DOE-STD-3014-2006 (Reaffirmed 2006), Accident Analysis for Aircraft Crash into Hazardous Facilities

NOT MEASUREMENT SENSITIVE DOE STANDARD October 1 996 Reaffirmation May 2006 ACCIDENT CRASH INTO ANALYSIS HAZARDOUS FACILITIES U.S. Department of Energy Washington, DC 20585 AREA SAFT DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. FOR AIRCRAFT This document has been reproduced directly from the best available copy. Available to DOE and DOE contractors from the Office of Scientific and Technical Information, P.O. Box 62, Oak Ridge, TN 37831; (423) 576-8401. Available to the public from the U.S. Department of Commerce, Technology Administration, National Technical Information Service, Springfield, VA 22161; (703) 487-4650. Order No. DE97000162 DOE-STD-3014-96 iii TABLE OF CONTENTS PARAGRAPH PAGE FOREWORD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1. INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1.1 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1.2 Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 1.3 Applicability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 1.4 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2. DEFINITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 3. GENERAL IMPLEMENTATION GUIDANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 3.1 Exposure Screening . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 3.2 Impact Frequency Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 3.3 Structural Screening and Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 3.4 Release Frequency Screening . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 3.5 Release Frequency Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 3.6 Exposure Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 3.7 Further Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 4. SCREENING AND EVALUATION GUIDELINES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 4.1 Exposure Screening Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 4.2 Impact Frequency Evaluation Guideline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 4.3 Structural Screening and Evaluation Guideline . . . . . . . . . . . . . . . . . . . . . . . . . . 34 4.4 Release Frequency Screening Guideline. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 4.5 Release Frequency Evaluation Guideline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

5. METHODOLOGY FOR EVALUATING AIRCRAFT CRASH IMPACT AND RELEASE FREQUENCY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 5.2 Methodology for Impact Frequency Screening . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 5.3 Methodology for Impact Frequency Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 5.4 Methodology for Aircraft Crash Release Frequency Screening . . . . . . . . . . . . . . . 47 5.5 Methodology for Aircraft Crash Release Frequency Evaluation . . . . . . . . . . . . . . 48 5.6 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 6. METHODOLOGY FOR EVALUATING THE INTEGRITY OF STRUCTURES, SYSTEMS, AND COMPONENTS SUBJECTED TO AIRCRAFT IMPACT . . . . . . . . . . . . . . . . . . . . . 53 6.1 Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 6.2 Structural Screening . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 6.3 Structural Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 6.4 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 DOE-STD-3014-96 iv 7. METHODOLOGY FOR EVALUATING EXPOSURE DUE TO AIRCRAFT IMPACT . . . . . 80 7.1 Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 7.2 Exposure Screening . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 7.3 Exposure Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 7.4 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 LIST OF TABLES Table I. Empirical formulas for local response evaluation of reinforced concrete targets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 Table II. Fraction of radioactive material released and respirable . . . . . . . . . . . . 82 LIST OF FIGURES Figure 1. Flowchart implementing the standard . . . . . . . . . . . . . . . . . . . . . . . 21-23 Figure 2. Structural evaluation approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 Figure 3. Sequence of local target response to missile impact . . . . . . . . . . . . . . . 65 APPENDICES APPENDIX A Basis for Screening and Evaluation Guidelines APPENDIX B Guidance and Data for Impact Frequency Calculation APPENDIX C Guidance for Structural Response Evaluation APPENDIX D Additional Guidance for Exposure Evaluation FOREWORD 1. This Department of Energy standard is approved for use by all DOE components and contractors. 2. Beneficial comments (recommendations, additions, deletions) and any pertinent data that may improve this document should be sent by letter or by using the pre-addressed Document Improvement Proposal (DOE F 1300.3), which is included with this document, to the Tony Eng Director, Office of Facility Authorization Bases EH-23 U. S. Department of Energy 20300 Century Blvd Germantown, MD 20874 Copies of this correspondence should also be sent to the Office of Nuclear Safety Policy

and Standards (EH-31), U.S. Department of Energy, Washington, DC 20585. 3. DOE technical standards, such as this technical standard, do not establish requirements. However, all or part of the provisions in a technical standard can become requirements under the following circumstances: a. They are explicitly stated to be requirements in a DOE requirements document; or b. The organization makes a commitment to meet a standard in a contract or in a plan or program required by a DOE requirements document. Throughout this standard, the word "shall" is used to denote actions which must be performed if this standard is to be met. If the provisions in this technical stand ard are made requirements through one of the two ways discussed above, then the "shall" statements would become requirements. DOE-STD-3014-96 2 4. This volume comprises the main body of the standard, including appendices, and is intended to provide sufficient information for the knowledgeable practitioner to conduct an aircraft crash safety analysis. The standard does not contain all of the details regarding the basis for the methodology or the detailed technical information required to fully understand how the standard was developed. This information is contained in a series of detailed technical support documents, which have not been distributed with the standard, but which are available by request. The support documents are: a. Kimura, C.Y. et al. Data Development Technical Support Document for the Aircraft Crash Risk Analysis Methodology (ACRAM) Standard. UCRL-ID-124837. Lawrence Livermore National Laboratory, 1996. b. Sanzo, D. et al. ACRAM Modeling Technical Support Document. LA-UR-96-2460, TSA-11-95-R112. Los Alamos National Laboratory, 1996. c. Hossain, Q.A. et al. Structures, Systems, and Components Evaluation Technical Support Document for the DOE Standard, Accident Analysis for Aircraft Crash into Hazardous Facilities. UCRL-ID-123577. Lawrence Livermore National Laboratory, 1996. d. Everett, H.C. et al. Background Information on Source Term and Atmospheric Dispersion Modeling for the Aircraft Crash Risk Assessment Methodology Standard. SAIC/95-1193. Prepared for the United States Department of Energy. Science Applications International Corporation, June 1995. e. Everett, H.C. et al. Screening for Potential Consequences of Accidental Releases of Radioactive and Chemical Materials to the Atmosphere. SAIC/95-1192. Prepared for the United States Department of Energy. Science Applications International Corporation, June 1995. http://nssc.llnl.gov/NetWeave/Review/ACRAM_Data1/data-Contents.html http://nssc.llnl.gov/NetWeave/Review/ACRAM_Model_new/ACRAM_Modeling_t.html http://nssc.llnl.gov/NetWeave/Review/UCRL/HTML/TSD-TOC-htm.html http://nssc.llnl.gov/NetWeave/Review/SAIC-1193/SAIC-1193.html http://nssc.llnl.gov/NetWeave/Review/SAIC-1192/SAIC-1192.html We encourage interested individuals to request copies of the supporting documents by writing to: Accident Analysis for Aircraft Crash into Hazardous Facilities Attn.: David Pyatt, Safety Engineer Office of Facility Authorization Bases (EH-23) U.S. Department of Energy 20300 Century Blvd Germantown, MD 20874 Tel: (301) 903-5614 Fax: (301) 903-4594 DOE-STD-3014-96 4 The membership of the Interagency Working Group (IWG) on Accident Analysis for Aircraft Crash into Hazardous Facilities changed several times during the course of this standard’s development. The individuals listed below served as members of the IWG at some time during the development process.

Organization Represented Name of Representative United States Department of Energy, Defense Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Kamiar Jamali, Chairman Defense Nuclear Agency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Capt. Brent Bredehoff Westinghouse Savannah River Corporation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Michael Hitchler United States Department of Energy, Office of Nuclear Safety Policy and Standards . . . . . . . . . . . . . . . . . . . . David Pyatt United States Department of Energy, Office of Nuclear Safety Policy and Standards . . . . . . . . . . . . . . . . . . Richard Stark Federal Aviation Administration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Charles Thorpe United States Environmental Protection Agency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Paul Tobin United States Nuclear Regulatory Commission (Observer Status Only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . James Wing The responsibility for the contents of the standard lies with the Interagency Working Group Chairman and the Expert Panel on Accident Analysis for Aircraft Crash into Hazardous Facilities. The Expert Panel had the following membership at the time this standard was prepared. Paul Amico, Chair, Science Applications International Corporation Timothy Haley, Secretary, Science Applications International Corporation Robert Budnitz, Future Resources Associates Chris Kimura, Lawrence Livermore National Laboratory Robert Murray, Lawrence Livermore National Laboratory Richard Smith, Sandia National Laboratories Desmond Stack, Los Alamos National Laboratory The Technical Support Teams had the following membership at the time this standard was prepared. Data Team Structural Team Chris Kimura, Team Leader, Lawrence Livermore Robert Murray, Team Leader, Lawrence Livermore National Laboratory National Laboratory Andrew Barto, Science Applications International Quazi Hossain, Lawrence Livermore National Corporation Laboratory Martin Fuentes, Sandia National Laboratories Robert Kennedy, RPK Structural Mechanics Ronald Glaser, Lawrence Livermore National Consulting, Inc. Laboratory Krish Mutreja, U.S. Department of Energy Timothy Haley, Science Applications International P. K. Niyogi, U.S. Department of Energy Corporation Subir Sen, U.S. Department of Energy Paul Kvam, Los Alamos National Laboratory Bhasker Tripathi, Science Applications International Tom Lin, Sandia National Laboratories Corporation Ernest Lofgren, Science Applications International Corporation Richard Mensing, Logicon RDA Martin Stutzke, Science Applications International Corporation Modeling Team Desmond Stack, Team Leader, Los Alamos National Geoffrey Kaiser, Science Applications International Laboratory Corporation Charles Bolig, Los Alamos National Laboratory Roy Karimi, Science Applications International Robert Budnitz, Future Resources Associates Corporation Ronald Glaser, Lawrence Livermore National Phouc Le, Science Applications International Laboratory Corporation Roy Karimi, Science Applications International Christina Rotolo, Science Applications International Corporation Corporation Richard Mensing, Logicon RDA Wendy Ting, Science Applications International David Pyatt, U.S. Department of Energy Corporation Dean Sanzo, Los Alamos National Laboratory

Exposure Team Paul Amico, Team Leader, Science Applications International Corporation Chris Everett, Science Applications International Corporation Norman Grandjean, Sandia National Laboratories DOE-STD-3014-96 The thresholds for what constitutes "significant quantities" of material are established in Section 1.3, “Applicability.”1 5 1. INTRODUCTION 1.1 Scope. This standard provides the user with sufficient information to evaluate and assess the significance of aircraft crash risk on facility safety without expending excessive effort where it is not required. The implementation guidance provides a framework of step-wise increases in analytical sophistication aimed at eliciting only that amount of analysis needed to demonstrate that aircraft crash either does or does not exceed a risk level of concern equivalent to what is generally applied to other sources of risk from the operation of hazardous material facilities. This standard establishes an approach for performing a conservative analysis of the risk posed by a release of hazardous radioactive or chemical material resulting from an aircraft crash into a facility containing significant quantities of such material. This approach can establish whether a facility has a significant potential1 for an aircraft impact, and, given an aircraft impact, whether a facility has the potential for an accident producing significant offsite or onsite consequences. The analysis is based on the structural properties of a facility and the inventory at a facility. This approach contains several interrelated analytical modules: (1) a methodology for determining the frequency of aircraft impact into a facility, based upon a conservative simplified equation; (2) a methodology to determine the effect of an aircraft impact into a facility through the performance of structural response analysis; (3) a methodology to determine the frequency of a release from a facility, given the effect of an aircraft impact; and (4) a methodology for evaluating the exposure resulting from a release. Evaluation guidelines are provided to aid in determining the need to conduct each subsequent analytical step. The methodologies take into consideration items determined to be important to understanding the risk from aircraft crash into hazardous facilities. These items include number of aircraft operations/flights; crash probabilities; aircraft characteristics; crash kinematics; impacting missiles; local, global, and vibratory structural damage; structure characteristics; source terms; release energy; and meteorological conditions. DOE-STD-3014-96 6 The analysis approach is consistent with an accident analysis (as in a Safety Analysis Report) that defines an approximate level of risk, rather than a detailed risk assessment. Thus, it adopts the typical accident analysis practice of addressing uncertainty through the use of analytical margin (i.e., conservatism) instead of through a formal uncertainty analysis. The philosophy is not one of providing substantial margin in every parameter used in the approach, as the combination of these margins would yield a final result so conservative as to be totally useless. Instead, margin is provided in each parameter based on the standard development team’s judgement of the level of uncertainty in the parameter and the level of margin needed to address the uncertainty. Adjustments were made to assure that the level of margin provided at each step and throughout the process

as a whole is adequate and reasonable. When applied as a complete approach, the methodologies in this standard will result in a technically justified, conservative analysis of the risk posed by releases resulting from aircraft crash. The risk will be defined at a sufficient level of detail to document the safety of the facility with respect to aircraft crash, and at the same level of detail as would be expected for other types of accident analyses. The standard will also be sufficient to support safety findings, decision making, and design, and will free the user from justifying the techniques and models used in the assessment. However, it is not the intent of this standard to imply that these are the only methodologies acceptable for such an assessment. Alternative methodologies that meet the intent of the standard may be proposed and used, but their acceptability needs to be assessed on a case-by-case basis. 1.2 Purpose. This is an analytical standard intended to provide a sound, technically justifiable, and consistent approach to analyzing the risk posed by an aircraft crash into a facility containing radioactive or hazardous chemical materials. The focus is on analyzing the risk posed to the health and safety of the public and onsite workers from a release of hazardous material following an aircraft crash. Thus, this is not a standard on aviation safety and does not consider the risk to the occupants of the aircraft; the risk to individuals inside a building affected by the crash itself; or the risk to other individuals on the ground, either inside or outside a facility boundary, who might be directly impacted by the crash. This focus forms the basis for the standard's assumptions about excluding the DOE-STD-3014-96 7 consideration of consequences within a certain distance from the hazardous material release point. Another important consideration in the development of this standard is the focus on analyzing the risk, as opposed to estimating the risk. This may seem to be a purely semantic distinction, but it emphasizes that application of this standard is intended to provide an organization (whether it be the facility operator or some cognizant safety oversight organization) with sufficient information to make a decision about the extent to which releases following an aircraft crash are a safety concern. It is also intended to provide sufficient information to identify where the risk is coming from and to determine what actions, if any, would be prudent to reduce the frequency or to mitigate the consequences of an aircraft crash into the facility. In most cases, this does not require an accurate estimate of the risk. Rather, it is sufficient to determine that the risk (or the individual subelements of frequency and consequences) does not exceed a predetermined level of concern (i.e., it is not large compared to other risks). This standard allows the analysis to proceed along a series of increasingly complex steps; the results at each step are used to determine whether it is necessary to proceed to the next step or whether sufficient information has been provided and the analysis can be stopped and documented. As one proceeds through the steps, the results will get closer to an actual estimate of the risk, but even after fully implementing this standard, the results will still be more conservative than would be expected from a best-estimate risk

assessment. In summary, following this standard will, in the vast majority of cases, provide sufficient information to document facility safety and support sound decision making for addressing the effects of an aircraft crash in the context of facility safety. In those rare cases where additional analysis is considered necessary to achieve these goals, an organization may perform a more detailed analysis. This standard does not provide guidance on completing such an analysis. A necessary corollary to the above discussion is that this is not a criterion-based standard. It does not provide any hard and fast rules prescribing what actions should be taken in response to the results; it does not even prescribe whether any action should be considered. It does provide quantitative guidelines against which the results for each step DOE-STD-3014-96 8 in the analysis can be measured; however, these are only for the purpose of determining whether further analysis should be performed. Meeting or not meeting these guidelines should not be interpreted as indicating that preventive or mitigative actions either are or are not required. This standard does not include consideration of malicious acts (e.g., sabotage, terrorism, and war). The available data on aircraft crashes do not support assessment of such acts. Further, such acts are not unique to aircraft, nor are they initiated by failures and errors associated with aircraft. However, the parts of this standard that address structural response and exposure due to a release could be useful (to a limited extent) in assessing the effects of such an assault. 1.3 Applicability. This standard is applicable to all facilities containing significant quantities of radioactive or hazardous chemical materials. For the purposes of this standard, a facility contains significant quantities of such material if it meets one or more of the following conditions: a. The facility contains radioactive material, and the inventory of such material would cause the facility to be classified as a Hazard Category 1 or Hazard Category 2 facility in accordance with the criteria established by the U.S. Department of Energy (DOE) (Reference 1); or b. The facility contains hazardous chemicals in quantities that make it subject to the requirements of 29 Code of Federal Regulations (CFR) 1910.119 (Reference 2); or c. The facility contains hazardous chemicals that make it subject to the requirements of the Environmental Protection Agency's (EPA's) Risk Management Program (Reference 3). The conditions above specify the minimum circumstances under which this standard should apply. However, they do not preclude applying this standard or its parts to facilities that do not meet any of these conditions. Users are encouraged to consider whether there are special circumstances in which a particular facility should be subject to this standard DOE-STD-3014-96 9 even though none of the above conditions are met. Such special circumstances could include (1) the presence of large amounts of material that were excluded from the inventory due to their enclosure in Department of Transportation (DOT) Type B shipping containers or sealed sources, per recommendation by DOE (Reference 1), but which may be subject to release in an aircraft crash; (2) the presence of large quantities of other materials which are known to pose a hazard but are not covered under conditions b and c;

