PAG Manual:

Protective Action Guides

and Planning Guidance for Radiological Incidents

EPA-400/R-17/001 | January 2017 

www.epa.gov/radiation/protective-action-guides-pags
PAG Manual

Protective Action Guides 

and Planning Guidance for 

Radiological Incidents

JANUARY 2017 

FINAL REVISION: SUPERSEDES 1992, 2013 AND 2016 MANUALS

Office of Radiation and Indoor Air

Radiation Protection Division

U.S. Environmental Protection Agency

Washington, DC 20460
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LIMITS ON SCOPE

This guidance does not address or impact site cleanups occurring under other statutory authorities such as 

the United States Environmental Protection Agency’s (EPA) Superfund program, the Nuclear Regulatory 

Commission’s (NRC) decommissioning program, or other federal or state cleanup programs. 

As indicated by the use of non-mandatory language such as “may,” “should” and “can,” this Manual only 

provides recommendations and does not confer any legal rights or impose any legally binding 

requirements upon any member of the public, state, tribe, locality, or any federal agency.
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TABLE OF CONTENTS

LIMITS ON SCOPE ................................................................................................................................... ii

TABLE OF CONTENTS .......................................................................................................................... iv

LIST OF TABLES .................................................................................................................................... vii

LIST OF FIGURES ................................................................................................................................. viii

CHAPTER 1. OVERVIEW ....................................................................................................................... 1

1.1 PLANNING GUIDANCE AND PROTECTIVE ACTION GUIDES ......................................... 1

1.2 APPLICABILITY ........................................................................................................................ 1

1.3 BACKGROUND ON THE UPDATED PAGS ............................................................................ 2

1.3.1 Legal Basis ...................................................................................................................... 2

1.3.2 Interaction with Federal Radiation Council (FRC) Reports No. 5 and 7 ........................ 3

1.3.3 Technical Basis ................................................................................................................ 3

1.3.4 Changes in Scenarios since the Issuance of the 1992 PAG Manual ................................ 3

1.3.5 Key Changes to PAGs in this Updated Manual ............................................................... 4

1.4 RADIOLOGICAL INCIDENT PHASES AND APPLICABILITY OF PROTECTIVE 

ACTIONS ..................................................................................................................................... 5

1.4.1 Implementation of Protective Action Guides and Protective Actions ............................. 7

1.4.2 Early Phase Protective Action Guides and Protective Actions ........................................ 7

1.4.3 Intermediate Phase Protective Action Guides and Protective Actions ............................ 8

1.4.4 Late Phase ........................................................................................................................ 9

1.4.5 Precaution built into the PAGs ...................................................................................... 10

KEY POINTS IN CHAPTER 1 – OVERVIEW ............................................................................. 12

CHAPTER 2. EARLY PHASE PROTECTIVE ACTION GUIDES ................................................... 13

2.1 EXPOSURE PATHWAYS DURING THE EARLY PHASE ................................................... 13

2.1.1 Exposure Pathways from Airborne Releases ................................................................. 13

2.1.2 Establishment of Exposure Patterns .............................................................................. 14

2.2 THE PROTECTIVE ACTION GUIDES AND PROTECTIVE ACTIONS FOR THE EARLY 

PHASE: EVACUATION, SHELTERING-IN-PLACE, AND ADMINISTRATION OF 

POTASSIUM IODIDE ............................................................................................................... 15

2.2.1 Thyroid Based Evacuation ............................................................................................. 15

2.2.2 Evacuation vs. Sheltering-in-Place ................................................................................ 16

2.2.3 Considerations for Potassium Iodide (KI) ..................................................................... 20

2.2.4 PAGs and Nuclear Facilities Emergency Planning Zones (EPZ) .................................. 22

2.3 DOSE PROJECTIONS ............................................................................................................... 23

2.3.1 Dose Projection during the Early Phase ........................................................................ 24

2.3.2 Duration of Exposure ..................................................................................................... 24

2.3.3 Derived Response Levels and Dose Parameters ............................................................ 25

2.3.4 Higher PAGs for Special Circumstances ....................................................................... 26

2.4 CONTAMINATION LEVELS AND MONITORING OF THE ENVIRONMENT AND 

POPULATIONS ......................................................................................................................... 26

2.4.1 Surface Contamination Control ..................................................................................... 27

2.4.2 Priorities for Control of Contaminated Areas ................................................................ 27

2.4.3 Recommendations for Emergency Screening in Areas Not Qualifying as Low 

Background Areas ......................................................................................................... 28

2.4.4 Recommendations for Screening in Low Background Areas ........................................ 29
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2.5 BASIS FOR EARLY PHASE PAGS ......................................................................................... 29

KEY POINTS IN CHAPTER 2 – EARLY PHASE ............................................................................. 32

CHAPTER 3. EMERGENCY WORKER PROTECTION .................................................................. 33

3.1 CONTROLLING OCCUPATIONAL EXPOSURE AND DOSES TO EMERGENCY 

WORKERS ................................................................................................................................. 34

3.1.1 Maintaining the ALARA Principle ................................................................................ 34

3.1.2 Understanding Dose and Risk Relationships ................................................................. 34

3.2 OCCUPATIONAL SAFETY REGULATIONS FOR RADIOLOGICAL 

EMERGENCY RESPONSE ............................................................................................. 37

KEY POINTS IN CHAPTER 3 – EMERGENCY WORKER PROTECTION ................................... 39

CHAPTER 4. INTERMEDIATE PHASE PROTECTIVE ACTION GUIDES ................................. 40

4.1 EXPOSURE PATHWAYS DURING THE INTERMEDIATE PHASE ................................... 40

4.2 THE PROTECTIVE ACTION GUIDES AND PROTECTIVE ACTIONS FOR THE 

INTERMEDIATE PHASE: RELOCATION AND DOSE REDUCTION ................................ 41

4.2.1 Removal of the 50 Year Relocation PAG...................................................................... 43

4.2.2 The Population Affected ................................................................................................ 43

4.2.3 Areas Involved ............................................................................................................... 43

4.2.4 Priorities ........................................................................................................................ 45

4.3 SEQUENCE OF EVENTS ......................................................................................................... 45

4.3.1 Establishment of Isodose-Rate Lines ............................................................................. 46

4.3.2 Dose Projections ............................................................................................................ 46

4.3.3 Projected External Gamma Dose ................................................................................... 47

4.3.4 Exposure Limits for People Reentering the Relocation Area ........................................ 48

4.4 LONGER-TERM OBJECTIVES OF THE PROTECTIVE ACTION GUIDES FOR THE 

INTERMEDIATE PHASE ......................................................................................................... 48

4.5 REENTRY MATRIX FOLLOWING A RADIOLOGICAL INCIDENT OR ACCIDENT ...... 49

4.6 PROTECTIVE ACTION GUIDANCE FOR FOOD AND DRINKING WATER .................... 53

4.6.1 Protective Action Guide for Drinking Water ................................................................. 53

4.6.2 Factors EPA considered when establishing the drinking water PAG ............................ 55

4.6.3 Rationale for a two-tier Drinking Water PAG ............................................................... 55

4.6.4 Interpreting and Applying the PAG ............................................................................... 56

4.6.5 Planning and Taking Action .......................................................................................... 58

4.6.6 Derived Response Levels (DRLs) ................................................................................. 61

4.7 BASIS FOR INTERMEDIATE PHASE PAGs ......................................................................... 66

KEY POINTS IN CHAPTER 4 – INTERMEDIATE PHASE ............................................................ 68

CHAPTER 5. PLANNING GUIDANCE FOR THE LATE PHASE ................................................... 69

5.1 LATE PHASE CLEANUP PROCESS ....................................................................................... 69

5.1.1 Transitioning from Intermediate to Late Phase Cleanup ............................................... 69

5.1.2 Characterization and Stabilization ................................................................................. 70

5.1.3 Goals and Strategies ...................................................................................................... 70

5.1.4 Implementation and Reoccupancy ................................................................................. 72

5.1.5 Stakeholder Involvement ............................................................................................... 73

5.1.6 Cleanup Process Implementation and Organization: An Example ................................ 73

5.2 DISPOSAL OF LARGE VOLUMES OF RADIOLOGICAL WASTE .................................... 77

5.2.1 General Considerations for Waste Disposal Options and Waste Volumes ................... 78

5.2.2 Existing Disposal Options ............................................................................................. 79
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5.2.3 Planning and Coordination among Federal and State Entities for Disposal Options .... 82

5.2.4 Considerations for Modified Use of Existing Disposal Options ................................... 82

5.2.5 Potential Federal Properties to Develop New Disposal Capacity .................................. 84

KEY POINTS IN CHAPTER 5 – LATE PHASE ................................................................................ 86

APPENDIX A – REFERENCES ............................................................................................................. 87

APPENDIX B – GLOSSARY .................................................................................................................. 94

APPENDIX C – LIST OF ACRONYMS ................................................................................................ 99
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LIST OF TABLES

Table 1-1. Summary Table for PAGs, Guidelines, and Planning Guidance for Radiological Incidents ...... 6

Table 2-1. PAGs and Protective Actions for the Early Phase of a Radiological Incident .......................... 16

Table 2-2. Threshold Thyroid Radioactive Exposures and Recommended Doses of KI for Different Risk 

Groups ......................................................................................................................................................... 21

Table 3-1. Emergency Worker Guidelines .................................................................................................. 35

Table 3-2. Acute Radiation Syndrome ........................................................................................................ 36

Table 3-3. Regulations for Worker Protection ............................................................................................ 38

Table 4-1. PAGs and Protective Actions for Exposure to Deposited Radioactivity during the Intermediate 

Phase of a Radiological Incident ................................................................................................................. 42

Table 4-2. Reentry Matrix: Quick Reference to Operational Guidelines ................................................... 50

Table 4-3. Default Derived Response Levels (DRLs) – Drinking Water Concentrations Corresponding to 

Specified Doses (mrem) of Select Radionuclides, Assuming One Year of Exposure at Constant Levels . 62

Table 4-4. Mean Drinking Water Ingestion Rates from Federal Guidance Report #13 ............................. 65

Table 4-5. Dose Conversion Factors ........................................................................................................... 66
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LIST OF FIGURES

Figure 2-1. Exposure Reduction from External Radiation from Nuclear Fallout as a function of Building 

Type and Location ...................................................................................................................................... 19

Figure 4-1. Generalized Protective Action Areas for NPP Incident ........................................................... 44
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CHAPTER 1. OVERVIEW

1.1 PLANNING GUIDANCE AND PROTECTIVE ACTION GUIDES

The U.S. Environmental Protection Agency (EPA) has developed this Manual to assist public officials in

planning for emergency response to radiological incidents. For purposes of this document, a radiological 

incident is an event or a series of events, deliberate or accidental, leading to the release or potential

release into the environment of radioactive materials in sufficient quantity to warrant consideration of 

protective actions. This Manual provides radiological protection criteria for application to all incidents 

that would require consideration of protective actions.

During an incident with an uncontrolled source of radiation, protection of the public from unnecessary

exposure to radiation may require some form of intervention that will disrupt normal living. Such 

intervention is termed a protective action. Examples of protective actions include: 

 Evacuating an area;

 Sheltering-in-place within a building or protective structure;

 Administering potassium iodide (KI) as a supplemental action; 

 Relocation; 

 Acquiring an alternate source of drinking water; and

 Interdiction of food/milk.

This Manual provides recommended numerical protective action guides (PAGs) for the principal 

protective actions available to public officials during a radiological incident. A PAG is defined for 

purposes of this document as the projected dose to an individual from a release of radioactive material at 

which a specific protective action to reduce or avoid that dose is recommended. (See Section 2.3 for a 

discussion of projected dose.) PAGs are guides to help officials select protective actions under emergency

conditions during which exposures would occur for relatively short time periods. They are not meant to be 

applied as strict numeric criteria, but rather as guidelines to be considered in the context of incidentspecific factors. PAGs do not establish an acceptable level of risk for normal, non-emergency conditions, 

nor do they represent the boundary between safe and unsafe conditions. The PAGs are not legally binding 

regulations or standards and do not supersede any environmental laws. For information on roles,

responsibilities and authorities during emergency response and recovery, please refer to the National 

Response Framework: http://www.fema.gov/national-response-framework (FEMA 2008a) and 

specifically for radiological incidents, the Nuclear Radiological Incident Annex: 

http://www.fema.gov/pdf/about/divisions/thd/IncidentNucRad.pdf (FEMA 2008b).

Some protective actions are not associated with a numerical PAG. For example, the control of access to 

areas is a protective action implemented in concert with other protective actions; it does not have its own 

PAG. Any reasonable action to reduce radiation dose is encouraged even if it is not associated with a 

PAG, such as recommending that individuals use ad hoc respiratory protection with a handkerchief or 

piece of folded cloth. In areas where PAGs are not exceeded, but airborne radioactivity is present, people 

might be asked to stay indoors to the extent practicable to reduce their exposures. To further develop 

radiological emergency plans, brief planning guides have been provided for reentry to relocation areas, 

the cleanup planning process, and considerations for radioactive waste disposal (see Sections 4.5, 

5.1 and 5.2). 

1.2 APPLICABILITY

Protective actions may be recommended for a wide range of incidents, but generally apply to incidents 

involving relatively significant releases of radionuclides. Radiological incidents with potential for 

significant releases include:
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 A fire in a major facility such as a nuclear fuel manufacturing plant; 

 An accident at a federal nuclear weapons complex facility;

 An accident at a commercial nuclear power plant (NPP);

 A transportation accident involving radioactive material; and

 A terrorist act involving a radiological dispersal device (RDD) or yield-producing improvised nuclear 

device (IND).

Each type of incident would pose a unique threat to public health and should be planned for and managed 

accordingly. Emergency response planning for a given facility or scenario should consider:

 The radionuclides involved; 

 The dynamics of the release, including size and magnitude; 

 The feasibility of specific protective actions; and

 The timing of notification, response, and protective action implementation. 

The decision to advise members of the public to take a protective action during a radiological incident 

involves a complex judgment in which the radiological risk must be weighed against the action’s inherent 

risks. This decision may have to be made under emergency conditions, with limited information and little 

time to analyze options. Advance planning reduces the complexity of the decision-making process during 

an incident. The planning process can identify the viability of responses to various incidents, the courses 

of action that can be set in motion in advance and the decisions that can only be made during an actual 

emergency. While many aspects of protective actions can be considered well in advance of an emergency, 

the situations and conditions that exist at the time of emergency must be considered if the most effective 

action is to be selected.

The unpredictable locations of certain radiological incidents make advance planning challenging. For 

example, an RDD could detonate anywhere and spread radiological contaminants over a wide variety of 

surfaces and terrain. Emergency planners should be prepared to apply PAGs to a wide scope of facilities 

and circumstances.

1.3 BACKGROUND ON THE UPDATED PAGS

This Manual updates the “Manual of Protective Action Guides and Protective Actions for Nuclear

Incidents” (EPA-400-R-92-001, May 1992), published by EPA (EPA 1992b) (hereinafter referred to as

the “1992 PAG Manual”). The guidance in this Manual was developed cooperatively with the Federal

Radiological Preparedness Coordination Committee (FRPCC), with representation from the EPA; the 

Department of Energy (DOE); the Department of Defense (DoD); the Department of Homeland Security 

(DHS) Federal Emergency Management Agency (FEMA); the Nuclear Regulatory Commission (NRC);

the Department of Health and Human Services (HHS), including the Centers for Disease Control and 

Prevention (CDC) and the Food and Drug Administration (FDA); the U.S. Department of Agriculture 

(USDA); and the Department of Labor (DOL).

1.3.1 Legal Basis

The historical and legal basis of EPA’s role in developing this guidance begins with Reorganization Plan 

No. 3 of 1970, in which the Administrator of EPA assumed all the functions of the Federal Radiation

Council (FRC), including the charge to “...advise the President with respect to radiation matters, directly 

or indirectly affecting health, including guidance for all federal agencies in the formulation of radiation 

standards and in the establishment and execution of programs of cooperation with states” (Reorg. Plan

No. 3 of 1970, sec. 2(a) (7), 6(a) (2); § 274.h of the Atomic Energy Act of 1954, as amended (AEA), 

codified at 42 U.S.C. § 2021(h)). Recognizing this role, FEMA, in its Radiological Emergency Planning 

and Preparedness Regulations, directed EPA to “establish Protective Action Guides (PAGs) for all aspects

of radiological emergency planning in coordination with appropriate federal agencies” (44 Code of 
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Federal Regulations (CFR) §351.22(a)). FEMA also tasked EPA with preparing “guidance for state and 

local governments on implementing PAGs, including recommendations on protective actions which can 

be taken to mitigate the potential radiation dose to the population” (44 CFR §351.22(b)). All of this 

information was to “be presented in the EPA Manual of Protective Action Guides and Protective Actions

for Nuclear Incidents” (44 CFR §351.22(b)). 

Additionally, section 2021(h) charged the Administrator with performing “such other functions as the

President may assign to him [or her] by Executive Order.” Executive Order 12656 states that the 

Administrator shall “develop, for national security emergencies, guidance on acceptable emergency levels 

of nuclear radiation....” (Executive Order No. 12656, sec. 1601(2)). EPA’s role in the development of 

PAGs was also recognized in the “Nuclear Radiological Incident Annex of the National Response 

Framework” of June 2008 (FEMA 2008b). 

1.3.2 Interaction with Federal Radiation Council (FRC) Reports No. 5 and 7

In the 1960s, the Federal Radiation Council (FRC) defined PAGs and established limiting guides for 

ingestion of strontium-89, strontium-90, cesium-137, and iodine-131 (FRC 1964; FRC 1965). That 

guidance applied to restricting the use of food products that had become contaminated as the result of 

release of radioactivity to the stratosphere from weapons testing. Since the 1960s, experience with other 

exposure scenarios such as accidents and terrorism made more guidance necessary. During the period 

immediately following an incident at any domestic nuclear facility, when the critical source of exposure is 

expected to be a nearby airborne plume, the principal protective actions are evacuation or sheltering. The 

PAGs developed here thus do not supersede previous guidance, but provide additional guidance for 

promptly addressing exposure pathways specific to a domestic nuclear incident. 

1.3.3 Technical Basis

The FRC introduced the concept of a PAG in a series of recommendations issued in the 1960s. A key 

concept about PAGs is that the decision to implement protective actions should be based on the projected

dose that would be avoided if the protective actions were implemented. Developers of the EPA PAGs

considered the following three principles in establishing exposure levels for the PAGs— 

1. Prevent acute effects.

2. Balance protection with other important factors and ensure that actions result in more benefit

than harm.

3. Reduce risk of chronic effects.

These principles apply to the determination of any PAG. Principles 1 and 2 have been proposed for use by 

the international community as essential bases for decisions to intervene during an incident. Principle 3 

has been recognized as an appropriate additional consideration (IAEA 2002). Although it is important 

during emergency planning to consider a range of source terms to assess the costs associated with their

implementation, the PAGs are pre-determined for use in emergencies without regard to the magnitude or 

type of radiological release.

1.3.4 Changes in Scenarios since the Issuance of the 1992 PAG Manual

EPA’s 1992 PAG Manual provided emergency management officials at the federal, state, tribal and local

levels with the technical basis to plan responses to radiological emergencies. The 1992 PAG Manual was

written to accommodate the worst release scenario deemed likely at the time – a major accident at a 

commercial NPP that would result in a significant off-site release of radioactive material. (“Site” and “offsite” in this Manual refer to locations where the radiological incident occurs and are not limited to 

facility-type incidents.) Certain characteristics typify NPPs, including: fixed locations at which an 

accident might occur; a known suite of radionuclides on site, the dose from which is dominated by shortlived radioisotopes; tight regulatory controls and requirements; skilled operational personnel who plan for 
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and exercise emergency responses; state and local involvement in emergency planning; well-developed 

and zoned emergency evacuation plans and routes; and advance notice (generally hours to days) from 

deteriorating plant conditions prior to accidental release of radioactive material into the environment. 

Therefore, the 1992 PAG Manual provided decision-makers with radiation dose-based PAG values for 

various exposure pathways (such as whole body, skin dose, and food ingestion) and associated protective 

actions that were adapted to the mix of radionuclides and operational environments associated with

commercial NPPs.

In late 1991, EPA conducted a symposium titled “Implementing Protective Actions for Radiological 

Incidents at Other Than Nuclear Power Reactors,” to evaluate PAGs for incidents other than accidents at 

NPPs and concluded that the PAGs could be applied to all radiological incidents (EPA 1992a). Since

then, new radiological and nuclear scenarios involving terrorist use of radioactive materials have gained

status in radiological emergency response planning. 

In 2008, DHS published “Planning Guidance for Protection and Recovery Following Radiological 

Dispersal Device (RDD) and Improvised Nuclear Device (IND) Incidents” (DHS 2008). An RDD is a 

device or mechanism that is intended to spread radioactive material from the detonation of conventional 

explosives or other means. An IND is a crude, yield-producing nuclear weapon fabricated from diverted

fissile material. Incidents like these may occur anywhere with little or no warning. The DHS guidance, 

developed cooperatively with EPA, DOE, DoD, DOL, HHS, Department of Commerce, and the NRC, 

affirms the applicability of existing 1992 EPA PAGs to terrorist acts, while acknowledging that the PAGs 

were inadequate for early response planning needs specific to an IND. To address this gap, “Planning 

Guidance for Response to a Nuclear Detonation” (NSS 2010) was subsequently published. 

This Manual substantively incorporates late phase cleanup guidance provided in the 2008 DHS document 

and refers readers to additional planning resources.

1.3.5 Key Changes to PAGs in this Updated Manual

This updated Manual applies PAGs and protective actions to an expanded range of sources of potential 

radiological releases, including commercial nuclear power facilities, uranium fuel cycle facilities, nuclear

weapons facilities, transportation accidents, radiopharmaceutical manufacturers and users, space vehicle 

launch and reentry, RDDs and INDs.

Dosimetry for all the PAGs was updated using the International Commission on Radiological Protection

(ICRP) Publication 60 series (ICRP 1991). The PAGs in this Manual may be implemented using 

calculated, measurable values contained in the Federal Radiological Monitoring and Assessment Center 

(FRMAC) Assessment Manuals,1 though using other incident-specific dose assessment methodologies is

encouraged, where appropriate. EPA anticipates that radiological assessment methods will be periodically 

updated as improved models and methods become available. Therefore, readers are encouraged to review 

the current version of the FRMAC Assessment Manual to understand the most current, default 

radiological assessment methods. For simplicity, specific organ dose thresholds for evacuation and 

sheltering were removed from the Manual. 

While most of the PAGs and corresponding protective actions from the 1992 PAG Manual remain

unchanged, this Manual incorporates several related guidance documents published subsequent to the 

1992 guidance, including FDA’s 1998 update of the PAGs for interdiction of food. This Manual also

incorporates FDA’s 2001 guidance to lower the PAG for administration of potassium iodide (KI ) to 5 rem

(50 millisieverts (mSv)) projected child thyroid dose. In addition to guidance on KI, this updated Manual 

includes references to other FDA-approved medical countermeasures potentially useful in mitigating 

effects associated with radiation emergencies. Such countermeasures include the radioisotope 

 

1 See FRMAC Assessment Manuals at http://nnss.gov/pages/programs/FRMAC/FRMAC_DocumentsManuals.html. 
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decorporation agents calcium-DTPA, zinc-DTPA, and Prussian blue, and the leukocyte growth factors 

filgrastim and pegfilgrastim. This update removes the intermediate phase relocation PAG of 5 rem (50 

mSv) over 50 years to avoid confusion with long-term cleanup. 

