities in the organ. A thyroid scan and lung function test are examples.
Since the radioisotope is internally deposited either by mouth or by injection, it
should decay by emitting only photons. Isotopes emitting alpha or beta particles
would be locally absorbed in the organ and would not contribute to the
information signal. Another consideration in radionuclide selection would be the
effective half-life. To maintain organ doses ALARA, isotopes with a few hour
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half-life are optimum. Technetium-99m and Indium-113m are commonly used
radiopharmaceuticals.
Radiation Oncology (study/treatment of tumors) uses radionuclides for tumor
treatment. In the United States Cobalt-60 is generally used for the high activity
sealed source. This consists of a mechanical device which moves the source to an
opening in a collimator which projects a beam of photons used for treatment.
A typical 6,000 curie Cobalt-60 source delivers about 100 rad/minute to a tumor.
1.05.02 Identify the following four sources of artificially produced radiation and the
magnitude of dose received from each.
c. Consumer Products
Consumer Products
In NCRP Report 56, a number of consumer products and miscellaneous sources of
radiation exposure to the U.S. population are discussed. In general, two groups of sources
have been found:
1. Those in which the dose equivalent is relatively large and many people are exposed.
2. Those in which the dose equivalent is small but many people are exposed or the
dose equivalent is large but only a few people are exposed.
Such products as television sets, luminous-dial watches, smoke detectors, static
eliminators, tobacco products, airport luggage inspection systems, building materials and
many other sources have been studied. The estimated annual average whole body dose
equivalent to the U.S. population from consumer products is approximately 10 mrem
(100 µSv). The major portion of this exposure (approximately 70%) is due to
radioactivity in building materials.
Television Receivers
Television receivers have the potential for three X-rays sources: the picture tube, the
shunt regulator and the vacuum tube regulator. In 1960 the ICRP and the NCRP
recommended limits be established such that receivers produce less than 0.5 mrem/hr at
any access point 5 cm from the surface of the set. In May of 1967 a major manufacturer
recalled 149 big screen sets. Of this group, two sets were found to produce exposures in
excess of 100 mR/hr. Due to the ever increasing improvements in TV manufacturing,
solid state, and the use of "hold down" circuits, the annual exposure is being reduced. X-
ray emissions can be kept below 0.1 mR/hr with low voltage within manufacture
specifications. Higher emissions can result if the voltage is increased by repairman in
order to increase picture quality. It is estimated that the U.S. total average exposure from
watching TV is between 0.5 and 1.5 mrem/yr.
Section 53
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Shoe-Fitting Fluoroscopes
In the 1950's the use of fluoroscopes was wide spread in shoe stores. It was estimated that
10,000 of these were in use in 1953. Exposures to the feet ranged from 7 to 14 Roentgens
per 20 second exposure. The concurrent exposure to the pelvis ranged between 30 and
170 mR per exposure. Shoe-fitting fluoroscopes have been banned or restricted in most
states.
Radioluminous Watches
Radium-226 was used widely in the earlier part of this century for it's luminescence in
watches, clocks and dials. No radium-226 watches have been sold in the U.S. since 1970.
It is estimated that 10 million of these watches are still in use. Individual dose can reach
310 mrem/yr for the wearer of a watch containing 4.5 uCi of radium-226. The average
dose to radium watch wearers is approximately 3 mrem/yr.
The majority of luminescent watches on the market today contain either tritium (H-3) or
promethium-147. It's estimated that the 16 million who wear tritium watches receive 0.6
mrem/yr, and the 2 million who wear promethium watches receive 0.25 mrem/yr.
Miscellaneous
There are many additional consumer products that may be included as a source of
radiation. Polonium and lead isotopes have been found in tobacco products and
contribute a dose-equivalent to small areas of the bronchial epithelium of up to 8 rem/yr to
smokers. Building materials, smoke detectors, lantern mantles, and ceramic glazes are all
known sources. Another source of radiation exposure to the public arises from the wide
use of coal. Coal contains C-14, K-40, uranium and thorium and when burned, the
resulting flyash released to the atmosphere carries some of this radioactivity with it. This
leads to inhalation of airborne flyash producing lung exposure. The dose equivalent rate
in the vicinity of one of these plants has been estimated to be in the range of 0.25-4
mrem/y (2.5-40 µSv/y).
1.05.02 Identify the following four sources of artificially produced radiation and the
magnitude of dose received from each.
d. Nuclear Facilities
Nuclear Facilities
By 1988, 90 nuclear power plants had been licensed in the U.S. In addition, over 300
other reactors, classed as non-power reactors, are being operated. In order to provide fuel
for these reactors, mining and milling of uranium ore is carried out and fuel fabrication
plants are operating. There are several hundred mines, 20 uranium mills and 21 fuel
fabrication facilities.
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Sources of radiation from nuclear reactors consist of prompt neutrons, gamma rays and
possible exposures from contamination or environmental releases. The NRC has been
tasked by the federal government to calculate doses for populations living within 50 miles
of a nuclear facility. Three radionuclides released during routine operations, which
contribute to the population dose, are H-3, C-14, and Kr-85. Current estimates of the
yearly average dose equivalent in the U.S. from environmental releases is <1 mrem (10
µSv).
Total Background Radiation
The average annual total effective dose to the general population (non-smokers) from naturally occurring
and manmade sources is about 620 mrem.
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