(3) the close proximity of an unusually large number of members of the public; (4) the presence of environmental resources that are particularly susceptible to the materials in the facility (e.g., endangered species) or that can spread contaminants over long distances (e.g., waterways); or (5) other similar circumstances. 1.4 References. 1. United States Department of Energy. Hazard Categorization and Accident Analysis Techniques for Compliance with DOE Order 5480.23, Nuclear Safety Analysis Reports. DOE-STD-1027-92. December 1992. 2. Title 29 Code of Federal Regulations, Part 1910, Section 119, Process Safety Management of Highly Hazardous Chemicals. 1994. 3. Title 40 Code of Federal Regulations, Part 68. 1996. http://www.doe.gov/techstds/standard/std1027/std1027.pdf DOE-STD-3014-96 10 2. DEFINITIONS. The first step in the development of this standard was to identify and define several critical terms. The terms are listed here in alphabetical order, and, where possible, the source of the definition has been identified. Air Carrier: As defined by the Federal Aviation Administration (FAA), the commercial system of air transportation consisting of certificated air carriers, air taxis (including commuters), supplemental air carriers, commercial operators of large aircraft, and air travel clubs. Air Taxi: As defined by the FAA, a classification of air carriers that transports persons, property, and mail using small aircraft (under 30 seats or a maximum payload capacity of less than 3401 kg [7,500 lb]) in accordance with 14 CFR 135. Airborne Release Fraction (ARF): The coefficient used to estimate the amount of radioactive material suspended in air as an aerosol and thus available for transport due to physical stresses from a specific accident. Aircraft Accident: As defined by the National Transportation Safety Board (NTSB), an occurrence associated with the operation of an aircraft that takes place between the time any person boards the aircraft with the intention of flight until such time as all such persons have disembarked, and in which any person suffers a fatal or serious injury as a result of being in or upon the aircraft or by direct contact with the aircraft or anything attached thereto, or in which the aircraft receives substantial damage. Aircraft Category: The broadest, most general level of classification for aircraft and aviation used in this standard. There are three categories: (1) commercial aviation, (2) military aviation, and (3) general aviation. Aircraft Crash: For the purpose of this standard, any aircraft accident that results in destruction of or substantial damage to the aircraft. Fatal or serious injury sustained as a result of the aircraft accident by itself, without related destruction or substantial damage to the aircraft, does not make an aircraft accident qualify as an aircraft crash. DOE-STD-3014-96 11 Aircraft Subcategory: The most detailed level of classification used in this standard for aircraft and aviation. For use in performing the specified analyses, the aircraft categories are divided into subcategories that consist of aircraft types having similar physical characteristics and distributions of crash parameters. Aircraft Type: As defined by the FAA and used in this standard, a specific make and basic model of aircraft. Airport: As defined by the FAA, an area of land or water that is used or intended to be used for

the landing and takeoff of aircraft. This includes any buildings or facilities on the area. Airport Operation: As defined by the FAA, the number of arrivals and departures from the airport at which the airport traffic control tower is located. There are two types of airport operations, local and itinerant. Local operations are those performed by aircraft that (1) operate in the local traffic pattern or within sight of the airport; (2) depart for or arrive from flight in practice areas located within a 37-km (20-mile [assuming nautical miles]) radius of the airport; or (3) execute simulated instrument approaches or low passes at the airport. All aircraft operations other than local operations are itinerant operations. ARTCC: Air Route Traffic Control Center. Barrier: A building, structural component, or object (e.g., equipment) that has the potential to prevent a missile from impacting a target, or to mitigate the effects of a missile impacting a target. Certificated Air Carrier: As defined by the FAA, an air carrier holding a Certificate of Public Convenience and Necessity issued by the U.S. Department of Transportation (DOT) to conduct scheduled services interstate. Nonscheduled or charter operations may also be conducted by these carriers. Certificated air carriers operate large aircraft (30 seats or more or a maximum payload of 3401 kg [7,500 lb] or more) in accordance with 14 CFR 121. Commercial Aviation: For the purpose of this standard, any aircraft activity performed under 14 CFR Parts 121, 125, 127, and 135. DOE-STD-3014-96 12 Crash: See the definition of an aircraft crash. Crash Location Distribution: The normalized conditional probability distribution (i.e., given that the crash occurs) in terms of the x and y coordinates of a coordinate system centered at the relevant runway. Damage Ratio: The fraction of material at risk (MAR) actually impacted by the accident- generated conditions. Distance Inclusion Criteria: The specified distance between the facility of interest and the flight sources within which aircraft operations are assumed to have a measurable impact on the aircraft crash impact frequency and are to be included in the analysis. ERPG-2 (Emergency Response Planning Guidelines - Level 2): The maximum airborne concentrations below which it is believed that nearly all individuals could be exposed for up to 1 hour without experiencing or developing irreversible or other serious health effects or symptoms that could impair an individual's ability to take protective actions. ERPG-3 (Emergency Response Planning Guidelines - Level 3): The maximum airborne concentrations below which it is believed that nearly all individuals could be exposed for up to 1 hour without experiencing or developing life-threatening health effects. Effective Area: The area of a potential target that is vulnerable to an aircraft crash. This area is a planar, or “horizontal,” mapping of areas that an aircraft could crash into. It is derived as a function of physical target characteristics (width, length, and height), as well as aircraft and flight characteristics such as wing span, impact angle, and heading. Exposure Evaluation: A calculation of the predicted airborne dose, as a function of distance, to which an individual would be exposed as a result of the accidental release of hazardous chemical or radioactive materials in specified weather conditions. DOE-STD-3014-96 13

Exposure Screening: A preliminary conservative estimate of the potential offsite effects from an aircraft crash impact that allows all identified hazardous chemical and radioactive materials to be released. Facilities meeting recommended guidelines do not have to be evaluated in terms of aircraft impact frequency analysis. Facility: As used in this standard, an area of interest for the purpose of performing aircraft crash impact analysis involving either individual structures or buildings; portions of structures or buildings (such as critical structures, systems, and components [SSCs]); or a multibuilding or multistructure conglomeration such as a storage tank farm or munition magazine complex. The facility should be defined as the collection of such structures that could be affected by a single aircraft impact. Fatal Injury: As defined by the NTSB, any injury that results in death within 30 days after the accident. Flight Phase: The portions of an aircraft flight that are distinctly different due to the configuration of the aircraft and/or the conditions under which the flight is taking place. In general, there are seven distinct phases per flight. These are: takeoff roll, initial climb, climb to cruise, cruise/in-flight, descent from cruise, approach, and landing roll. For this standard, the seven phases were grouped into three main flight phases: 1. Takeoff phase, which includes the takeoff roll and the initial climb; 2. In-flight phase, which includes the climb to cruise, cruise/in-flight, and the descent from cruise; and 3. Landing phase, which includes the landing approach and the landing roll. Flight Source: An aircraft activity (e.g., either airport operations or nonairport operations) that is assumed to contribute to the overall aircraft crash impact frequency and, thus, is included in the analysis. This standard addresses two types of flight source: (1) airport operations and (2) in-flight or nonairport activities, including the special case of deliberate overflights involving observation and local operations aircraft. For example, if there are three airports within the distance inclusion criteria, then there are four flight sources to be included in the analysis (three airport sources and one nonairport source). DOE-STD-3014-96 14 Frequency: The expected number of events that occur or are expected to occur over some measured interval, such as events per unit time or events per aircraft operation. General Aviation: As defined by the NTSB in their compilation of accident data and as used in this standard, all operations involving U.S. registered aircraft that are not conducting air carrier revenue operations (i.e., not air carriers or air taxis). Global Response: Response of the overall target structure, as measured by its state of strain or displacement, which may result in global structural failure due to collapse or excessive structural deformation. Global response may also result in the functional failure of SSCs. Hazard: An inherent physical or chemical characteristic that has the potential for causing harm to people, property, or the environment. It is the combination of a hazardous material, an operating environment, and certain unplanned events that could result in an accident. High Altitude (Jet) Route: The designated route between VOR (very high frequency omnidirection radio) or VORTAC stations for aircraft flying between 5486 m or 5.5 km (18,000 ft)

mean sea level (MSL) and 13,716 m or 13.7 km (45,000 ft) MSL. IFR Flight: As defined by the FAA, flight conducted in accordance with Instrument Flight Rules. Immediately Dangerous to Life or Health (IDLH): The maximum concentration of a (chemical) substance in air from which healthy male workers can escape without loss of life or irreversible health effects under conditions of a maximum 30-minute exposure time. Impact Frequency: The frequency, per unit time, of an aircraft impacting a facility of interest. In-flight Flight Phase: Refer to “Flight Phase” for definition. Jet Route: Same as high altitude route. Landing Flight Phase: Refer to “Flight Phase” for definition. DOE-STD-3014-96 15 Leakpath Factor: The fraction of the radionuclides in the aerosol transported through some confinement deposition of filtration mechanism. Level of Concern: The concentration of an extremely hazardous substance in air above which there may be serious irreversible health effects or death as a result of a single exposure for a relatively short period of time. Local Response or Damage: Penetration and spalling, scabbing, punching shear, and perforation of building structural components (e.g., a wall or floor) that may not result in the overall failure or collapse of the whole building structure. Low Altitude (Victor) Route: The designated route between VOR or VORTAC stations for aircraft flying at or below 5486 m or 5.5 km (18,000 ft) MSL. Material at Risk (MAR): The amount of radionuclides available to be acted on by a given physical stress. Military Aviation: As used in this standard, the aircraft category pertaining to any aircraft activity performed by the U.S. Air Force (USAF), U.S. Navy (USN), U.S. Marine Corps (USMC), U.S. Army (USA), and the U.S. Coast Guard (USCG). Missile: A general term used to denote both primary and secondary missiles. See also “primary missile” and “secondary missile.” Near-Airport Analysis: The aircraft crash impact frequency analysis involving the airport flight phases (takeoff and landing) for aircraft using airports within specified distances from a facility. Nonairport Analysis: The aircraft crash impact frequency analysis involving aircraft in the in-flight flight phase. DOE-STD-3014-96 16 Pattern Side: A well-defined side of the runway at a military airport where the downwind leg of landings, touch-and-goes, etc. take place. A pattern side could also be present at a civilian airport if that airport is used for military aviation. Penetration: A local damage that signifies displacement of the missile into the target and is a measure of the depth of crater formed at the zone of impact. Perforation: A local damage that signifies that the missile fully penetrates the target or passes through the target. Primary Missile: An aircraft or a detached part of an aircraft (e.g., engine) that can hit a target directly from the air or after skidding on the ground. Probability: A unitless quantitative measure of the likelihood of a given event with a value ranging from 0 to 1. Punching Shear: Local shear failure occurring in the immediate vicinity of the impacted zone. Punching shear may occur as part of the perforation process. REM: Acronym of roentgen equivalent man. Respirable Fraction (RF): The fraction of airborne radionuclides as particles that can be transported through air and inhaled into the human respiratory system. These are commonly

assumed to include particles 10µm Aerodynamic Equivalent Diameter (AED) and less. Respirable Release Fraction: Product of airborne release fraction and respirable fraction. Risk: The measure of a potentially hazardous event in terms of its likelihood and the severity of its consequences. Risk can be determined following the release analysis for specified aircraft crash scenarios that have been evaluated for both impact and structural response likelihoods. Prior to this step, risk is evaluated: first by inventory screening (risk's severity parameter) and then by frequency (risk's likelihood parameter). DOE-STD-3014-96 17 SSC Functionality: As used in this standard, the function that a structure, system, or component (SSC) performs to ensure that no significant threat to the general public (from release of hazardous material) results from an aircraft crash accident. Scabbing: A local damage that signifies the peeling off (or ejection) of material from the back face of the target. Scenario: A succession of specified events beginning with an initiating event, followed by other events (such as failures of structures or systems), and ending with the release of hazardous material. Secondary Missile: A part of the breakaway aircraft segments or a facility SSC (e.g., a chimney structure) that becomes detached as a result of the impact of a primary missile on a facility. Spalling: A local damage that signifies the ejection of target material from the front face of the target. Structures, Systems, and Components (SSCs): Buildings; building components (e.g., a roof slab or wall); other structures (e.g., tanks, bunkers); mechanical or electrical systems (e.g., a heating, ventilating, and air conditioning [HVAC] system or a cable-tray system); and mechanical or electrical components or equipment (e.g., a motor control center or a pump). In this standard it is generally used to refer to SSCs whose failure as a result of aircraft crash could result in a release of hazardous material. TACAN: Tactical Air Navigation, a military aviation navigational aid. Takeoff Flight Phase: Refer to “Flight Phase” for definition. Target: A facility, SSC, or other structure under evaluation that has the potential to be impacted by an aircraft or aircraft-generated missile where such impact could ultimately lead to a release of hazardous material. DOE-STD-3014-96 18 Threshold Quantity (TQ): The quantity of a hazardous chemical below which exposure screening or evaluation is not necessary. VFR Flight: As defined by the FAA, flight conducted in accordance with Visual Flight Rules. VOR: As defined by the FAA, very high frequency omnidirection radio range. Used as a basis for navigation in the national airspace system. VORTAC: As defined by the FAA, a navigation aid providing azimuth and distance measuring equipment at one site. A combination of VOR and TACAN navigational aids. Victor Route: Same as low altitude route. DOE-STD-3014-96 19 3. GENERAL IMPLEMENTATION GUIDANCE. This chapter provides an overview of the approach described in this standard. The approach is summarized in the flowchart in Figure 1. The flowchart depicts an approach that provides maximum flexibility in implementing this standard. The components of the approach are modular, so they may be used in a different order and still be applicable. For example, a facility that is located relatively far from airports with limited operations may decide that the best route

through the approach is to begin with impact frequency evaluation. Likewise, a facility with a low quantity of hazardous material may decide to start with exposure screening. In fact, the analyst is not limited to these selections and can start the implementation anywhere in the flowchart. The chronological order of activities presented in Figure 1 is believed to provide the most efficient method for implementing the approach. As can be seen by the boxes in Figure 1, the approach consists of three distinct phases, which aim to answer the following three questions: Phase I: Does the total hazardous material in the facility pose a threat to the public? Phase II: Does aircraft crash impact pose a threat to the facility? Phase III: What is the extent of the threat posed to the facility and the public? The steps in the first phase are intended to determine whether the facility in question contains sufficient inventory of hazardous radioactive or chemical material to pose a potential hazard if an aircraft crash could result in the release of the available material. If the steps in this phase indicate that the facility contains sufficient inventory to pose such a hazard, then the analysis moves to the second phase. The second phase is intended to demonstrate whether an aircraft crash poses a significant threat of release from the facility. This phase primarily considers whether the frequency of aircraft impact into the facility is significant and whether those aircraft that have a high impact frequency could actually do damage to the facility. If the steps in this phase indicate that aircraft crash poses a threat of release from the facility, the analysis moves to the third phase. The third phase comprises a “graded” analytical approach for assessing the extent of the damage to the facility, the extent of any release associated with the damage, and the exposures associated with the release. In this context, a “graded” analysis means DOE-STD-3014-96 20 performing the steps in this phase to the extent necessary to (1) understand the level of threat posed by an aircraft crash and (2) provide sufficient information to allow the facility operator to determine the need for (and type of) preventive and/or mitigative measures. Another key aspect of the approach is that it must be integrated with the analysis of other potential facility safety hazards. While the adverse effects of aircraft impact on safety-related structures systems or components (SSCs) are being evaluated, the effect of the failure of nonsafety-related SSCs (due to aircraft impact) on the safety-related SSCs, if any, should also be evaluated. The consideration of aircraft crash is not an independent safety assessment. This concept is illustrated in Figure 1 by the inputs to the various steps from facility design, operation, and safety documentation. The analysis of aircraft crash should not be addressed outside the context of this other information. The individual steps in the analysis are briefly described in this section. Each subsection provides a list of inputs to and outputs from the analytical steps. The sources of inputs are identified as follows: a. Available - Information that should be available in other documents describing the specific facility and its operation. Such information is generally not specific to aircraft crash analysis and can be readily located by an analyst. Whenever

information is indicated as available, a potential source of that information is indicated. b. Defined - Information that exists in this standard, its supporting documents, or a technical document referenced by this standard. Such information is generic in nature (i.e., it is not a function of the specific facility being analyzed) and is intended to be accepted as a given in the analysis (e.g., a constant to be used in an equation). Is Stored Material Quantity Less Than The Screening Guideline? DocumentYes Facility Dimensions from Design Documentation Perform Exposure Frequency Screening 5.2 DocumentYes A Material Inventory from Hazards Assessment Determine Applicability 1.3 (See Note 1) Screen Out Insignificant Hazardous Facilities Screen Out Facilities with an Insignificant Threat No No Is Impact Frequency Less Than Impact Frequency Screening Guideline? (Note 1). Dashed lines depict the continuation of the implementation process based on the analyst's choice of starting location. FIGURE 1. Flowchart implementing the standard Perform Exposure Screening 7.2 Material Inventory from Hazards Assessment Determine Applicability 1.3 D O E -S T D -3014-96 21 Perform Exposure Frequency Screening 5.2 Screen Out Facil ities with an Insignificant Threat Structural Design Information from Design Documentation Yes Are There Building Supported Safety Related SSCs In The Vicinity Of Impact Locations? Accident Scenario Insights from Faci lity Safety Analysis Systems, Structures, & Components from Facil ity Safety Analysis Does Structural Screening Show That All Relevant Aircraft Types Meet Structural Response Guidel ine? DocumentYes C No B A FIGURE 1. Flowchart implementing the standard 22 DOE-STD-3014-96 DOE-STD-3014-96 Perform Structural Screening Using Boundary Missile At Locations Without Safety- Perform Structural Evaluation Using Critical Missiles For Release Frequency Screen Related SSCs in Vicinity Perform Release Frequency Screening Perform Structural Evaluation Using Critical Missiles For Release Frequency Evaluation Perform a "Graded" Analysis to Assess the Level of Threat for the Purpose of Determining the Need for Preventive/Mitigation Measures FIGURE 1. Flowchart implementing the standard 23 DOE-STD-3014-96 24 c. Data - Information that is specific to the facility being analyzed but is unlikely to have already been compiled in other documents. Such information is generally needed only for aircraft crash analysis and would therefore not be readily available unless a previous analysis has been performed. d. Derived - Information that results from the application of this standard. Generally, a derived input was an output of one of the previous steps of the analysis. 3.1 Exposure Screening. Exposure screening consists of performing a simplified, conservative analysis of the potential hazardous material exposure to any member of the public resulting from an aircraft crash into a facility. For the purpose of this screening, it is assumed that the building is destroyed and all of the hazardous material available in the building is impacted; conservative values for the amount of material that can be transported and ingested are used, and it is assumed that the most direct and harmful path is taken to the site boundary. Exclusions of well-confined material from the hazardous materials inventory may be made, but should be justified on the basis of the

robustness of the material containment in a postulated aircraft impact environment. The purpose of this step is to determine whether there is sufficient hazardous material inventory in the facility that the worst possible release could cause measurable harm to a member of the public (or, in certain cases, to a worker near the facility). The guidelines (given in Section 4.1) are expressed in terms of a dose (for radioactive materials) or a concentration (for chemical hazards) to the maximally exposed individual at or beyond the site boundary. The methodology for the analysis is provided in Section 7.2. The result of the analysis allows the analyst to determine what amount of radioactive or hazardous chemical material would have to be present in the facility to exceed the guidelines at or beyond the site boundary (see Chapter 4). The analyst can then determine whether the facility inventory would exceed those guidelines. If the facility inventory does not exceed the thresholds, the risk is deemed to be small and the results are documented. If the facility inventory does exceed the thresholds, the analysis should proceed to the next step. DOE-STD-3014-96 25 Inputs: a. The exposure screening guidelines. (Defined) b. The amount and form of hazardous material contained in the facility. (Available from existing facility design and operation documents) c. The distance from the facility to the site boundary. (Available from existing facility site drawings) Outputs: a. The amount of material that would have to be present in the facility to create the potential for site boundary exposure guidelines to be exceeded. 3.2 Impact Frequency Evaluation. The impact frequency evaluation consists of performing a conservative assessment of the expected frequency per year of an aircraft impacting a facility of interest. This evaluation takes into account the site-specific and crash-specific parameters that affect aircraft impact frequency. No assessment is made of the severity of the postulated aircraft impact into the facility, nor are the specific aircraft types identified as part of the analysis. However, these data are available if, after this evaluation, structural response analysis is required. The results of the impact frequency evaluation are expressed in terms of the annual impact frequency for the facility of interest. The requirements for the impact frequency evaluation are provided in Section 5.3. The calculated total annual impact frequency (summed over all aircraft categories) is compared to the impact frequency evaluation guideline provided in Section 4.2. If the guideline is not exceeded, the results are documented. If the guideline is exceeded, the analysis should proceed to the next step. Inputs: a. The impact frequency evaluation guideline. (Defined) b. A list of the applicable flight sources within specified distances from the facility. (Data) c. A list of aircraft categories/subcategories for each applicable flight source. (Data) DOE-STD-3014-96 26 d. The estimated number of operations per year at each source, for each candidate aircraft category/subcategory, and flight phase. (Data) e. The representative crash probability for each candidate aircraft category/subcategory and flight phase. (Defined) f. The crash location probability for each candidate aircraft category/subcategory and flight phase. (Defined) g. The mean of the cotangent of the impact angle for each candidate