Recommended limits of exposure for emergency workers also remain unchanged from the 1992 PAG 

Manual. The emergency worker guidelines in this manual are consistent with federal and state

regulations. To further develop radiological emergency plans, brief planning guides have been provided 

for reentry to relocation areas, a cleanup planning process, and considerations for radioactive waste

disposal. In this Manual, the term reentry is used for emergency workers and members of the public going

into relocation areas temporarily, under controlled conditions. Table 1-1 (see below) presents PAGs with 

their principal associated protective actions and also presents related guidelines, and planning guidance. 

1.4 RADIOLOGICAL INCIDENT PHASES AND APPLICABILITY OF 

PROTECTIVE ACTIONS

Emergency planners divide responses to radiological incidents into three phases of activity— 

 Early Phase — The beginning of a radiological incident for which immediate decisions for 

effective use of protective actions are required and must therefore be based primarily on the status 

of the radiological incident and the prognosis for worsening conditions. When available,

predictions of radiological conditions in the environment based on the condition of the source or 

actual environmental measurements may be used. Protective actions based on the PAGs may be 

preceded by precautionary actions during the period. This phase may last from hours to days. 

 Intermediate Phase — The period beginning after the source and releases have been brought

under control (has not necessarily stopped but is no longer growing) and reliable environmental 

measurements are available for use as a basis for decisions on protective actions and extending 

until these additional protective actions are no longer needed. This phase may overlap the early

phase and late phase and may last from weeks to months. 

 Late Phase — The period beginning when recovery actions designed to reduce radiation levels in

the environment to acceptable levels are commenced and ending when all recovery actions have 

been completed. This phase may extend from months to years. A PAG level, or dose to avoid, is

not appropriate for long-term cleanup. 

The phases cannot be represented by precise periods of time – and may even overlap – but to view them

in terms of activities, rather than time spans, can provide a useful framework for emergency response 

planning. 

In the early phase, sheltering-in-place and evacuation are the principal protective actions. These actions 

are meant to avoid inhalation of gases or particulates in an atmospheric plume and to minimize external 

radiation exposures. Administration of prophylactic drugs may be employed depending on the specific 

radionuclides released; in particular, KI, also called “stable iodine,” may be administered as a 

supplementary protective action in incidents involving the release of significant quantities of radioactive 

iodine, such as NPP incidents. Some protective actions may begin prior to the release of radioactive 

material when there is advance notice.

Planning considerations for reentry and relocation are suggested and basic planning guidance for late 

phase cleanup is provided in Chapters 4 and 5. 
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Table 1-1. Summary Table for PAGs, Guidelines, and Planning Guidance for Radiological Incidentsa

Phase Protective Action Recommendation PAG, Guideline, or Planning Guidance

Early Phase

Sheltering-in-place or evacuation of the

publicb

PAG: 1 to 5 rem (10 to 50 mSv) projected dose over 

four daysc

Supplementary administration of

prophylactic drugs – KId

PAG: 5 rem (50 mSv) projected child thyroid dosee

from exposure to radioactive iodine

Limit emergency worker exposure (total 

dose incurred over entire response)

Guideline: 5 rem (50 mSv)/year (or greater under

exceptional circumstances)f

Intermediate 

Phase

Relocation of the public PAG: > 2 rem (20 mSv) projected dosec in the first

year

0.5 rem (5 mSv)/year projected dose in the second

and subsequent years

Apply simple dose reduction techniques Guideline: < 2 rem (20 mSv) projected dosec in the 

first year

Food interdictiong PAG: 0.5 rem (5 mSv)/year projected whole body

dose, or 5 rem (50 mSv)/year to any individual organ

or tissue, whichever is limiting

Drinking water PAG: 100 mrem (1 mSv or 0.1 rem) projected dose, 

for one year, to the most sensitive populations (e.g., 

infants, children, pregnant women and nursing 

women); 

500 mrem (5 mSv or 0.5 rem) projected dose, for one 

year, to the general population

Limit emergency worker exposure (total 

dose incurred over entire response)

Guideline: 5 rem (50 mSv)/year

Reentry Guideline: Operational Guidelinesh (stay times and

concentrations) for specific reentry activities (see 

Section 4.5) 

Late Phase

Cleanupi Planning Guidance: Brief description of planning

process (see Section 5.1) 

Waste Disposal Planning Guidance: Brief description of planning

process (see Section 5.2) 

a This guidance does not address or impact site cleanups occurring under other statutory authorities such as the United States 

Environmental Protection Agency’s (EPA) Superfund program, the Nuclear Regulatory Commission’s (NRC) 

decommissioning program, or other federal or state cleanup programs.

b Should begin at 1 rem (10 mSv); take whichever action (or combination of actions) that results in the lowest exposure for the 

majority of the population. Sheltering may begin at lower levels if advantageous.

c Projected dose is the sum of the effective dose from external radiation exposure (e.g., groundshine and plume submersion)

and the committed effective dose from inhaled radioactive material.

Note: Footnotes continued on next page
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Table 1-1. Summary Table for PAGs, Guidelines, and Planning Guidance for Radiological Incidents

(continued) 

d Provides thyroid protection from radioactive iodines only. See the complete 2001 FDA guidance, “Potassium Iodide as a 

Thyroid Blocking Agent in Radiation Emergencies” (FDA 2001). Further information is also available in “KI in Radiation 

Emergencies – Questions and Answers” (FDA 2002), and “Frequently Asked Questions on Potassium Iodide (KI).” 

` For information on radiological prophylactics and treatment other than KI, refer to 

http://www.fda.gov/Drugs/EmergencyPreparedness/BioterrorismandDrugPreparedness/ucm063807.htm, 

https://www.emergency.cdc.gov/radiation, and www.orau.gov/reacts. 

e Thyroid dose. See Section 1.4.2. The one-year old age group is expected to receive the largest dose to the thyroid from 

exposure to radioactive iodine. Therefore, it is recommended that the one-year old age group is considered when considering 

the administration of prophylactic KI.

f When radiation control options are not available, or, due to the magnitude of the incident, are not sufficient, doses to

emergency workers above 5 rem (50 mSv) may be unavoidable and are generally approved by competent authority. For 

further discussion see Chapter 3, Section 3.1.2. Each emergency worker should be fully informed of the risks of exposure 

they may experience and trained, to the extent feasible, on actions to be taken. Each emergency worker should make an 

informed decision as to how much radiation risk they are willing to accept to save lives.

g For more information on food and animal feeds guidance, the complete FDA guidance (FDA 1998) may be found at 

http://www.fda.gov/downloads/MedicalDevices/DeviceRegulationandGuidance/GuidanceDocuments/UCM094513.pdf. 

h For extensive technical and practical implementation information please see “Preliminary Report on Operational Guidelines 

Developed for Use in Emergency Preparedness and Response to a Radiological Dispersal Device Incident” (DOE 2009).

i This cleanup process does not rely on and does not affect any authority, including the Comprehensive Environmental 

Response, Compensation and Liability Act (CERCLA), 42 U.S.C. 9601 et seq. and the National Contingency Plan (NCP), 40 

CFR Part 300. This document expresses no view as to the availability of legal authority to implement this process in any 

particular situation.

1.4.1 Implementation of Protective Action Guides and Protective Actions

Immediately upon becoming aware that an incident is about to occur or has occurred that may result in

exposure of the population, responsible authorities should make a preliminary evaluation to determine the 

nature and potential magnitude of the incident. This evaluation should determine whether conditions 

indicate a significant possibility of a major release and, to the extent feasible, determine potential 

exposure pathways, populations at risk, and projected doses. The incident evaluation and 

recommendations should then be presented to emergency response authorities for consideration and 

implementation.

During the early phase, the sequence of events includes evaluation of conditions at the location of the 

incident, notification of responsible authorities, prediction or evaluation of potential consequences to the 

general public, recommendations for action and implementation of actions for the protection of the public. 

In the intermediate phase, dose projections used to support decisions about protective actions may be 

based on measurements of actual levels of environmental radioactivity and refined dose models, reducing 

the need for worst-case scenarios. When conditions warrant relocation of populations, the collection of

extensive radiological and cost-of-cleanup data will be necessary to form the decision basis for cleanup

and recovery of the affected areas.

1.4.2 Early Phase Protective Action Guides and Protective Actions 

In the early phase, there may be little or no data on actual releases to the environment and responders may 

have to rely on crude estimates of airborne releases. Decision time frames are short and preparation is 

critical to make prudent decisions when data are lacking or insufficient.

The principal protective actions for the early phase are evacuation and sheltering-in-place. These

protective actions would be taken if whole body doses are projected to exceed 1 to 5 rem (10 to 50 mSv) 
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over four days. The decision to evacuate must weigh the anticipated radiation dose to individuals in the 

affected population against the feasibility of evacuating within a determined time frame and the risks 

associated with the evacuation itself. For example, evacuating a population of 50,000 carries with it a 

statistical risk of injury or death from transportation hazards or increased exposure. Evacuation also takes 

time. In the case of an accident at an NPP, there will likely be time for an orderly and relatively safe

evacuation. In the case of a fire or explosion of an RDD in an urban area, evacuating a large group of

people could leave them exposed to the plume and actually increase radiation dose. Sheltering-in-place 

may be warranted in situations where evacuation poses a greater risk of exposure or physical harm.

In addition, there are actions that are advisable, but not associated with a numerical PAG. For example, 

individuals should be instructed to cover airways (nose and mouth) with available filtering material when

airborne radionuclides may be present. Decontamination is another protective action that may be utilized 

in the early phase and may include washing of contaminated individuals, removing contaminated clothing, 

and decontaminating surfaces of critical areas and objects. Further, in areas where airborne radioactivity

is present but PAGs are not exceeded, officials can consider asking people to stay indoors to the extent 

practicable. In such cases, individuals are not prevented from carrying out necessary tasks (e.g., seeking

medical care, purchasing food). Similar to actions used in major cities on high pollution days, these 

measures can be effective to reduce radiation doses when prolonged releases occur, as was the case for 

the Fukushima accident in Japan. 

In cases where significant quantities of radioiodine may have been released, administration of the 

radioprotectant KI should be considered as a supplementary protective action if the projected child thyroid 

dose exceeds 5 rem (50 mSv). This PAG is lower than the 1992 guidance. The lower dose, which FDA 

adopted in 2001, is for protection of children based on early studies of Chernobyl exposure data. Of the 

age groups in ICRP 60 series (ICRP 1991), the one-year old age group is expected to be limiting for 

thyroid dose projections. Therefore, it is recommended that the one-year old age group thyroid dose be 

projected when considering the administration of prophylactic KI. 

The choice of protective action will be based on the status of the incident site and the prognosis for 

worsening conditions. In the early phase, precautionary actions based on worst-case scenarios may be 

used before implementation of protective actions based on PAGs. For example, in the case of RDD

detonation, governments may instruct affected populations to shelter-in-place as a precautionary action 

while radiation levels are being measured to determine appropriate PAG-based protective actions.

Officials should plan for rapid broadcast and dissemination of protective action orders to the public. 

When available, predictions of radiological conditions in the environment based on an estimate of the 

source or actual environmental measurements may be used. Nuclear facilities, for example, have 

continuous, real-time radioactive effluent monitoring capabilities to monitor radioactive material released 

to the environment and may have a network of off-site measurement stations.

1.4.3 Intermediate Phase Protective Action Guides and Protective Actions

Intermediate phase activities are intended to reduce or avoid dose to the public, to control worker

exposures, to control the spread of radioactive contamination, and to prepare for late phase cleanup

operations. During the intermediate phase, relocation is the principal protective action against whole body 

external exposure from deposited radioactive material and internal exposure from inhalation of

radioactive particulates. People may need to be relocated for weeks or months.

It is necessary to distinguish between evacuation and relocation. Evacuation is the urgent removal of 

people from an area to avoid or reduce high-level, short-term exposure from the plume or deposited 

radioactivity. Relocation is the removal or continued exclusion of people (households) from contaminated 

areas to avoid chronic radiation exposure. Site-specific conditions may allow some groups evacuated in 
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an emergency to return, while others may have to relocate. In other cases, some groups that were not 

previously evacuated may have to relocate (see Section 4.2.3 for more details).

Intermediate phase PAGs are based on doses projected in the first several years. The PAG for relocation 

of the public is 2 rem (20 mSv) in the first year and 0.5 rem (5 mSv) in any subsequent year. (Note:

Relocation PAGs are treated separately from food and water ingestion. That is, projection of intermediate 

phase doses should not include these ingestion pathways. In some instances, however, where withdrawal 

of food and/or water from use would, in itself, create a health risk, relocation may be an appropriate 

alternative protective action. In this case, the ingestion dose should be considered along with the projected 

dose from deposited radionuclides via other pathways, for decisions on relocation.) When projected doses 

are less than the relocation PAG of 2 rem (20 mSv) in the first year, focused environmental 

decontamination and cleanup may be able to reduce doses to populations that are not relocated. 

Decontamination and focused cleanup techniques can range from simple actions such as the scrubbing 

and flushing of surfaces with uncontaminated water to the removal and disposal of soil and contaminated 

debris. 

Keeping projected doses below the 0.5 rem (5 mSv) PAG – in the second and subsequent years – may be 

achieved through the decay of shorter half-life radioisotopes (as in the case of an accident at an NPP), 

through environmental decontamination and cleanup efforts or through other means of controlling public 

exposures, such as limiting access to certain areas. Information on food and animal feeds protective action 

guidance is contained in FDA’s “Accidental Radioactive Contamination of Human Food and Animal

Feeds: Recommendations for State and Local Agencies” (FDA 1998). Workers and members of the 

public may be allowed to re-enter a relocation area for tasks related to critical infrastructure and key 

resources, to care for animals and to assess the condition of closed zones. By the intermediate phase when 

relocation has been implemented, it is likely that no more lifesaving missions would be needed. Some 

critical infrastructure/key resources or lifesaving missions may arise in later phases, however, for which

the emergency worker guides in Chapter 3, Section 3.1.2 would apply. Reoccupancy may be allowed 

under dose constraints acceptable to the community. In this Manual, the term reoccupancy refers to 

households and communities moving back into relocation areas where the cleanup process is still

ongoing, based on radiation levels acceptable to those communities.

As data are obtained from monitoring, officials should benchmark observed concentrations against default 

derived response levels (DRLs) in FRMAC Assessment Manual, Volume 1, Appendix C,2

 or incidentspecific DRLs that account for nuclide mix present, release patterns, and decay. Officials would then be 

in a position to make informed decisions about the need to implement protective actions. 

During the intermediate phase, government officials may convene to discuss late phase cleanup and site

restoration strategies. All actions taken during the early and intermediate phases should be considered 

with respect to the impact they may have on late phase remediation, such as avoiding the use of fixatives

that could hinder surface decontamination at a later date.

1.4.4 Late Phase

The late phase, as used in this Manual, is the period beginning when cleanup and recovery actions have 

begun and ending when all recovery actions have been completed. This phase may extend from months to 

years.

The late phase cleanup process, as described in this guidance, begins sometime after the commencement 

of the intermediate phase and proceeds independently of intermediate phase protective action activities. 

The transition is characterized by a change in approach, from strategies predominantly driven by urgency, 

to strategies aimed at both reducing longer-term exposures and improving living conditions. The late 

 

2 See FRMAC Assessment Manuals at http://nnss.gov/pages/programs/FRMAC/FRMAC_DocumentsManuals.html. 
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phase involves the final cleanup of areas and property at which contamination directly attributable to the 

incident is present. It is in the late phase that final cleanup decisions are made and final recovery efforts 

following a radiological incident are implemented.

During the late phase of a radiological incident, decision-makers will have more time and information 

allowing for better data collection, more complex modeling, stakeholder involvement, and options 

analysis. Community members will influence decisions such as if and when to allow people to return 

home to contaminated areas. There will be populations, who were not relocated or evacuated, living in 

contaminated areas where efforts to reduce exposures will be ongoing. Implicit in these decisions is the 

ability to balance health protection with the desire of the community to resume normal life.

Radiation protection considerations must be addressed in concert with health, environmental, economic, 

social, psychological, cultural, ethical, political and other considerations. Many federal, state, and local 

agencies have important roles to play. It is recognized that experience from existing programs, such as the

EPA’s Superfund program, the NRC’s process for decommissioning and decontamination to terminate a 

nuclear facility license, and other national recommendations may be useful for designing cleanup and 

recovery efforts that could apply to a radiological incident. The cleanup process described in Chapter 5, 

however, does not rely on and does not affect any authority, including the Comprehensive Environmental 

Response, Compensation and Liability Act (CERCLA), 42 U.S.C. 9601 et seq., and the National

Contingency Plan (NCP), 40 CFR Part 300. For information on roles, responsibilities and authorities 

during emergency response and recovery please refer to the National Response Framework: 

http://www.fema.gov/national-response-framework (FEMA 2008a) and specifically for radiological

incidents, the Nuclear Radiological Incident Annex: 

http://www.fema.gov/pdf/about/divisions/thd/IncidentNucRad.pdf (FEMA 2008b).

The late phase or cleanup process described in Chapter 5 consists of multiple steps, namely: 

1) characterization and stabilization; 2) development of goals and strategies; and 3) implementation and 

reoccupancy. Meaningful stakeholder involvement should be integrated throughout the process.

While radioactive waste handling and disposal will be an ongoing endeavor during the entire emergency

response, brief planning guidance is provided in Chapter 5, the late phase. This guidance addresses two 

types of disposal locations – those that may be identified and regulated by state and local officials, and 

locations owned by the federal government – and lists criteria for evaluating their suitability for disposal,

as well as actions that can be taken to facilitate their use. Legal and other considerations are also 

discussed. This guidance assumes that on-site disposal at a location affected by the incident, where 

appropriate, will be one of the locations of choice. Though recommended as the first consideration for 

discussion post-accident or attack, this guidance assumes that existing non-federal radioactive waste

disposal capacity that is available to impacted states and their regions is overwhelmed or otherwise 

eliminated from consideration, which drives the need to identify other disposal options or develop new 

disposal capacity. 

1.4.5 Precaution built into the PAGs

As noted above, a PAG is defined for purposes of this document as the projected dose to an individual 

from a release of radioactive material at which a specific protective action to reduce or avoid that dose is 

recommended. PAGs do not establish an acceptable level of risk for normal, non-emergency conditions, 

nor do they represent the boundary between safe and unsafe conditions. 

As described in Sections 2.5 and 4.7, a risk-benefit balancing process, designed to prevent acute effects, 

balance protection with other important factors and ensure that actions result in more benefit than harm, 

and reduce risk of chronic effects was used to derive the PAGs. Such a risk-benefit balancing incorporates 

a level of precaution into the PAGs.
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Assumptions made to generate default parameters and derived response levels in the FRMAC Assessment 

Manual, Volume 1, Appendix C,3 include some worst-case assumptions to ensure PAGs are appropriate 

emergency guides for all members of the public, including sensitive subpopulations such as young 

children. For example, early phase derived levels are based on the assumption that a person is outdoors 24 

hours a day for four days being exposed to the plume. Intermediate phase derived levels also 

conservatively do not account for shielding provided by being indoors part of each day of the projection 

year. People are assumed to remain in the contaminated area during the entire time (not going to work or 

school in an uncontaminated area, for instance.) Another example of conservatism is assuming that 

radionuclides are in the chemical and physical form that yields the highest dose (e.g., the particle size is 

one micrometer mean aerodynamic diameter). These conservatisms allow dose assessors to project whole 

body doses or total effective dose (TED) to a reference person, for simplicity, and then decision-makers 

can make protective action decisions that apply to entire communities including children, adults and the 

elderly. 

Radiological assessors are encouraged to utilize realistic inputs when site- or source-specific information 

is available to limit the amount of conservatism built into the calculations. For example, if the 

radionuclide does not exist in a chemical or physical form or particle size that yields the highest dose, 

then assessors should use appropriate inputs to avoid overly conservative dose estimates that may lead to 

unnecessary protective actions.

Other incident-specific factors that should be considered include: the nuclide mix released; the rate and 

timing of dispersion/deposition; the rate of natural attenuation in specific media; and realistic intake 

parameters, for example.

Certain guidelines that lend themselves to different PAGs for different subpopulations are the PAGs for 

KI (potassium iodide), food, and water. These guidelines provide age-specific recommendations because 

of the radiosensitivity of the thyroid and young children with respect to ingestion and inhalation doses in 

particular. Taking protective actions like use of KI, avoiding certain foods, or using alternative sources of 

drinking water can be relatively simple to implement by the parents of younger children. Clear public 

messages can convey which age groups should take which action, unlike how an evacuation or relocation 

order should apply to entire households or neighborhoods. 

EPA evaluated the dose consequences to several age groups across many radiological scenarios and, for 

the early phase including the plume, child whole body doses are typically no more than 15 percent higher 

than adult whole body doses. That margin is well within the conservatism discussed above, so that 

separate PAGs or projections need not be required. Therefore, basing evacuation, shelter-in-place, and 

relocation dose projections on an adult is appropriate for all age groups. Sensitive age groups should be 

evaluated separately for KI, food, and water decisions. Keeping calculations and decision-making simple 

in the face of a disaster can enable timely actions to protect communities.

 

3 See FRMAC Assessment Manuals at http://nnss.gov/pages/programs/FRMAC/FRMAC_DocumentsManuals.html. 
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KEY POINTS IN CHAPTER 1 – OVERVIEW

 A PAG is the projected dose to an individual from a release of radioactive material at which a 

specific protective action to reduce or avoid that dose is recommended. PAGs are guides to help 

officials select protective actions under emergency conditions when exposures would occur over 

relatively short time periods.

 EPA provides the PAG Manual to assist public officials with their radiological emergency

response planning activities. The PAG Manual is a guidance document, not a legally binding 

regulation and does not affect or supersede any environmental laws. The PAG recommendations

do not represent the boundary between safe and unsafe conditions.

 PAGs may be implemented to protect the public in a wide variety of radiological emergencies,

including terrorist incidents and accidents involving nuclear power plants (NPPs), transportation, 

and the space program.

 PAGs are appropriate for implementation in the early and intermediate phases of radiological 

incidents. The early phase—lasting hours to days—is the period beginning at the projected (or 

actual) initiation of a release when immediate decisions for effective use of protective actions are 

required and must therefore be based primarily on the status of the release and the prognosis for 

worsening conditions. Little environmental data may be available in the early phase. The 

intermediate phase—lasting weeks to months—is the period beginning after the source and 

releases have been brought under control and environmental measurements are available for use as

a basis for decisions on protective actions.

 Reentry and reoccupancy decisions will be made using incident-specific circumstances and the

Operational Guidelines (DOE 2009). 

 Cleanup and waste disposal decisions may be informed by planning guidance provided in

Chapter 5. 