aircraft category/subcategory and flight phase. (Defined) h. The mean skid length for each candidate aircraft category/subcategory and flight phase. (Defined) i. The facility/site dimensions. (Available from existing facility and site design documents) j. Crash location expected frequency of an in-flight crash for each candidate aircraft category/subcategory. (Defined) Outputs: a. The annual impact frequency for each candidate aircraft category/subcategory. b. The total annual impact frequency for all candidate aircraft categories/subcategories. c. A list of aircraft categories/subcategories that contribute to exceeding the impact frequency evaluation guideline (if any). 3.3 Structural Screening and Evaluation. 3.3.1 Structural Screening. Structural screening consists of simplified but conservative structural evaluation of the facility using two bounding missiles, one for building local damage evaluation and the other for building collapse evaluation (Section 6.2). If this evaluation indicates that the building components meet the structural screening guidelines (Section 4.3) for all impact locations and if there is no safety-related equipment supported from the building structure in the vicinity of the postulated impact, the risk is deemed small and the results are documented. If the guidelines are exceeded for any impact location or if there is any safety-related DOE-STD-3014-96 27 equipment in the vicinity of the postulated impact, the analysis should proceed to the next step. Inputs: a. The structural screening guideline. (Defined) b. Mass (for aircraft and aircraft engine) and speed data for the candidate aircraft categories/subcategories identified in Section 3.2. (Defined partially in References 1 and 2 of Chapter 5) c. Structural design information for the facility. (Available from existing facility design documents) d. A list of building-supported equipment whose failure could result in a release (safety-related equipment) and its locations. (Available from existing facility safety analyses) e. The location of hazardous material within the facility and accident scenario information. (Available from existing facility design, operation, and safety analysis documents) Outputs: a. A list of impact locations and/or aircraft categories/subcategories that can be screened out from further evaluation. 3.3.2 Structural Evaluation. The structural response evaluation step consists of determining the type and extent of damage (local damage, excessive structural deformation, and/or SSC functional failure due to vibration) to the facility when subjected to impacts from aircraft subcategories that were identified in the previous step as contributing to an annual impact frequency greater than the frequency guideline. The results of the response analysis are reported as the damage status for systems and structures, including confinement barriers, meaning the level of damage an aircraft causes. In the case of individual components, the damage status is limited to operable/nonoperable. Each aircraft subcategory may be represented by a surrogate aircraft design for the purpose of structural response evaluation. This surrogate aircraft design provides design parameters such as aircraft mass, mass distribution, impact velocity, cross- DOE-STD-3014-96 28 sectional area of missile, and impact angle. These parameters reasonably represent the important characteristics of the aircraft types that are included in the

subcategory. Alternatively, one or more critical aircraft may be selected, considering all contributing aircraft subcategories for the particular site. Guidelines for selecting these critical aircraft are provided in Chapter 6, along with guidelines for selecting critical impact locations and impact angles. Interactions between safety and nonsafety systems, structures, and components are also considered. If the structural response evaluation indicates that the facility (including any equipment supported by the structure) meets the structural response evaluation guidelines (Section 4.3) for all impact locations of all aircraft subcategories considered, the risk is deemed small and the results are documented. If the guidelines are exceeded for any impact location and for any of the aircraft subcategories considered, the analysis should proceed to the next step. Inputs: a. The structural response evaluation guideline. (Defined) b. Design information for the representative aircraft used as a surrogate for the aircraft types contained in the aircraft subcategory (mass, speed, angle of impact, mass distribution, etc.). (Defined) c. A list of aircraft subcategories that contribute to exceeding the impact frequency evaluation guideline. (Derived) d. Structural design information for the facility. (Available from existing facility design documents) e. A list of, and design information about, SSCs whose failure could result in a release. (Available from existing facility safety analyses) f. The location of hazardous material within the facility and accident scenario information. (Available from existing facility design, operation, and safety analysis documents) Outputs: a. A list of aircraft types or subcategories whose impact into the facility could result in facility damage (if any) potentially leading to a release. DOE-STD-3014-96 29 b. For each of these aircraft types or subcategories, the impact locations that could result in such facility damage. c. For each such impact location, the level of damage that would result from an impact, including (1) location and depth of penetration, (2) identification of structural failures, (3) path and final location of missiles, (4) post-crash location of fuel tanks, and (5) damage status of SSCs of concern. 3.4 Release Frequency Screening. The release frequency screening is a simple, conservative calculation. For this analysis, an aircraft category is considered to have no effect on a facility only if no impact results in structure damage (i.e., damage does not exceed the structural response guideline). Thus, if any impact from a given aircraft subcategory will cause a release, then it is assumed that all impacts from that aircraft subcategory will result in a release. Any aircraft subcategory considered to have no effect on the facility is deleted from further consideration in the analysis. The release frequency is calculated by summing the impact frequencies for all remaining aircraft subcategories. Note that this calculation includes the impact frequencies of any aircraft subcategories that have not been subject to a structural response analysis, unless it can be documented that they will not cause sufficient damage to cause a release. The methodology for the analysis is provided in Section 5.4. This result is compared to the release frequency screening guideline provided in Section 4.4. If the guideline is not

exceeded, the results are documented. If the guideline is exceeded, the analysis should proceed to the next step. Inputs: a. The release frequency screening guideline. (Defined) b. A list of aircraft subcategories subjected to structural response analysis. (Derived) c. The annual aircraft impact frequency for all aircraft subcategories. (Derived) d. Accident scenario information. (Available from existing facility safety analysis documents) DOE-STD-3014-96 30 Outputs: a. The total annual impact frequency for those aircraft categories/subcategories that have not been shown to have no effect on the facility, i.e., those aircraft subcategories that could result in facility damage affecting hazardous material or its confinement (i.e., the initial release frequency) 3.5 Release Frequency Evaluation. The release frequency evaluation step is a refinement that takes into account the fact that not all impacts from aircraft subcategories that damage the facility will necessarily result in a release. This process considers how much of the facility is damaged, whether the hazardous material available in the facility is impacted or affected through secondary mechanisms, and (to a limited extent) what release mechanisms impact the material. For each impact location that results in damage, the structural analysis has already provided the extent of that damage (the "damage level"). Each of these damage levels would now be converted into an event scenario to determine whether a release could actually occur. For each scenario, the frequency of the aircraft impact would be modified to account for the fraction of the overall facility area to which that level of damage applies. The release frequency is calculated by summing the event scenario frequencies for all event scenarios that are determined to lead to an actual release. The methodology for the analysis is provided in Section 5.5. This result is compared to the release frequency evaluation guideline provided in Section 4.5. If the guideline is not exceeded, the results are documented. If the guideline is exceeded, the analysis should proceed to the next step. Inputs: a. The release frequency evaluation guideline. (Defined) b. The list of aircraft subcategories whose impact into the facility could result in facility damage potentially leading to a release. (Derived) c. The annual impact frequency for each such aircraft subcategory. (Derived) d. For each of these subcategories, the impact locations that could result in such facility damage. (Derived) DOE-STD-3014-96 31 e. For each such impact location, (1) the extent of local and global damage and depth of penetration, (2) identification of structural failures, (3) path and final location of missiles, (4) location of fuel, and (5) damage status of safety-class SSCs. (Derived) f. Accident scenario information. (Available from existing facility safety analysis documents) Outputs: a. Release scenarios for each of the aircraft subcategory impact locations that could result in damage that could lead to a release (or a finding that no release would actually occur). b. For each release scenario, the fraction of the facility area and/or skid area where the aircraft impact could lead to the scenario. c. The annual frequency of each such release scenario and the total of all such frequencies (i.e., the final release frequency). d. A list of the release scenarios that contribute to the total annual release

frequency exceeding the release frequency evaluation guideline (if any). 3.6 Exposure Evaluation. Exposure evaluation consists of performing a detailed but still conservative analysis of the potential hazardous material exposure to any member of the public (and, where appropriate, to onsite workers) resulting from an aircraft crash into the facility. The results of the release frequency evaluation (for those scenarios that could result in a material release) are used to define the specific source term and exposure scenarios. This process considers how much of the facility is damaged, how much of the hazardous material available in the facility is affected, what release mechanisms affect the material, how much of the material is converted into a form that can be absorbed into the body and do harm, and what energy is associated with the release. The result of this analysis is expressed as a dose (for radioactive materials) or a concentration (for chemical hazards) to the maximally exposed individual at or beyond the site boundary. The methodology for the analysis is provided in Section 7.3. Once this step is accomplished, the analysis required under this standard is complete and the results are documented. DOE-STD-3014-96 32 Inputs: a. The list of the release scenarios that contribute to the total release frequency exceeding the release frequency evaluation guideline. (Derived) b. The frequency of each such release scenario. (Derived) Outputs: a. The hazardous material source term for each of the listed release scenarios. b. The exposure level to the maximally exposed individual at or beyond the site boundary for each of the listed release scenarios. 3.7 Further Analysis. No further analysis is envisioned by this standard. In the vast majority of cases, analysis taken to this point should provide sufficient information and insights upon which to base decisions regarding the need for preventive or mitigative actions to reduce risk from aircraft crash. However, the standard recognizes that this may not always be the case, and therefore does not preclude further analysis. Such an analysis would likely be a formal probabilistic risk assessment incorporating features such as evaluation of crash/impact/release frequencies and structural response by specific aircraft type (rather than subcategory), development of probabilistic fragility curves for structural response, and quantification of distributions representing the analyst’s state of knowledge concerning total population exposures, health effects, and cleanup area associated with the release scenarios. Guidance on the methods for performing such additional analysis is beyond the scope of this standard. DOE-STD-3014-96 33 4. SCREENING AND EVALUATION GUIDELINES. This chapter provides the numerical screening and evaluation guidelines referred to in Chapter 3. These guidelines are used to determine at what stage in the approach the analysis is sufficient. It is extremely important to note that these guidelines were developed in full consideration of and integration with the analytical requirements and methodologies presented in this standard. Thus, they are only valid when used in conjunction with those requirements and methodologies (e.g., the atmospheric conditions specified in this standard should be used). In order to utilize the guidelines in this standard to apply a graded approach to accident

analysis, the conservatisms embedded in alternative approaches should be equivalent to those in the standard; otherwise, the guidelines do not provide a valid comparison with the results of the alternative approach. 4.1 Exposure Screening Guidelines. The results of the exposure screening step will be compared to the following guidelines for exposure to the maximally exposed offsite individual: a. Radiological exposure - 25 rem (0.25 Sv) committed effective dose equivalent (CEDE); b. Hazardous material exposure - Emergency Response Planning Guidelines - Level 2 (ERPG-2), as established by the American Industrial Hygiene Association (AIHA); or c. Hazardous material exposure where ERPG-2 has not been established - the Level of Concern established by the U.S. Environmental Protection Agency (EPA) specified in the 1987 EPA Technical Guidance on Hazards Analysis (or a successor document). Generally, dose to the maximally exposed offsite individual is deemed to be a sufficient measure of potential hazard from aircraft crash. However, there may be special circumstances in which exposure to onsite workers located outside the facility needs to be considered (see discussion in Appendix A, DOE-STD-3014-96 Threshold quantities for criticality are not used for comparison to the facility inventory, since the comparison is based2 on dose. 34 Section A.1). In those rare cases, the following additional screening guidelines may be applied: d. Radiological exposures - the facility inventory exceeds 25 times the Hazard Category 2 threshold quantities provided in DOE-STD-1027-92;2 e. Hazardous material exposure - Emergency Response Planning Guidelines - Level 3 (ERPG-3), as established by the AIHA to the maximally exposed worker located at or beyond 300 m (984 ft) from the facility; or f. Hazardous material exposure where ERPG-3 has not been established - the Immediately Dangerous to Life and Health (IDLH) criteria specified in the latest National Institute of Occupational Safety and Health (NIOSH) recommendation (or a successor document) to the maximally exposed worker located at or beyond 300 m (984 ft) from the facility. 4.2 Impact Frequency Evaluation Guideline. The results of the impact frequency evaluation step will be compared to the following guideline for the frequency of aircraft impact: a. Frequency of aircraft impact into a facility from all types of aircraft - 1E-6/y. 4.3 Structural Screening and Evaluation Guideline. The results of the structural response calculation will be compared to the following guidelines for various types of damage: a. Local damage to reinforced concrete targets: 1. scabbing - to prevent scabbing, required wall thickness is 110 percent of the predicted scabbing thickness; http://www.doe.gov/techstds/standard/std1027/std1027.pdf DOE-STD-3014-96 35 2. perforation - to prevent perforation, required wall thickness is 120 percent of the predicted perforation thickness; 3. punching shear - to prevent punching shear failure, the predicted punching shear stress should not exceed four times the square root of the compressive strength of concrete (f' ) at the perimeter one-half thec effective depth away from the load, unless higher values can be justified using Long’s formula given in Appendix C, Section C.6.3.2.1.3. b. Local damage to steel targets: 1. penetration - to prevent perforation of a steel target, the minimum wall thickness required is at least 125 percent of the predicted penetration

depth. c. Excessive structural deformation or collapse: 1. for concrete structural components - permissible ductility ratios as specified in American Concrete Institute (ACI) Code 349; 2. for steel structural components - permissible ductility ratios as specified in section Q1.5.8 of American Institute of Steel Construction (AISC) Nuclear Specifications, American National Standards Institute (ANSI) N690. d. Structure, system, and component (SSC) functionality: 1. for evaluation by analysis - up to code allowable acceptance criteria given in American Society of Civil Engineers (ASCE-4), American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, Institute of Electrical and Electronic Engineers (IEEE)-344, and NUREG-0800, as specified for safety-related SSCs; DOE-STD-3014-96 36 2. for evaluation by testing - using the instructure spectra generated from transient response analysis, following the methods described in IEEE-344. 4.4 Release Frequency Screening Guideline. The results of the release frequency screening step will be compared to the following guideline for the frequency of hazardous material release: a. Frequency of hazardous material release due to an aircraft impact into a facility from all types of aircraft - 1E-6/y. 4.5 Release Frequency Evaluation Guideline. The results of the release frequency evaluation step will be compared to the following guideline for the frequency of hazardous material release: a. Frequency of hazardous material release due to an aircraft impact into a facility from all types of aircraft - 1E-6/y. DOE-STD-3014-96 37 5. METHODOLOGY FOR EVALUATING AIRCRAFT CRASH IMPACT AND RELEASE FREQUENCY 5.1 Introduction. This chapter establishes a set of guidelines and methods for calculating and analyzing the impact frequency of aircraft crashes into a facility and the release frequency for radioactive and/or hazardous materials. The approach to analyzing frequency is divided into three parts: a. Impact Frequency Evaluation: The fundamental analysis, based on estimating the frequency of aircraft crashes into a facility. This provides basic frequencies for subsequent screening and evaluation analyses. b. Release Frequency Screening: An analysis based on including the structural response evaluation in the impact frequency evaluation. c. Release Frequency Evaluation: An analysis based on developing release scenarios from the time of an aircraft crash until the time exposure occurs due to the release of hazardous material. The method used to estimate the frequency in each part is based on the same technical principle; however, each part consists of varying degrees of complexity and conservatism. After each part is completed, the results are compared with the guideline value given in Chapter 4. If the result exceeds the guideline value, then additional analyses are performed; otherwise, no further work is required beyond documenting the analysis. The technical information provided in this chapter covers only the basic guidelines for implementing the three parts, along with a description of the frequency estimation models and the corresponding important input parameters for each model. Further technical information required to perform the analysis is provided in Appendix B. Detailed technical evaluations that support the development of each frequency model are provided in the modeling and data technical support documents (References 1 and 2).

These support documents should be consulted if additional information on the specifics of F i, j,k Nijk Pijk fijk(x,y) Aij DOE-STD-3014-96 38 (5-1) each method is needed. Neither this standard nor the modeling and data technical support documents contain site-specific information; rather, they provide guidance on what site-specific information is necessary and how to develop it. Aircraft crash frequencies are estimated using a "four-factor formula" which considers (1) the number of operations, (2) the probability that an aircraft will crash, (3) given a crash, the probability that the aircraft crashes into a 1-square-mile area where the facility is located, and (4) the size of the facility. In this standard, the four-factor formula is implemented in two different ways, depending on the flight phase: a. For near-airport activities, which consist of takeoffs (i=1) and landings (i=3), the four-factor formula is implemented through a combination of site-specific information and data obtained by the user of the standard, and a set of tables (whose origins are discussed in Reference 2) provided in Appendix B of this standard. b. For nonairport activities (i=2), DOE site-specific values, as well as reasonable estimates applicable throughout the continental United States, for the expected number of crashes per square mile per year in the vicinity of the sites (i.e., the value of the product NPf(x,y)) are provided in Appendix B of this standard; the four-factor formula is implemented by combining these with the facility effective areas to assess frequencies. Mathematically, the four-factor formula is: where: F = estimated annual aircraft crash impact frequency for the facility of interest (no./y); DOE-STD-3014-96 39 N = estimated annual number of site-specific aircraft operations (i.e.,ijk takeoffs, landings, and in-flights) for each applicable summation parameter (no./y); P = aircraft crash rate (per takeoff or landing for near-airport phases andijk per flight for the in-flight (nonairport) phase of operation for each applicable summation parameter; f (x,y) = aircraft crash location conditional probability (per square mile) givenijk a crash evaluated at the facility location for each applicable summation parameter; A = the site-specific effective area for the facility of interest that includesij skid and fly-in effective areas (square miles) for each applicable summation parameter, aircraft category or subcategory, and flight phase for military aviation (see Appendix B); i = (index for flight phases): i=1, 2, and 3 (takeoff, in-flight, and landing); j = (index for aircraft category or subcategory): j=1, 2,..., 11; k = (index for flight source): k=1, 2,..., K (there could be multiple runways, and nonairport operations); = ;k j i ijk = site-specific summation over flight phase, i; aircraft category or subcategory, j; and flight source, k. It should be noted that there is uncertainty associated with the frequency estimates produced using the four-factor formula, caused by the need to model complex physical processes using parameters that are based upon limited historical data. Experience-based judgements have been made as needed to supplement historical data, introducing additional uncertainties. This standard does not provide a quantitative estimate of the uncertainties involved; rather, the mathematical formulations and supporting parameter estimates have been made so as to provide a

reasonable point estimate of the frequency of aircraft crash impacts into specified facilities. 5.2 Methodology for Impact Frequency Screening. Although the desirability of a simple impact frequency screen based on the number of operations at nearby airfields was DOE-STD-3014-96 40 recognized, the high value of the maximum expected frequency of an in-flight mishap resulting in an aircraft impacting an arbitrary square mile in the continental United States precluded the development of a useable impact frequency screening methodology. 5.3 Methodology for Impact Frequency Evaluation. This section describes the approach for implementing the impact frequency evaluation, using the four-factor formula as given in Equation 5-1. The following guidance provides a set of steps for calculating impact frequency. Steps 1 through 6 are for determining the impact frequency from airport operations; Steps 7 through 19 are for determining the impact frequency from nonairport operations (Steps 7-8 for general aviation, Steps 9-12 for commercial aviation, Steps 13-16 for military aviation; and Steps 17-19 for helicopters); and Steps 20 and 21 are for comparing the results with the guidelines. An example of the use of these steps is included as Section B.5 of Appendix B. 5.3.1 Impact Frequency from Airport Operations. Step 1. Identify the flight sources affecting the facility. To do this, identify any airports that can be located within the boundaries of the aircraft crash location probabilities (Tables B-2 through B-13). Contact these airports to get an estimate of the annual number of takeoffs and landings, N, for each aircraft category or subcategory. This information can usually be provided by the airport on a category basis. If the airport can only provide total operations and is not able to discriminate between operation activities, assume that one-half (50 percent) of the operations are takeoffs and one-half (50 percent) are landings. This assumption will result in very conservative numbers because total operations include activities other than takeoff and landing, such as an aircraft contacting the tower for a change of vector. Finally, have the airport identify the pattern side of the runway for military aviation, if applicable. Step 2. For each flight source, determine the orthonormal distance (Cartesian distance, both x and y coordinates) from the facility, measured from the facility’s closest point, to the center of each runway at the flight source (for guidance on determining the orthonormal distance see Appendix B, Section B.3.1, and the example in Section B.5). DOE-STD-3014-96 41 Step 3. Given the orthonormal distance of the facility from each flight source, obtain the generic aircraft crash location probability per square mile, i.e., f(x,y), for takeoff and landing for each aircraft category/subcategory. This information is included in Appendix B as Tables B-2 through B-13. If the orthonormal distance of a facility falls outside the boundaries of these tables, the corresponding f(x,y) is assumed to be zero (a noncontributor). Step 4. Obtain the aircraft takeoff and landing crash rates, P, for each aircraft category or subcategory. This information is provided in Table B-1 of Appendix B. Step 5. Calculate the effective area, A, for each aircraft category or subcategory. The calculation of the effective area consists of two components: the aircraft can crash into

the structure either by skidding or by flying directly into it. To calculate the effective area, assume that the aircraft skids or flies into the structure in the direction that produces the largest area, i.e., crashing in a direction perpendicular to the largest diagonal of the building. The formula for calculating the skid- and fly-in areas of an aircraft crashing into a facility are provided as Equations B-3 through B-5 in Section B.4 of Appendix B. The effective area is a function of the cotangent of the impact angle, wingspan, and skid distance of the crashing aircraft. Values of these parameters are given in Section B.4 of Appendix B. Step 6. Multiply the values for N, P, f(x,y), and A for each combination of flight source, flight phase, and aircraft category/subcategory. Sum over flight sources and flight phases to calculate an impact frequency for each aircraft category/subcategory. (Do not sum the categories yet; this will be included in a later step.) 5.3.2 Impact Frequency from Nonairport Operations. Even though the expected frequency of aircraft crashes into a facility due to mishaps occurring during the in- flight phase of operation, is expected to be lower than the frequency associated with airport operations, the expected frequency cannot be shown to be a noncontributor to the overall frequency for all facilities. Thus, nonairport operations must be considered in the impact frequency analysis. Fj Nj Pj fj (x,y) Aj DOE-STD-3014-96 42 (5-2) The analysis of the nonairport operations impact frequency for all categories of aircraft is based on the same four-factor formula (Equation 5-1) as is used for airport operations; i.e., the frequency, F , for the class of aircraft, j, is j where the product NP represents the expected number of in-flight crashes per year; f(x,y) is the probability, given a crash, that the crash occurs in a 1-square-mile area surrounding the facility of interest; and A is the effective area of the facility. Ideally, values for NP and f(x,y) would be provided for any location within the continental United States (CONUS), similar to those provided for airport operations. However, this is impractical because of the large area of the CONUS. For this standard, values of the product NPf(x,y) applicable to selected DOE sites are provided in Tables B-14 and B-15. Also included are minimum, U.S. average, and maximum values, which can be used for facilities at other locations within the CONUS, for each category of aircraft. Development of the values in the tables is based on an analysis of the locations of past aircraft crashes within the CONUS. For general aviation, this record is substantial (over 1000 crashes) while the available data for other aircraft categories/subcategories, e.g., air carrier and large military, are very limited. Discussion of the bases of the values in Tables B-14 and B-15 and an outline of the analysis steps follow. a. General Aviation. The distribution of general aviation (GA) aircraft crashes throughout the CONUS is based on GA aircraft flying under both VFR and IFR conditions. Except for certain restrictions, e.g., restricted airspace, a GA aircraft can fly almost anywhere in the CONUS. In addition, once an in-flight mishap does occur, with an eventual loss of control, there is nothing to prevent a disabled aircraft from crashing into any location, even within a restricted airspace area. Thus, it is DOE-STD-3014-96 43

reasonable to assume that GA aircraft can crash anywhere in the CONUS. Crash location probabilities for GA aircraft are based on the assumption that future levels of GA aircraft activity and flight patterns will be similar to the historical record. The model for estimating the distribution of GA aircraft crash locations uses historical locations as the most likely but assumes that future locations will deviate within some area about the historical locations. Several models of the variation of future crash locations based on different hypotheses formed the basis for conducting a parametric study of the product NPf(x,y). The models and the associated sensitivity studies are discussed in Reference 1. The DOE site-specific values provided in Table B-14 of Appendix B represent reasonably conservative estimates obtained through a collective consideration of the sensitivity study results. Step 7. Refer to Appendix B, Table B-14, and obtain the appropriate site-specific or generic value for NPf(x,y). Step 8. Multiply the value of NPf(x,y) by the corresponding value for A determined in Step 5. This is the estimated GA nonairport impact frequency. b. Commercial and Military Aviation. Nonairport commercial and military impact frequency calculations are based on the assumption that the aircraft will fly point to point under the new FAA regulations rather than in specific airways. The values of NPf(x,y) in Table B-15 are derived from values developed for the ARTCC spanning the CONUS. The model assumes that the traffic density within an ARTCC is uniform and, given a crash in the ARTCC, the location of the crash is random. DOE-STD-3014-96 44 For commercial and large military aviation, crashes are assumed to occur at random throughout the CONUS, and the variation in traffic volume is reflected by the variation in the number of aircraft handled in each ARTCC. For small military aviation, the number of crashes varies among the ARTCCs. Thus, the expected number of crashes per year is estimated for each ARTCC based on the distribution of crash locations in the historical record. Table B-15 in Appendix B provides reasonable estimates of NPf(x,y) for selected DOE sites, as well as estimates of a minimum, average, and maximum value applicable for facilities at other locations within the CONUS. It is important to recognize that the in-flight analysis for military aviation given below only applies to normal in-flight operations outside military operations areas and low level flight ranges. For facilities at or near these latter types of areas, it is necessary to perform a site-specific assessment of the impact frequencies associated with activities in these areas. The analyses for each of the commercial and military subcategories are as follows: 1. Commercial Aviation Air Carrier. Step 9. Refer to Appendix B, Table B-15, and obtain the appropriate site-specific or generic value of NPf(x,y). Step 10. Multiply the value of NPf(x,y) by the A value determined for air carriers in Step 5. DOE-STD-3014-96 45 2. Commercial Aviation Air Taxi. Step 11. Refer to Appendix B, Table B-15, and obtain the appropriate site-specific or generic value for NPf(x,y). Step 12. Multiply the value NPf(x,y) by the A value determined for air taxis in Step 5. 3. Large Military Aviation. Step 13. Refer to Appendix B, Table B-15, and obtain the appropriate site-specific or generic value for NPf(x,y).

Step 14. Multiply the value NPf(x,y) by the takeoff effective area value, A, determined for large military takeoff in Step 5. The takeoff effective area, A, is used because it more closely represents in-flight crashes. 4. Small Military Aviation. Step 15. Refer to Appendix B, Table B-15, and obtain the appropriate site-specific or generic value for NPf(x,y). Step 16. Multiply the value NPf(x,y) by the takeoff effective area value, A, determined for small military takeoff in Step 5. The takeoff effective area, A, is used because it more closely represents in-flight crashes. c. Helicopter Aviation. Based on an analysis of historical helicopter crash data, the contribution to impact frequencies associated with nonlocal helicopter overflights is insignificant and need not be considered in the impact frequency calculations. However, it is necessary to consider local overflights, either planned overflights associated with the facility operations, e.g., security flights, or flights associated with area operations, e.g., spraying flights. Thus, the calculation of in-flight helicopter impact frequencies is a site-specific calculation. For FH NH PH 2 LH AH DOE-STD-3014-96 46 (5-3) application of this standard, each facility needs to obtain (1) the expected number, N, of helicopter local overflights per year; (2) the average length, L, in miles, of the flights corresponding to the site- specific overflights; and (3) the effective area for helicopter in-flight crashes, using Equation B-4, assuming an impact angle of 60 degrees, i.e., cot = 0.58 (note skid length is assumed to be 0). For these calculations, as shown in Equation 5-3, the lateral variations in crash locations for a helicopter are conservatively assumed to be one-quarter a mile on the average from the centerline of its flight path. The analysis for helicopter impact frequency calculations is as follows: Step 17. Obtain N , the expected number of local helicopter overflights per year, and L ,H H the average length of a flight. Step 18. Compute the effective area, A , using Equation B-4.H Step 19. Using the values of the probability of a helicopter crash per flight, P , inH Table B-1 in Appendix B, compute the helicopter impact frequency, F .H 5.3.3 Calculated Impact Frequency. Step 20. Sum the calculated impact frequency for airport and nonairport operations for each aircraft category or subcategory. For example, add up all the general aviation impact frequencies calculated in Steps 6 and 8. Rank the impact frequencies for all aircraft categories/subcategories in decreasing order. Sum the impact frequencies over the aircraft categories/subcategories to get the total impact frequency for the facility of interest. DOE-STD-3014-96 47 Step 21. If the total impact frequency is below the guideline value, the safety risk is below the level of concern; stop the analysis and document the results. If the total impact frequency is greater than the guideline value, it is necessary to identify the aircraft categories/subcategories to be used for the structural response and release frequency analyses. A certain amount of judgment is required in making this selection. It is recommended that the analyst interact with the facility structural engineers and/or analysts to identify a subset of those aircraft categories/subcategories that are significant contributors to the impact frequencies.

5.4 Methodology for Aircraft Crash Release Frequency Screening. The assessment of impact frequency, as evaluated above, assumes that all impacts will lead to facility damage and a possible release of radioactive or hazardous chemical material. This assumption is due to the lack of information about the response of the structure to impact during the impact frequency stage of the analysis. Following completion of the structural analysis, as described in Chapter 6, it is possible to determine the initial release frequency, which is the total impact frequency minus the impact frequencies of the aircraft categories/subcategories shown to have little or no effect on the facility, i.e., will not lead to a release. This section explains the process of calculating the initial release frequency using results from the structural analysis. The approach for the initial release frequency analysis is to exclude those aircraft categories/subcategories that are known and/or shown by the structural response analysis to inflict little or no damage should they impact the facility. The major assumption in this analysis is that if any of the impact locations analyzed in the structural response analysis for a particular aircraft category/subcategory can be shown to cause sufficient damage to lead to release, then all impact locations will lead to a release. This simplifies the analysis. The screening is performed in the following steps: Step 1. From the structural response analysis results, identify the aircraft categories/subcategories whose impact into the facility would result in little or no damage to the facility, i.e., would not result in a release. DOE-STD-3014-96 48 Step 2. From the list of impact frequencies compiled for the impact frequency evaluation, delete the impact frequencies corresponding to the aircraft categories/subcategories identified in Step 1. Step 3. Sum the impact frequencies for the remaining aircraft categories/subcategories. The calculated sum is the release frequency screening value. Step 4. Compare the release frequency screening value to the guideline. If the guideline is met, the safety risk associated with aircraft impact is below the level of concern and no further analysis is needed; document the results. If the guideline is exceeded, proceed to the release frequency evaluation (Section 5.5). 5.5 Methodology for Aircraft Crash Release Frequency Evaluation. The release frequency screening does not take into account the fact that, even if a particular aircraft category or subcategory can cause damage that could potentially lead to a release, only certain impact locations will have that effect. By making better use of the structural analysis and the impact frequency calculations, the analyst can define specific release scenarios and estimate the frequency associated with those scenarios. This makes it possible to determine the extent to which the actual release frequency may be lower than the initial release frequency. This section addresses the evaluation process for making this determination. For each impact location which is determined in the structural response analysis to exceed the structural response guideline, a release scenario associated with the level of damage resulting from the impact should be developed. The intent is to specify the most realistic conditions that can be justified. The scenario selected should be physically possible and

rational within the physical constraints of the level of damage incurred (including the occurrence of process accidents as a result of system failures). Once it has been determined that a release can occur, the overall facility dimensions used to assess the impact frequency are replaced with a partial facility dimension representing the impact location (a new effective area) for the specific release scenario. The new effective area is input into the four-factor formula (Equation 5-1) for the appropriate aircraft subcategory, resulting in a revised impact frequency specific to the impact location being evaluated. DOE-STD-3014-96 49 This process is performed on each of the impact locations that exceeds the structural response guidelines, following the steps listed below. Step 1. From the results of the structural analysis, take the description of the level of damage. This description will provide a conservative estimate of the structural damage that has occurred, including the path and location of penetrators; the damage state of walls, barriers, and equipment; the location of the aircraft fuel; and other pertinent information, as described in Chapter 6. Step 2. Assume that all available fuel burns, as well as any other combustibles that are in the path of the penetrators. Assume also that any high explosive material undergoes a high explosive violent reaction (HEVR). High explosive material includes such things as TNT, ion exchange resins, and the like, but not highly flammable materials that are subject to burning (i.e., prompt thermal releases) rather than true explosion (e.g., aircraft fuel, hydrogen gas). Note that this assumption pertains only to combustibles and explosives that are directly affected by the penetrators; that is, they are in areas or compartments that are actually breached by the penetrators. Step 3. Evaluate the extent to which secondary effects cause the scenario to spread beyond the area directly damaged by the crash. Comprehensive guidance cannot be provided for this step because situations will vary greatly from facility to facility. However, these are some questions to consider: - Is there sufficient combustible material to breach additional barriers and spread further through the facility? Remember that fire can also spread through ducts and along wiring conduits. Credit can be taken for the existence of fire barriers and breaks, if they have not been damaged by the crash. The basis for taking credit (e.g., short duration of the fire) should be documented. Therefore, a characterization of fire duration will almost certainly be required, although the level of detail will depend on how much sophistication is required to determine the duration of the fire relative to the capability of the fire barriers. Due to the difficulty of demonstrating that active systems can function following a crash, credit should DOE-STD-3014-96 50 not be allowed for fire suppression systems unless an explicit analysis shows that they will remain effective. - Is the force of any explosion capable of causing further barriers to be damaged or destroyed? Can it cause additional fires and/or explosions in the facility? Again, credit can be taken for the dissipation of explosive energy by existing barriers, if they have not been damaged by the crash. Credit can also be taken for diversion of the explosive force through breaches caused by the crash, thus reducing the

shock to intact barriers. The basis for taking credit should be documented. Again, characterization of the explosive force generated relative to barrier strength and the force transmitted to collocated explosives is required to justify the credit. Step 4. Based on the findings of the previous step, determine if a release could occur, given the scenario as defined. Again, specific guidance cannot be provided, but the following questions should guide the analyst's thinking: - Could any of the material at risk in the facility be impacted by any release mechanism (e.g., shock, fire, explosion) as a result of the scenario? The answer to this question should be “yes” if there is any material that is not separated from the energy available from the release mechanism by an intact barrier capable of dissipating that energy. - Could the primary confinement around any of that material be breached as a result of the scenario? The answer to this question should be “yes” if the structural integrity of the primary confinement is degraded below that required under accident conditions and if there is a driving force capable of causing the material to migrate through the breach. - Could a path to the atmosphere result from the scenario? The answer to this question should be “yes” if there are no longer any intact barriers between the material and the atmosphere, assuming that the primary confinement is failed and that there is a driving force capable of causing the material to migrate along the path. DOE-STD-3014-96 51 In this context, the word "could" should be taken to mean "is it mechanistically possible, given the level of damage." The possibility that failures occurring away from the material could cause system failures resulting in process accidents should also be considered. Therefore, intersystem dependencies and support system interactions should be explicitly evaluated. If there is any doubt about the answer to any of the three questions listed in this step, the answer should be assumed to be “yes.” If, for the given crash location, the answer to any of these questions is “no,” the scenario can be designated as a nonrelease scenario and eliminated from further consideration. Step 5. If the scenario has not been eliminated (i.e., the analysis has shown that it could lead to a release), calculate the impact frequency by rerunning the four-factor formula for the appropriate aircraft subcategory, using facility dimensions specific to the impact location associated with the scenario. The analyst will need to better define the location as an area (rather than just a single point) where impact could result in the release scenario. This requires judgement and consultation with the analyst(s) who conducted the structural response evaluation. Use this information to develop a set of "scenario facility dimensions" that represents what the target would look like if it encompassed an area equal to the target area associated with the release scenario being evaluated. Credit should be taken for shielding effects from other facilities to further reduce the scenario facility dimensions (Appendix B, Section B-4). The development of the scenario facility dimensions should be well justified and documented in detail. Once these dimensions have been established, run the appropriate four-factor formula to calculate the scenario release frequency. Step 6. Repeat Steps 1 through 5 for all of the impact locations that exceed the structural

response guidelines. Adding together the scenario release frequencies from each pass through Step 5 gives the final release frequency for the evaluation step. Step 7. Compare the final release frequency value to the guideline. If the guideline is met, no additional analysis of aircraft impact is required. If the guideline is not met, a more detailed analysis of the exposure associated with each release scenario needs to be performed in accordance with Section 7.3 of this standard. For the purpose of that DOE-STD-3014-96 52 analysis, each scenario that contributes to the release frequency exceeding the guideline should be fully documented. In particular, a full description of the damage state of the facility should be provided, including details about what parts of the facility are subject to each of the release mechanisms considered (e.g., fire, explosion, and crush/impact). 5.6 References. 1. Sanzo, D. et al. ACRAM Modeling Technical Support Document. LA-UR-95-X, TSA-11- 95-R112. Los Alamos National Laboratory, 1996. 2. Kimura, C.Y. et al. Data Development Technical Support Document for the Aircraft Crash Risk Analysis Methodology (ACRAM) Standard. UCRL-ID-124837. Lawrence Livermore National Laboratory, 1996. http://nssc.llnl.gov/NetWeave/Review/ACRAM_Model_new/ACRAM_Modeling_t.html http://nssc.llnl.gov/NetWeave/Review/ACRAM_Data1/data-Contents.html DOE-STD-3014-96 53 6. METHODOLOGY FOR EVALUATING THE INTEGRITY OF STRUCTURES, SYSTEMS, AND COMPONENTS SUBJECTED TO AIRCRAFT IMPACT 6.1 Purpose. This chapter establishes a methodology for deterministically evaluating the structural integrity of targets (or barriers) and the functionality of safety-related structures, systems, and components (SSCs) in a facility that may be subjected to impact from one or more subcategories of aircraft with frequencies greater than frequency guidelines. It also provides the technique for selecting critical missiles from the site-specific list of aircraft that may potentially impact the facility. The design/evaluation procedures in this chapter are generally conservative and consistent with nuclear power industry practices. However, the use of a more precise and detailed methodology is not precluded if the intent of this chapter is satisfied. Alternative methods and technical discussions are provided in Appendix C, and the justification for these recommended methods and examples is provided in Reference 1. 6.1.1 Adverse Effects. The following potential adverse effects of a missile impact on a target should be considered: a. Local Structural Damage: A missile may hit a target, causing excessive local damage (i.e., penetration and spalling, scabbing, perforation). b. Global Structural Damage: When subjected to the impact from a missile, a target may undergo excessive structural deformation or displacement (without collapse) or may structurally collapse or overturn. c. Functional Failure of SSCs: When a building structure is impacted, attached SSCs in close proximity to the impact location may be subjected to shock and vibration, resulting in their functional failure. DOE-STD-3014-96 54 An outline of the structural evaluation process to analyze the adverse effects of an aircraft impact is provided in Figure 2. The process allows for some initial screening prior to performing a detailed structural evaluation. The amount of screening depends on the existence of building supported safety-related