 What’s new in this updated Manual— 

o The PAGs in this Manual are implemented using the calculations and methods in the FRMAC 

Assessment Manual. Dosimetry in that Manual has been updated using the ICRP Publication 

60 series (ICRP 1991). 

o EPA adopts the FDA guidance issued in 2001 that recommended lowering the projected 

thyroid dose at which the administration of KI is warranted as a supplementary protective 

action. 

o EPA adopts the 1998 FDA food PAGs. 

o Planning guidance has been provided for reentry, late phase cleanup, and waste disposal.
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CHAPTER 2. EARLY PHASE PROTECTIVE ACTION GUIDES

Decisions regarding protective actions for workers and the public during radiological incidents are risk

management decisions and the recommendations in this Manual are provided in that context. Rapid action 

may be required to protect members of the public in the event of an incident involving a large release of 

radioactive materials into the environment. In all cases, all practical and reasonable means should be used 

to reduce or eliminate exposures.

This chapter presents PAGs for use in the early phase of a radiological incident. A PAG is the projected 

dose to an individual from a release of radioactive material at which a specific protective action should be 

taken to reduce or avoid that dose. The early phase begins at the actual or projected start of a release—

most likely before ambient environmental and radiological data become available for quantitative riskbased actions. The exact duration of the early phase depends upon site conditions, but one should plan to 

project doses for four days.

Many radiological emergency scenarios would involve airborne releases, so this chapter provides 

guidance for estimating projected doses from exposure to an airborne plume of radioactive material and 

for implementing protective actions. Dose calculations for implementing the PAGs are made using the 

dose parameter (DP) and derived response level (DRL) methods referenced in the FRMAC Assessment

Manuals.4 Note that FRMAC refers to dose parameters in emergency response dose assessment methods 

to avoid confusion with dose coefficients and dose conversion factors published for radiation protection in 

general. Other calculation methods to implement PAGs may be appropriate. 

2.1 EXPOSURE PATHWAYS DURING THE EARLY PHASE

To make decisions about rapid actions to protect the public in a radiological emergency, it is important to 

understand exposure pathways from airborne releases. It may also be necessary to make estimates 

about exposure patterns to make initial dose projections and determine whether protective actions are 

needed, before environmental monitoring is complete. 

2.1.1 Exposure Pathways from Airborne Releases

During the early phase of an incident, there are three main exposure pathways from airborne releases— 

 Direct exposure to radioactive materials in an atmospheric plume. The contents of such a plume

will depend on the source of radiation involved and conditions of the incident. For example, in the 

case of an incident at an NPP, the plume may contain radioactive noble gases, radioiodines, and 

radioactive particulate materials. Many of these materials emit gamma radiation that can expose 

people in the vicinity of the passing plume.

 Inhalation of radionuclides from immersion in a radioactive atmospheric plume and inhalation of 

ground-deposited radionuclides that are resuspended into a breathing zone. Inhaled radioactive 

particulates, depending on their solubility in body fluids, may remain in the lungs or move via the

bloodstream to other organs, prior to elimination from the body. Some radionuclides become 

concentrated in a single body organ, with only small amounts going to other organs. For example, 

a significant fraction of inhaled radioiodines will move through the bloodstream to the thyroid 

gland. 

 Deposition of radioiodine and particulates from a radioactive plume. Deposited materials can 

continue to emit “groundshine” (e.g., beta and gamma radiation) after the plume has passed 

causing continued exposure to skin and internal body organs. 

 

4 See FRMAC Assessment Manuals at http://nnss.gov/pages/programs/FRMAC/FRMAC_DocumentsManuals.html. 
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A plume may deposit materials on surfaces, posing a risk of longer-term exposures via ingestion, direct 

external exposure, and inhalation pathways. If the release contains large quantities of radioactive iodines 

or particulates, the resulting long-term exposure to this “groundshine” can be more significant than 

external exposure from the passing plume if the exposure time to the ground contamination is long in 

comparison to the plume passage time. The early phase PAGs assume four days of exposure to ground 

contamination to address this possibility. Doses from groundshine can be readily measured by field 

monitoring teams dispatched at the onset of a significant radioactive release. Holding a detector probe 

horizontal and three feet (approximately one meter) above the contaminated surface provides a direct

measurement that can be used to approximate groundshine dose. Such assessments can confirm dose 

projections based upon effluent release data and the adequacy of protective actions in the early phase. 

More detailed analyses (e.g., isotopic) would be needed to support long-term dose projections in the 

intermediate phase. Doses for groundshine can be calculated during the intermediate phase (see Chapter

4). Exposure pathways that contribute less than 10 percent to the total dose incurred need not be 

considered during the early phase.

2.1.2 Establishment of Exposure Patterns

It is unlikely that sufficient environmental data will be available for accurate dose projections during and 

immediately following the early response to a radiological incident. Dose projections are needed to 

determine whether protective actions should be implemented in additional areas during the early phase. 

For dose projections in the early phase there are two sources of data: current data from initial 

environmental measurements or estimates of the source term and estimated data using modeled or 

historical atmospheric transport data. Source term measurements, or exposure rates or concentrations 

measured in the plume at a few selected locations, may be used to estimate the extent of the exposed area 

in a variety of ways, depending on the types of data and computation methods available. The most 

accurate method of projecting doses is through the use of an atmospheric diffusion and transport model 

that has been verified for use at the site in question or for similar site conditions. A variety of computer 

software packages can be used to estimate dose in real time, or to extrapolate a series of previouslyprepared isopleths for unit releases under various meteorological conditions. The latter can be adjusted for 

the estimated source magnitude or environmental measurements at a few locations during the incident. If 

the model projections have some semblance of consistency with environmental measurements,

extrapolation to other distances and areas can be made with greater confidence. If projections using a 

sophisticated site-specific model are not available, a simple but crude method is to measure the plume 

centerline exposure rate5 at ground level measured at approximately three feet (one meter) height at a 

known distance downwind from the release point and then to calculate exposure rates at other downwind 

locations by assuming that the plume centerline exposure rate is a known function of the distance from the 

release point.

The following relationship can be used for this calculation:

D2 = D1 (R1/R2)

y

where D1 and D2 are exposure rates at the centerline of the plume at distances R1 and R2 from the release,

respectively and y is a constant that depends on atmospheric stability. For stability classes6 A and B, y = 

2; for stability classes C and D, y = 1.5; and for stability classes E and F, y = 1. Classes A and B 

(unstable) occur with light winds and strong sunlight and classes E and F (stable) with light winds at

 

5 The centerline exposure rate can be determined by traversing the plume at a point sufficiently far downwind that it has

stabilized (usually more than one mile from the release point) while taking continuous exposure rate measurements. 6 Pasquill stability classes categorize atmospheric turbulence into six stability classes named A, B, C, D, E and F, class A being the

most unstable or most turbulence and class F the most stable or least turbulence. Pasquill, F. 1961. The Estimation of the

Dispersion of Windborne Material. Meteorological Magazine. 90, 33-49. (Pasquill 1961)
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night. Classes C and D generally occur with winds stronger than about 10 mph. This method of 

extrapolation is risky because the measurements available at the reference distance may be 

unrepresentative, especially if the plume is aloft and has a looping behavior. In the case of an elevated 

plume, the ground level concentration increases with distance from the source and then decreases, 

whereas any high-energy gamma radiation from the overhead cloud continuously decreases with distance.

For these reasons, this method of extrapolation will perform best for surface releases or if the point of 

measurement for an elevated release is sufficiently distant (usually more than 1 mile or 1.61 kilometers 

(km)) from the point of release for the plume to have expanded to ground level. The accuracy of this 

method will be improved by the use of measurements from many locations averaged over time.

2.2 THE PROTECTIVE ACTION GUIDES AND PROTECTIVE ACTIONS FOR 

THE EARLY PHASE: EVACUATION, SHELTERING-IN-PLACE, AND 

ADMINISTRATION OF POTASSIUM IODIDE

The principal protective actions for the early phase are evacuation or sheltering-in-place. Evacuation is 

the urgent removal of people from an area to avoid or reduce high-level, short-term exposure from the 

plume or deposited radioactivity. Sheltering-in-place is the action of staying or going indoors 

immediately. The administration of KI (potassium iodide) to partially block the uptake of radioiodines by 

the thyroid is a supplemental protective action.

In addition, washing the body and changing clothing as soon as possible after significant exposure to a 

radioactive plume of any composition may be recommended protective actions. Changing of clothing is 

recommended to provide protection from particulate materials deposited on the clothing, as well as to 

minimize the spread of contamination. 

The PAGs and corresponding protective actions for response during the early phase of an incident are 

summarized in Table 2-1. Evacuation or sheltering-in-place will be justified when the projected dose to an 

individual is 1 rem (10 mSv) projected over four days. This conclusion is based primarily on EPA’s 

determination concerning acceptable levels of risk of health effects from radiation exposure in an 

emergency situation, while weighing costs and risks associated with any protective action. 

2.2.1 Thyroid Based Evacuation

This revised PAG Manual does not include a footnote from the 1992 PAG Manual early phase PAG table, 

which noted that “thyroid and skin may be 5 and 50 times larger, respectively.” That footnote effectively 

provided organ dose-based evacuation thresholds in addition to the whole body dose PAG range of 1 to 5 

rem (10 to 50 mSv). Because of the factors described above, these organ dose-based early phase PAGs 

are not necessary. 

Regarding sensitive subpopulations, child thyroid doses typically are about twice as high as adult thyroid 

doses. The former range recommended for thyroid dose-based evacuation (5 to 25 rem adult thyroid dose) 

is well covered by projections of whole body dose, with evacuation recommended at 1 to 5 rem (10 to 50 

mSv) adult TED. The conservatism built into the PAG levels when they were set results in an appropriate 

level of dose avoidance for the whole community, including all age groups, for an emergency. Planners 

should consider instituting public messaging templates in advance to address concerns the public may 

have about how protective the PAG recommendations are for all members of an impacted community. 

The PAG Manual is guidance, and intentionally not prescriptive. This set of recommendations does not 

preclude an emergency manager from setting local or state protective action guidelines for actions based 

on specific organ or age group dose levels, as warranted by specific needs of that community.
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Table 2-1. PAGs and Protective Actions for the Early Phase of a Radiological Incidenta

Protective Action

Recommendation

PAG Comments

Sheltering-in-place or evacuation of

the publicb

PAG: 1 to 5 rem (10 to 50 mSv) 

projected dose over four daysc

Evacuation (or, for some situations,

sheltering-in-place) should be

initiated when projected dose is 1 

rem (10 mSv).

Supplementary administration of

prophylactic drugs – KId

PAG: 5 rem (50 mSv) projected

child thyroid dosee from exposure to 

radioactive iodine

KI is most effective if taken prior to

exposure. May require approval of

state medical officials (or in

accordance with established

emergency plans).

a This guidance does not address or impact site cleanups occurring under other statutory authorities such as the United States 

Environmental Protection Agency’s (EPA) Superfund program, the Nuclear Regulatory Commission’s (NRC) 

decommissioning program, or other federal or state cleanup programs.

b Should begin at 1 rem (10 mSv) if advantageous except when practical or safety considerations warrant using 5 rem (50 mSv);

take whichever action (or combination of actions) that results in the lowest exposure for the majority of the population.

Sheltering may begin at lower levels if advantageous.

c Projected dose is the sum of the effective dose from external radiation exposure (e.g., groundshine and plume submersion)

and the committed effective dose from inhaled radioactive material.

d Provides thyroid protection from radioactive iodines only. See the complete 2001 FDA guidance, “Potassium Iodide as a 

Thyroid Blocking Agent in Radiation Emergencies” (FDA 2001). Further information is also available in “KI in Radiation 

Emergencies – Questions and Answers” (FDA 2002), and “Frequently Asked Questions on Potassium Iodide (KI).” 

` For information on radiological prophylactics and treatment other than KI, refer to 

http://www.fda.gov/Drugs/EmergencyPreparedness/BioterrorismandDrugPreparedness/ucm063807.htm,

https://www.emergency.cdc.gov/radiation, and www.orau.gov/reacts. 

e Thyroid dose. See Section 1.4.2. The one-year old age group is expected to receive the largest dose to the thyroid from 

exposure to radioactive iodine. Therefore, it is recommended that the one-year old age group is considered when considering 

the administration of prophylactic KI.

2.2.2 Evacuation vs. Sheltering-in-Place

Evacuation and sheltering-in-place provide different levels of dose reduction from the principal exposure 

pathways: direct gamma exposure and inhalation. Both sheltering-in-place and evacuation may be 

implemented during the same response in different areas or timeframes. Evacuation, if completed before 

plume arrival, can be 100 percent effective in avoiding radiation exposure. A decontamination station, 

with simple decontamination actions, may need to be collocated at shelters during the pre-evacuation 

period. This may reduce the spread of contamination and provide for greater protection during evacuation. 

Medical stations should also be collocated at shelters during the pre-evacuation period to ensure simple 

triage capabilities are met and to manage the distribution of prophylactic drugs. The effectiveness of 

evacuation will depend on many factors, such as how rapidly it can be implemented and the nature of the 

incident. For incidents where the principal source of dose is inhalation, evacuation could increase 

exposure if it is implemented during the passage of a short-term plume, because the air inside a vehicle 

rapidly equalizes with the outside air even when all of the windows and vents are closed (DOE 1990). 

When dose projections are at levels less than 1 rem (10 mSv) over the first four days, evacuation is not 

recommended due to the associated risks of moving large numbers of people. 

Sheltering-in-place is a low-cost, low-risk protective action that can provide protection with an efficiency 

ranging from zero to almost 100 percent, depending on the type of release, the type of shelter available, 

the duration of the plume passage, and climatic conditions. Because of these advantages, planners and 
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decision-makers may consider implementing sheltering-in-place when projected doses are below 1 rem 

(10 mSv) over the first four days. More guidance on the unique challenges posed by an IND can be found 

in the “Planning Guidance for Response to a Nuclear Detonation” (NSS 2010).7

Sheltering-in-place may be preferred for special populations (e.g., those who are not readily mobile) as a 

protective action at projected doses of up to 5 rem (50 mSv) over four days. When environmental, 

physical, or weather hazards impede evacuation, sheltering-in-place may be justified at projected doses up 

to 5 rem (50 mSv) for the general population (and up to 10 rem (100 mSv) for special populations). It is

also comparatively easy to communicate with populations that have sheltered-in-place. Dose projections 

use a four-day exposure duration, but sheltering-in-place duration is intentionally not specified. Incidentspecific decisions must be made to determine how long people should shelter-in-place.

Selection of evacuation or sheltering-in-place is far from an exact science, particularly in light of time

constraints that may prevent thorough analysis at the time of an incident. The selection process should be 

based on realistic or “best estimate” dose models and should take into account the unavoidable dose 

incurred during evacuation and potential failure scenarios for sheltering-in-place (e.g., leaking ventilation 

system).

Advance planning and exercises can facilitate the decision process. 

In a commercial NPP incident, early decisions should be based on

information from the response plans for the emergency planning 

zone (EPZ) and on actual conditions at the nuclear facility. For 

transportation accidents, RDDs, INDs and other incident scenarios 

for which EPZs are not practicable, best estimates of dose 

projections should be used for deciding on evacuation, shelteringin-place or a combination thereof.

The following is a summary of planning guidance for evacuation and sheltering-in-place— 

 Evacuation may be the only effective protective action close to the plume source.

 Evacuation will be most effective if it is completed before arrival of the plume. 

 Evacuation may increase exposure if carried out during the plume passage.

 Evacuation is appropriate for protection from groundshine in areas with high exposure rates from

deposited radioactive materials when suitable shelter is not available.

 Sheltering-in-place may be appropriate for areas not designated for immediate evacuation— 

o It may provide protection equal to or greater than evacuation for rapidly developing releases

(e.g., RDDs) if followed by evacuation.

o It positions the public to receive additional instructions.

o Since it may be implemented rapidly, sheltering-in-place may be the protective action of choice 

(followed with evacuation when feasible) if rapid evacuation is impeded by: 

• severe environmental conditions (e.g., severe weather or floods); 

• uncertainty about contamination levels along routes;

• health constraints (e.g., patients and workers in hospitals and nursing homes); 

• long mobilization times that may be associated with certain individuals, such as industrial 

and farm workers, or prisoners and guards; or

• physical constraints to evacuation (e.g., inadequate roads or blockage due to debris).

 If a major release of radioiodine or particulate materials occurs, inhalation dose may be a 

controlling criterion for protective actions— 

 

7 See: https://www.remm.nlm.gov/PlanningGuidanceNuclearDetonation.pdf.

Sheltering-in-place should be 

preferred to evacuation 

whenever it provides equal or 

greater protection. 

Sheltering-in-place followed 

by informed evacuation may be 

most protective.
Protective Action Guides and Planning Guidance for Radiological Incidents 18

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o Breathing air filtered through common household items (e.g., folded handkerchiefs or towels) 

may help reduce exposures. 

o After confirmation that the plume has passed, continued sheltering-in-place should be 

re-evaluated. People should remain sheltered until receiving official notice about leaving high 

exposure areas to avoid exposure to deposited radioactive material. Shelters may be opened to

vent any airborne radioactivity trapped inside.

Advance planning is essential to identify potential problems that may occur in an evacuation. An NRC 

case study cites the following aspects of planning as contributing to efficiency and effectiveness of 

evacuation (NRC 2005)— 

 High level of cooperation among agencies.

 Use of multiple forms of emergency communications.

 Community familiarity with alerting methods, the nature of the hazard, and evacuation procedures. 

 Community communication. 

 Well-trained emergency workers.

The NRC 2005 study included an evaluation of 50 incidents of public evacuation involving 1,000 or more 

people. The evacuations studied were initiated in response to natural disasters, technological hazards, and 

malevolent acts occurring between January 1, 1990 and June 30, 2003. The report indicated that public 

familiarity with alerting methods and door-to-door notification were statistically significant factors for the

efficiency of evacuation. The report also indicated that many communities are making improvements to 

response capabilities by modernizing communication systems, improving traffic flow, local education 

awareness, and developing interagency and cross-boundary coordination plans.

Large or small population groups can be evacuated effectively with minimal risk of injury or death. In the 

NRC report, only six of the 50 cases studied involved deaths from the hazard and of those six, only one 

involved death from the evacuation itself (NRC 2005). 

However, in 2005, not long after this report was published, the gulf coast of the United States was hit by a 

series of hurricanes that resulted in the evacuation of approximately 5 million people. During the 

evacuation that accompanied Hurricane Rita in Houston, Texas, at least 106 people were reported to have 

died as a direct result of the evacuation. It is estimated that at least two-thirds of the evacuees did not need 

to evacuate but did so because of poor communication, fear, and poor traffic management (NRC 2008). 

In a study of 230 mass evacuations in the U.S. (“Identification and Analysis of Factors Affecting 

Emergency Evacuations” NUREG/CR-6864 (NRC 2005)) only six cases involved deaths from the hazard 

itself, and of these six, only one case involved deaths during the evacuation itself. Only two cases 

involved injuries during the evacuation. Traffic issues, such as traffic congestion, were reported in 28 

percent of the evacuation cases studied. However, traffic accidents occurred in only 8 percent of the 

cases.

During the tsunami and nuclear disaster response in Japan in 2011, over 1,000 deaths occurred during 

evacuations, primarily among elderly hospital patients being moved from areas without power. 

Compounded disaster conditions including aftershocks, widespread power outages, and radiation releases 

led to prolonged transit along routes extended to avoid hazards. 

The emergency planning process for radiological incidents should include effective traffic management 

plans and communications plans, including pre-scripted messages, provisions for evacuation of special 

needs populations, such as children in schools and child care facilities, people in institutions, and people 

who have impaired mobility or lack personal transportation. 
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The degree of protection provided by structures is affected by factors such as attenuation of gamma 

radiation (shielding) by structural components (the mass of walls, ceilings, etc.) and outside/inside air 

exchange rates (see Figure 2-1). The use of large structures, such as shopping centers, schools, churches 

and commercial buildings, as collection points during evacuation mobilization will generally provide 

greater protection against gamma radiation than use of small structures. As with evacuation, delay in 

taking shelter during plume passage will result in higher exposure to radiation. 

Figure 2-1. Exposure Reduction from External Radiation from Nuclear Fallout as a function of 

Building Type and Location

The numbers represent dose reduction factors. A dose reduction factor of 10 indicates that a person in that area 

would receive 1/10th of the dose of a person in the open. A dose reduction factor of 200 indicates that a person 

in that area would receive 1/200th of the dose of a person out in the open.

Figure taken from “Planning Guidance for Response to a Nuclear Detonation,” Second Edition, National 

Security Staff, Interagency Policy Coordination Subcommittee for Preparedness and Response to Radiological 

and Nuclear Threats, June 2010, courtesy of Lawrence Livermore National Laboratory. The protection factors 

in this figure are specific to nuclear detonation fallout, but the variations in factors throughout typical buildings 

may be informative for other airborne radiological releases.
Protective Action Guides and Planning Guidance for Radiological Incidents 20

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2.2.3 Considerations for Potassium Iodide (KI)

FDA updated its guidance on the use of KI, also called “stable iodine,” as a thyroid blocking agent during 

radiological emergencies in 2001 (FDA 20018

 and FDA 20029). FDA based these dose recommendations 

on a review of the thyroid cancer data from the Chernobyl reactor accident of April 1986 and the 

experience of Poland in administering KI following the Chernobyl release (FDA 2001).

However, FDA understands that a KI administration program that sets different projected thyroid 

radioactive exposure thresholds for treatment of different population groups may be logistically 

impractical to implement during a radiological emergency. In such cases, FDA recommends that KI be 

administered to both children and adults at the lowest intervention threshold (i.e., >5 rem (50 mSv) 

predicted internal thyroid exposure in children (FDA 2002). The one-year old age group thyroid dose is 

expected to be limiting. Therefore, it is recommended that the one-year old age group thyroid dose is 

projected when considering the administration of prophylactic KI. See Table 2-2 for a summary of 

recommended doses of KI for different risk groups.

Regarding dosage of KI, FDA’s guidance adheres to principles of minimum effective dose and therefore 

recommends graded dosing according to age (and thus, in effect, body size). There is ample evidence that 

the recommended doses, as well as higher doses (e.g., up to 130 milligram), will effectively block 

thyroidal uptake of radioactive iodine if taken in advance of exposure. Furthermore, particularly among 

school-age children, higher milligram (mg) doses are extremely safe. However, FDA continues to 

emphasize attention to KI dosing in infants. Excess iodine intake can lead to transient iodine-induced 

hypothyroidism. Individuals who are intolerant of KI at protective doses, as well as neonates (i.e., a 

newborn infant, especially an infant less than one month old) and pregnant or lactating women, should be 

given priority with regard to other protective measures (i.e., sheltering, evacuation, and control of the 

food supply). In summary, if local emergency planners conclude that graded dosing is logistically 

impractical, FDA believes that for populations at risk for radioiodine exposure, the overall benefits of 

taking up to 130 mg of KI instead of the lower doses recommended for certain age groups far exceed the 

small risks of overdosing. However, where feasible, adherence to FDA guidance should be attempted 

when dosing infants (FDA 2002).