structures, systems, and components (SSCs) in the vicinity of the potential impact locations. If no safety-related SSCs are present in the vicinity of potential impact locations, optional structural and release frequency screening is possible prior to performing a detailed structural evaluation. If safety-related SSCs are present, the structural screening, although it cannot be used to screen out entire structures, is still useful for identifying nonsafety-related SSC locations, which can be screened out from further structural response analysis. 6.2 Structural Screening. Given that the frequency of aircraft impact from all types of aircraft in the Impact Frequency Evaluation (Section 5.3) exceeds the guideline (see Section 4.2), the first step in the structural evaluation analysis, as an option, is to perform a structural screening prior to undertaking a more detailed structural response evaluation. If there are no building supported safety-related SSCs in the vicinity of the impact locations and if the entire structure passes the structural response guideline in Section 4.3, no further analysis and evaluation will be needed. The structural screening assumes that the various types of aircraft applicable to the structure under consideration are identified and their mass and an estimate of maximum speed are available for estimating maximum kinetic energy. These data, along with the data/information listed as inputs in Section 3.3.1, will be used to perform structural screening, which consists of the following steps: Step 1. Identify locations for screening. Based on the location of hazardous materials within the facility, accident scenario information, the location of safety-related equipment, and the facility layout, prepare a list of potential aircraft impact locations. Identify those locations where building-supported safety-related SSCs are present. These impact locations cannot be screened out from further evaluation. The structural screening is performed on the remaining locations. DOE-STD-3014-96 Figure 2: Structural Evaluation Outline 55 DOE-STD-3014-96 Go to Release Frequency Screen (see Figure 2) Figure 2a: Structural Evaluation for Release Frequency Screen 56 DOE-STD-3014-96 Figure 2b: Go to Release Frequency Evaluation (see Figure 2) Structural Evaluation for Release Frequency Evaluation 57 DOE-STD-3014-96 58 Step 2. Identify critical missiles. Identify a set of missiles to be used for local and global structural response evaluations by either (1) performing a site-wide basis aircraft hazard analysis (see Section 2.1 of Reference 1) or (2) as follows: Select two bounding missiles considering all applicable categories/subcategories and types of aircraft, one for structural local damage evaluation and the other for structural collapse evaluation. The bounding missile for local damage evaluation will be the aircraft engine (or any of the nearly rigid and compact components) having the highest kinetic energy (i.e. one-half the engine mass times the square of the impact velocity). The bounding missile for structural collapse evaluation will be the aircraft having the highest kinetic energy of impact (i.e. one-half the total aircraft mass times the square of the impact velocity). Reasonable estimates of horizontal and vertical velocities to be used for assessing bounding kinetic energy values are the highest velocity values (corresponding to probability 0.0075) given,

for each aircraft subcategory, in Table 2-1 of Reference 1. Step 3. Perform structural response evaluations. Perform a building local damage evaluation in accordance with Section 6.3.2. If the local damage evaluation results meet the guideline provided in Section 4.3, perform a building collapse evaluation using the energy balance method in accordance with Section 6.3.3. If standardized charts, tables, or nomographs are available, they can be used for structural screening if they are developed using conservative criteria and methods equivalent to those described in Section 6.3. Step 4. Identify locations meeting guidelines. Identify the structure locations meeting the guidelines in Section 4.3, i.e., identify the structure locations that are not susceptible to significant local and global structure damage when impacted by a crashing aircraft. Note that in the vicinity of these locations, there must not be any building-supported safety- related SSCs. Step 5. Test if structure meets guidelines. If there are no building-supported safety- related SSCs in the vicinity of impact locations, evaluate if all locations within the structure meet the structural response guidelines of Section 4.3. If yes, the analysis should be DOE-STD-3014-96 59 terminated and the results documented. Otherwise, go to the Structural Evaluation for Release Frequency Screening (see Section 6.3). If there are safety-related SSCs in the vicinity of impact locations, identify the nonsafety- related SSC locations which are not vulnerable to aircraft impacts. These locations need not be further evaluated. Go to the Structural Evaluation for Release Frequency Evaluation (see Section 6.3). 6.3 Structural Evaluation. If there are building-supported safety-related SSCs in the vicinity of the impact locations, or if the entire structure does not meet the structural response guidelines for Structural Screening, a more detailed structural evaluation is necessary. The structural evaluation is performed leading up to either a Release Frequency Screening or Release Frequency Evaluation. Outlines of the structural evaluation for Release Frequency Screening and Release Frequency Evaluation are given in Figures 2a and 2b, respectively. Details for implementing the evaluation are given in this section. The structural evaluation process involves the following steps: Step 1. Identify locations for evaluation. Prepare a list of potential aircraft impact locations (see Section 6.2 Step 1). Include locations associated with building-supported safety-related equipment, but delete any location that has been screened out by the Structural Screening. Step 2. Identify critical missiles. Identify a set of missiles to be used for the structural response evaluation for Release Frequency Screening by either (1) performing category/subcategory aircraft hazard analyses (see Situation 1, Section 2.1 of Reference 1) for all applicable aircraft categories/subcategories as identified in the impact frequency evaluation (see Section 5.3), or (2) selecting appropriate aircraft as discussed in Section 6.3.1, keeping in mind that a pair of bounding aircraft types must be identified for each applicable aircraft category/subcategory. For the Release Frequency Evaluation, the identification of a set of missiles to be used for the structural evaluation can be done by either (1) selecting a set of aircraft types for each DOE-STD-3014-96 60

category/subcategory as outlined above, (2) performing a site-wide basis aircraft hazard analysis (see situation 2, Section 2. i of Reference 1) to identify a set of aircraft types to represent all applicable categories/subcategories of aircraft, or (3) selecting appropriate aircraft types as discussed in Section 6.3.1. Step 3. Perform structural response evaluations. Sequentially perform structural local response, global response and SSC functionality evaluations as outlined in Figures 2a and 2b and discussed in Sections 6.3.2, 6.3.3, and 6.3.4, respectively, at all locations except those previously screened out from consideration. Additional analysis should be consistent with the analyses associated with the Release Frequency Screening and Release Frequency Evaluation methods as described in Sections 5.4 and 5.5 respectively. For Release Frequency Screening, SSC functionality is not evaluated, and global response is based on the Energy Balance Method discussed in Section 6.3.3.1. For Release Frequency Evaluation, global response evaluations for locations related to building- supported safety-related SSCs are based on the Time-History Analysis Method, discussed in Section 6.3.3.2. Step 4. Identify categories/subcategories of aircraft. For the Release Frequency Screening, identify the aircraft categories/subcategories meeting the structural response guidelines in Section 4.3. These are the aircraft categories/subcategories which inflict insignificant structural damage upon impact. For the Release Frequency Evaluation, identify the locations within the facility at which the impact of a crashing aircraft will inflict insignificant damage and need not be considered in assessing the effective area of the facility in evaluating impact frequencies. Step 5. Proceed to the Release Frequency Screening or Evaluation. See Sections 5.4 and 5.5, respectively. DOE-STD-3014-96 61 6.3.1 Missile and Target Selection. 6.3.1.1 Selection and Characterization of Critical Missiles. a. Aircraft subcategories identified in the site-specific hazard study (see Chapter 5) should be considered as sources of missiles for the facility being evaluated. The mass, velocity, and stiffness characteristics and configuration of these aircraft subcategories and their major heavy and rigid components should be used to select the critical missiles. b. Nondeformable missiles are the rigid and heavy components (e.g., landing gear, engine shaft) of the aircraft. Deformable missiles are relatively soft components (e.g., wings, fuselage). As evidenced in some recent tests, aircraft engines deform significantly upon impact with rigid barriers and hence can be considered as deformable. Critical missiles should be selected by considering the three adverse effects listed in Section 6.1.1. The local damage evaluation should be performed using relatively nondeformable components of the aircraft as the candidate missiles. Typically, the aircraft as a whole is critical for global response evaluation. For SSC functionality evaluation, the whole aircraft and its rigid and heavy components can be critical. c. In selecting critical missiles, consideration should also be given to the relative location, orientation, and configuration of SSCs and their barriers at the facility. d. When more than one missile can potentially impact a target, select the missile with the maximum kinetic energy as the critical missile for global response evaluation. For local

response, also consider the penetration characteristics of the DOE-STD-3014-96 62 missiles (Reference 1). For evaluating SSC functionality (discussed in detail in Section 6.3.4), in addition to the kinetic energy of the impacting aircraft, the mass and stiffness characteristics of the missiles should also be considered because these are likely to affect the frequency content of the vibration resulting from the impact. e. For evaluating local response, the selection of critical missiles should be based on the postulated aircraft impact velocity and the relative sizes and weights of the heaviest rigid-type components, considering all candidate aircraft subcategories. Consideration should also be given to the mode of local damage (see Section 6.3.2). One aircraft component may not be critical for all modes of local damage. Also, for each mode of local damage, more than one missile may need to be selected unless one particular missile’s combination of velocity, size, and weight is clearly more critical than that of other candidate missiles. f. A representative weight and velocity for the aircraft in each subcategory should be established based on the review of aircraft subcategory data in the Data Development Technical Support Document for the Aircraft Crash Risk Analysis Methodology Standard (Reference 2) and the results of the site-specific hazard study performed in accordance with the guidance given in Chapter 5 of this standard. The analyst should consider the representative aircraft weights and velocities associated with both takeoff and landing scenarios. g. Mass distribution of the aircraft along the length of the fuselage can be obtained from Reference 2, from the aircraft manufacturer, or by calculation based on the weights and http://nssc.llnl.gov/NetWeave/Review/ACRAM_Data1/data-Contents.html http://nssc.llnl.gov/NetWeave/Review/ACRAM_Data1/data-Contents.html DOE-STD-3014-96 63 locations of major components and fuel, which can be obtained from published literature on the same type of aircraft. h. The variation of load capacity due to fuselage buckling or crushing (whichever is lower) as the crushing length progresses from the aircraft nose toward the rear can be obtained from the manufacturer or calculated using pertinent data from published literature on the same type of aircraft. i. When an aircraft impacts a target, the potential for damage from secondary missiles should be considered in order to evaluate the adequacies of safety-related SSCs in the vicinity of the primary impact area. j. The velocity of the secondary missiles at the instant of detachment from the main body of the aircraft can be calculated by methods that are well established in the industry, such as the method developed by Riera (Reference 3). Alternatively, it should be conservative to assume that the initial velocity of such secondary aircraft missiles is equal to the impact velocity of the primary aircraft missile. 6.3.1.2 Selection of Target SSCs, Angle, and Location of Impact. a. The list of target SSCs and their barriers that should be evaluated for adverse effects (listed in Section 6.1.1) from aircraft missile impacts can be based on available facility safety analyses. The selection of these targets is a joint activity of the structural engineer and the facility safety analyst. Using insights derived from any existing safety analysis, the safety analyst should provide the structural engineer with

lists of potential targets whose failure could lead to the release of DOE-STD-3014-96 64 hazardous material, the location of the affected material, and the failure modes that could lead to the release. b. For each target SSC or its barrier selected above, more than one impact location should be considered so that the worst adverse effects can be determined. It is possible that the impact location that produces the worst global response is different from the location that produces the worst local damage or SSC functional failure. c. The angle of impact should be based on the orientation of the SSC or barrier being evaluated, the worst impact angle from SSC/barrier vulnerability considerations, and the most probable angle of impact for the aircraft subcategory to which the critical missile belongs. 6.3.2 Local Response Evaluation. The local response of the target will be initiated with spalling and subsequently result in penetration, scabbing of target material from the back face of the target, and the eventual perforation of the target, transporting the missile through the target (Figure 3). Empirical formulas validated by tests have been used to predict these local responses for predominantly rigid (nondeformable) missiles (see Table I). Empirical formulas are for the case of normal (90-degree) impact. When the impacting missile strikes normal to the target face, the local responses are maximized. The angle of strike can substantially influence the extent of local damage and should be appropriately considered. For further guidance see the technical support document for SSC evaluation (Reference 1). Typically, spalling is not of any safety concern, and it is sufficient to evaluate safety-related targets against only scabbing and perforation (i.e., full penetration) using the methods provided herein. If the results of such evaluation do not meet Section 4.3 guidelines, it is not necessary to perform global response or building collapse evaluation, and the evaluation should proceed to consequence analysis in accordance with Chapter 7. FIGURE 3. Sequence of local target response to missile impact (a) Missile pentration and spalling (b) Target scabbing (c) Perforation Spalling Scabbing D O E -S T D -3014-96 65 ts = 1.84 U V 0.13 (MV2)0.4 D 0.2 (f / c) 0.4 DOE-STD-3014-96 66 (6-1) 6.3.2.1 Evaluation of Reinforced Concrete Targets. 6.3.2.1.1 Scabbing Thickness. The scabbing thickness (t ) is defined ass the panel thickness that is just large enough to prevent the peeling off of the back face of the panel opposite to the face of impact. In 1981, Chang (Reference 4) proposed an empirical formula based on lower velocity missiles (less than about 500 ft/sec [152 m/s]) to predict mean scabbing thickness for reinforced concrete panels subjected to a cylindrical rigid (nondeformable) steel missile impact: where: U = reference velocity = 200 ft/sec; V = missile impact velocity (ft/sec); M = mass of the missile = W/g, where: W = missile weight (lb), g = 32.2 ft/sec ;2 D = effective missile diameter (ft); f = ultimate compressive strength of concrete/ c (lb/ft ).2 t = scabbing thickness (ft)s To prevent scabbing, minimum concrete thickness, t , shouldd be 1.1t , where t is given by the above formula. Others s formulas, as listed in Table I and discussed in Appendix C, may also be used if the missile and target characteristics (missile size, velocity, and deformability, and target rigidity and

thickness) are comparable to those used in the formula above. DOE-STD-3014-96 67 TABLE I.* Empirical formulas for local response evaluation of reinforced concrete targets (see Note 1). DAMAGE MODE MISSILE MISSILE RIGID SOFT (NONDEFORMABLE) (DEFORMABLE) (See Note 2) Penetration (x) -Modified NDRC 50% of Rigid 3 Scabbing (t ) - Modified NDRC 60% of Rigids 4 - Bechtel or - Chang - Stone &7 - CRIEPI Webster Perforation (t ) - Modified NDRC 70% of Rigidp 5 - CEA - EDF - Degen - Chang7 - CRIEPI Punching Shear - ACI 6 7 - Long NOTES: 1. For a typical example using these empirical formulas and a discussion of their relative merits, please refer to Section 3 of the technical support document (Reference 1) and Table A-1 therein. These formulas are not applicable to unreinforced concrete or masonry structures. 2. The reduction factors for deformable missiles acknowledge the fact that they produce relatively less local damage, and the impact forces do not exceed the crushing strength of these missiles. They are based on recent aircraft engine missile tests and comparison of various empirical formulas and their agreement with the actual test results, as reported by Sugano (Reference 5). 3. Penetration (x) is computed to determine t and t (Modified NDRC and Degen formulas only).s p 4. To prevent scabbing, minimum required thickness t should be > 1.1 t .d s 5. To prevent perforation, minimum required thickness t should be > 1.2 t .d p 6. Punching shear considerations for small nondeformable missiles are implicit in the formulas for penetration and perforation. 7. Recommended formula (see Section 6.3.2.1). References for all other formulas are given in Appendix C. *All of the formulas presented in this table are based on data for lightly reinforced (0.3 percent - 1.5 percent each way) concrete targets. Application to heavily reinforced targets would give a conservative estimate of local response. tp U V 0.25 MV2 Df / c 0.5 4 fc DOE-STD-3014-96 68 (6-2) 6.3.2.1.2 Perforation Thickness. The perforation thickness (t ) isp defined as the panel thickness that is just great enough to allow a missile to pass through the panel without any exit velocity. The mean perforation thickness, t (ft), for reinforcedp concrete panels subjected to a cylindrical rigid (nondeformable) steel missile impact, based on Reference 4, is: The parameters U, V, M, D, and f are the same as those/ c defined in Equation 6-1. To prevent perforation, minimum concrete thickness, t , should be 1.2 t , where t is given byd p p the above formula. Other formulas, as listed in Table I and discussed in Appendix C, may also be used if applicable. For further discussion and an example using these formulas, refer to the technical support document for Chapter 6 (Reference 1). 6.3.2.1.3 Punching Shear. Missile impact on a concrete wall or slab can induce shear failure, either near the periphery of the impact area or at the edge of the wall or slab. The former is called punching shear failure, and the latter is known as the reaction shear failure. The following punching shear criterion is applicable for this standard. For design against punching shear, capacity is limited by the diagonal tension failure in the concrete adjacent to the load. The ACI 318 and ACI 349 Codes (References 7 and 8) limit the punching shear stress (psi) to T 1.5 0.5MV2 17,400KsD 1.5 DOE-STD-3014-96 69 (6-3)

(where f = ultimate compressive strength of concrete in psi)/ c at the perimeter, one-half the effective depth away from the load. This criterion is very conservative compared to recent test results, but may be used conservatively for structural screening purposes and for cases where punching shear is not likely to be critical. For marginal or critical cases, the alternative formula in Appendix C of this standard can be used as applicable. For punching shear evaluation, the dynamic increase factor, strength reduction factor, and ultimate load factors are given in Appendix C of ACI 349. 6.3.2.2 Evaluation of Steel Targets. A widely accepted formula for predicting penetration of steel targets is the Ballistic Research Laboratory (BRL) formula: where: T = predicted thickness to just perforate a steel plate (in.); M = W/g missile mass (lb-sec /ft);2 V = missile impact velocity (ft/sec); K = constant depending on the grade of steel s (usually 1); D = missile diameter (in.). The range of test data parameters used in developing this formula and their scope of applicability are not defined. However, the formula is independent of target size or support conditions. It should be used only to predict local perforation of steel structures by small rigid missiles. To prevent perforation of steel targets, the minimum thickness, t , should bed > 1.25T. DOE-STD-3014-96 70 Alternative formulas such as the Stanford Research Institute (SRI) formula and the Hagg-Sankey formula can be used as applicable. 6.3.3 Global Response Evaluation. a. The objective of the global response evaluation is to determine if the impact of the aircraft results in the excessive deformation or collapse of the target structure. A localized collapse evaluation (i.e., the collapse of a segment, a component, or a portion of the structure) may be sufficient if it can be demonstrated that such a localized collapse would not adversely affect the structure’s function or the function of any systems or components. Global response evaluation of a building or a structure typically involves characterization of the nonlinear behavior of both the aircraft and the target, including soil-structure interaction. b. Global response evaluation can be performed by either the energy- balance method or the time-history analysis method. The energy-balance method discussed in Section 6.3.3.1 can be used for global response or collapse evaluation if the following conditions are met: (1) there are no safety-related SSCs supported by the target in the vicinity of the impact; (2) the configuration of the target is simple, such that the overall dynamic characteristics of the structure can be adequately represented by a single-degree-of-freedom (SDOF) nonlinear energy-absorbing system; and (3) the resulting response of the SDOF system would be compatible with the strength and ductility limits of the various components and supports of the impacted structure. If these conditions are not met, then the time-history analysis method described in Section 6.3.3.2, or in Appendix C, Section C.6.3.3.2, should be used to evaluate the global response. DOE-STD-3014-96 71 6.3.3.1 Energy-Balance Method. a. The objective of the energy-balance method of global response evaluation is to determine whether the target structure can absorb the energy that is imparted to it without deforming excessively. This method uses the principles of conservation of energy and

conservation of momentum, and requires that the energy absorption capability (SE) of the target be greater than the kinetic energy imparted to it (E ). It recognizes that, since a significant portion of thea impact energy is dissipated in deforming the aircraft body, the effective missile mass is less than the total mass of the aircraft but more than the mass of the rigid components, such as the engines. The effective missile mass for calculating the total kinetic energy of impact (E ) will depend on the mass of the enginesi and the relative rigidity of the aircraft body. b. To calculate E , the effective missile mass (m) can be conservativelyi estimated based on Chelapati (Reference 10): 1. For small aircraft with airframes that are flexible relative to the target structure, m=2 times the combined mass of the engines. 2. For large aircraft, m=8 times the combined mass of the engines. However, m should not be less than 30 percent, nor more than the total mass of the aircraft. c. To calculate E , the effective target mass (M ) may conservatively bea e taken as the mass of the target structure that is included within d/2 of the periphery of the impact interface, where d is the thickness of the target in the direction of missile travel. On the basis of the predicted deformed shape of the target, less conservative but practical values may be used if justified. However, M need not be less than one-e tenth of the total mass of the target structure panel (Reference 10). Ea 1 2 MeV 2 t , when m Me < e Ea 1 2 MeV 2 t 1 2 mV2 m, when m Me > e Vm Vo m Me e 1 m Me Vt m/Me 1 (m/Me) [Vo(1 e)] DOE-STD-3014-96 72 (6-4) (6-5) (6-6) (6-7) d. If the coefficient of restitution between the aircraft and the target (e) can be estimated, the portion of the total impact kinetic energy (E )i that will be transmitted to the target structure (E ) can be computeda as follows. or where: E = kinetic energy imparted to the target;a M = target effective mass (represents inertial resistance);e V = velocity of missile after impact.m V = velocity of target after impact;t and Vt Vm Vo ; Ea 1 2 mV 2 o m/Me 1 m/Me . DOE-STD-3014-96 73 (6-8) (6-9) where: m = effective missile mass; e = coefficient of restitution V = velocity of missile beforeo impact. For the entire aircraft impact (which is relatively deformable) on hard structures, e is between 0 (plastic impact) and 1 (elastic impact). The value of e is estimated based on the relative mass and stiffness of the target and the missile. If the value of e cannot be easily estimated, the lower and upper bounds of E can be calculated as in Paragraphsa e and f below. e. Lower Bound E : A lower bound E can be obtained by assuming aa a plastic impact (i.e., the aircraft moves along with the target after impact), for which e equals zero and is less than m/M . For suche cases, f. Upper Bound E : An upper bound E can be obtained by assuming ana a elastic impact (i.e., the aircraft and the target velocities after impact are different), for which e=1. For such cases, Ea 1 2 mV2 0 4m/Me (1 m/Me) 2 when m/Me 1, Ea 1 2 mV2 0 when m/Me >> 1. SE Rm Xe (µ 0.5). min Ea RmXe 0.5 DOE-STD-3014-96 74 (6-10) (6-11) (6-12) (6-13) and g. The energy absorption capability (SE) of the target structure is determined as The ductility ratio ( ) may then be computed as where: R = static collapse load;m X = effective yield displacement.e

The static collapse load, R , can be computed by methods discussedm in standard handbooks and structural analysis/design texts and references. It is a function of the ultimate capacity of the structural member and varies for different end support configurations. The "effective yield" point is found by extending the initial elastic deformation line to its intersection with the limit or collapse load line. F(t) Pc[x(t)] m[x(t)][v(t)]2 DOE-STD-3014-96 75 (6-14) The permissible ductility ratio, µ, is defined as the ratio between maximum permissible deflection of a structural system and the deflection at the effective yield for the system (see Section 6.3.3.3). 6.3.3.2 Time-History Analysis Method. A time-history response analysis method of evaluating the global response or collapse of the target structure uses the inertial and stiffness characteristics of both the aircraft and the target structure (including its foundation flexibility). One of the acceptable methods that has been extensively used is outlined below. This method, called the force time-history analysis method, consists of two major steps. The first step is to determine impact force time-history based on the aircraft mass distribution, crushing/buckling characteristics, impact velocity, aircraft length, and other aircraft structural data, and conservatively assuming that the target structure is rigid. Impact force time-history is determined using the momentum principle, similar to the method developed by Riera (Reference 3) and modified by Muto et al. (Reference 9). Accordingly, the impact force, F(t), acting on the rigid fixed target at time, t, is expressed as where: P = load necessary to crush or buckle the fuselage;c x(t) = distance from the nose of the aircraft to the point up to which crushing has progressed at time, t; m = longitudinal mass per unit length of the uncrushed aircraft; v(t) = velocity of the uncrushed portion of the aircraft at time, t; = empirical correlation factor (use a value of 0.9 unless justified otherwise). DOE-STD-3014-96 76 When necessary data for the given aircraft are not available, an approximate method given in Appendix C may be used to determine F(t), by scaling available impact force time-histories of other similar aircraft (see Reference 1). The second step is to develop a structural model of the impacted structure and perform a dynamic analysis using the impact force time- history computed in the first step or the one obtained from Reference 1. 6.3.3.3 Structural Evaluation Criteria. Deformation responses computed for various target structural components by either the energy-balance method or the time-history analysis method are then used to compute the ductility ratio (the ratio of computed displacement to elastic displacement). Computed ductility ratios are then compared to the permissible ductility ratios specified below to determine if the component would deform excessively or collapse under impact loads. a. For concrete structural components, the permissible ductility ratios shall be as specified in ACI Code 349, Appendix C, Section C-3. For beam columns, walls, and slabs carrying axial compression loads, the provisions of Paragraph C 3-8 of ACI Code 349, Appendix C, shall be followed. b. For steel structural components, the permissible ductility ratios shall be as specified in Section Q1.5.8 of AISC Nuclear Specifications, ANSI-N690 (Reference 11). For plate structures, the permissible

ductility ratio of 10 is recommended. Potential loss of SSC safety functions resulting from structural deformation and degradation due to aircraft impact should also be evaluated. DOE-STD-3014-96 77 6.3.4 SSC Functionality Evaluation. a. SSCs that are supported by target structures should be evaluated for aircraft impact-related vibratory loads. Such an evaluation consists of (1) generation of instructure vibratory motion at SSC support locations resulting from impact force time-history; (2) structural evaluation of SSC supports, including anchorage; and (3) evaluation of the SSC functionality. Both support and SSC functionality evaluation can be performed either by analysis or by testing. b. For evaluation by analysis, the SSCs can be modeled, analyzed, and evaluated in accordance with the applicable industry-accepted dynamic analysis methods and acceptance criteria for safety-related SSCs, such as those given in ASCE-4, ASME Boiler and Pressure Vessel Code, IEEE-344, and NUREG-0800 (References 12, 13, 14, and 15), recognizing that impact of some aircraft may generate vibratory loads with more high frequency contents than those from typical seismic loads. c. For evaluation by testing, the SSCs can be subjected to shake table testing, using the instructure spectra generated from transient response analysis as input spectra and following the methods described in IEEE-344. 6.3.5 Evaluation of Earth-covered Structures. a. Penetration of a rigid missile into earth media can be determined using analytical or empirical formulas, which provide good agreement with test data. Because most of the tests have been performed using ballistic missiles, care should be exercised in applying the formulas to aircraft missiles. b. If the earth cover exceeds 1.2 times the penetration depth calculated by assuming a rigid missile, the missile should be assumed not to directly DOE-STD-3014-96 78 impact the structure. The resistance force developed by the penetrating missile may be used to determine the response of the buried structures. c. If the earth cover does not meet the requirements in b, above, the missile should be assumed to impact the structure. In these instances, the structure may be evaluated for missile impact using techniques similar to those given in Sections 6.3.2 and 6.3.3. d. Forcing functions developed for aircraft impact on rigid barriers may be used as a conservative estimate of the missile impact loading for earth- covered structures. 6.3.6 Structural Evaluation Results. If there are no adverse effects as listed in Section 6.1.1, then no further analysis is necessary, and the structural evaluation results should be documented. However, if there are any adverse effects, then further analysis, as described in Chapter 7, should be performed. 6.4 References. 1. Hossain, Q.A. et al. Structures, Systems, and Components Evaluation Technical Support Document for the DOE Standard, Accident Analysis for Aircraft Crash into Hazardous Facilities. UCRL-ID-123577. Lawrence Livermore National Laboratory, 1996. 2. Kimura, C.Y. et al. Data Development Technical Support Document for the Aircraft Crash Risk Analysis Methodology (ACRAM) Standard. UCRL-ID-124837. Lawrence Livermore National Laboratory, 1996. 3. Riera, J. “On the Stress Analysis of Structures Subjected to Aircraft Impact Forces,” Nuclear Engineering and Design, Vol. 8, 1968. 4. Chang, W.S. “Impact of Solid Missiles on Concrete Barriers,” The Journal of the Structural

Division, American Society of Civil Engineers, Vol. 107, No. ST2, February 1981. 5. Sugano, T. et al. “Local Damage to Reinforced Concrete Structures Caused by Impact of Aircraft Engine Missiles, Part 2,” Nuclear Engineering and Design, Vol. 140, 1993, pp. 407-423. http://nssc.llnl.gov/NetWeave/Review/UCRL/HTML/TSD-TOC-htm.html http://nssc.llnl.gov/NetWeave/Review/ACRAM_Data1/data-Contents.html DOE-STD-3014-96 79 6. Kennedy, R.P. “A Review of Procedures for the Analysis and Design of Concrete Structures to Resist Missile Impact Effects,” Nuclear Engineering and Design, Vol. 37, No. 2, May 1976. [Modified NDRC formula] 7. American Concrete Institute. Building Code Requirements for Reinforced Concrete (revised). ACI-318-89. July 1, 1992. 8. American Concrete Institute. Code Requirements for Nuclear Safety Related Concrete Structures. ACI-349-85. 1985. 9. Muto, K. et al. “Experimental Studies on Local Damage of Reinforced Concrete Structures by the Impact of Deformable Missiles,” SMIRT, Vol. J, 1989. 10. Chelapati, C.V. et al. “Probabilistic Assessment of Aircraft Hazard for Nuclear Power Plants,” Nuclear Engineering and Design, Vol. 19, No. 2, May 1972. 11. American Institute of Steel Construction. American National Standard Nuclear Facilities - Steel Safety-Related Structures for Design Fabrication and Erection. ANSI-N690. 1984. 12. American Society of Civil Engineers. Seismic Analysis of Safety-Related Nuclear Structures and Commentary on Standard for Seismic Analysis of Safety-Related Nuclear Structures. ASCE-4. September 1986. 13. American Society of Mechanical Engineers. ASME Boiler and Pressure Vessel Code, Division 1. Latest edition. 14. Institute of Electrical and Electronic Engineers. Recommended Practice for Seismic Qualification of Class 1E Equipment for Nuclear Power Generating Stations. IEEE-344. August 1987. 15. United States Nuclear Regulatory Commission. Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants. NUREG-0800. June 1987. DOE-STD-3014-96 80 7. METHODOLOGY FOR EVALUATING EXPOSURE DUE TO AIRCRAFT IMPACT 7.1 Purpose. This chapter provides the methodology for evaluating exposure resulting from aircraft impact on a facility. The methodology by which exposure is assessed can be divided into two broad areas: exposure screening and exposure evaluation. 7.2 Exposure Screening. The purpose of exposure screening is to determine, on the basis of overall facility inventory and generic expected release mechanisms associated with aircraft impact (e.g., fuel fire, missile impact shock, building collapse), whether a facility has the potential for significant onsite or offsite exposure, given an aircraft impact. 7.2.1 Applicability. Exposure screening will be performed for all facilities subject to the provisions of this standard. 7.2.2 Hazard Identification. Hazard identification will be performed to identify and inventory hazardous materials and energy sources (in terms of quantity, form, and location) associated with the facility processes or related operations. Standard industrial hazards will be identified only to the degree that they may exacerbate a postulated aircraft impact on the facility. Well-confined material may be excluded from the hazardous materials inventory, but such exclusions should be justified based on the robustness of the material containment in a postulated aircraft impact

environment (i.e., such assumptions should be shown to be valid for the class of accidents being evaluated). References 1 and 2 may be used in performing hazard identification. 7.2.3 Radioactive Materials. This section summarizes the screening approach for radioactive materials. More detail is provided in a separate report, Screening for the Potential Consequences of Accidental Releases of Radioactive and Chemical Materials to the Atmosphere (Reference 3). 7.2.3.1 Radioactive Material Source Term Determination. A bounding source term will be developed based upon an assumed loss of containment for all hazardous radioactive material associated with the facility, except the DOE-STD-3014-96 81 material excluded from the hazardous material inventory, as discussed in Section 7.2.2 of this document. Facility segmentation (as discussed in DOE-STD-1027-92) or other means of demonstrating the lack of facility- wide release potential may be used, as appropriate, to reduce the inventory for direct comparison with guidelines. In all cases, however, such reductions should be justified in terms of the unavailability of common-cause release mechanisms stemming from aircraft impact. 7.2.3.2 Radioactive Material Offsite Exposure Determination. The exposure to the maximally exposed individual at or beyond the site boundary will be estimated in terms consistent with the screening guidelines presented in Section 4.1. Source term values will be based upon a bounding release consistent with the following assumptions: a. All material in close proximity to high explosives present at the facility will be assumed to be subjected to the energetics associated with high explosive detonation. b. No credit will be taken for mitigation, either passive or active, including ventilation, fire suppression, building confinement, and rubble effects. c. The fraction of radioactive material assumed to be driven airborne and respirable will be based on Table II, which is derived from DOE- HDBK-3010-94 and explained in Reference 8. http://www.doe.gov/techstds/standard/std1027/std1027.pdf http://www.doe.gov/techstds/standard/hdbk3010/hdbk3010.pdf DOE-STD-3014-96 82 TABLE II. Fraction of radioactive material released and respirable. Material Form Fraction Released and Respirable Gases/Vapors 1.0 Liquids: Aqueous 2E-3 Combustible Organic 1E-2 Subject to Explosive Stress TNT Equivalent Mass* Solids: Pyrophoric Metals 3E-4 Uranium 1E-3 Subject to Explosive Stress TNT Equivalent Mass*,** Powders 2E-3 Surface Contamination Combustible Solids 1E-2 Noncombustible Solids 1E-3 Other 1E-3 HEPA Filters 1E-2 The amount of material released and respirable will be equivalent to the TNT* equivalent mass of the explosive, except where the TNT equivalent mass exceeds the total mass of the material at risk, in which case the amount of material released and respirable will be the total mass of the material at risk. High explosive detonations involving nuclear weapons and associated** assemblies will use a value for the fraction of material released and respirable equal to 2E-1. Additional discussion of airborne release resulting from such detonations can be found in DOE-HDBK-3010-94, Section 4.1 (Reference 5). Dose n i 1 Qi SAi CEDEi BR y z u DOE-STD-3014-96 83 (7-1) 7.2.3.2 Radioactive Material Offsite Exposure Determination. The exposure to the maximally exposed individual at or beyond the site boundary will be

estimated in terms consistent with the screening guidelines presented in Section 4.1. For radioactive material releases, Reference 3 contains a series of nomographs for common radioactive materials that provide dose estimates under various conditions relevant to aircraft crash scenarios. These nomographs may be used to provide a screening value for the site boundary dose for the materials and conditions specified. Using the nomographs to calculate doses should account for the additive property of dose over all isotopes of concern, so that isotopes are evaluated cumulatively, as opposed to individually, against guidelines. If a particular facility has materials or conditions not covered by the nomographs provided, the simple Gaussian dispersion equation that was used to develop the nomographs will be used to estimate the dose at the site boundary, using the shortest distance to the site boundary as the evaluation point and an atmospheric stability of F, with a wind speed of 2 m/s, as explained in Reference 8. For releases that are potentially buoyant, the buoyancy will be ignored for the purposes of screening calculations. The centerline dose can be estimated using the following equation: where: Dose = dose (sievert [rem]) - CEDE; Q = material released and respirable (i.e., source term) (g); SA = specific activity (Curies/gram [Ci/g], [Bq/g] ); CEDE = committed effective dose equivalent (rem/Ci [Sv/Bq] inhaled assuming a 1-µm activity median aerodynamic diameter particle size); BR = breathing rate (3E-4 m /s);3 X i MARi 25 Threshi DOE-STD-3014-96 84 (7-2) = crosswind concentration standard deviation fory F stability at 2 m/s ( = 0.067 d , where d = distancey 0.9 to site boundary); = vertical concentration standard deviation for F stabilityz at 2 m/s ( = 0.057 d , 100m < d 500m, d = distancez 0.8 to site boundary; log = -1.91 + 1.37 log d - 0.11910 z 10 log d, 500m < d < 10 m, d = distance to site10 2 4 boundary); u = wind speed (2 m/s); i = a unique designator for each material/form found in the facility. 7.2.3.3 Radioactive Material Onsite Exposure Determination. In the rare instance when assessment of exposure to onsite personnel outside the facility is desired (see discussion in Appendix A, Section A.1.2), the exposure to the maximally exposed individual at 300 m (984 ft) should be estimated in a manner consistent with the assumptions used in DOE-STD-1027-92, Attachment 1, for the calculation of Category 2 radiological thresholds, but with a dose threshold of 25 rem (0.25 Sv) instead of the 1 rem (0.01 Sv) used in this standard. Equivalently, the Category 2 radiological thresholds identified in DOE-STD-1027-92 can be used as the basis for exposure determination, using the following equation. where: MAR = material at risk (g or Ci); DOE-STD-3014-96 Exposure determination will not use the criticality lists for U, U, and Pu, since these values are unrelated3 233 235 239 to onsite receptor dose. 85 Thresh = DOE-STD-1027-92 Category 2 threshold (g or Ci) ;3 ¬ = a unique designator for each isotope found in the facility. If X exceeds unity, the threshold has been exceeded. 7.2.4 Hazardous Chemicals. This section summarizes the screening approach for hazardous materials. More detailed information is provided in Reference 3. 7.2.4.1 Hazardous Chemical Material Source Term. The source term value will be based on a bounding release consistent with the following