Note that KI is effective only against uptake of radioiodine, and is best taken prior to or just after 

exposure. The protective effect of a single dose of KI lasts approximately 24 hours. It should be 

administered as directed by state/local health officials until the risk of significant exposure to radioiodine 

(either by inhalation or ingestion) no longer exists (i.e., once the plume has passed). KI is a supplemental 

action, secondary to evacuation or sheltering. It should not be used as a substitute for evacuation or 

sheltering-in-place. Many communities do not use KI.

It should be noted that adults over 40 years of age need to take KI only in the case of a projected large 

internal radiation dose to the thyroid (>500 rem (5 Sv)) to prevent hypothyroidism which could lead to 

lifelong dependence on thyroid hormone replacement therapy. Thyroid irradiation in adults over 40 years 

of age is associated with an extremely low incidence of cancer (FDA 2001). 

Some people should not take KI. As a rule, individuals with known allergy to iodine or with pre-existing 

thyroid disease (e.g., Graves' disease, thyroid nodules, Hashimoto's thyroiditis) that might predispose 

 

8 Food and Drug Administration [FDA]. Notice: Guidance on Use of Potassium Iodide as a Thyroid Blocking Agent in Radiation 

Emergencies. Federal Register, 66, 64046: 2001. Published as “Guidance: Potassium Iodide as a Thyroid Blocking Agent in 

Radiation Emergencies,” FDA, Center for Drug Evaluation and Research. Procedural, December 2001. (FDA 2001) 9 Food and Drug Administration [FDA]. “Guidance for Industry: KI in Radiation Emergencies – Questions and Answers,” FDA, 

Center for Drug Evaluation and Research, Procedural, Revision 1, December 2002. (FDA 2002)
Protective Action Guides and Planning Guidance for Radiological Incidents 21

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them to adverse reactions should avoid KI. Allergies to iodine and to shellfish are not related. People 

allergic to shellfish need not worry about cross reactions with KI.

10 

Table 2-2. Threshold Thyroid Radioactive Exposures 

and Recommended Doses of KI for Different Risk Groups 

Predicted 

Thyroid gland 

exposure (cGy)

(1 cGy = 1 rem)

KI dose (mg) Number or 

fraction of 

130 mg 

tablets

Number or 

fraction of 

65 mg tablets 

Adults over 40 years ≥ 500

130 1 2 

Adults over 18 through 40 years ≥ 10

Pregnant or lactating women

≥ 5 

Adolescents, 12 through 18 yearsa

65 1/2 1 Children over 3 years through 12 years

Children over 1 month through 3 years 32 Use KI oral 

solutionb 1/2

Infants birth through 1 month 16 Use KI oral 

solutionb

Use KI oral 

solutionb

a Adolescents approaching adult size (> 150 pounds) should receive the full adult dose (130 mg). 

b Potassium iodide oral solution is supplied in 1 ounce (30 mL) bottles with a dropper marked for 1, 0.5, and 0.25 mL 

dosing. Each mL contains 65 mg potassium iodide. 

Source: FDA, “Guidance: Potassium Iodide as a Thyroid Blocking Agent in Radiation Emergencies” (December 2001): 

http://www.fda.gov/downloads/Drugs/GuidanceComplianceRegulatoryInformation/Guidances/UCM080542.pdf (FDA 

2001); and FDA, Frequently Asked Questions on Potassium Iodide (KI): 

http://www.fda.gov/Drugs/EmergencyPreparedness/BioterrorismandDrugPreparedness/ucm072265.htm (Last Updated: 

10/27/2014).

Pregnant women should be given KI for their own protection and for that of the fetus, as iodine (whether 

stable or radioactive) readily crosses the placenta. However, because of the risk of blocking fetal thyroid 

function with excess KI, repeat dosing with KI of pregnant women should be avoided. 

Lactating females should be administered KI for their own protection, as for other young adults, and 

potentially to reduce the radioiodine content of the breast milk, but not as a means to deliver KI to infants, 

who should be administered KI directly. As for direct administration of KI, stable iodine as a component

of breast milk may also pose a risk of hypothyroidism in nursing neonates. Therefore, repeat dosing with 

KI should be avoided in the lactating mother, except during continuing severe contamination. If repeat

dosing of the mother is necessary, the nursing neonate should be monitored. 

Once the plume has passed, protective actions such as evacuation and/or sheltering-in-place and food 

control measures to limit exposure to radioiodine should be implemented and the administration of KI 

should be suspended. Food control measures include providing the public with non-contaminated food 

supplies while awaiting the eventual radioactive decay of contaminated food. Consumption of 

contaminated food may be permitted on a case-by-case basis after surveying the foodstuffs and 

determining the level of contamination consistent with FDA food and animal feeds guidance. As a result 

 

10 More information is available at: http://www.foodallergy.org/allergens/shellfish-allergy and 

http://www.acaai.org/allergist/Resources/ask-allergist/Pages/Is_Shellfish_Allergy_Related_to_Iodine.aspx. 
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of radioactive decay, grain products and canned milk and vegetables from sources affected by radioactive 

fallout will not present a risk from radioiodine if they have been stored for weeks to months after 

production. 

An RDD is not likely to contain radioiodine, so administration of KI would not be necessary in such 

incidents. The administration of other prophylactic drugs should be evaluated on a case-by-case basis 

depending on the nature of the event and the radioisotopes involved. For more information on radiological

prophylactics and treatments, see: 

http://www.fda.gov/Drugs/EmergencyPreparedness/BioterrorismandDrugPreparedness. 

2.2.4 PAGs and Nuclear Facilities Emergency Planning Zones (EPZ)

Under NRC regulations, before a nuclear power reactor may be issued a license, the NRC must find that 

licensee, state and local emergency plans are adequate and that they can be implemented. For nuclear 

power reactors, there is a plume exposure EPZ within a 10 mile (16.1 km) radius of the plant and for a 

separate ingestion pathway EPZ within a 50 mile (80.5 km) radius. The sizes of these EPZs were 

developed by the NRC/EPA Task Force Report on Emergency Planning, NUREG-0396/EPA-520/1-78-

016 (NRC and EPA 1978) and are based, in part, on the numerical values of the PAGs for the plume

exposure and ingestion pathway EPZ. The licensee develops and maintains a detailed emergency plan for

its facility while state and local authorities within the EPZ develop and maintain detailed emergency

response plans for their respective jurisdictions. Guidance to these licensees, states and local agencies for 

developing these emergency response plans, including guidance on arrangements for implementing 

immediate protective actions is primarily contained in NUREG-0654/FEMA-REP-1 (NRC 1980)11 and 

supplemented with other guidance issued by NRC (for licensees) and FEMA (for off-site response 

organizations). 

Planning for incidents at other types of nuclear facilities should be developed using similar

considerations. Emergency preparedness requirements for non-power reactors (e.g., test and research 

facilities) are provided in 10 CFR Part 50 Appendix E with supporting guidance in NRC Regulatory 

Guide 2.6, “Emergency Planning for Research and Test Reactors” (NRC 1983). Emergency preparedness 

requirements for fuel cycle and materials facilities are provided in 10 CFR Parts 30, 40, and 70 with 

supporting guidance in NRC Regulatory Guide 3.67, “Standard Format and Content for Emergency Plans 

for Fuel Cycle and Materials Facilities” (NRC 2011). Because of the relatively limited number and 

diverse nature of these facilities, the size of the EPZ is determined, if needed, on a case-by-case basis for 

reactors with an authorized power level less than 250 megawatt thermal.

Within an EPZ, an area should be pre-designated for immediate response based on specified plant 

conditions prior to a release, or, given a release, prior to the availability of information on quantities of 

radioactive materials released. The shape of this area will depend on local topography, as well as political 

and other boundaries. Additional areas of the EPZ, particularly in the downwind direction, may require 

evacuation or sheltering-in-place, as determined by dose projections. The size of these areas will be based 

 

11 Immediate protective actions based on in-plant conditions and EPZs established by NUREG-0654/FEMA-REP-1 are not 

applicable to naval nuclear propulsion plants. The largest naval reactors are rated at less than one-fifth of a large U.S. commercial 

NPP. In addition, since reactor power is directly linked to propulsion requirements, naval nuclear propulsion plants typically 

operate at low power when the ship is close to shore where high speeds are not required and are normally shut down when in 

port. Prototype reactor plants are typically operated at low power because of their training mission. Therefore, less than about one 

percent of the radioactivity contained in a typical commercial NPP could be released from a naval nuclear propulsion plant, 

limiting the possible dose to the general public and the size of the area of potential concern. Therefore, there is no need for towns 

and cities to have special emergency response plans such as those required for cities near commercial NPPs. Instead, existing allhazards emergency response plans for responding to natural and industrial disasters are adequate to protect the public in areas 

around facilities where naval nuclear propulsion plants are located. However, the Naval Nuclear Propulsion Program (NNPP) 

maintains close relationships with civil authorities to ensure that communications and emergency responses are coordinated, if 

required. Periodic exercises are conducted with all States and Guam where U.S. nuclear-powered warships are homeported and 

NNPP facilities are located.
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on the potential magnitude of the release and on an angular spread determined by meteorological 

conditions and any other relevant factors.

The pre-designated areas for immediate protective action may be reserved for use only in the most severe

incidents and in cases when the facility operator cannot provide a quick estimate of projected dose based 

on actual releases. For lesser incidents, or if the facility operator is able to provide prompt off-site dose

projections, the area for immediate protective action may be specified at the time of the incident instead 

of using a pre-designated area. Regardless of the basis for the initial protective action, radiological 

assessments need to continue through the duration of the event, and if warranted, the initial protective 

actions extended into additional geographical areas.

Such prompt off-site dose projections may be possible when the facility operator can estimate the 

potential off-site dose based on information at the facility, using relationships developed during planning 

that relate abnormal plant conditions and meteorological conditions to potential off-site doses. After the 

release starts and the release rate is measurable, or when plant conditions or measurements can be used to 

estimate the characteristics and rate of the release, then these factors, along with atmospheric stability,

wind speed, and wind direction, can be used to estimate integrated concentrations of radioactive materials 

as a function of location downwind. Although such projections are useful for initiating protective 

action, the accuracy of these methods for estimating projected dose will be uncertain prior to confirmatory

field measurements because of unknown or uncertain factors affecting environmental pathways, 

inadequacies of computer modeling, and uncertainty in the data for release terms.

The EPZs should be large enough to cover affected urban and rural areas and accommodate the various 

organizations needed for emergency response.12Although the size of the EPZ is based on the maximum 

distance at which a PAG might be exceeded, the actual boundary of an EPZ should be demarcated by 

features readily identifiable by people within that area. Such boundaries generally include major 

topographical features (e.g., rivers, roads, transmission line corridors, rail rights of way) and political 

boundaries. The EPZ should be further subdivided, using similarly identifiable features, to facilitate 

implementing protective actions when the entire EPZ is not affected. Maps, showing the boundaries of the 

EPZ and the sub-areas and evacuation routes, should be provided to the public within the EPZ on a 

periodic basis in a format that will likely be available if the emergency occurs (e.g., inserted sections in

local phone directories, wall calendars, etc.). 

2.3 DOSE PROJECTIONS

The PAGs in this chapter are specified in terms of the projected whole body dose. This projected dose is 

the sum of the effective dose from external exposure to the plume and the committed effective dose from 

inhaled radionuclides. Guidance is also provided on the thyroid equivalent dose. Further references to 

effective or organ dose equivalent refer to these two quantities, respectively. The FRMAC Assessment 

Manuals13 provide detailed methods for estimating projected dose. These methods require knowledge of, 

or assumptions for, the intensity and duration of exposure and make use of standard assumptions on the

relation, for each radioisotope, between exposure and dose. Exposure and dose projections should be

based on the best estimates available. The FRMAC methods and models may be modified as necessary for 

specific sites for improved accuracy. Emergency response organizations are encouraged to use the most 

current, applicable tools and methods for implementing PAGs, understanding that differing approaches 

and assumptions will produce results with minor differences. 

 

12 The development of EPZs for nuclear power facilities is discussed in the NUREG-0396 (NRC 1978). 13 See FRMAC Assessment Manuals at http://nnss.gov/pages/programs/FRMAC/FRMAC_DocumentsManuals.html. 
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2.3.1 Dose Projection during the Early Phase

PAGs are expressed in terms of projected dose. The calculation of projected doses should be based on 

realistic dose models, to the extent practicable. Public protection decisions should be based upon the 

dose that can be avoided (i.e., avoidable dose) by taking some protective action (e.g., evacuation, 

sheltering-in-place). Unavoidable dose or doses incurred before the start of the protective action being 

considered generally should not be included in evaluating the need for protective action. Similarly, doses 

that may be incurred at later times than those affected by the specific protective action should not be 

included. As noted earlier, the projection of doses in the early phase needs to include only those exposure 

pathways that contribute a significant fraction (i.e., more than 10 percent) of the dose to an individual. 

In the early phase of an incident, parameters other than projected dose may provide a more appropriate 

basis for decisions to implement protective actions. When a facility is operating outside its design basis 

and a substantial release to the environment has started, or is imminent but has not yet occurred, data 

adequate to directly estimate the projected dose may not be available. Emergency response plans should 

anticipate specific conditions at the source of a potential release and the possible consequences off-site.

Emergency response plans for NPPs and facilities should make use of emergency action levels (EALs), 

based on in-plant conditions, to trigger notification and initial protective action recommendations to offsite officials.14 Once the initial protective actions have been implemented, accident assessment should 

continue. Although initial assessments may be uncertain, the subsequent assessments will be less 

uncertain as additional information on facility condition and prognosis, effluent radiation monitoring data 

and environmental data become available. The results of these continuing radiological assessments, 

including dose projections, should be used as the basis for refining the initial protective actions. In the 

case of transportation accidents, an RDD or IND, or other incidents that are not related to a facility, it may 

not be practicable to establish EALs.

Doses that may be incurred from ingestion of food and water, long-term radiation exposure (i.e., longer 

than four days), radiation exposure to deposited radioactive materials, or long-term inhalation of 

resuspended materials are chronic exposures for which neither emergency evacuation nor sheltering-inplace are appropriate protective actions. PAGs for the intermediate phase cover these exposure pathways 

(see Chapter 4).

2.3.2 Duration of Exposure

The projected dose for comparison to the early phase PAGs is calculated for exposure during the first four 

days following the anticipated (or actual) start of a release. The objective is to encompass the entire 

period of exposure to the radioactive plume and deposited material prior to implementation of any further,

longer-term protective action such as relocation. For planning purposes, the four-day period is chosen as

the duration of exposure during the early phase because it is a reasonable estimate of the time necessary to 

make measurements, reach decisions, and prepare to implement further protective actions (such as 

relocation) if necessary. However, officials at the site at the time of the emergency may decide that a 

different time frame is more appropriate.

For example, doses incurred through ingestion pathways or long-term exposure to deposited radioactive 

materials take place over a longer time period. Protective actions for such exposures should be based on 

guidance addressed in Chapter 4. 

The projected dose from each radionuclide in a plume is proportional to the time-integrated concentration 

of the radionuclide in the plume at each location. This concentration will depend on the rate and the 

duration of the release and meteorological conditions. Release rates will vary with time and this time-

 

14 Immediate protective actions based on in-plant conditions are not applicable to naval nuclear propulsion plants. See Footnote 

10 for additional information. In addition, because of differences in design and operation, EALs based on in-plant conditions are 

not applicable to naval nuclear propulsion plants.
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dependence cannot usually be predicted accurately. In the absence of more specific information, the 

release rate may be assumed to be constant. 

Another factor affecting the estimation of projected dose is the duration of the plume at a particular 

location. For purposes of calculating projected dose from most pathways, exposure will start at a 

particular location when the plume arrives and will end when the plume is no longer present. Exposure 

from deposited materials will continue for an extended period as long as people are present. Other factors 

such as the aerodynamic diameter and solubility of particles, shape of the plume, and terrain may also 

affect estimated dose and may be considered on a site- or source-specific basis.

Prediction of time frames for releases is difficult because of the wide range associated with the spectrum 

of potential incidents. Therefore, planners should consider the possible time periods between an initiating 

event and arrival of a plume and the duration of releases in relation to the time needed to implement 

competing protective actions (i.e., evacuation and sheltering-in-place). Analyses of commercial nuclear 

power reactors (NRC 1975) have shown that some incidents may take several days to develop to the point 

of a release while others may begin as early as a half hour after an initiating event. Furthermore, the 

duration of a release may range from less than one hour to several days, with the major portion of the 

release likely occurring within the first day.

Wind speed also influences radiological exposure rates from a plume. As a general rule, air concentration 

is inversely related to the wind speed at the point of release. Concentrations are also affected by the 

turbulence of the air, which tends to increase with wind speed and sunlight and by wandering of the 

plume, which is greater at the lower wind speeds. This results in higher concentrations generally being 

associated with low winds near the source and with moderate winds at larger distances. Higher wind 

speed also shortens the travel time of the plume. Planning information on time frames for releases from 

nuclear power facilities may be found in references NRC 1978 and EPA 1978(a, b). Time frames for 

releases from other facilities will depend on the characteristics of the facility.

2.3.3 Derived Response Levels and Dose Parameters

A Derived Response Level (DRL) is a level of radioactivity in an environmental medium that would be 

expected to produce a dose equal to its corresponding PAG. Depending on the exposure pathway, many 

factors such as ground roughness, weathering, and resuspension may be required to calculate the Dose 

Parameter (DP) that converts an environmental measurement into a projected dose over a given time 

period (e.g., early phase).

The FRMAC Assessment Manuals15 provide guidance in calculating DRLs and DPs based on the ICRP

dosimetry models (currently the ICRP 60 series). In addition, the FRPCC encourages the use of 

computational tools such as DOE’s Turbo FRMAC and NRC’s Radiological Assessment System for 

Consequence Analysis (RASCAL) as well as other appropriate or more current tools to implement the 

PAGs.

In the early phase, for precautionary reasons, it is recommended that default DRLs provided in the 

FRMAC Assessment Manual, Appendix C, be used. These defaults allow local entities to make decisions 

quickly in the event of a radiological emergency. They include worst-case or most likely assumptions. 

Further into the intermediate phase when incident characteristics have been assessed, more realistic 

incident-specific factors may be considered by local decision makers in projecting risks and adapting 

mitigation measures. 

 

15 See FRMAC Assessment Manuals at http://nnss.gov/pages/programs/FRMAC/FRMAC_DocumentsManuals.html.
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2.3.4 Higher PAGs for Special Circumstances

Hazardous environmental conditions (e.g., severe weather or a competing disaster) could create 

transportation risks from evacuation that would be higher than normal. It is therefore appropriate to allow 

higher projected doses for evacuation decisions under these circumstances. In the absence of any 

definitive information on such higher risks from evacuation, one should assume that it would be 

appropriate to increase the recommended projected dose for evacuation of the general population under 

hazardous environmental conditions up to a factor of five higher than that used under normal 

environmental conditions. 

It is also recognized that people who are not readily mobile are at higher risk from evacuation than are 

average members of the population. It would be appropriate to adopt higher PAGs for evacuation of 

individuals who would be at greater risk from evacuation itself than for the typically healthy members of 

the population, who are at low risk from evacuation. In the absence of definitive information on the 

higher risk associated with the evacuation of this group, one should assume that it is appropriate to adopt 

PAGs a factor of five higher for evacuation of high risk groups under normal environmental conditions. If 

both conditions (high risk groups and hazardous environmental conditions) exist, projected doses up to 

ten times higher than the PAGs for evacuation of the general population under normal conditions may be 

justified.16 

2.4 CONTAMINATION LEVELS AND MONITORING OF THE ENVIRONMENT 

AND POPULATIONS

Areas under the plume can be expected to contain deposited radioactive materials if aerosols or 

particulate materials were released during the incident. In extreme cases, individuals and equipment may 

be highly contaminated and monitoring stations will be required for emergency monitoring, 

decontamination of individuals, and medical evaluations. Equipment should be checked and 

decontaminated as necessary to avoid the spread of contamination to other locations. This monitoring 

service would be required for only a few days following plume passage until all have been evacuated. 

Guidance on surface contamination levels for use at such monitoring stations is provided below. 

Adults may reenter restricted (limited access) areas under controlled conditions in accordance with 

occupational exposure standards. The need for monitoring stations should be evaluated along highways, 

which serve as the major evacuation or transportation routes, to control surface contamination at exits 

from the more highly contaminated areas. Decontamination and other measures should be implemented to 

maintain low exposure rates at monitoring stations.

As a general rule, contaminated items should not be released to an unrestricted area. Based on incident 

and locality specific considerations, it may be acceptable to release contaminated materials if the level of 

surface contamination is below acceptable release criteria. As an alternative to decontamination, 

contaminated items (i.e., not people or animals) may be retained in the restricted area while the 

radiological contamination decays.

In some extreme cases, decontamination may be impractical. Evacuating a large area requires resources, 

and decontamination may conflict with priority use of those resources. Screening and decontamination 

can slow egress, which could result in increased dose to the evacuees. Emergency managers should 

consult with their state radiation control authority to establish proposed radiation screening criteria. Refer 

to CDC's "Population Monitoring in Radiation Emergencies: A Guide for State and Local Public Health 

Planners" (CDC 2014b)17 for additional in-depth discussion in Appendix D on radiological screening 

criteria for external contamination. These simple initial screening guides from CDC are more general than 

 

16 These doses are expected to satisfy Principle 4 without violating Principles 1 and 3. Although they violate Principle 2, 

Principle 4 becomes, for such cases, the overriding consideration. See Section 2.5 for more information about these principles. 17 See: http://emergency.cdc.gov/radiation/pdf/population-monitoring-guide.pdf. (CDC 2014b) 
Protective Action Guides and Planning Guidance for Radiological Incidents 27

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FEMA REP-21 (FEMA 1995) and FEMA REP-22 (FEMA 2002) on use of handheld instruments and 

portal monitors for screening the public. 

2.4.1 Surface Contamination Control

Surface contamination must be controlled both before and after evacuation protective actions are 

implemented. The contamination level for screening people, animals and objects for surface 

contamination at monitoring stations should be influenced by the potential for the contamination to be 

ingested, inhaled or transferred to other locations. The principal exposure pathways for loose surface 

contamination on people, clothing and equipment are: 

 Internal doses from ingestion by direct transfer;

 Internal doses from inhalation of resuspended materials;

 Beta dose to skin from contaminated skin or clothing or from nearby surfaces; 

 Dose to the whole body from external gamma radiation; and 

 Internal doses from absorption of contamination into wounds. 

It is not practical to set surface contamination screening levels significantly lower than residual 

contamination levels in uncontrolled areas. Although the contamination levels recommended in this 

Manual are accordingly set high, consideration should be given as the incident progresses to using lower 

contamination screening levels (and more sensitive monitoring instruments) once people are removed 

from areas causing high external doses. Such efforts will minimize cross-contamination of people located 

outside of the affected areas. For incidents involving fixed nuclear facilities, some evacuation reception 

centers or shelters will have walk-through portal monitors. 

The recommended "2x existing background” level for screening for surface contamination at monitoring 

stations is merely a simplified basis for responders to set their own instrument trigger levels based on 

practical circumstances at the time and location of each screening center. Local and state officials may 

choose to establish a screening level expressed in measurement units (e.g., counts per minute (cpm), 

μR/h) that are compatible with radiation detection instruments being used and appropriate for local 

conditions, taking into account the number of people in need of screening and available resources.18 The 

following guidance documents from the National Council on Radiation Protection and Measurements 

(NCRP) provide more detailed information about initial screening levels: 

 “Population Monitoring and Radionuclide Decorporation Following a Radiological or Nuclear 

Incident,” (NCRP Report No. 166), Bethesda, MD, 2011. (NCRP 2011) 

 “Responding to a Radiological or Nuclear Terrorism Incident: A Guide for Decision Makers,” (NCRP 

Report No. 165), Bethesda, MD, 2010. (NCRP 2010) 

 “Management of Persons Contaminated with Radionuclides: Scientific and Technical Bases,” (NCRP 

Report No. 161, Vol. II), Bethesda, MD, 2010. Chapter 5: Performing Surveys and Controlling 

Personnel and Area Contamination. (NCRP 2008) 

 “Management of Persons Contaminated with Radionuclides: Handbook,” (NCRP Report No. 161, 

Vol. I), Bethesda, MD, 2008. (NCRP 2008) 

2.4.2 Priorities for Control of Contaminated Areas 

The following priorities are recommended— 

 Do not delay urgent medical care for decontamination efforts or for time-consuming protection of 

attendants, such as donning of additional anti-contamination clothing. 

 

18 See: http://emergency.cdc.gov/radiation/pdf/population-monitoring-guide.pdf. (CDC 2014b) 
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 In early phase scenarios where it might not be practical or would interfere with other lifesaving and 

public health protection priorities, do not waste effort trying to contain contaminated wash water but 

be sure to notify sewage treatment plants.

 Do not allow monitoring and decontamination to delay an ordered evacuation. 

 When early screening is needed after a major incident — After plume passage, it may be necessary to 

establish emergency contamination monitoring stations in areas not qualifying as low background 

areas. These monitoring stations should be used only during the early phase after major atmospheric 

releases to monitor people emerging from possible high exposure areas. The stations should be set up 

to provide simple (rapid) decontamination if needed and to evaluate whether affected people should 

undergo more extensive decontamination or other special care. Section 2.4.3 provides guidance on 

surface contamination levels for use, if such emergency contamination monitoring stations centers are 

needed.

 Establish screening to control surface contamination — Establish monitoring and decontamination 

(e.g., bathing) facilities at evacuation centers or other locations in low background areas (less than 0.1 

mrem (1 μSv) per hour gamma exposure rate). Section 2.4.4 provides surface contamination guidance 

for monitoring stations in low background areas. These surface contamination screening levels are 

examples derived primarily on the basis of easily measurable radiation levels using portable 

instruments. The background may be elevated because of the incident, so these screening levels refer 

to a “2x existing background” level in a low radiation area. 

 Encourage self-decontamination — Encourage evacuated people who were exposed in areas where 

release of particulate materials would have warranted evacuation to change and bag the clothes they 

were wearing and store them in an area away from people and pets until authorities provide further 

instructions on their disposition, to wash other exposed surfaces such as cars and trucks and their 

contents, and then report to evacuation centers or other established locations for monitoring. 

 After the evacuation area has been established, consider the need to set up monitoring and 

decontamination stations at exits from the more highly contaminated parts of the area. Low levels of 

contamination may be undetectable because of high background radiation levels at these locations. 

Monitoring should be done at lowest practical background levels. Nevertheless, these individuals 

should be advised to bathe and change clothes at their first opportunity—no later than within the next 

24 hours. If, after decontamination, people still exceed the surface contamination screening levels for 

the station, they should be sent for further decontamination or for medical or other special attention. 

2.4.3 Recommendations for Emergency Screening in Areas Not Qualifying as Low 

Background Areas

This section provides the recommended surface contamination screening levels for emergency screening 

of people and objects at monitoring stations in areas with elevated background radiation (exceeding 0.1 

mR/h or 1 μSv/h gamma exposure rate). Monitoring stations in such high exposure rate areas are for use 

only during the early phase of an incident involving major atmospheric releases of particulates (otherwise 

see Section 2.4.4). For such emergency screening at monitoring stations, recommended actions for a 

detection instrument reading at either less than or greater than 2x existing background are outlined below. 

 Before Decontamination: 

o If <2x existing background — Recommended action: Release for further screening outside 

affected area.

o If >2x existing background — Recommended action: Perform gross decontamination (carefully 

remove outer layer of clothing) and/or simple decontamination (examples include washing 

hands and face, wiping of exposed skin, washing feet or soles of shoes). Equipment may be 

stored for decay, reuse, or disposal in the same area, as appropriate.
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 After Decontamination: 

o If <2x existing background — Recommended action: Release for further screening outside 

affected area.

o If >2x existing background — Recommended action: Continue to decontaminate or refer to low 

background monitoring and decontamination station. Equipment may be stored for decay, 

reuse, or disposal in the same area, as appropriate. 

2.4.4 Recommendations for Screening in Low Background Areas 

This section provides the recommended surface contamination screening levels for people and objects at 

monitoring stations in low background radiation areas (<0.1 mR/h or 1 μSv/h gamma exposure rate). 

People reporting to monitoring stations in low background radiation areas have been previously instructed 

to change and bag clothes, wash other exposed surfaces such as cars and their contents, and then report to 

these centers for monitoring. Levels higher than 2x existing background (not to exceed the meter reading 

corresponding to 0.1 mR/h) may be used to speed the monitoring of evacuees in very low background 

areas. For screening at monitoring stations in low background areas, recommended actions for a detection 

instrument reading at either less than or greater than 2x existing background are outlined below. 

 Before Decontamination: 

o If <2x existing background — Recommended action: Unconditional release. 

o If >2x existing background — Recommended action: Perform gross decontamination (carefully 

remove outer layer of clothing) and/or simple decontamination (examples include washing 

hands and face, wiping of exposed skin, washing feet or soles of shoes).

 After Simple Decontamination Effort: 

o If <2x existing background — Recommended action: Unconditional release. 

o If >2x existing background — Recommended action: Full decontamination. 

 After Full Decontamination Effort (Changing clothes and/or showering are examples of a full 

decontamination effort. Washing or gentle scrubbing with soap or other mild detergent followed 

by flushing is another example of a full decontamination effort.): 

o If <2x existing background — Recommended action: Unconditional release. 

o If >2x existing background — Recommended action: Continue to decontaminate people.

 After Additional Full Decontamination Effort: 

o If <2x existing background — Recommended action: Unconditional full release. 

o If >2x existing background — Recommended action: Send people for further evaluation.

The recommended "2x existing background” level for screening for surface contamination at monitoring 

stations is merely a simplified basis for responders to set their own instrument trigger levels based on 

practical circumstances at the time and location of each screening center. Local and state officials may 

choose to establish a screening level expressed in measurement units (e.g., cpm, μR/h) that are compatible 

with radiation detection instruments being used and appropriate for local conditions, taking into account 

the number of people in need of screening and available resources.19

2.5 BASIS FOR EARLY PHASE PAGS 

For a full description of the risk-benefit analysis used to set the PAG levels, refer to the 1992 PAG 

Manual, Appendices B, C and E. The 1992 PAG Manual is available online in a searchable format. Below 

is a short summary of the basis for the early phase evacuation/sheltering PAG of 1 to 5 rem (10 to 50 

mSv) projected over four days.

 

19 See: http://emergency.cdc.gov/radiation/pdf/population-monitoring-guide.pdf. (CDC 2014b) 
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PAGs are intended to apply to all individuals in a population. However, there may be identifiable groups 

that have different average sensitivity to radiation or, because of their living situation, will receive higher 

or lower doses. In addition, some groups may be at greater risk from taking a given protective action. 

Special circumstances and age groups (e.g., fetal dose) were considered, when appropriate, in establishing 

values for the PAGs.

The following four principles provided the basis for establishing values for Protective Action Guides: 

1. Acute effects on health (those that would be observable within a short period of time and which 

have a dose threshold below which they are not likely to occur) should be avoided. 

2. The risk of delayed effects on health (primarily cancer and genetic effects, for which linear nonthreshold relationships to dose are assumed) should not exceed upper bounds that are judged to be 

adequately protective of public health, under emergency conditions, and are reasonably 

achievable.

3. PAGs should not be higher than justified on the basis of optimization of cost and the collective 

risk of effects on health. That is, any reduction of risk to public health achievable at acceptable 

cost should be carried out. 

4. Regardless of the above principles, the risk to health from a protective action should not itself 

exceed the risk to health from the dose that would be avoided.20

EPA considered the acceptable range of costs for avoiding a statistical death from pollutants other than 

radiation and using a rounded value from the BEIR III risk of 0.0003 cancer deaths per person-rem.21

Further evaluation of thyroid, skin, and fetal dose consequences was conducted as well.

Costs of evacuation: 

Based on a prior published study (EPA 1987a), evaluating evacuation options for several accident types, 

an analysis focused on the smallest category of fuel melt accident yielding effective dose equivalents 

during the first four days of exposure that are greater than 0.5 rem outside the assumed 2-mile evacuation 

circle for all stability classes. For that scenario, total and incremental costs were calculated for several 

different sized evacuation areas. Data on costs versus dose avoided for several meteorological stability 

classes and evacuation options (sizes) were summarized in tables in the 1992 PAG Manual, Appendix C. 

For a risk of 0.0003 cancer deaths per person-rem, the range of evacuation costs can be compared to the 

marginal cost-effectiveness (dollars per person-rem) of evacuation over an angle of 90 degrees. The 

resulting ranges of upper bounds on dose are found in tables in the 1992 PAG Manual, Appendix C, for 

three different accident scenarios. The maximum upper bounds (based on minimum costs for avoiding 

risk) range from 1 to 10 rem, with most values being approximately 5 rem. The minimum upper bounds 

(based on maximum costs for avoiding risk) range from 0.15 to 0.8 rem, with 0.5 rem dose incurred being 

representative of most situations.

From these data we conclude that, based on the cost of evacuation, a PAG larger than the range of values 

0.5 to 5 rem would be incompatible with Principle 3. 

Based on comparison of exposures from evacuation versus the presumed alternative of sheltering in 

various building types for several timeframes, the dose actually avoided by evacuation is one half of the 

projected dose.

 

20 These four principles were used in developing the 1992 PAG Manual; now presented as three principles. 21 For more information on BEIR III risk, see the 1992 PAG Manual. BEIR III refers to the 1980 report from the Committee on 

the Biological Effects of Ionizing Radiation (BEIR) of the National Academy of Sciences (NAS), National Research Council, 

The Effects on Populations of Exposure to Low Levels of Ionizing Radiation: BEIR III. (NAS 1980)
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Risk from evacuation: 

Principle 4 requires that the risk of the protective action not exceed the risk associated with the dose that 

will be avoided. Risk from evacuation can come from several sources, including: 1) transportation 

incidents for both pedestrians and vehicle passengers; 2) exposure to severe weather conditions or a 

competing disaster; and 3) in the case of immobile persons, anxiety, unusual activity, and separation from 

medical care or services. While all these factors must be considered, transportation incidents is the only 

category for which the risk has been quantified. 

Conformance to Principle 1 (avoidance of acute health effects) is assured by the low risk required to 

satisfy Principle 2 (acceptable risk of delayed health effects), and thus requires no additional 

consideration. Based on Principle 2, evacuation of the general population is not justified below 0.5 rem. 

This represents a risk of about 0.0002 of fatal cancer. Maximum lifetime risk levels considered acceptable 

by EPA from routine operations of individual sources range from 0.000001 to 0.0001. Risk levels that are 

higher than this must be justified on the basis of the emergency nature of a situation. In this case, we 

judge that up to an order of magnitude higher combined risk from all phases of an incident may be 

justifiable. The choice of 0.5 rem avoided dose as an appropriate criterion for an acceptable level of risk 

during the early phase is a subjective judgment that includes consideration of possible contributions from 

exposure during other phases of the incident. 

Principle 4 (risk from the protective action must be less than that from the radiation risk avoided) supplies 

a lower bound of 0.03 rem on the dose at which evacuation of most members of the public is justified. 

The lower bound was derived from the risk of death from traffic accidents in emergency evacuations, 

using the factor of 0.0003 cancer deaths per person-rem. Finally, under Principle 3 (cost/risk 

considerations) evacuation is justified only at values equal to or greater than 0.5 rem. This will be limiting 

unless lower values are required for purely health-based reasons (Principle 2). But this is not the case. 

In summary, we have selected the value 0.5 rem as the avoided dose which justifies evacuation, because: 

1) it limits the risk of delayed effects on health to levels adequately protective of public health under 

emergency conditions; 2) the cost of implementation is justified; and 3) it satisfies the two bounding 

requirements to avoid acute radiation effects and to avoid increasing risk through the protective action 

itself. 

The value of the PAG for evacuation of the general public is therefore chosen as one rem projected total 

effective dose from inhalation of radionuclides and exposure to external radiation.
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KEY POINTS IN CHAPTER 2 – EARLY PHASE

 The principal protective actions for the early phase are evacuation or sheltering-in-place. 

Evacuation is the urgent removal of people from an area to avoid or reduce high-level, short-term

exposure from the plume or deposited radioactivity. Sheltering-in-place refers to the use of a 

readily available structure that will provide protection from exposure to the plume.

 The PAG for evacuation or sheltering-in-place is a projected whole body dose of 1 to 5 rem (10 – 

50 mSv) total effective dose (TED) over four days.

 Evacuation is appropriate when its risks and secondary effects are less severe than the risk of the 

projected radiation dose. Evacuation will be most effective in avoiding dose if completed before 

plume arrival.

 In general, sheltering-in-place should be preferred to evacuation whenever it provides equal or 

greater protection. After confirmation that the plume has passed, continued sheltering-in-place

should be re-evaluated by public officials. 

 The administration of KI to partially block the uptake of radioiodines by the thyroid is a 

supplemental protective action. The PAG for administration of KI is 5 rem (50 mSv) projected 

child thyroid dose. 

 Dose calculations for PAGs are made using the dose parameter (DP) and derived response level 

(DRL) calculation methods referenced in the FRMAC Assessment Manuals. Emergency response 

organizations are encouraged to use the most current, applicable tools and methods for 

implementing the PAGs. 
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CHAPTER 3. EMERGENCY WORKER PROTECTION

The emergency worker guidelines in this chapter were developed for a wide range of possible radiological 

scenarios, from a small transportation accident that may impact a single roadway to an IND that could 

potentially impact a large geographic region. Therefore, the 5, 10 and 25 rem (50, 100 and 250 mSv) 

guidelines (see Table 3-1, Section 3.1.2) should not be viewed as inflexible limits applicable to the range 

of early phase emergency actions covered by this guidance. For instance, by the intermediate phase when 

relocation has been implemented, it is likely that no more lifesaving missions would be needed. Some 

critical infrastructure/key resources or lifesaving missions may arise in later phases, however, for which 

the emergency worker guides in Section 3.1.2 would apply. 

Because of the range of impacts and case-specific information needed, it is impossible to develop a single 

turn-back dose level for all responders to use in all events, especially those that involve lifesaving 

operations. Indeed, with proper preparedness measures (training, personal protective equipment (PPE), 

etc.) most radiological emergencies addressed by this document, even lifesaving operations, may be 

manageable within the 5 rem (50 mSv) occupational limit.22 Moreover, incident commanders should 

make every effort to employ the “as low as reasonably achievable” (ALARA) principle after an incident. 

Still, in some incidents doses above the annual occupational 5 rem (50 mSv) dose limit may be 

unavoidable. For instance, in the case of a catastrophic incident, such as an IND, incident commanders 

may need to consider raising the lifesaving and critical infrastructure (i.e., necessary for public welfare) 

emergency worker guidelines in order to prevent further loss of life and prevent the spread of massive 

destruction. It is essential that emergency workers have full knowledge of the associated risks prior to 

initiating emergency action and receive medical evaluations after such exposure.

Worker and public protection guidance and standards for normal operations are developed through risk 

management approaches and are implemented in federal and state regulations (e.g., 10 CFR Part 20; 10 

CFR Part 835; 29 CFR Part 1910.1096). However, many factors or decision criteria in a radiological 

emergency differ from those in normal operations. Standards for normal operations provide a margin of 

safety that is greater than that in guidelines for emergency response because that margin can be provided 

in a manner that ensures no significant increase in public health risk or detriment to the public welfare. 

Currently, the development of standards and guidelines for normal operations is done in a manner that 

provides reasonable assurance that implementation of the standards will not cause more risk than it averts.

Response organizations need to develop plans and protocols that address radiation protection during a 

radiological incident and that ensure appropriate training is provided to responders and decision-makers. 

Detailed reports on radiation risk, risk management decision-making, training and public communication 

should be consulted in the development of plans, protocols and training materials and may be obtained 

from organizations such as ICRP, NCRP, International Atomic Energy Agency (IAEA), the American 

Nuclear Society (ANS), and the Health Physics Society (HPS). Detailed information on the risks of 

radiological emergency response and worker protection procedures can be found in the FRMAC 

“Radiological Emergency Response Health and Safety Manual” (DOE 2012) and the NCRP’s 

“Management of Terrorist Events Involving Radioactive Material, Report No. 138” (NCRP 2001) and 

“Responding to a Radiological or Nuclear Terrorism Incident: A Guide for Decision Makers, Report No. 

165” (NCRP 2010). 

 

22 See 29 CFR Part 1910.1096 (Ionizing Radiation) for OSHA’s occupational limit. Under the OSHA Ionizing Radiation 

standard, the annual occupational limit for whole body radiation exposure for adults (age ≥18 years) is 5 rem (50 

mSv). Employers must comply with all applicable OSHA requirements, including worker dose limits for ionizing radiation, 

during emergency response and recovery operations. 
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3.1 CONTROLLING OCCUPATI ONAL EXPOSURE AND DOSES TO

EMERGENCY WORKERS 

This section provides guidance on occupational doses of radiation during an emergency response. In

many radiological incidents, actual exposure of workers, including emergency responders, may be 

controlled to low doses when proper precautions are taken. During some emergencies, radiation exposures

to responders may be unavoidable and may have the potential to exceed limits used for normal operations. 

However, even in emergency conditions, every reasonable effort should be made to control doses to levels

that are as low as practicable (consider NCRP 13823 and NCRP 16524 for recommendations that support 

ALARA).

3.1.1 Maintaining the ALARA Principle

To minimize the risks from exposure to ionizing radiation, employers of emergency workers (or incident 

commanders, who may or may not be the same) should prepare emergency response plans and protocols 

in advance to keep worker exposures ALARA, an acronym for "as low as reasonably achievable," which 

means making every reasonable effort to maintain exposures to radiation as far below the dose limits as is 

practical consistent with the purpose for which the activity is undertaken. Plans and protocols should 

include the following health physics and industrial hygiene practices to the maximum extent possible— 

 Minimizing the time spent in the contaminated area.

 Maximizing the distance from sources of radiation. 

 Shielding of radiation sources.

 Tailoring of hazard controls to the work performed.

 Properly selecting and using respirators (see 29 CFR Part 1910.134) and other PPE.

 Using prophylactic medications, where medically appropriate, that either block the uptake or

reduce the retention time of radioactive material in the body. 

The incident commander’s staff should be prepared to identify, to the extent possible, all hazardous 

conditions or substances and to perform appropriate site hazard analysis. Emergency management plans 

need to include protocols to control worker exposures, establish exposure guidelines in advance, and 

outline procedures for worker protection. Emergency procedures need to include provisions for exposure 

monitoring, worker training commensurate with the hazards involved in response operations, ways to 

control those hazards, and medical monitoring. 

3.1.2 Understanding Dose and Risk Relationships

Emergency worker guidelines are based on cumulative dose constraint levels. These are based on an 

assumption that doses acquired in response to a radiological incident would be “once in a lifetime” doses 

and that future radiological exposures would be substantially lower.

Recommendations in this Manual provide a guideline level of 5 rem (50 mSv) for worker protection and 

alternative emergency worker guidelines (see Table 3-1) for certain activities where doses above 5 rem

(50 mSv) cannot be avoided. For most radiological incidents, radiation control measures (e.g., minimizing

time, maximizing distance, using shielding) will prevent doses from reaching the 5 rem (50 mSv)

occupational exposure guideline while performing typical emergency response activities such as 

transportation, firefighting and medical treatment of contaminated victims at hospitals. However, in those 

situations in which victims are injured or trapped in high radiation areas or can only be reached via high 

radiation areas, or for protection of critical infrastructure, exposure control options may be unavailable or 

insufficient and doses above 5 rem (50 mSv) may be unavoidable. 

 

23 “Management of Terrorist Events Involving Radioactive Material, Report No. 138.” (NCRP 2001) 24 “Responding to a Radiological or Nuclear Terrorism Incident: A Guide for Decision Makers, Report No. 165.” (NCRP 2010)
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Decisions to take response actions that could result in doses in excess of 5 rem (50 mSv) can only be 

made at the time of the incident, under consideration of the actual situation. In such situations, incident 

commanders and other responders need to understand the risk posed by such exposures in order to make 

informed decisions. The emergency worker guidelines for life and property saving activities in Table 3-1 

are provided to assist such decision-making. These guidelines apply to doses incurred over the duration of 

an emergency and are assumed to be once in a lifetime. After the early phase, it is likely that no more 

lifesaving missions would be needed. However, some critical infrastructure/key resources or lifesaving 

missions may arise in the intermediate phase, where these guidelines would apply.

Emergency personnel may be exposed to increased radiation during the unique catastrophic event of an 

IND detonation resulting in firestorm and widespread destruction of structures. The emergency 

intervention needed to prevent further destruction and loss of life may result in increased exposure.

Exceeding the emergency worker guidelines in Table 3-1 may be unavoidable in responding to such 

events. For all exposures, emergency workers must be fully informed of the risks of exposure they may 

experience, including numerical estimates of the risk of delayed health effects, and must be trained, to the 

extent feasible, on actions to be taken. Each emergency worker should make an informed decision as to 

how much radiation risk they are willing to accept to complete a particular mission. 

Table 3-1. Emergency Worker Guidelines

Guideline Activity Condition

5 rem (50 mSv) All occupational exposures All reasonably achievable actions

have been taken to minimize dose.

10 rem (100 mSv)a Protecting critical infrastructure

necessary for public welfare (e.g., a 

power plant)

Exceeding 5 rem (50 mSv)

unavoidable and all appropriate

actions taken to reduce dose.

Monitoring available to project or 

measure dose.

25 rem (250 mSv)b Lifesaving or protection of large

populations

Exceeding 5 rem (50 mSv)

unavoidable and all appropriate

actions taken to reduce dose.

Monitoring available to project or

measure dose.

>25 rem (250 mSv) Lifesaving or protection of large

populations

All conditions above and only for 

people fully aware of the risks 

involved (see Tables 3-2 and 3-3) 

a For potential doses >5 rem (50 mSv), medical monitoring programs should be considered.

b In the case of a very large incident, such as an IND, incident commanders may need to consider raising the property and

lifesaving emergency worker guidelines to prevent further loss of life and massive spread of destruction.

This guidance does not address or impact site cleanups occurring under other statutory authorities such as the United States 

Environmental Protection Agency’s (EPA) Superfund program, the Nuclear Regulatory Commission’s (NRC) 

decommissioning program, or other federal or state cleanup programs.