assumptions: a. No credit will be taken for mitigation, either passive or active, including ventilation, fire suppression, building confinement, and rubble effects. b. All materials will be released to the environment as a result of the impact. c. The state and form of the release will be determined as follows: 1. For gases liquefied under pressure (e.g., chlorine, ammonia, propane), the entire contents of the vessel will be assumed to become airborne as a puff. The same will apply to wholly gaseous releases. 2. For liquids with a boiling point above ambient and storage temperatures at ambient, the material will be assumed to spill DOE-STD-3014-96 86 instantaneously onto the ground and either spread to a depth of 1 cm (0.4 in.) or cover a well-defined diked area if there is one. The rate of evaporation will then be calculated using standard formulas such as those provided by the Center for Chemical Process Safety (CCPS) (Reference 6). 3. For refrigerated liquids, the material will likewise be assumed to spill onto the ground and either spread to a depth of 1 cm (0.4 in.) or cover a well-defined diked area. The rate of evaporation will again be calculated using standard formulas such as those provided by CCPS. 4. For a pipeline rupture, the complete contents of the pipeline up to the nearest undamaged isolation valve(s) will be assumed to be released as a puff. 5. For materials that can burn and form toxic products of combustion, the burning will be assumed to be instantaneous, with 100 percent efficient production of the toxic products. In the above determinations, the respirable fraction will be assumed to be 100 percent. For releases that are potentially buoyant, the buoyancy will be ignored for the purposes of the screening calculation. 7.2.4.2 Hazardous Material Offsite Exposure Determination. Reference 3 contains a series of nomographs for common hazardous chemicals that provide dosage estimates under various conditions relevant to aircraft crash scenarios. These nomographs serve to guide analysts and simplify the screening process. They can be used to provide a screening value for the site boundary Level of Concern for the materials and conditions specified. If a particular facility has materials or conditions not covered by the nomographs, an acceptable technique is given by the U.S. Environmental Protection Agency's (EPA's) TSCREEN Code DOE-STD-3014-96 87 (Reference 7), which does a range of calculations and selects the worst case. Alternatively, Reference 3 contains a simplified screening approach. 7.2.4.3 Hazardous Material Onsite Exposure Determination. In the rare instance when assessment of exposure to onsite personnel outside the facility is desired (see discussion in Appendix A, Section A.1.2), the onsite evaluation guideline, per Section 4.1, is that individuals should not be exposed to a concentration in excess of ERPG-3 (or an equivalent measure) at a distance of 300 m (984 ft) in Atmospheric Dispersion Category D with a windspeed of 4.25m/s (14 ft/sec). Reference 3 contains a tabulation of release rates for various chemicals that will just meet this criterion. 7.2.5 Other Methods. For both radioactive and chemical releases, other techniques may be proposed and will be evaluated for sufficiency on a case-by-case basis by the cognizant safety authority. 7.2.6 Comparison to Guidelines. The exposure to the maximally exposed individual at or

beyond the site boundary will be compared to the exposure screening guidelines. If the exposure screening guidelines are met, no additional analysis of aircraft impact is required. If the exposure screening guidelines cannot be met, a more detailed analysis will be performed, based on both an assessment of the aircraft impact frequency (Chapter 5) and an evaluation of the structural response of the facility/operation subjected to aircraft impact (Chapter 6), in accordance with the approach described in Chapter 3. 7.3 Exposure Evaluation. The purpose of exposure evaluation is to determine, based on the specific level of damage and phenomenology associated with a spectrum of aircraft crashes into the subject facility, the extent to which individual members of the public and/or site workers may be exposed to a release of radioactive or hazardous chemical material. This section provides an overview of the evaluation approach. Further details are provided in Appendix D. BST n i 1 m j 1 MARi DRij ARFij RFij LPFij DOE-STD-3014-96 88 (7-3) 7.3.1 Applicability. Exposure evaluation will be performed for all facilities for which the frequency of release has been shown to exceed the release frequency evaluation guideline. 7.3.2 Application Guidance. Exposure evaluation will be based on the results of the structural response analysis performed in accordance with Chapter 6 and the scenario development part of the release frequency evaluation performed in accordance with Section 5.5. For each scenario considered, exposure evaluation will consist of translating facility damage into a source term and exposure, based on the interaction between the energy generated during the accident and the facility hazardous material inventory. Exposures should be analyzed for receptors corresponding to the exceeded guidelines, but need not be evaluated for receptors for which the corresponding guidelines are met. Therefore, for cases in which offsite guidelines are met, exposure evaluation may be restricted to onsite impacts only. 7.3.2.1 Source Term Guidance for Radioactive Material Releases: Building source term (BST) development for exposure evaluation for radioactive material releases will be consistent with the guidance provided in DOE-HDBK-3010-94 (Reference 5), which is based on a five-component linear equation: where: MAR = material at risk - the amount of radionuclides available DOE-STD-3014-96 89 to be acted on by a given physical stress; DR = damage ratio - the fraction of MAR actually impacted by the accident-generated conditions; ARF = airborne release fraction - the coefficient used to estimate the amount of radioactive material suspended in air as an aerosol and thus available for transport due to a physical stress from a specific accident; LPF = leakpath factor - the fraction of the radionuclides in the aerosol transported through some confinement deposition of filtration mechanism; RF = respirable fraction - the fraction of airborne radionuclides as particles that can be transported through air and inhaled into the human respiratory system and is commonly assumed to include particles 10-µm Aerodynamic Equivalent Diameter (AED) and less; i = a unique designator for each particular material and form found in the facility; j = a unique designator for each release mechanism acting upon a given material and form found in the facility (e.g., j=1 for crush/impact, j=2 for fire, j=3 for

explosion). For valid application, the source term calculation should be based on the development of aircraft impact scenarios at a level of detail that allows for the specification of appropriate values for the above parameters. However, as discussed in DOE-STD-3009-94 (Reference 2), a graded approach should be applied to scenario development to ensure that the level of effort required to perform the analysis does not divert resources from areas where effort could be spent more appropriately. Further information on the development of radioactive material source terms is provided in Appendix D, Section D.1. DOE-STD-3014-96 90 7.3.2.2 Source Term Guidance for Hazardous Chemical Releases. Source term development for exposure evaluation for hazardous chemical releases will be consistent with the guidance provided in Appendix D, Section D.2. 7.3.3 Exposure Calculation. Once a refined source term has been developed based on the structural response of the facility to the postulated aircraft impact, onsite and offsite exposures can be reassessed in accordance with Section 7.2, “Exposure Screening.” If the offsite screening guideline (and the onsite screening guideline when deemed necessary) is met by the refined source term, no additional analysis of aircraft impact (i.e., meteorological dispersion and consequence assessment) is required. If the offsite screening guideline (and the onsite screening guideline when deemed necessary) cannot be met, additional analysis will be performed to assess the consequences of the release. Additional guidance is provided in Appendix D, Section D.1 (for radioactive material) and Section D.2 (for hazardous chemicals) to aid the analyst in defining the release scenarios and selecting the appropriate dispersion models and parameters. Notwithstanding the guidance provided, credit will not be taken for evacuation or medical treatment of receptors, or for passive or active mitigation due to building confinement and rubble effects. 7.4 References. 1. American Institute of Chemical Engineers, Guidelines for Hazard Evaluation Procedures, Second Edition with Worked Examples. Center for Chemical Process Safety, 1992. 2. United States Department of Energy, Preparation Guide for U.S. Department of Energy Nonreactor Nuclear Facility Safety Analysis Reports. DOE-STD-3009-94, July 1994. 3. Everett, H.E. et al., Screening for Potential Consequences of Accidental Releases of Radioactive and Chemical Materials to the Atmosphere. SAIC/95-1192. Prepared for the United States Department of Energy. Science Applications International Corporation, June 1995. 4. United States Department of Energy, Hazard Categorization and Accident Analysis Techniques for Compliance with DOE Order 5480.23, Nuclear Safety Analysis Reports. DOE-STD-1027-92, December 1992. 5. United States Department of Energy, Recommended Values and Technical Bases for http://www.doe.gov/techstds/standard/std3009/std3009.pdf http://nssc.llnl.gov/NetWeave/Review/SAIC-1192/SAIC-1192.html http://www.doe.gov/techstds/standard/std1027/std1027.pdf DOE-STD-3014-96 91 Airborne Release Fractions/Rates and Respirable Fractions at DOE Non-Reactor Nuclear Facilities. DOE-HDBK-3010-94. 1994. 6. American Institute of Chemical Engineers, Guidelines for Chemical Process Quantitative Risk Analysis. Center for Chemical Process Safety, 1989. 7. United States Environmental Protection Agency, Workbook of Screening Techniques for

Assessing Impacts of Toxic Air Pollutants (revised). 1992. 8. Everett, H.C. et al., Background Information on Source Term and Atmospheric Dispersion Modeling for the Aircraft Crash Risk Assessment Methodology Standard. Prepared for the United States Department of Energy. Science Applications International Corporation, June 1995. http://nssc.llnl.gov/NetWeave/Review/SAIC-1193/SAIC-1193.html http://www.doe.gov/techstds/standard/hdbk3010/hdbk3010.pdf DOE-STD-3014-96 92 INTENTIONALLY BLANK APPENDIX A BASIS FOR SCREENING AND EVALUATION GUIDELINES DOE-STD-3014-96 APPENDIX A A-iii TABLE OF CONTENTS Section Description Page A.1 Exposure Screening Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1 A.2 Frequency Screening Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-6 A.3 Structural Response Screening Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-8 A.4 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-8 DOE-STD-3014-96 APPENDIX A A-iv DOE-STD-3014-96 APPENDIX A A-1 Scope. Chapter 4 presents the numerical screening and evaluation guidelines used in this standard to determine at what stage in the approach the analysis of aircraft crash is sufficient. This appendix presents the basis for the selection of these guidelines. A.1 Exposure Screening Guidelines. Protecting the health and safety of the public is a primary concern when considering the risk from releases of hazardous material resulting from aircraft crash. This standard establishes three screening criteria for determining whether a particular facility poses a potential threat to the public. These criteria set exposure levels below which there are unlikely to be any significant health effects, even to the maximally exposed individual in the offsite population. Each of these criteria is listed below, along with the basis for its selection. Note that the criteria reflect a consistent approach toward the selection of radiological and chemical exposure guidelines, as opposed to an attempt to provide directly comparable guidelines. It would be ideal if there were total consistency between the guidelines for radioactive exposures and chemical exposures. However, given that chemicals act in different ways upon the human body, and given that regulation of hazardous chemicals and radioactive materials has historically never sought consistency (and given the desire to make as much use as possible of already established regulatory precedents), it is too much to expect that total consistency could be achieved here. A.1.1 Exposure Screening Guidelines for Exposures Evaluated at the Site Boundary. a. Radiological exposure - 25 rem (0.25 sievert [Sv]) committed effective dose equivalent (CEDE). Basis: First, note the distinction between committed effective dose equivalent (CEDE) and total effective dose equivalent (TEDE). The former is the accumulated dose over 50 years following inhalation or ingestion of radionuclides. The latter includes, in addition, the dose resulting from external irradiation. A TEDE of 25 rem (0.25 Sv) at the site boundary has precedent as a siting criterion, referenced in DOE Order 6430.1A, General Design DOE-STD-3014-96 APPENDIX A A-2 Criteria. A whole body dose of 25 rem (0.25 Sv) is generally accepted as

a dose that will not cause early health effects (that is, health effects that manifest themselves within a few hours or days of irradiation). The use of CEDE instead of TEDE may be nonconservative because it does not include external irradiation, if any. However, the predominant means of potential exposure at most U.S. nuclear facilities (i.e., nonreactor facilities) is through the inhalation of long-lived alpha emitters, from which there is a very small contribution to external irradiation. In general, therefore, the use of CEDE is approximately equivalent to the use of TEDE. b. Hazardous material exposure - Emergency Response Planning Guideline Level 2 (ERPG-2), as established by the American Industrial Hygiene Association (AIHA). Basis: The ERPG-2 is "The maximum airborne concentration below which it is believed that nearly all individuals could be exposed for up to 1 hour without experiencing or developing irreversible or other serious health effects or symptoms that could impair an individual's ability to take protective action." This guideline has clearly been developed as a threshold for emergency response and has been used in a number of regulatory situations (e.g., by agencies that administer the State of California's Risk Management and Prevention Program). The use of ERPG-2 also has precedent in DOE's Emergency Management Guide for Hazards Assessment, where it is chosen as a protective action guideline. c. Hazardous materials where ERPG-2 has not been established - the Level of Concern (LOC) as established by the U.S. Environmental Protection Agency (EPA), as specified in the 1987 EPA Technical Guidance on Hazards Analysis (or a successor document). DOE-STD-3014-96 APPENDIX A A-3 Basis: Currently, ERPGs have only been defined for 35 chemicals. In Appendix A of Technical Guidance on Hazards Analysis, the EPA discusses the options that are available for the definition of the LOC. For most chemicals, the Immediately Dangerous to Life and Health (IDLH) is tabulated. The IDLH has been developed by the National Institute for Occupational Safety and Health (NIOSH) and is defined as "The maximum concentration of a substance in air from which healthy male workers can escape without loss of life or irreversible health effects under conditions of a maximum 30-minute exposure time." EPA recommends 10 percent of the IDLH as an LOC. If neither the IDLH nor the ERPG is available, it is recommended that the analyst consult an expert toxicologist. Occasionally, the question arises as to whether worker exposure limits such as the Threshold Limit Value (TLV) could be used as LOCs in emergencies involving the public. The TLV has been developed by the American Conference of Government Industrial Hygienists (ACGIH) to limit workplace exposure. ACGIH explicitly advises against using or applying TLVs outside the workplace. A.1.2 Onsite Exposure Screening Guidelines. Much thought went into the issue of whether additional guidelines were required specifically to address the risk to onsite workers. That is, could there be cases in which more detailed analysis of aircraft crash scenarios would be desirable even if there no risk to the public? It was felt that, in the main, there would be no need for guidelines related to worker safety. The basis for this conclusion is the nature of aircraft crash itself. An aircraft crash violent enough to cause a release from a facility will result in death

to the occupants of the aircraft with near certainty. Further, the level of damage at the facility itself would also, with high probability, result in death or serious injury to occupants of the facility or neighboring areas directly affected by the crash and associated debris. When one considers these high probability consequences, exposure to hazardous material release is very unlikely to add significantly to the workers’ overall risk from the accident. In fact, the insights DOE-STD-3014-96 APPENDIX A A-4 developed from further analysis could prove to be misleading, since actions might be taken to protect workers from hazardous material release when the true risk is from the crash itself. For these reasons, this standard takes the position that incremental risk to the offsite public is the appropriate metric for determining whether the additional analysis of aircraft crash release scenarios is warranted. It is recognized, however, that there may be unique cases for which consideration of the impact of releases on onsite workers may be useful in the absence of any impact on the offsite public. Specifically, one could envision a situation where there is an unoccupied (or lightly occupied) facility containing very large amounts of hazardous material in close proximity to a large concentration of workers (but not close enough that these workers could be directly impacted by the same crash that would cause the release) and where the closest offsite member of the public is a great distance away. In such a case, it is possible that the offsite exposure guideline would not be exceeded, but the greatest risk to the workers would be from a hazardous material release. To address such rare circumstances, three onsite exposure guidelines were established. The basis for these guidelines is provided below. a. Radiological exposure - the facility inventory exceeds 25 times the Hazard Category 2 threshold quantities provided in DOE-STD-1027-92. Basis: DOE-STD-1027-92 contains a table of radionuclides, showing the maximum number of curies that could be released and cause a CEDE of 1 rem (0.01 Sv) at a distance of 300 m (984 ft) in atmospheric stability Category D with a wind speed of 4.5 m/s (14.8 ft/sec). These curie quantities are the thresholds for defining a facility as Hazard Category 2. Clearly, 25 times these quantities would lead to a radiation dose of 25 rem (0.25 Sv) CEDE at 300 m (984 ft) and, as noted above, 25 rem (0.25 Sv) CEDE is being taken as a surrogate threshold for 25 rem (0.25 Sv) to the whole body, which is a threshold for early injury. DOE-STD-3014-96 APPENDIX A A-5 Since the precedent has already been established in an existing DOE standard, it is reasonable to take 25 times the DOE-STD-1027-92 Hazard Category 2 thresholds as limiting inventories, above which there would be potential injuries to workers at a distance of 300 m (984 ft) in the above-specified weather conditions. b. Hazardous material exposure - Emergency Response Planning Guideline Level 3 (ERPG-3) as established by the AIHA, to the maximally exposed individual beyond 300 m (984 ft) from the facility. Basis: The ERPG-3 is "The maximum airborne concentration below which it is believed that nearly all individuals could be exposed for up to 1 hour without experiencing or developing life threatening health effects." In spirit, the ERPG-3 seems to be closer to the IDLH than does the

ERPG-2, so it is reasonable to choose it as a guideline for the impact on workers. c. Hazardous material exposure where ERPG-3 has not been established - the IDLH, as established by the NIOSH, to the maximally exposed individual beyond 300 m (984 ft) from the facility. Basis: As noted above, the IDLH is "The maximum concentration of a substance in air from which healthy male workers can escape without loss of life or irreversible health effects under conditions of a maximum 30-minute exposure time." Thus, the IDLH has been specifically defined with worker protection in mind. The analyst is warned against creating more work than is necessary by pursuing evaluation against the onsite screening guidelines when the circumstances do not warrant it. As discussed above, these guidelines are provided to address specific, unique cases in which special consideration of worker exposure resulting from aircraft crash would provide meaningful additional insights. The default position is that the DOE-STD-3014-96 APPENDIX A A-6 onsite guidelines are not needed. Thus, the analyst’s obligation is to justify why they should be used in a specific case, not why they are not being used. In particular, it should be noted that, because of the differences between the offsite and onsite guidelines and the way the exposure calculations are performed, the onsite guidelines are totally useless when the site boundary is within 300 m (984 ft) of the facility and are very likely to be useless when the site boundary is within 1000 m (3280 ft) of the facility. A.1.3 Potential Contamination to the Environment Exposure Screening Guidelines. The final topic considered in developing the exposure screening guidelines was potential contamination of the environment. In most cases, it was felt that exposure to the general public was a sufficient surrogate for offsite environmental contamination. Similarly, if onsite contamination were an issue, then exposure to onsite workers was considered a sufficient surrogate. Although it was recognized that this may not always be the case, there was no obvious set of accidental contamination guidelines readily available for incorporation into this standard. This is in large part due to the fact that there are many different types of environmental receptors (as opposed to only one, a human, for health and safety), and these receptors vary in their sensitivity to different hazards. For this reason, providing specific guidelines for environmental contamination was felt to be impractical. As stated in Section 1.3, “Applicability,” it is left to the analyst to determine whether special conditions exist that would warrant a specific evaluation of environmental impacts in those cases where such analysis is not warranted by health and safety concerns. Again, the default position is that such analyses are not needed, and the burden is on the analyst to justify their inclusion. A.2 Frequency Screening Guidelines. The DOE has issued a standard, DOE-STD-3009-94 (Reference 1), providing guidance for the preparation of Safety Analysis Reports (SARs). This standard states that an external event should be analyzed as a design basis accident (DBA) if its frequency of occurrence exceeds 1E-6/y conservatively estimated, or 1E-7/y, realistically estimated. Aircraft crash impacts are human-caused external DOE-STD-3014-96 APPENDIX A A-7 events, and this standard's methodology has been developed in a conservative manner.