The 25 rem (250 mSv) lifesaving emergency worker guidelines provide assurance that exposures will not 

result in detrimental deterministic health effects (i.e., prompt or acute effects). However, it could increase 

the risk of stochastic (chronic) effects, such as the risk of cancer. Response actions that could cause 

exposures in excess of the 25 rem (250 mSv) emergency worker guideline should only be undertaken with 

an understanding of the potential acute effects of radiation to the exposed responder (see Table 3-2) and 
Protective Action Guides and Planning Guidance for Radiological Incidents 36

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only when the benefits of the action (i.e., lifesaving or critical infrastructure/key resource protection)

clearly exceed the associated risks.

Table 3-2. Acute Radiation Syndromea

Feature or

Illness

Effects of Whole Body Absorbed Dose from External Radiation or Internal Absorption,

by dose range in rad (Gray)

0-100 

(0-1 Gy)

100-200

(1-2 Gy)

200-600

(2-6 Gy)

600-800

(6-8 Gy)

>800

(>8 Gy)

Nausea,

Vomiting None25

5-50% 50-100% 75-100% 90-100%

Time of Onset 3-6 hr 2-4 hr 1-2 hr < 1 hr to

minutes

Duration < 24 hr < 24 hr < 48 hr < 48 hr

Lymphocyte

Count

Unaffected Minimally 

Decreased

<1000 at 24 hr < 500 at 24 hr Decreases within

hours

Central Nervous

System Function

No

Impairment

No Impairment Cognitive

impairment for

6-20 hr

Cognitive

impairment for

> 20 hr

Rapid

incapacitation

Mortality None Minimal

Low with 

aggressive 

therapy26 High

Very High:

Significant

neurological

symptoms

indicate lethal

dose

a Percentage of people receiving whole body doses within a few hours expected to experience acute health effects.

Source: Medical Management of Radiological Casualties, Second Edition, Armed Forces Radiobiology Research Institute.

Bethesda, MD, April 2003 (DoD 2003). 

Higher doses could be received by emergency workers performing what NCRP Report No. 165, 

"Responding to a Radiological or Nuclear Terrorism Incident: A Guide for Decision Makers" calls 

"Time-Sensitive Mission-Critical" activities that could result in radiation doses higher than 25 rem (250 

mSv) (NCRP 2010). NCRP Report No. 165 expands the discussion on a Decision Dose of 50 rad 

(approximately 50 rem or 500 mSv). A Decision Dose can be used by the incident commander as a tool to 

address the need to and the consequences of exposing emergency workers to higher doses to accomplish 

Mission Critical actions. This is especially important in an IND incident.

The estimated excess risk of fatal cancer

27 for workers exposed to 10 rem (100 mSv) is slightly less than 

the corresponding general population risk of 0.6 percent (6 cases per thousand exposed). Workers exposed 

to 25 rem (250 mSv) have an estimated excess risk of fatal cancer of 1.5 percent (15 cases per thousand 

 

25 A small number of exposed individuals may experience symptoms such as nausea and vomiting at doses between 50 and 100 

rad (0.5 and 1 Gy).

26 The LD 50/60 or the lethal dose with NO medical intervention to 50 percent of the population after 60 days is between 320 and 

450 rad or 3.2 - 4.5 Gy. 27 Risk per dose of a fatal cancer is assumed to be about 6x10-4 per rem (6x10-5 per mSv). Cancer incidence is assumed to be 

about 8x10-4 per rem (8x10-5 per mSv). (EPA 1999)
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exposed). Because of the latency period of cancer, younger workers face a larger risk of fatal cancer than 

older workers (e.g., when exposed to 25 rem (250 mSv), 20 to 30-year-olds have a 9.1 per thousand risk

of premature death, while 40 to 50-year-olds have a 5.3 per thousand risk of premature death).28

More specific risk determinations can be made when there is adequate information about the contaminants

and the potential for human exposure. EPA’s Federal Guidance Report #13 (EPA 1999) and Health 

Effects Assessment Summary Tables (EPA 1997) have risk factors for specific radionuclides.

Prior to the 5 rem (50 mSv) guideline being exceeded, workers should be provided the following— 

 Site-specific training, if no prior training was available, with respect to the risk associated with 

exposure to ionizing radiation (incident commanders and responders should consider having

someone on each team with radiation safety experience).

 A thorough explanation of the latent risks associated with receiving exposures greater than 5 rem

(50 mSv). 

 After this training and thorough explanation of the risks, each emergency worker should make an 

informed decision as to how much radiation risk they are willing to accept when undertaking a 

particular mission.

If the 5 rem (50 mSv) guideline is exceeded, workers should be provided with a medical follow-up and 

monitoring should be considered.

In addition, these guidelines represent dose constraint levels (e.g., when this level of dose is accumulated, 

the responder should not take part in the later stages of the response that may significantly increase their 

dose). The FRMAC “Radiological Emergency Response Health and Safety Manual” (DOE 2012) 

provides detailed information. Additional resources for advance planning are available on the Radiation

Emergency Medical Management (REMM) website: http://www.remm.nlm.gov/.

3.2 OCCUPATI ONAL SAFETY REGULATIONS FOR RADIOLOGICAL 

EMERGENCY RESPONSE

The Occupational Safety and Health Act requires employers to be responsible for the health and safety of 

their employees during routine and emergency operations. The primary occupational safety and health 

standard for emergency response is the Hazardous Waste Operations and Emergency Response 

(HAZWOPER) standard (29 CFR Part 1910.120). Information about how the Occupational Safety and 

Health Administration (OSHA) applies HAZWOPER and other OSHA standards to emergency responses 

and cleanup operations is available at www.osha.gov. 

Many U.S. states operate their own OSHA-approved state plans, which are required to be “at least as 

effective as" Federal OSHA standards and may impose additional or more stringent requirements.29 Some 

states operate “complete” plans that cover both the private sector and state and local government 

employees, while others cover state and local government employees only. EPA’s Worker Protection 

Standard (40 CFR 311) applies the HAZWOPER standard to state and local government workers in states

that do not have occupational health and safety plans. 

 

28 The numerical estimate of cancer risk presented above (from Federal Guidance Report #13) was obtained by linear 

extrapolation using the nominal risk estimates based on data from human exposures at high doses and high dose rates. Other 

methods of extrapolation to the low-dose region could yield higher or lower numerical estimates of cancer deaths. Studies of 

human populations exposed at low doses are inadequate to demonstrate the actual magnitude of risk at low doses (about 0.1 Sv or 

10 rem and below). There is scientific uncertainty about cancer risk in the low-dose region below the range of epidemiological 

observation and the possibility of no risk cannot be excluded. (EPA 1999)

29 For a list of state plans, see: http://www.osha.gov/dcsp/osp/index.html.
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In addition to OSHA, several federal agencies (DOE and NRC) and Agreement States issue occupational 

radiation safety standards (see Table 3-3). The occupational standards are not guidelines but instead are 

regulatory limits that cannot be exceeded except under certain conditions. These occupational limits allow 

workers to receive radiation exposure during the course of performing their jobs. 

Some federal and state radiation safety standards may allow workers to exceed dose limits in order to take 

critical lifesaving actions. However, even during emergency response and recovery operations, OSHA 

standards always apply. During the initial emergency response following a nuclear detonation, OSHA 

will likely operate in a technical assistance and support mode, pursuant to the National Response 

Framework, rather than issuing citations for workplace violations. OSHA retains its enforcement 

authority under the Occupational Safety and Health (OSH) Act of 1970. 

Table 3-3. Regulations for Worker Protection

Agency Regulatory Requirement Title

Occupational Safety and Health

Administrationa

29 CFR Part 1910.120 Safety and Health — HAZWOPER

29 CFR Part 1910.1096 IonizingRadiation

Environmental Protection Agencya 40 CFR Part 311 Occupational Radiation Protection

Nuclear RegulatoryCommissionb 10 CFR Part 20 Standards for Protection Against Radiation

Department of Energyc 10 CFR Part 835 Radiation Protection Regulations

a Worker safety and health is regulated in all states by federal OSHA or by respective state regulations under an OSHAapproved state plan. 40 CFR Part 311 applies the OSHA HAZWOPER standard (29 CFR 1910.120) to public-sector workers 

in states that do not operate their own occupational safety and health programs.

b It is the NRC’s position (56 FR 23365) that dose limits for normal operations should remain the primary guideline in 

emergencies to the extent practicable. However, in accordance with 10 CFR 20.1001(b), conformance with such dose limits 

should not hinder an NRC licensee from taking actions that may be necessary to protect public health and safety in an 

emergency.

c These requirements apply to all DOE employees and contractors (except for Naval Nuclear Propulsion Program (NNPP))

who may be exposed to ionizing radiation as a result of their work for DOE, including work relating to emergency response 

activities. The NNPP has established requirements consistent with those contained in 10 CFR Part 835.
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KEY POINTS IN CHAPTER 3 – EMERGENCY WORKER PROTECTION

 Emergency worker guidelines of 5, 10 or 25 rem (50, 100 or 250 mSv) are based on the urgency of 

activities and knowledge of the risks involved. 

 Worker safety is key to a successful emergency response.

 Incident commanders are responsible for balancing the individual risks and public benefits of each 

worker action.

 Emergency workers should be adequately informed of, and have an adequate understanding of, the 

risks they may experience during any missions they accept, including the risk of short-term and 

long-term health effects from exposure to ionizing radiation. 

 Emergency workers should have relevant training, personal protective equipment (PPE), and 

monitoring instruments so they are able to protect themselves and others.

 Since there is assumed to be no threshold below which there is not an associated risk from 

radiation dose, workers who are reasonably expected to receive more than 25 percent of the 

occupational dose limit should be properly trained and monitored. 

 Emergency workers should be trained, to the extent feasible, on actions to be taken. All reasonable 

steps should be taken to provide appropriate protection during the emergency activity. 

 Worker protection regulations are listed in Table 3-3. 
Protective Action Guides and Planning Guidance for Radiological Incidents 40

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CHAPTER 4. INTERMEDIATE PHASE PROTECTIVE ACTION GUIDES 

This chapter presents PAGs for the intermediate phase and provides guidance for the implementation of 

corresponding protective actions. A PAG is the projected dose to an individual from the release of 

radioactive material at which a specific protective action should be taken to reduce or avoid that dose. The 

intermediate phase is defined as the period beginning after the source and releases have been brought 

under control and environmental measurements are available for use as a basis for decisions on protective 

actions and extending until these protective actions are terminated. The intermediate phase may last from 

weeks to months but is projected for one year for calculation purposes.

During the early phase, decisions must be made and implemented quickly by state and local officials 

before federal assistance may be available. In contrast, many decisions and actions during the intermediate 

phase may be taken after federal resources are present, as described in the “Nuclear Radiological Incident 

Annex of the National Response Framework” (FEMA 2008b). Decisions will be made during the 

intermediate phase concerning whether particular areas or properties from which people have been 

evacuated will be decontaminated and reoccupied or the occupants relocated for an extended period. 

This chapter provides the PAGs and corresponding protective actions for use by state and local officials in 

developing their radiological emergency response plans to protect the public from exposure to radiation 

from deposited radioactive materials. Due to the wide variety of types of radiological incidents and 

radionuclide releases that could occur, it is not practical to provide implementing guidance for every 

possible situation. 

This chapter also provides guidance for translating radiological conditions in the environment into 

projected doses that serve as the basis for decisions to take appropriate protective actions and basic 

planning guidance on reentry as informed by the Operational Guidelines (DOE 2009). 

4.1 EXPOSURE PATHWAYS DURING THE INTERMEDIATE PHASE

During the intermediate phase, the following are the principal exposure pathways for the public 

occupying areas contaminated with deposited radioactive materials— 

 External exposure to radiation from deposited radioactive materials (groundshine). External 

gamma radiation is the expected dominant pathway for NPP incidents and incidents involving 

RDDs and INDs. Typically, the health risks from other pathways are expected to be minor in 

comparison to the risks from external gamma radiation.

 Internal exposure from the inhalation of resuspended materials. Although normally expected to 

be of only minor importance for NPP incidents, the inhalation pathway would contribute additional 

doses to internal organs. Inhalation dose, however, would be an important exposure pathway for 

radiological incidents with significant fractions of pure beta emitters or alpha emitters.

 Internal exposure from the ingestion of food and water. In rare cases, where food or drinking 

water are contaminated to levels above the PAG for ingestion, and withdrawal of food and/or 

water from use would, in itself, create a health risk greater than that from the radiation dose, the 

committed effective dose from ingestion should be added to the dose from the above pathways for 

comparison to the relocation PAG. 

Other potentially significant exposure pathways include exposure to beta radiation from surface 

contamination (e.g., beta dose to skin) and direct ingestion of contaminated soil. These pathways are not

expected to be controlling for NPP incidents (Aaberg 1989). 
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4.2 THE PROTECTIVE ACTION GUIDES AND PROTECTIVE ACTIONS FOR 

THE INTERMEDIATE PHASE: RELOCATION AND DOSE REDUCTION

The principal protective actions for reducing exposure of the public to deposited radioactive materials are: 

 Relocation; 

 Decontamination; 

 Shielding; 

 Time limits on exposure; and 

 Control of the spread of surface contamination.

The most effective of these actions is relocation—the removal or continued exclusion of people 

(households) from contaminated areas to avoid chronic radiation exposure. Relocation is highly disruptive 

and therefore only implemented when the dose is sufficiently high to warrant it. The PAG for relocation is 

2 rem (20 mSv) projected over the first year of exposure. After the first year, the PAG for relocation is 0.5 

rem (5 mSv) per year.

The PAG level for relocation applies to doses that can be avoided by relocation; doses already incurred 

prior to relocation are not included in the calculations. PAGs for protection from deposited radioactivity 

during the intermediate phase are summarized in Table 4-1. The decision to relocate will be considered on

a case-by-case basis. Efforts to decontaminate and remediate the contaminated area and the shielding 

offered by buildings and the residency factor attributable to the building, must be considered to see if 

either relocation PAG will be exceeded. 

It may be difficult to avoid exceeding the relocation PAGs for the radionuclides most likely associated 

with RDDs because of their longer half-lives. If these radionuclides are released, it may be necessary to 

relocate people in the affected areas even if exposure is less than 2 rem (20 mSv) in the first year, 

provided decontamination and remediation measures during the first year are unsuccessful.

In most scenarios, relocation decisions will be based on doses from external exposure to the whole body 

from deposited radioactive materials and internal exposure from inhalation of resuspended deposited 

material. 

Food and milk ingestion dose should be considered separately with decisions based on the FDA PAGs 

(FDA 1998).30 The FRMAC Assessment Manuals

31 provide guidance in calculating Ingestion Derived 

Response Levels (DRLs) that indicate the levels of deposited radioactive materials that may result in food 

exceeding the FDA PAGs. 

Other protective actions, such as simple dose reduction techniques, can be applied in areas where levels of 

deposited radioactivity are not high enough to warrant relocation. Dose reduction actions can range from 

the simple—scrubbing or flushing surfaces, removal and disposal of small spots of highly contaminated 

soil (e.g., from settlement of water), and spending more time than usual in lower exposure rate areas (e.g., 

indoors)—to the difficult and time consuming processes of removal, disposal and replacement of 

contaminated surfaces. The simple processes would probably be most appropriate in contaminated areas 

outside the relocation area. Many of these can be carried out by the residents with support from officials 

for monitoring and guidance on appropriate actions and disposal. The more difficult processes will be 

appropriate for recovery of areas where contamination is fixed (not removable) and from which the 

population is relocated. 

 

30 See: http://www.fda.gov/downloads/MedicalDevices/DeviceRegulationandGuidance/GuidanceDocuments/UCM094513.pdf. 31 See FRMAC Assessment Manuals at http://nnss.gov/pages/programs/FRMAC/FRMAC_DocumentsManuals.html. 
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Access to and/or activities within large areas may have to be restricted under these PAGs. As the land area

increases, protective actions become more difficult and costly to implement, especially when the affected 

area is densely populated. There may be situations where full implementation of early and intermediate 

phase protective actions is impracticable (e.g., a release in a large city). Informed judgment must be 

exercised to assure priority of protection for individuals in areas having the highest exposure rates.

Table 4-1. PAGs and Protective Actions for Exposure to Deposited Radioactivity during the 

Intermediate Phase of a Radiological Incidenta

Protective Action

Recommendation

PAG or Guideline Comments

Relocation of the publicb PAG: > 2 rem (20 mSv) projected dosec in the first

year,

0.5 rem (5 mSv)/year projected dose

c in the second

and subsequent years

Projected dose over one

year of exposure. 

Apply simple dose reduction

techniquesd

Guideline: < 2 rem (20 mSv) projected dose

c in 

the first year

These protective actions 

should be taken to reduce

doses to as low as

practicable levels. 

Food interdictione PAG: 0.5 rem (5 mSv)/year projected whole body

dose, or 5 rem (50 mSv)/year to any individual

organ or tissue, whichever is limiting

Drinking Water PAG: 100 mrem (1 mSv or 0.1 rem) projected 

dose, for one year, to the most sensitive 

populations (e.g., infants, children, pregnant 

women and nursing women); 

500 mrem (5 mSv or 0.5 rem) projected dose, for 

one year, to the general population

See Section 4.6

Reentry Guideline: Operational Guidelinesf (stay times and

concentrations) for specific reentry activities (see

Section 4.5) 

a This guidance does not address or impact site cleanups occurring under other statutory authorities such as the United States 

Environmental Protection Agency’s (EPA) Superfund program, the Nuclear Regulatory Commission’s (NRC)

decommissioning program, or other federal or state cleanup programs.

b People previously evacuated from areas outside the relocation area defined by this PAG may return to occupy their 

residences. Cases involving relocation of people at high risk from such action (e.g., patients under intensive care) may be

evaluated individually.

c Projected dose refers to the dose that would be received, by default, in the absence of shielding from structures or the

application of dose reduction techniques. These PAGs may not provide adequate protection from some long-lived

radionuclides (see Section 4.4). Incident-specific factors should be considered.

d Simple dose reduction techniques include scrubbing or flushing hard surfaces, minor removal of soil from spots where

radioactive materials have concentrated, and spending more time than usual indoors or in other low exposure rate areas.

e For more information on food and animal feeds guidance, the complete FDA guidance (FDA 1998) may be found at

http://www.fda.gov/downloads/MedicalDevices/DeviceRegulationandGuidance/GuidanceDocuments/UCM094513.pdf. 

f For extensive technical and practical implementation information please see “Preliminary Report on Operational Guidelines

Developed for Use in Emergency Preparedness and Response to a Radiological Dispersal Device Incident” (DOE 2009).
Protective Action Guides and Planning Guidance for Radiological Incidents 43

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4.2.1 Removal of the 50 Year Relocation PAG

For simplicity, the 1992 relocation PAG of 5 rem (50 mSv) over 50 years has been removed from this 

Manual. It is rarely, if ever, the driver for extending a relocation area beyond that prompted by the first or 

second year relocation PAGs in scenarios that have been analyzed. Additionally, dose projections over 50 

years after a radiological incident for various age groups show no significant differences for individuals 

exposed at 3 months of age versus adult. A response organization may wish to project 50-year doses to 

inform decision-making, but should consider weathering, decay, credit for time spent indoors, and to the 

extent it can be predicted, dose reduction from mitigation activities. To keep emergency management 

decisions as simple as possible, the recommended relocation PAGs are 2 rem (20 mSv) projected over the 

first year, and 0.5 rem (5 mSv) projected over any subsequent year. 

4.2.2 The Population Affected

The PAGs for relocation are intended for use in establishing the boundary of a relocation area within an 

area where radioactive materials have been deposited. The relocation PAGs have been established at a 

level that will provide adequate protection for the general population, including higher risk groups such as 

children and fetuses. People residing in contaminated areas outside the relocation area will be at some risk 

from radiation dose. Therefore, guidance on the reduction of dose during the first year to residents outside 

this zone is also provided. Monitoring and simple dose reduction efforts are recommended in these areas 

to reduce doses to the extent practical. Such actions are unlikely to be practical where the dose reduction 

achieved is less than 10 percent.

Affected populations may perceive that intermediate phase protective actions are not consistent with those 

taken in the early phase. Early-phase decisions on sheltering-in-place and evacuation may have been 

implemented prior to verification of the path of the plume. Therefore, some people may have been 

evacuated from areas where validated doses are much lower than were projected. Others who were in the 

path of the plume may have been sheltered or not protected at all. During the intermediate phase of the 

response, dose projections may be revised based on environmental measurements. People should be 

relocated from areas where the projected dose exceeds the PAG for relocation without regard to prior 

evacuation status. 

4.2.3 Areas Involved

Figure 4-1 provides a generalized example of the areas affected by different protective actions. Area 1 

represents the plume deposition area. (In reality, variations in meteorological conditions would almost 

certainly produce a more complicated shape, but the same principles would apply.) 

In situations such as an NPP accident, where early warning is given prior to a release of radioactive 

materials, people may already have been evacuated from Area 2 and sheltered in Area 3. People who have 

been evacuated from Area 2 or sheltered in Area 3 may go home if environmental monitoring verifies that 

their residences are outside the plume deposition area (Area 1). 

Area 4 is the relocation area where projected doses are equal to or greater than the relocation PAG. People 

residing just outside the boundary of the relocation area may receive a dose approaching the PAG for

relocation if decontamination or other dose reduction efforts are not implemented. 

Area 1, with the exception of the relocation area, represents the area of contamination that may continue 

to be occupied by the general public during the intermediate phase. Nevertheless, there will be 

contamination levels in this area that will require continued monitoring and dose reduction efforts other 

than relocation. Incident-specific levels below the PAGs may be used to control exposure to 

contamination. The relative positions of the boundaries shown in Figure 4-1 depend on areas evacuated 

and sheltered and the radiological and meteorological characteristics of the release. For example, Area 4 

(the relocation area) could fall entirely inside Area 2 (area evacuated), so that the only people to be 
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PAG Manual EPA-400/R-17/001

relocated would be those residing in Area 4 who were either missed in the evacuation process or who, 

because of mobility constraints for their evacuation, had remained sheltered-in-place during plume 

passage.

Establishing the boundary of a relocation area creates three groups of affected people— 

 People who have already been evacuated from an area that is now designated as a relocation area 

and who now must be assigned relocation status.

 People who were not previously evacuated, but who reside inside the relocation area and should 

now relocate.

 People who were previously evacuated, but reside outside the relocation area and may now return 

home. A staged and deliberate return is recommended. 

Small adjustments to the boundary of the relocation area established based on the PAG may be justified 

based on ease of implementation. For example, the use of a convenient natural boundary could be a 

logical reason for adjustment of the relocation area. However, such decisions should be supported by 

demonstration that exposure rates to people not relocated can be promptly reduced by methods other than 

relocation to meet the PAG, as well as the longer-term dose guidelines addressed in Section 4.4. 

Figure 4-1. Generalized Protective Action Areas for NPP Incident

The relocation PAGs apply principally to personal residences but may impact other facilities as well. For 

example, it could impact work locations, hospitals and park lands as well as the use of highways and other 

transportation facilities. For each type of facility, the occupancy time of individuals should be taken into 

account to determine the criteria for using a facility or area. It might be necessary to avoid continuous use 

of homes in an area because radiation levels are too high. However, a factory or office building in the 

same area could be used because occupancy times are shorter. Similarly, a highway could be used at 
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higher contamination levels because the exposure time of highway users would be considerably less than 

the time spent at home. 

4.2.4 Priorities

In most cases, protective actions during the intermediate phase will be carried out over a relatively long 

period of time (e.g., months). Setting priorities will be important, especially when the affected area is so 

large that it is impractical to relocate members of the public from areas that barely exceed the relocation 

PAGs. The following priorities are appropriate— 

 First, protect all people from doses that could cause acute health effects from all exposure pathways, 

including previous exposure to the plume. 

 Conduct radiological surveys to verify or adjust estimates of radiological impacts.

 Recommend that affected people reduce their exposures by using simple decontamination techniques 

and remaining indoors. 

4.3 SEQUENCE OF EVENTS

The high-priority decisions on whether to relocate people from high exposure rate areas requires exposure 

rate measurements and dose analyses. Monitoring and dose assessment will be an ongoing process, with 

priority given to the areas with the highest exposure rates.

Following passage of the airborne plume, a number of tasks must be accomplished for the timely 

protection of the public. The general sequence of events is itemized below, but the time frames will 

overlap.

1. Determine the areas where the projected first-year dose will exceed the 2 rem (20 mSv)

relocation PAG and relocate people from those areas, with priority given to people in the 

highest exposure rate areas.

2. Allow previously evacuated people to return as quickly as possible to areas where field 

measurements indicate that exposure rates are near normal background levels. If there is a 

possibility that particles from high deposition areas could drift into the occupied areas, establish 

a buffer zone to restrict residential use until radiological measurements and assessments confirm 

that it is no longer necessary. Buffer zones are set with the understanding that conservatism is 

inherent in the PAGs.

3. Based on isodose-rate boundary (see Section 4.3.1), assign any evacuees who reside within the 

relocation area to be relocated. Evacuated people whose residence is in the area between the 

boundary of the plume deposition and the boundary to the relocation area may return gradually 

as dose projections allow.

4. Evaluate the dose reduction effectiveness of simple decontamination techniques and of 

sheltering-in-place in response to exposure from partial occupancy of residences and 

workplaces. Results of these evaluations may influence recommendations for reducing exposure 

rates for people who are not relocated from areas near, but outside, the relocation area.

5. Control access to and egress from the relocation area. This would be accomplished through 

control points at roadway accesses to the relocation area.

6. Establish monitoring and decontamination stations to support control of the relocation area.

7. Implement simple decontamination techniques in contaminated areas outside the relocation 

area, giving priority to areas with higher exposure rates.

8. Collect data needed to establish long-term radiation protection criteria for decontamination and 

dose reduction and data to determine the effectiveness of various decontamination or other dose 

reduction techniques. 

9. Begin operations to clean up and recover contaminated property in the relocation area.
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10. If not already done, evaluate whether foods grown or produced within the plume deposition area 

need to be interdicted per the FDA PAGs and evaluate drinking water systems within the plume 

deposition area. Provide guidance on planting or harvesting specific agricultural products. 

4.3.1 Establishment of Isodose-Rate Lines

As soon as federal or other assistance is available for aerial and ground monitoring, a concentrated effort 

should begin to establish isodose-rate lines on maps and identify boundaries of the relocation area. 

Standard maps should be developed on which all response organizations would record monitoring data. 

Records on monitoring and decontamination of the public and workers should also be collected.

Aerial monitoring can be used to collect data for establishing general patterns of radiation exposure rates 

and may form the primary basis for the development of dose lines out to the limit of aerial detectability.

Initially during the early phase, detectability is limited to exposure rate changes of a few times natural 

background levels. Later during the intermediate phase, more sensitive measurements detect levels of 

radioactivity that are a small fraction of the natural background. Periodic air sample measurements will 

also be needed to verify the contribution to dose from inhalation of resuspended materials.

Gamma exposure rates measured at approximately three feet (one meter) will vary within a very small

area because different surfaces have different deposition rates (e.g., smooth surfaces versus heavy

vegetation). Rinsing or precipitation could also reduce levels in some areas and raise levels in others (e.g., 

where runoff settles). In general, where exposure rates vary within designated areas, dose projections 

should be estimated using an appropriate average exposure rate.

4.3.2 Dose Projections

The FRMAC Assessment Manuals32 provide detailed guidance for dose projection and calculating DRLs 

and DPs. The FRMAC Assessment Manuals incorporate the ICRP dosimetry models (currently the ICRP

60 series). In addition, the FRPCC encourages the use of computational tools such as DOE’s Turbo 

FRMAC and NRC’s RASCAL or other appropriate tools and methods to implement the PAGs.

The primary dose of interest in the intermediate phase is the sum of the effective dose from external 

exposure and the committed effective dose from inhalation. The exposure periods of interest are the first 

year and subsequent years after the incident. Other pathways should also be evaluated and their 

contributions considered, if significant. For example, any time alpha-emitting radionuclides are involved, 

the inhalation of resuspended material must be considered. Although beta exposure will contribute to skin 

dose, its contribution to the overall risk of health effects from the radionuclides expected to be associated 

with reactor incidents should not be controlling in comparison to the whole body gamma dose (Aaberg 

1989). However, the skin beta dose may be important for particulates deposited or transferred to the skin, 

as may be the case for an RDD that contains Strontium-90. 

The dominant intermediate phase exposure pathway for incidents involving alpha-emitters (e.g., a 

weapons accident) is inhalation of resuspended material. For these incidents, dispersal of alpha-emitting 

material must be monitored carefully using proper measurement techniques. It is possible that there will 

be little or no associated gamma radiation or beta activity.

Calculation of the projected gamma dose from measurements will require knowledge of the principal 

radionuclides contributing to exposure and their relative abundances. Radiological characteristics can be 

compiled either through the use of portable gamma spectrometers or by radionuclide analysis of 

environmental samples. Several measurement locations may be required to determine whether any 

selective radionuclide deposition occurred as a function of meteorology, surface type, distance from the 

 

32 See FRMAC Assessment Manuals at http://nnss.gov/pages/programs/FRMAC/FRMAC_DocumentsManuals.html.
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point of release, or other factors. In accordance with the “Nuclear Radiological Incident Annex to the 

National Response Framework,” DOE, EPA and other federal agencies have the capability to assist state 

officials in performing environmental measurements, including determination of radiological 

characteristics of deposited materials (FEMA 2008b).

The gamma exposure rate may decrease rapidly if deposited materials include a significant fraction of 

short-lived radionuclides. Therefore, the relationship between instantaneous exposure rate and projected 

first- and second-year annual doses will change as a function of time. These relationships must be 

established for the particular mix of deposited radioactive materials present at the time of the gamma 

exposure rate measurement. Over time, residual doses from gamma emitters will depend largely upon the 

half-lives of the radionuclides involved and could potentially remain significant over many years. It 

should be noted that natural attenuation as well as nuclear decay can affect long-term dose assessments.

Because intermediate phase public protection decisions (e.g., relocation, reentry) have less urgency than 

early phase decisions and the contamination is better characterized in the intermediate phase, it may be 

possible to improve the public protection decisions by modifying dose estimates with more realistic 

inputs. For example, the external dose reductions provided by building structures and dose reductions 

resulting from partial occupancy in the contaminated zone, which accounts for routine time spent outside 

the contaminated zone (e.g., work, school, shopping), may be included in the dose projections to make 

improved public protection decisions. 

Projected dose considers exposure rate reduction from radioactive decay and, generally, weathering. 

When one also considers the anticipated effects of shielding from normal part time occupancy in homes 

and other structures, people who are not relocated are likely to receive a dose substantially less than the 

projected dose. For commonly assumed reactor source-terms, it is estimated that 2 rem (20 mSv)

projected dose in the first year will be reduced to about 1.2 rem (12 mSv) by this factor. The application of 

simple decontamination techniques shortly after the incident can be assumed to provide a further 30 

percent or more reduction so that the maximum first year dose to people who are not relocated is expected 

to be less than 1 rem (10 mSv). Taking account of decay rates assumed to be associated with releases from 

NPP incidents (SNL 1982) and shielding from partial occupancy and weathering, a projected dose of 2

rem (20 mSv) in the first year is likely to amount to an actual dose of 0.5 rem (5 mSv) or less in the 

second year. The application of simple dose reduction techniques would reduce the dose further.

Calculations supporting these projections are summarized in Table E-6 of the 1992 PAG Manual.33

Keeping below the 0.5 rem (5 mSv) PAG for subsequent years—the second year and beyond—may be 

achieved through natural decay of shorter half-life radioisotopes, through decontamination efforts, or 

through other means of controlling public exposures (such as limiting access to certain areas). In the case 

of an RDD, in which a longer half-life radioisotope would likely be utilized, reductions in dose may prove 

difficult to achieve without longer-term measures (see Chapter 5).

Exposure from ingestion of food and water is considered independently of decisions for relocation and 

decontamination. In rare instances, however, where withdrawal of food or water from use would pose a 

health risk in itself, relocation may be an appropriate protective action against exposure via ingestion. In 

this case, the dose from ingestion should be considered along with the projected dose from other exposure 

pathways for decisions on relocation. 

4.3.3 Projected External Gamma Dose

Projected whole body external gamma doses at approximately three feet (one meter) height at particular 

locations during the first year and second year after the incident are the parameters of interest (DOE 

 

33 The 1992 PAG Manual is available as a historical reference online at: http://www.epa.gov/radiation/protective-action-guidespags. 
Protective Action Guides and Planning Guidance for Radiological Incidents 48

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1988). Measurements made at 1 meter to project whole body dose from gamma radiation should be made 

with instruments of the "closed window" type to avoid the detection of beta radiation. The environmental 

information available for calculating these doses is expected to be the current gamma exposure rate at 1 

meter height and the relative abundance of each radionuclide contributing significantly to that exposure 

rate. Calculation models are available for predicting future exposure rates as a function of time with

consideration of radioactive decay and weathering. 

Relocation decisions can generally be made on the basis of the first year projected dose. However, 

projected doses during the second year are needed for decisions on protective actions for people who are 

not relocated. Conversion factors are therefore needed to convert environmental measurements to 

projected dose during the first year and second year following the incident (see FRMAC Assessment

Manuals).34 Of the many types of environmental measurements that can be made to project whole body

external gamma dose, gamma exposure rate in air is the easiest to make and is the most directly linked to 

gamma dose rate. However, analyses of a few environmental samples (particularly soil samples) must be 

coupled with the gamma exposure rate to properly project decreasing dose rates.

In addition, measurements should be conducted to determine the dose reduction factors associated with 

simple, rapid, decontamination techniques so that these factors can be used in calculating dose to people 

who are not relocated. However, assumptions about these factors should not be included in calculating 

projected dose for decisions on relocation. Only dose reductions already accomplished should be 

considered. 

4.3.4 Exposure Limits for People Reentering the Relocation Area

After the relocation area is established, people will need to reenter for a variety of reasons, including 

recovery activities, retrieval of property, security patrol, operation of vital services and, in some cases, 

care and feeding of farm and other animals. It may be possible to quickly decontaminate access ways to 

vital institutions and businesses in certain areas so that they can be occupied by adults either for living 

(i.e., institutions such as nursing homes and hospitals) or for employment. Clearance for occupancy of 

such areas will require dose reduction to meet exposure limits (EPA 1987b). Dose projections should 

include both external exposure from deposited material and inhalation of resuspended deposited material 

for the duration of the planned exposure. People working in areas inside the relocation area should operate 

under the controlled conditions established for occupational exposure (EPA 1987b). The emergency 

worker dose limitation does not need to include ongoing doses received from living in a contaminated 

area outside the relocation area. It is also not necessary to consider dose received previously from the 

plume or groundshine during the early phase of the radiological incident. See the Reentry Matrix in 

Section 4.5, Table 4-2. It provides a quick reference for public and emergency worker dose guidelines and 

considerations for decontamination ongoing during this phase. 

4.4 LONGER-TERM OBJECTIVES OF THE PROTECTIVE ACTION GUIDES 

FOR THE INTERMEDIATE PHASE

It is an objective of the PAGs to ensure that doses in any single year after the first year will not exceed 0.5 

rem (5 mSv). For source terms from NPP incidents, the PAG of 2 rem (20 mSv) projected dose in the first 

year is expected to meet this longer-term objective through radioactive decay, weathering, and normal 

part-time occupancy in structures. If the release contains long-lived radionuclides, decontamination of 

areas outside the relocation area may be required during the first year to meet these objectives. For 

situations where it is impractical to meet these objectives through decontamination, relocation should be 

considered even if the projected first-year dose is lower than the relocation PAG.

 

34 See FRMAC Assessment Manuals at http://nnss.gov/pages/programs/FRMAC/FRMAC_DocumentsManuals.html. 
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Based on the relocation PAGs, reentry guidance can be found in the Reentry Matrix in Section 4.5, as well

as in the “Preliminary Report on Operational Guidelines Developed for Use in Emergency Preparedness

and Response to a Radiological Dispersal Device Incident” (DOE 2009),35 referred to as “Operational 

Guidelines.” After the population has been protected in accordance with the PAGs for relocation,

reoccupancy of the relocation areas should be governed on the basis of cleanup criteria and late phase

cleanup activities should proceed. Refer to the Operational Guidelines manual for more information on 

how to implement the reentry guides in emergency plans.

4.5 REENTRY MATRIX FOLLOWING A RADIOLOGICAL INCIDENT OR 

ACCIDENT

During the intermediate phase, people will need to enter the relocation area to collect their belongings, 

maintain or repair critical infrastructure, and to work on preliminary recovery activities. The Reentry 

Matrix in Table 4-2 provides a quick reference for public and worker dose guidelines and considerations 

for decontamination ongoing during this phase. 

The “Preliminary Report on Operational Guidelines Developed for Use in Emergency Preparedness and 

Response to a Radiological Dispersal Device Incident” (DOE 2009), referred to as “Operational 

Guidelines,” includes detailed numeric guidance, developed by a multi-agency working group as a 

follow-up to the RDD/IND Planning Guidance (DHS 2008). That work focused specifically on response 

and recovery for an RDD event; however, that work can be expanded to include isotopes from a variety of 

incident types.

The Operational Guidelines are informative for this guidance, specifically the discussions about 

applicable dose-based limits, timeframes and pathways of exposure related to reentry tasks. The term 

reentry is used for emergency workers and members of the public going into radiologically contaminated 

areas, temporarily, under controlled conditions. Food and agriculture guides use FRMAC methods and 

models as well as the Operational Guidelines for implementation. These tools allow derivation of

decontamination thresholds for the early and intermediate stages of a response.

As part of the U.S. response to the Japanese Fukushima accident, scientists performed dose calculations to 

ensure that passengers and workers on train trips through contaminated areas do not exceed doses 

typically received from cosmic radiation during an international flight. DOE’s Argonne National 

Laboratory scientists utilized the RESRAD-RDD tool and hand calculations to approximate doses from 

the NPP radionuclides.36

 

35 The Operational Guidelines were developed by federal agencies and published by DOE in February 2009, DOE/HS-0001; 

ANL/EVS/TM/09-1, online at http://web.ead.anl.gov/resrad/documents/ogt_manual_doe_hs_0001_2_24_2009c.pdf. (DOE 2009) 36 RESRAD Family of Codes; Environmental Science Division of Argonne National Laboratory, online at 

https://web.evs.anl.gov/resrad. 
Protective Action Guides and Planning Guidance for Radiological Incidents 50

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Table 4-2. Reentry Matrix: Quick Reference to Operational Guidelinesa

PHASE ACTIVITY SUGGESTED LEVELS CLEANUP ACTIONSb

Early 

Phase

Sheltering or

Evacuation

for the

Public

Public: 1-5 rem (10-50 mSv) 

projected over four days (see 

Chapter 2). A decision to 

evacuate weighs anticipated 

dose against feasibility of 

evacuating within a 

determined time frame, along 

with the risks associated with 

the evacuation itself.

It is too early for organized cleanup, due to chaos of 

the situation and higher priorities such as lifesaving 

activities and clearly identifying shelter and 

evacuation zones. Any cleanup or decontamination 

information should focus on personal 

decontamination. It is doubtful any large-scale 

effort could change evacuation or shelter 

recommendations during this period (first 4 days).

Once evacuation is completed, there are simple 

actions that cities can implement themselves: 

rinsing roofs and streets, street sweeping. The 

objective of these actions is to move the bulk 

amounts of contamination away from occupied 

areas or areas where reoccupation is a priority. 

These actions should be based on measured 

amounts of contamination and priority of the 

location.

Workers may face high dose levels and will need 

health physics support.

Emergency 

Worker

Protection

Emergency Worker: 5/10/25 

rem (50/100/250 mSv) 

incurred over the response 

duration. The higher limits are 

based on task (e.g., protecting 

large populations or critical 

infrastructure or lifesaving). 

Emergency worker doses will 

be tracked with dosimeters.

Emergency workers have 

knowledge of the risks 

associated with radiation 

exposure, training to protect 

themselves, and dosimeters to 

track their doses (see 

Chapter 3).

Intermediate 

Phase

Relocation 

for the 

Public

Public: 2 rem (20 mSv) 

projected first year, 0.5 rem (5 

mSv) per year projected in 

subsequent years (see 

Chapter 4).

In this phase, scientists run 

dose calculations with 

RESRAD-RDD or Turbo 

FRMAC; the user can choose 

sensitive age groups, or enter 

lower guidelines, if desired. 

Additionally, local decisionmakers can adapt the 

guidelines with incidentspecific considerations and 

implement variations as 

needed.

Early cleanup efforts should focus on the removable 

portion of the contamination: vacuuming, washing, 

vegetation removal. 

 Vacuuming has the advantage of collecting 

removable contamination without water or 

surface impact, but is limited by equipment 

availability and can also expose the 

operators to high dose levels as the 

vacuums collect the contamination. 

 Washing and rinsing are simple to 

implement, but only move the 

contamination to less-populated areas and 

may move contamination deeper into 

porous surfaces.

 For unpaved areas, vegetation removal can 

effectively reduce the amount of 

contamination present, but is labor 

intensive and can produce a large amount 

of waste.
Protective Action Guides and Planning Guidance for Radiological Incidents 51

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Table 4-2. Reentry Matrix: Quick Reference to Operational Guidelinesa

PHASE ACTIVITY SUGGESTED LEVELS CLEANUP ACTIONSb

Intermediate 

Phase

Reentry

For Use of 

Critical 

Infrastructure

Public: 2 rem (20 mSv) in 

first year (Preliminary Report 

on Operational Guidelines 

Developed for Use in 

Emergency Preparedness and 

Response to a Radiological 

Dispersal Device Incident,c

Operational Guidelines Group 

C). Dosimeters could be 

considered for the public.

Having addressed the removable part of the 

contamination, later efforts can focus on fixed 

contamination. 

 Paved surface removal is very effective, 

but requires specialized equipment and 

trained operators. 

 Surface sealing is easier, but leaves the 

contamination in place, making it viable 

only in locations where the dose rates are 

low enough for occupation, or in lowoccupancy areas. 

 Repaving roads, lots and other paved 

surfaces is easy to implement, but can

generate significant waste volumes. 

 Unpaved areas can be further remediated 

by soil skimming (surface removal), deep 

plowing (turning the top foot or so of soil 

over), and appropriate chemical soil 

amendment methods like liming or 

chelating.

As the intermediate phase progresses, knowledge 

and experience increases and these methods can be 

re-applied, refined or customized for problem areas. 

Decisions about more difficult areas will benefit 

from professional judgment, additional analyses, 

and application of more sophisticated technologies.

Emergency 

Worker 

Protection

Emergency Worker 

Protection: (dose not to 

exceed) 5 rem (50 mSv) per 

year (Radiation Protection 

Guidance to Federal Agencies 

for Occupational Exposure, 

EPA 1987).

Emergency workers have 

knowledge of the risks 

associated with radiation 

exposure, training to protect 

themselves, and dosimeters to 

track their doses (see 

Chapter 3).

During an incident response, 

workers (police, waste 

handlers) needed in 

contaminated areas could be 

trained and given dosimeters. 

The guidance for emergency 

workers applies throughout the 

response.

Reentry

For Use of 

Roads and 

Walkways

Public: 2 rem (20 mSv) first 

year, 0.5 rem (5 mSv) per year 

in subsequent years 

(Operational Guidelines, 

Group E).

While the dose values here are 

similar to those for Use of 

Critical Infrastructure above, 

the derived concentrations 

measured as triggers are 

different because the exposure 

conditions are different.
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Table 4-2. Reentry Matrix: Quick Reference to Operational Guidelinesa

PHASE ACTIVITY SUGGESTED LEVELS CLEANUP ACTIONSb

Intermediate 

Phase

Reentry

For Access to 

the 

Relocation 

Zone

”Stay time” 

is a term of 

art used in 

the radiation 

safety field. 

Stay times 

are the 

amount of 

time a person 

may access 

the 

contaminated 

area. These

times vary 

based upon 

site-specific 

factors or 

incident 

characteristics such as 

indoor or 

outdoor 

work, 

sensitive 

populations, 

and level of 

radioactivity. 

Public: 0.5 rem (5 mSv) over 

one year for temporary access 

with stay times (see definition 

below) dependent on reentry 

tasks and site-specific 

conditions (Operational 

Guidelines, Group D).

Section 7.1 of the Operational 

Guidelines, “Worker Access 

to Businesses for Essential 

Actions,” provides tables and 

graphs of stay times at various 

limiting concentrations (see 

adjacent graph and table). For 

example, if the maximum 

surface street concentration of 

Cesium-137 is 3.00E+09 

pCi/m2 (1.11E+08 Bq/m2), 

people limited to 0.5 rem 

(5 mSv) should be in the 

contaminated area less than 

four 8-hour days if staying 

outdoors.

This may apply to individuals 

retrieving belongings from 

homes or to workers providing 

security patrols, or even to 

people reopening businesses in 

the area. As contamination 

levels are reduced during 

cleanup, stay times can be 

extended and total doses 

reduced.

These graphics below are examples based on 

Operational Guidelines.c Please refer to the full 

report for tables and graphics for use in emergency 

preparedness.

Operational Guidelines for 0.5 rem Annual Dose: 

Residents Access to Houses (Indoor Exposure)

Operational Guidelines provide stay times and concentrations for several different sets of assumptions about the exposure.

Residents retrieving possessions may spend most of their time indoors, where stay times are longer than they are for outdoor

tasks. Stay time recommendations can be used to guide decisions about allowing entry into the contaminated area for a limited

time and dose reduction techniques like wearing dust masks, cleaning shoes and car tires upon exit, and using time wisely to

keep radiation exposure “ALARA” below the Operational Guideline.

a This guidance does not address or impact site cleanups occurring under other statutory authorities such as the United States 

Environmental Protection Agency’s (EPA) Superfund program, the Nuclear Regulatory Commission’s (NRC)

decommissioning program, or other federal or state cleanup programs.

b This cleanup process does not rely on and does not affect any authority, including the Comprehensive Environmental 

Response, Compensation and Liability Act (CERCLA), 42 U.S.C. 9601 et seq. and the National Contingency Plan (NCP), 40 

CFR Part 300. This document expresses no view as to the availability of legal authority to implement this process in any 

particular situation.

c The Operational Guidelines were developed by federal agencies and published by DOE in February 2009, DOE/HS-0001; 

ANL/EVS/TM/09-1, online at http://web.ead.anl.gov/resrad/documents/ogt_manual_doe_hs_0001_2_24_2009c.pdf. (DOE 

2009)
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4.6 PROTECTIVE ACTION GUIDANCE FOR FOOD AND DRINKING WATER

Information on food and animal feeds protective action guidance is contained in FDA’s “Accidental 

Radioactive Contamination of Human Food and Animal Feeds: Recommendations for State and Local 

Agencies” (FDA 1998). 