Therefore, the DOE has provided the 1E-6/y screening value for aircraft crash impact accidents in terms of design basis considerations. DOE-STD-3009-94 also states that the use of this cutoff frequency represents a unique case, based on established NRC precedents for human-caused external events, such as aircraft crash. There are no universally accepted definitions of either risk acceptance criteria or screening values. It is impossible to use a "zero risk" philosophy because, short of terminating a program, there are always residual risks. In fact, terminating a program could actually result in higher risks because of the spreading of risks from one program area to another. Because of these and other difficulties, risk frequency screening as used in this standard has, as its primary objective, efficient resource allocation. The screened out scenarios are considered safe enough, for the purpose of this standard, that additional resources do not have to be expended in further analyzing them. However, those postulated accident scenarios that are screened out because they are located in the "risk acceptance" region of the risk curve or matrix can still be evaluated by reviewers. The FDA, EPA, DOE, NRC, and ANSI (References 1 through 8) have documented precedents that exclude events from further analysis if they have postulated accident frequencies less than 1E-6/y. DOE has further restricted this interpretation to apply only to external events, such as aircraft crash impact accident sequences. Only the FDA and EPA have attempted to codify a quantitative "incredible" cutoff frequency. The FDA assumed that "one in a million" is considered safe enough in terms of developing cancer. In the 1990 revised National Contingency Plan, EPA used accident frequencies of 1E-6/y as a point of departure, below which regulatory consideration is not warranted, and recognized that the acceptable risk frequency range could in fact be several orders of magnitude greater. This standard uses 1E-6/y as a benchmark for resource allocation. In other words, when postulated aircraft crash impact frequencies fall below the 1E-6/y cutoff frequency, this standard implies that, for the purpose of resource allocation, these scenarios can be regarded as "safe enough," and no further resource expenditures are necessary for DOE-STD-3014-96 APPENDIX A A-8 analyzing the scenarios and implementing risk reduction recommendations. This by no means implies that postulated accident scenarios that have frequencies less than 1E-6/y are acceptable risks because they lie below the boundary between risk rejection and risk acceptance. This standard uses the screening cutoff frequency in terms of the sum of all aircraft crash impact frequencies, which are also the initiating event frequencies. All individual aircraft type initiating event frequencies and subsequent accident sequences will have frequencies less than the cutoff. This criterion applies to the frequency screening, frequency evaluation, and damage assessment stages of the process. In all three stages, the sum of the applicable initiating event frequencies is determined and the same 1E-6/y screening value is applied. A.3 Structural Response Screening Guidelines. The basis for the structural response guidelines is predominantly the industry norms that are prescribed and uniformly accepted by structural engineering professionals through the national and consensus

codes. For local damage to reinforced concrete structures, it was felt that some degree of conservatism would be achieved by increasing the penetration thickness by 10 and 20 percent for scabbing and perforation, respectively. The rationale behind this increase is to account for any uncertainty; and because these are empirical formulas, in some cases validated by test results, a nominal increase would ensure consistency and lend some degree of assurance that failure would be prevented if these requirements were met. Similarly, for steel targets, an increase of 25 percent over the penetration depth was recommended to prevent any failure. As for excessive structural deformation/collapse and the SSCs' functionality, the national consensus codes were recommended to be consistent with the analysis/design evaluation for structures subjected to any other such accidental or abnormal load. A.4 References. 1. United States Department of Energy. Preparation Guide for U.S. Department of Energy Nonreactor Nuclear Facility Safety Analysis Reports. DOE-STD-3009-94. July, 1994. http://www.doe.gov/techstds/standard/std3009/std3009.pdf DOE-STD-3014-96 APPENDIX A A-9 2. American Nuclear Society. American National Standard Guidelines for Combining Natural and External Man-made Hazards at Power Reactor Sites. ANSI/ANS-2, 12-1978. 1978. 3. American Nuclear Society. American National Standard Nuclear Safety Criteria for the Design of Stationary Pressurized Water Reactor Plants. ANSI/ANS-51.1-1983. 1983. 4. United States Environmental Protection Agency. EPA Watch, Vol. 3, No. 17. The DeWeese Publishing Company, 1995. 5. United States Environmental Protection Agency. (1990 National Contingency Plan.) “National Oil and Hazardous Pollution Prevention Plan. Final Rule,” Federal Register, 8670-8852, March 8, 1990. 6. National Safety Council. Annual published data. 1990. 7. Travis, C.C. Environmental Science and Technology. 1991. 8. United States Department of Energy. Nuclear Safety Policy. SEN-35-91. September 9, 1991. DOE-STD-3014-96 APPENDIX A A-10 INTENTIONALLY BLANK APPENDIX B GUIDANCE AND DATA FOR IMPACT FREQUENCY CALCULATION B-iii DOE-STD-3014-96 APPENDIX B TABLE OF CONTENTS Section Description Page B.1 Determination of Number of Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-1 B.2 Aircraft Crash Rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-2 B.3 Crash Location Probability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-2 B.4 Effective Area Calculations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-26 B.5 Sample Problem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-30 B.6 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-49 LIST OF FIGURES Figure B-1. Coordinate convention for use with crash location probability tables for commercial and general aviation . . . . . . . . . . . . . . . . . . . . . B-5 Figure B-2. Coordinate convention and effect of pattern side, for use with crash location probability tables for military aviation . . . . . . . . . . . . . . B-7 Figure B-3. Rectangular facility effective target area elements . . . . . . . . . . . . . . . B-27 Figure B-4. Pictorial representation of sample facility and airport locations . . . . . B-30 Figure B-5. Orthonormal distance from Airport 2 to facility . . . . . . . . . . . . . . . . . B-37 Figure B-6. Dimensions of sample facility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-42

LIST OF TABLES Table B-1 Aircraft crash rates by category, subcategory, and flight phase . . . . . . B-3 Table B-2 Crash location probability f(x,y) for commercial aviation aircraft takeoff . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-12 Table B-3 Crash location probability f(x,y) for commercial aviation aircraft landing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-13 Table B-4 Crash location probability f(x,y) for general aviation aircraft takeoff . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-14 Table B-5 Crash location probability f(x,y) for general aviation aircraft landing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-15 Table B-6 Crash location probability f(x,y) for large military aircraft takeoff with the pattern side to the right of the direction of flight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-16 Table B-7 Crash location probability f(x,y) for large military aircraft takeoff with the pattern side to the left of the direction of flight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-17 Table B-8 Crash location probability f(x,y) for large military aircraft landing with the pattern side to the right of the direction of flight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-18 Table B-9 Crash location probability f(x,y) for large military aircraft landing with the pattern side to the left of the direction of flight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-19 Table B-10 Crash location probability f(x,y) for small military aircraft takeoff with the pattern side to the right of the direction of flight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-20 B-iv DOE-STD-3014-96 APPENDIX B Page Table B-11 Crash location probability f(x,y) for small military aircraft takeoff with the pattern side to the left of the direction of flight . . . . . . . . . . . . . . . . . . . . . . . . . . . B-21 Table B-12 Crash location probability f(x,y) for small military aircraft landing with the pattern side to the right of the direction of flight . . . . . . . . . . . . . . . . . . . . . . . . . . B-22 Table B-13 Crash location probability f(x,y) for small military aircraft landing with the pattern side to the left of the direction of flight . . . . . . . . . . . . . . . . . . . . . . . . . . . B-23 Table B-14 DOE site-specific values and maximum, minimum, and average CONUS values of Npf(x,y) for general aviation (GA) nonairport operations (in crashes per square mile, per year, centered at the site) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-24 Table B-15 DOE site-specific values and maximum, minimum, and average CONUS values of NPf(x,y) for commercial and military aviation nonairport operations (in crashes per square mile, per year, centered at the site) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-25 Table B-16 Representative wingspans (ws) for commercial, general aviation, and military aircraft . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-28 Table B-17 Values of the mean of the cotangent of the impact angle (cot ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-29

Table B-18 Mean skid distances (s) for each aircraft category . . . . . . . . . . . . . . . B-29 Table B-19 Airport information for sample facility . . . . . . . . . . . . . . . . . . . . . . . . . B-31 Table B-20 Information from the local airports . . . . . . . . . . . . . . . . . . . . . . . . . . . B-32 Table B-21 Data collection table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-33 Table B-22 Data collection table for Airport 1 Runway 10 . . . . . . . . . . . . . . . . . . B-34 Table B-23 Data collection table for Airport 1 Runway 28 . . . . . . . . . . . . . . . . . . B-34 Table B-24 Data collection table for Airport 2 Runway 18 . . . . . . . . . . . . . . . . . . B-35 Table B-25 Data collection table for Airport 2 Runway 0 . . . . . . . . . . . . . . . . . . . B-35 Table B-26 Data collection table for Airport 3 Runway 22 . . . . . . . . . . . . . . . . . . B-36 Table B-27 Data collection table for Airport 3 Runway 4 . . . . . . . . . . . . . . . . . . . B-36 Table B-28 Updated data collection table for Airport 1 Runway 10 showing f(x,y) value and crash rate . . . . . . . . . . . . . . . . . . . . . . . . . . B-39 Table B-29 Updated data collection table for Airport 1 Runway 28 showing f(x,y) value and crash rate . . . . . . . . . . . . . . . . . . . . . . . . . . B-39 Table B-30 Updated data collection table for Airport 2 Runway 18 showing f(x,y) value and crash rate . . . . . . . . . . . . . . . . . . . . . . . . . . B-40 Table B-31 Updated data collection table for Airport 2 Runway 0 showing f(x,y) value and crash rate . . . . . . . . . . . . . . . . . . . . . . . . . . B-40 Table B-32 Updated data collection table for Airport 3 Runway 22 showing f(x,y) value and crash rate . . . . . . . . . . . . . . . . . . . . . . . . . . B-41 Table B-33 Updated data collection table for Airport 3 Runway 4 showing f(x,y) value and crash rate . . . . . . . . . . . . . . . . . . . . . . . . . . B-41 Table B-34 Results of effective area calculations . . . . . . . . . . . . . . . . . . . . . . . . B-42 Table B-35 Completed data collection table for Airport 1 Runway 10 . . . . . . . . . . B-44 Table B-36 Completed data collection table for Airport 1 Runway 28 . . . . . . . . . . B-44 Table B-37 Completed data collection table for Airport 2 Runway 18 . . . . . . . . . . B-45 DOE-STD-3014-96 APPENDIX B B-v Page Table B-38 Completed data collection table for Airport 2 Runway 0 . . . . . . . . . . . B-45 Table B-39 Completed data collection table for Airport 3 Runway 22 . . . . . . . . . . B-46 Table B-40 Completed data collection table for Airport 3 Runway 4 . . . . . . . . . . . B-46 Table B-41 General aviation nonairport crash frequency . . . . . . . . . . . . . . . . . . . B-47 Table B-42 Commercial and military nonairport crash frequencies . . . . . . . . . . . . B-47 Table B-43 Helicopter Crash Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-48 Table B-44 Total impact frequencies by category/subcategory . . . . . . . . . . . . . . B-48 DOE-STD-3014-96 APPENDIX B B-vi DOE-STD-3014-96 APPENDIX B B-1 This appendix provides the information and guidance necessary to implement the frequency calculation methods described in Chapter 5 of the standard. B.1 Determination of Number of Operations. The first factor in determining the aircraft impact frequency, F, is the number of annual aircraft flight activities, N, near the site under consideration. Because of the different ways in which flight operations are conducted,

aircraft flight activities are tabulated differently for the airport environment and the nonairport environment. In the airport environment, aircraft flight activities may be tabulated in terms of aircraft operations or airport operations. The analyst may have to use data concerning either aircraft operations or airport operations or both to derive a value for N. Aircraft operations, as defined by the Federal Aviation Administration (FAA), include the arrivals at and departures from an airport at which an airport traffic control tower is located. Airport operations are defined as either local or itinerant. Local airport operations are flights in which the aircraft flies to a nearby airport or performs simulated approaches to the airport. Also classified as local operations are those which include aircraft that (1) operate in the local traffic pattern or within sight of the airport, (2) are known to be departing for or arriving from practice areas located within a 22-mile radius of the airport, or (3) execute simulated instrument approaches or low passes at the airport. All other airport operations are classified as itinerant operations. Itinerant operations are basically flights which land at the airport after a trip from somewhere else, or take off from the airport for a trip elsewhere. For both itinerant and local airport operations, each takeoff, landing, or approach without landing is an operation. For historical data on airport operations at airports with FAA control towers, the analyst should obtain the document, FAA Air Traffic Activity, distributed by the FAA Office of Aviation Policy, Plans and Management Analysis each fiscal year. For the nonairport environment, values for the NPf(x,y) product have been determined. If additional information is needed, the analyst should consult the ACRAM Modeling Technical Support Document (Reference 1) and the Data Development Technical http://nssc.llnl.gov/NetWeave/Review/ACRAM_Model_new/ACRAM_Modeling_t.html http://nssc.llnl.gov/NetWeave/Review/ACRAM_Model_new/ACRAM_Modeling_t.html http://nssc.llnl.gov/NetWeave/Review/ACRAM_Data1/data-Contents.html DOE-STD-3014-96 APPENDIX B B-2 Support Document for the Aircraft Crash Risk Analysis Methodology (ACRAM) Standard (Reference 2) for further information. B.2 Aircraft Crash Rates. Generic crash rates for each aircraft category and subcategory were calculated based on a review of accident reports published by FAA and/or the National Transportation Safety Board (NTSB) for civilian aircraft, and by the United States military for military aircraft. The evaluation techniques used to estimate specific crash rates for each aircraft category or subcategory are documented in Reference 2. See this document for more information on the databases and evaluation techniques. Table B-1 provides the generic crash rates for each aircraft category (and subcategory as available). B.3 Crash Location Probability. Crash location probabilities per square mile in the vicinity of a runway were calculated based on a review of accident reports published by FAA and/or NTSB for civilian aircraft, and by the United States Air Force for military aircraft. The probability values are given in a tabular format for commercial, general aviation, and military aircraft categories (or subcategories as available). The probability values are a function of distance from an intended runway. Each probability value reflects the

conditional probability that, given a crash, the crash will occur within a specific one- square-mile bin in the vicinity of an airport. The data and calculations used to determine the probability values are provided in Reference 2. Since the crash location probabilities are a function of distance from a runway, it is important that the coordinate convention specified in this standard be used. Using this convention, the analyst will determine the facility’s location coordinates (x and y distances) and find the appropriate probability value for the facility. http://nssc.llnl.gov/NetWeave/Review/ACRAM_Data1/data-Contents.html DOE-STD-3014-96 APPENDIX B B-3 TABLE B-1. Aircraft crash rates by category, subcategory, and flight phase.1 AIRCRAFT CRASH RATE (P) Takeoff Landing (per takeoff) (per landing) General Aviation 1. Fixed Wing Single Engine 1.1E-5 2.0E-5 Reciprocating 2. Fixed Wing Multiengine 9.3E-6 2.3E-5 Reciprocating 3. Fixed Wing Turboprop 3.5E-6 8.3E-6 4. Fixed Wing Turbojet 1.4E-6 4.7E-6 Representative Fixed Wing 1.1E-5 2.0E-5 Representative Helicopter 2.5E-5 See Note 22 Commercial 1. Air Carrier 1.9E-7 2.8E-7 2. Air Taxi 1.0E-6 2.3E-6 Military 1. Large Aircraft 5.7E-7 1.6E-6 3 2. Small Aircraft 1.8E-6 3.3E-6 4 Notes: Reference 1 provides additional information, such as the crash rate per mile for these aircraft1 categories. Helicopter crashes are considered on a per-flight basis and are reported under takeoff for 2 convenience. Large military aircraft includes bombers, cargo aircraft, and tankers.3 Small military aircraft includes fighters, attack aircraft, and trainers.4 DOE-STD-3014-96 APPENDIX B B-4 B.3.1 Coordinate Convention. At an airport, each runway is designated by two numbers (one for each end). Each number designation is approximately one-tenth of the angle that the extended runway direction makes with magnetic north. For example, depending on its direction of use, a runway may be called Runway 4 or Runway 22. An aircraft departing Runway 4 flies an approximate course of 40 degrees with respect to magnetic north; similarly, an aircraft landing on Runway 4 also flies an approximate course of 40 degrees prior to touchdown. Use of Runway 22 sets the flight course at 220 degrees with respect to magnetic north. Parallel runways receive similar numbers with right (R) and left (L) designations. To define aircraft crash locations relative to airfield runways and facilities, it is necessary to establish a location coordinate system. This standard uses the Cartesian coordinate convention with the following characteristics: 1. The origin of the coordinate system is at the center of the relevant runway. 2. The x axis coincides with the extended runway centerline; the positive direction is the direction of flight. 3. The y axis is perpendicular to the x axis with the positive direction created by a 90-degree counterclockwise rotation of the positive x axis. The coordinate system is depicted in Figure B-1. DOE-STD-3014-96 APPENDIX B B-5 This figure is used for determining f(x,y) for: Commercial Aircraft Takeoff - Table B-2 Commercial Aircraft Landing - Table B-3 General Aviation Takeoff - Table B-4 General Aviation Landing - Table B-5 FIGURE B- 1. Coordinate convention for use with crash location probability tables for commercial and general aviation Often, the location of a facility is expressed in terms of the distance, R, and bearing, ,

from the facility to the airfield. For purposes of this standard, it is appropriate to assume that these measurements represent the distance and bearing from the corner of the facility closest to the runway to the center of the relevant runway. To determine the x,y values of the facility in the specified coordinate system, apply Equations B-1 and B-2. x R cos ( ) y R sin ( ) DOE-STD-3014-96 APPENDIX B B-6 (B-1) (B-2) and where: R = distance from the facility (miles); = bearing from the facility to the airport; = runway bearing as an angle with respect to magnetic north (this equals the runway number times ten). B.3.2 Pattern Side for Military Aviation. For military aviation, a landing often involves an initial approach over the runway followed by a turn to a downwind leg parallel to the runway, a base leg turn, and a final approach to a full-stop landing. This flight pattern is usually performed on a specified side of the runway, referred to as the pattern side. All local operations, e.g., touch-and-goes, also involve pattern side flight. This concentration of traffic on the pattern side of the runway is reflected in the crash locations, thus influencing crash location probabilities. In other words, there tends to be a bias toward the pattern side. To accommodate this, separate tables of crash location probabilities are provided for cases when the pattern side is to the left of the direction of flight and cases when it is to the right of the direction of flight. The pattern side is shown in Figure B-2 +x +x +y Origin +y Origin Pattern side is indicated by Direction of Flight DOE-STD-3014-96 APPENDIX B B-7 This figure is used for determining f(x,y) for: A. Pattern side to the right of the direction of flight B. Pattern side to the left of the direction of flight Large Military Aircraft Takeoff - Table B-6 Large Military Aircraft Takeoff - Table B-7 Large Military Aircraft Landing - Table B-8 Large Military Aircraft Landing - Table B-9 Small Military Aircraft Takeoff - Table B-10 Small Military Aircraft Takeoff - Table B-11 Small Military Aircraft Landing - Table B-12 Small Military Aircraft Landing - Table B-13 FIGURE B-2. Coordinate convention and effect of pattern side, for use with crash location probability tables for military aviation B.3.3 Crash Location Probabilities for Near-airport Operations. Tables B-2 through B-13 provide crash location probabilities for near-airport operations. Each entry in the tables represents the conditional probability that, given an aircraft crash, the aircraft will crash in the one-mile-square area defined by the 1-mile x direction and 1-mile y direction intervals in the horizontal and vertical headings of the table. Tables B-2 and B-3 are for commercial aviation and are relevant to both air carriers and air taxis. Tables B-4 and B-5 are for general aviation and are applicable to all fixed wing general aviation aircraft. Separate tables are provided for large and small military aircraft and for the pattern side to the right and to the left of the runway. Tables B-6 and B-8 are DOE-STD-3014-96 APPENDIX B B-8 for large military aircraft with the pattern side to the right of the runw