EPA developed a new drinking water PAG as non-regulatory guidance to protect the public in the event 

of a radiological incident that affects drinking water supplies. The drinking water PAG will help federal, 

state, local and public water system officials make decisions about use of water during radiological 

emergencies. 

The drinking water PAG is for use only during an emergency; it is not a substitute for compliance with 

EPA’s National Primary Drinking Water Regulations (NPDWRs) for Radionuclides. EPA expects that 

any drinking water system adversely impacted during a radiation incident will take action to return to 

compliance as soon as possible.

4.6.1 Protective Action Guide for Drinking Water

The purpose of the protective action for the drinking water exposure pathway is to restrict the use of 

contaminated water for drinking and to provide recommendations for local communities to consider in 

providing alternative drinking water for the affected community during a nationally significant 

radiological incident, such as a disaster at a nuclear power plant, an RDD or an IDD. The drinking water 

PAGs apply during the intermediate phase of an incident, which may last for weeks to months but not 

longer than one year.37 This guidance only provides recommendations and does not confer any legal 

rights or impose any legally binding requirements upon any member of the public, states, or any other 

federal agency.

38

EPA recommends a two-tier drinking water PAG for use during the intermediate phase following a 

nationally significant radiation incident: 500mrem (5 mSv or 0.5 rem) projected dose39 for the general 

population (defined as anyone over age 15, excluding pregnant women and nursing women), and 100 

mrem (1 mSv or 0.1 rem) projected dose for pregnant women, nursing women, and children age 15 and 

under.40 

This guidance does not in any way affect public water systems' compliance obligations under applicable 

NPDWRs promulgated under the Safe Drinking Water Act (SDWA). EPA expects that the responsible 

party for any drinking water system adversely impacted during a radiation incident will take action to 

return to compliance with SDWA maximum contaminant levels (MCLs) as soon as practicable. The 

drinking water PAG provides a level of protection for the general population consistent with PAGs 

currently in place for other media in the intermediate phase (i.e., the FDA’s 500 mrem PAG for ingestion 

of food; FDA 1998, FDA 2004) and provides an additional level of protection for the most sensitive life 

stages. Intermediate phase doses can be projected using a 1-year duration and compared to the PAG so 

 

37 The intermediate phase is defined as the period beginning after the source and releases have been brought under control (has 

not necessarily stopped but is no longer growing) and reliable environmental measurements are available for use as a basis for 

decisions on protective actions and extending until these protective actions are no longer needed. The intermediate phase includes 

protective action recommendations for relocation of the public, worker exposure, reentry, food interdiction, and water 

interdiction.

38 This guidance does not address or impact actions occurring under other statutory authorities such as the United States 

Environmental Protection Agency’s (EPA) Superfund program, the Nuclear Regulatory Commission’s (NRC) decommissioning 

program, or other federal or state programs. As indicated by the use of non-mandatory language such as “may,” “should” and 

“can,” this guidance only provides recommendations and does not confer any legal rights or impose any legally binding 

requirements upon any member of the public, states, or any other federal agency.

39 All dose values are expressed as Committed Effective Dose projected over a person’s lifetime based on one year of intake. 40 Emergency management officials may consider whether it is appropriate to extend the lower tier to individuals beyond age 15 

or to women who are trying to get pregnant or who believe they might be pregnant.
Protective Action Guides and Planning Guidance for Radiological Incidents 54

PAG Manual EPA-400/R-17/001

that actions can be taken to avoid the exposure. PAG levels were calculated based on a maximum 1-year 

exposure and provide a level of protection roughly equivalent to applicable NPDWRs for radiation, which 

are based on 70 years of exposure. 

The FDA food PAG (FDA 1998) and the drinking water PAG are designed to complement each other, 

and allow emergency response officials to account for and address doses from both eating contaminated 

food and drinking contaminated water. The food ingestion and drinking water pathways are inherently 

related because both address exposure through ingestion. In addition, water may be used in the 

preparation of some food products, and radionuclides in water may affect crops and ultimately enter the 

food supply. The FDA food PAG accounts for water intrinsic in food as purchased and EPA’s water PAG 

accounts for drinking water, including water added to foods during preparation.41

PAGs for both food and drinking water are needed because a radiological incident may affect the food 

supply and drinking water differently. In addition, because drinking water is usually locally controlled 

and food is frequently shipped in from distant locations, different and separate interdiction approaches 

would be appropriate. Finally, the various PAGs are designed to work in concert, allowing emergency 

responders to choose the exposure reduction strategies that match the exposure scenario, community 

needs, and resources available in the particular emergency.

While food safety and drinking water personnel would work closely together in a radiological response, 

the authorities related to food and drinking water safety are separate, and different strategies may be 

needed to protect drinking water and the food supply. 

A PAG is intended as a point of reference to aid emergency response managers in their decision-making. 

After an emergency situation stabilizes and becomes more clearly defined, local authorities may wish to 

modify the PAG level they consider to be appropriate in order to implement longer-term dose reduction 

strategies. EPA expects that the responsible party for any drinking water system adversely impacted 

during a radiation incident will take action to return to compliance with SDWA MCLs as soon as 

practicable. 

Should a major radiological event occur, emergency response officials should consider potential doses 

from all affected pathways (e.g., airborne plume, ground contamination, drinking water, foods) when 

making protective action decisions. The drinking water PAG is focused solely on drinking water 

exposures and does not take into account other exposure pathways; decision makers may want to adjust to 

account for cumulative doses (see Section 1.4.3). Consideration of the specific conditions facing a 

community should be used in determining how each PAG should be implemented. Protective actions 

might include restrictions on consumption of garden produce or locally produced foods, or an embargo on 

sales of certain products, as well as drinking water actions described in Section 4.6.5 of this guidance. 

Local decision makers will need to determine the appropriate protective actions depending on projected 

dose. Guidance in this Manual is intentionally flexible to allow the many different potential protective 

actions to be tailored to the specific risks that must be addressed. 

Section 4.6.6 explains how to calculate Derived Response Levels (DRLs) for radionuclides likely to 

appear in drinking water following a radiological contamination incident.42 DRLs are concentrations of 

radionuclides in drinking water that correspond to EPA’s recommended PAGs of 100 mrem and 500 

mrem. DRLs are essential because a PAG identifies a radiation dose rather than a quantity of 

radionuclides that can be measured directly in drinking water. DRLs are expressed in units of picocuries 

per liter (pCi/L) or becquerel per liter (Bq/L), and can be directly compared to measured radionuclide 

 

41 Liquid beverages as well as milk are covered under the FDA food PAG (FDA 1998). 42 EPA selected I-131, Sr-90/Y-90, and Cs-137 as indicator isotopes likely to appear in water following a radiation contamination 

incident, and these were selected based on previous documented experience. However, DRLs can be calculated for different 

isotopes by using dose conversion factors included in Federal Guidance Report #13 (EPA 1999).
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PAG Manual EPA-400/R-17/001

concentrations in finished drinking water. In most situations, by the intermediate phase, responders will 

have enough information about the source of radiation to develop site-specific DRLs. In the absence of 

information about local emissions sources and isotopes, particularly in the early phase, EPA recommends 

using conservative assumptions to fill information gaps, which might include assuming no decay of 

isotopes over the calculated 1-year exposure period, to guide actions to protect the public in the event of a 

major radiological incident that affects drinking water sources.

4.6.2 Factors EPA considered when establishing the drinking water PAG

Section 1.3.2 of this PAG manual provides the following three principles for establishing PAGs. 

1. Prevent acute effects. 

2. Balance protection with other important factors and ensure that actions result in more benefit than 

harm. 

3. Reduce risk of chronic effects. 

EPA crafted the drinking water PAG with these same principles in mind. Specifically, consideration was 

given to the acute effects of exposure to radiation and lifetime risk of cancer based on age and drinking 

water intake. EPA made use of the risk conversion factors set forth in Federal Guidance Report #13 (EPA 

1999) and considerations of risk to the unborn set forth in NCRP Report No. 174 (NCRP 2013). 

The drinking water PAG was developed based on reducing risks associated with ingesting drinking water 

contaminated with radionuclides. EPA also considered the potential radiation dose people could receive 

from various other uses of contaminated water, including showering, bathing, and dishwashing. In the 

United States, people typically shower, bathe, and wash dishes using the same source of water that they 

use to drink, but, for the radionuclides of interest, dermal and inhalation exposures from these activities 

generally represent much smaller risk than drinking contaminated water. Protection of a community’s 

drinking water supply based on assumptions about ingestion will also protect the population from undue 

risk from contaminated drinking water by other routes of exposure. 

4.6.3 Rationale for a two-tier Drinking Water PAG

The two-tier PAG consists of 500 mrem (5 mSv or 0.5 rem) for the general population, and a more 

stringent PAG of 100 mrem (1 mSv or 0.1 rem) to inform protective actions for pregnant women, nursing 

women, and children age 15 and under. Fetuses, infants and children are at greater risk from radiological 

exposures than adults due to the greater sensitivity of the developing body to the potential harmful effects 

of radiation and the longer dose commitment period for the longer-lived radionuclides that clear slowly 

from the body. A newborn that ingests radioactive material in water (e.g., through formula) would be 

expected to be subject to the effects of that radiation for a longer period of time than if the same dose was 

experienced by an adult. 

For the sake of establishing clear and executable decisions in the intermediate phase of emergency 

response, EPA recommends a uniform PAG for fetuses, infants and children, even though there may be 

considerable differences in the transmission of radiological drinking water contaminants to a fetus via the 

placenta, to an infant via formula or breast milk, and to a child via direct consumption. Specifically, we 

have developed a PAG level designed to provide additional protection to the most sensitive of the three 

subgroups from exposure to radioactivity in drinking water following a radiological incident. Keeping 

PAGs relatively simple helps to minimize confusion during their implementation; however, federal, state, 

and local officials should consider resource availability as they determine when and how to apply either 

of these guidelines. 

The PAG of 500 mrem (5 mSv or 0.5 rem) for the general population is designed to be used in concert 

with the FDA food PAG (FDA 1998) since many of the considerations for a food PAG also apply to 

drinking water. It is also consistent with the guidance value of 500 mrem over one year established by the 
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DHS as an intermediate-phase PAG for drinking water interdiction (DHS 2008). A PAG of 100 mrem (1 

mSv or 0.1 rem) for the most sensitive members of the population provides them with a significant 

additional protection from exposure to radioactivity in drinking water following a radiological incident. 

4.6.3.1 Other Standards

NRC regulations (i.e., 10 CFR Part 20.1301) have established a public radiation protection standard of 

100 mrem per year effective dose. The ICRP recommends reference levels in the range of 2,000 to 10,000 

mrem (20 to 100 mSv) for protection of human health in emergencies, and in the range of 100 to 2,000 

mrem (1 to 20 mSv) for occupational exposure, exposure by caregivers, or residential radon exposure 

(ICRP 2007). Based on a risk reduction approach, EPA recommends that the drinking water PAGs be set 

at the lower (more stringent) end of the latter range to ensure protection of public health. 

Under the SDWA, EPA established MCLs for radiological contaminants in drinking water. The NPDWR 

for Radionuclides, set forth in 40 CFR Part 141, effectively adopted a dose-based limit of 4 mrem per 

year for beta particle and photon radioactivity. These requirements are based on lifetime exposure criteria, 

which assume 70 years of continued exposure to contaminants in drinking water. EPA determined that it 

may not be possible to base protective actions during short-term emergency incidents on lifetime 

exposure criteria. While the SDWA framework is appropriate for day-to-day normal operations, it does 

not provide the necessary tools to assist emergency responders with determining the need for prioritizing 

protective actions during the intermediate phase of a response. However, regardless of the cause of an 

incident, EPA expects that actions will be taken to return the impacted drinking water system to 

compliance with the NPDWR levels by the earliest feasible time. 

4.6.4 Interpreting and Applying the PAG

The drinking water PAG is intended primarily to guide planning and decision-making efforts by local and 

state officials, including drinking water providers, during the intermediate phase of a radiological 

emergency when surface water sources are particularly vulnerable to contamination from deposition of 

radioactive material from the atmosphere. Actions to protect water sources may be implemented at other 

levels and at any time following a radiological incident, and even before an anticipated release occurs. 

The goal is to keep the dose to the public as low as reasonably achievable. Radiation doses should be 

reduced to below SDWA MCLs as soon as practicable.

4.6.4.1 Interpreting the Two-tier PAG

EPA recommends a two-tier PAG: 500 mrem (5 mSv or 0.5 rem) for the general population (anyone over 

age 15, excluding pregnant women and nursing women) and 100 mrem (1 mSv or 0.1 rem) for pregnant 

women, nursing women, and children age 15 and under. 

Authorities have flexibility on how to apply the PAG. In some cases they may find it feasible to use the 

PAG of 100 mrem as a target for the whole population, while in other circumstances, authorities may find 

that it makes sense to use both targets simultaneously. For example, emergency managers can use a twotiered approach to focus on protecting the most sensitive population with limited alternate water 

resources. If bottled water must be rationed, for example, authorities may make the bottled water 

available to children, pregnant women and nursing women, and instruct the rest of the population to use a 

public drinking water supply that will not trigger the 500 mrem PAG. 

As stated above, the PAGs are intended as guidance only, and local authorities should take into account 

local circumstances (e.g., incident scope and community needs) when implementing any course of action 

to protect the public. 
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4.6.4.2 Converting PAGs into Derived Response Levels (DRLs)

The PAG specifies a radiation dose to avoid via drinking water exposure projected over one year. In order 

to determine whether a PAG should be implemented, authorities will need to establish a relationship 

between the measured concentration of one or more radionuclides in finished drinking water and the 

radiation dose members of the population might experience as a result of drinking contaminated water. 

Incident-specific factors that may be taken into consideration include: 

1. The particular radionuclides being emitted in this emergency situation 

2. The rate and timing of entry of the radionuclides into the drinking water supply, via atmospheric 

deposition or by other means 

3. The rate of natural attenuation of the radionuclides 

4. The estimated potential duration of public exposure to contaminated drinking water 

5. The estimated daily consumption of contaminated drinking water. 

Those responsible for implementing PAGs will need to convert PAGs into Derived Response Levels 

(DRLs) in units of Bq/L or pCi/L for each radionuclide of interest. Section 4.6.6 of this Manual provides 

DRLs and explains how they can be calculated. Selected dose conversion factors and standard estimates 

of daily drinking water consumption for various age groups are also provided, along with references to 

informational resources. 

While the PAG Manual is primarily for advance planning, there are specific radionuclides, including 

cesium-137 (Cs-137), iodine-131 (I-131) and strontium/yttrium-90 (Sr-90/Y-90) that are of particular 

interest for major radiological incident scenarios where drinking water sources might be contaminated. 

Section 4.6.6 presents default DRLs for these radionuclides to aid emergency managers in making water 

restriction decisions involving these contaminants. DRLs for these radionuclides are presented as 

examples for purpose of illustration. If other radionuclides are present, DRLs should be calculated using 

the same methodology, as discussed in Section 4.6.6. 

4.6.4.3 Practical Considerations 

After deposition has ended, radionuclide concentrations present in a water supply may decline at rates 

determined by the half-lives of the individual nuclides, may decline faster by dilution with 

uncontaminated water, or may even increase after rainfall and seasonal thaw events in an affected 

watershed. The concentration of radionuclides in drinking water as a function of time after the incident 

can be measured, estimated or modeled based on knowledge of the incident, including radionuclide 

sources and the properties of the drinking water supply. Models and estimates should be validated by 

monitoring or sampling, as discussed in Section 4.6.5.1.

Unlike naturally-occurring radionuclide contamination of drinking water from minerals present in 

geological formations, for a radiation release incident, ground water sources are expected to be less 

vulnerable to contamination than surface water sources, but this should be confirmed by monitoring or 

sampling. The potential for ground water to become contaminated will greatly depend on whether the 

ground water resource is close to the surface or is from a deep aquifer bounded by an aquitard, as well as 

on rainfall rate and the composition of the overlying soil (which will affect the rate at which contaminants 

deposited on soil will migrate to the ground water resource).

Section 4.6.5.3 discusses actions that authorities can take to minimize radiation doses from drinking 

water. Because radionuclides decay over time, early interventions such as restricting use of contaminated 

water immediately after the incident may be most effective in reducing radiation dose to the population. 

Such decisions may need to be made based on limited information. Authorities may find it prudent to take 
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such action even before field sample measurements or modeled estimates of radiation dose have been 

calculated and validated. 

4.6.5 Planning and Taking Action

This section discusses actions that state and/or local authorities and drinking water utilities can take to 

protect the public in the event that a water supply is affected by a nationally significant radiological 

contamination incident. Different actions described here may be appropriate for early and intermediate 

phases depending on local resources. This section does not constitute a complete handbook for 

radiological emergency response, but it describes considerations that can be included in comprehensive 

emergency planning at the state, local and utility level. Actions that public authorities and drinking water 

providers should take are described below, including water monitoring, public notification, and mitigation 

measures to protect the water supply and the water-consuming public. 

Preventive action, such as temporary closure of water system intake valves to prevent a contaminant 

plume from entering the system, may be taken in advance of an anticipated release; it is not necessary to 

wait until drinking water contamination is detected. Emergency response plans need to consider whether 

sufficient storage capacity is available to support the community’s fire suppression and sanitation needs 

while the intake valves are closed. 

Emergency planning provides the opportunity to develop state, local and utility-specific plans and 

implementation procedures that reflect the unique needs of a particular community. Advance planning can 

provide clarity and facilitate the decision-making process during a radiological emergency. 

4.6.5.1 Monitoring and Characterization of Contaminants 

A comprehensive radiological surveillance program to monitor concentrations of radionuclides of interest 

in both source water (including both upstream and downstream of intakes, as applicable) and finished 

drinking water would provide an indication of whether any adjustments are necessary or if the actions 

being taken are effective.

The NPDWR for radionuclides requires community water systems (CWSs) to conduct monitoring at each 

entry point to the distribution system to ensure that every customer’s water does not exceed the MCLs for 

radionuclides.43 All CWSs are required to monitor for gross alpha, radium-226/228, and uranium. In 

addition, CWSs designated by the state as “vulnerable”44 and those using waters “contaminated”45 by 

effluents from nuclear facilities must also conduct monitoring for beta particle and photon radioactivity. If 

a water system is directed by the primacy agency to collect samples for compliance purposes, approved 

analytical methods must be used. 

In the event of a radiological contamination incident, state officials may require public water systems to 

immediately collect additional samples for radionuclides, including beta particle and photon activity. 

However, EPA recognizes that during an emergency situation it may be necessary to identify alternative 

sampling and analytical approaches to obtain data to inform short-term actions by emergency response 

personnel. Many states have established Radiological Emergency Preparedness46 programs designed to 

guide sample collection and analysis and to advise emergency managers in a radiological emergency. 

Additionally, FRMAC can deploy monitoring and sampling field teams and provide dose assessment 

expertise to assist states and local communities in responding to an emergency. See the National 

 

43 For more information about monitoring requirements for the Radionuclides Rule see the “Radionuclides Rule: A Quick 

Reference Guide” EPA-816-F-01-003 (EPA 2001) or “Implementation Guidance for Radionuclides” EPA-816-F-00-002 (EPA 

2002b). 44 For more information see 40 CFR 141.26(b)(1). 45 For more information see 40 CFR 141.26(b)(2). 46 See: http://www.fema.gov/radiological-emergency-preparedness-program. 
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Response Framework, Nuclear Radiological Incident Annex (FEMA 2008b) for information on roles and 

capabilities. 

EPA provides rapid laboratory analysis methods for selected radionuclides to expedite the analytical 

turnaround time while simultaneously meeting measurement quality objectives (EPA 2014).47 Samples 

should be collected from entry points to the distribution system. Challenges may arise from variability in 

environmental matrices. Advance emergency planning can help to achieve sample representativeness and 

homogeneity relative to routine samples. 

Once the situation is better characterized and systems are working towards returning to compliance, 

monitoring should be conducted at entry points to the distribution system using only approved analytical 

compliance methods. 

If members of the public are served by drinking water from household cisterns or private wells, local 

officials should consider how monitoring should be undertaken to determine levels of target radionuclides 

and assess the risks posed to these populations. 

4.6.5.2 Public Notification

An emergency response plan should include a strategy for keeping the community informed of the actions 

being taken by authorities and clearly delineate roles and responsibilities of local officials and emergency 

responders. This includes communicating to customers of CWSs and (if applicable) to those who rely on 

household cisterns and private wells. It is critical for water utilities to participate in the emergency 

response planning activities. 

If compliance monitoring indicates that contamination levels exceed the MCL for any radionuclide, water 

systems are required to issue public notice on a “Tier 2” time frame (i.e., as soon as practical, but no later 

than 30 days after the system learns of the violation). CWSs should be able to issue repeat notices as 

required. However, states may determine that the notification requirement should be elevated to a “Tier 

1” Public Notification (i.e., as soon as practical, but no later than 24 hours) based on a significant 

potential for serious adverse effects on human health due to short-term exposure.48 

During a response to a major radiological incident, water systems may have difficulty with issuing public 

notifications in addition to managing the response to the contamination event. The state may issue public 

notification on behalf of the water system (40 CFR 141.210(a)). This would allow the state to deliver a 

consistent message to all affected customers and allow the system to concentrate its efforts on returning to 

operation or returning to compliance in the event of radionuclide(s) MCL violation(s). For more 

information see the Revised Public Notification Handbook, EPA-816-R-09-013 (EPA 2010b).

State and local authorities should be proactive in communicating about risks and uncertainties and 

providing clear instructions to the public. For any incident response requiring coordinated federal support, 

refer to the National Response Framework and Emergency Support Function 15, External Affairs Annex 

(FEMA 2016b), for roles and response protocols.

4.6.5.3 Additional Actions to Reduce Levels of Contamination 

In the initial phase following a radiological incident, officials should take reasonable precautionary 

measures (i.e., closing intake valves) to protect water sources as soon as notification of a radiological 

release or impending release is received. Moving into the intermediate phase, as data are obtained from 

 

47 Rapid methods are available online at: http://www.epa.gov/narel/rapid_methods.html. 48 For more information see 40 CFR 141.202(a), Table 1(9), Special public notices: Occurrence of a waterborne disease outbreak 

or other waterborne emergency.
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monitoring programs (including sampling and analysis of water upstream and downstream of a water 

system intake structure and within the distribution system), officials should benchmark observed 

concentrations against the default DRLs discussed in Section 4.6.6 or situation-specific DRLs that 

account for specific isotopes present, release patterns, and decay. Officials would then be in a position to 

make informed decisions about the need to implement protective actions. Water system officials should 

be in close communication with their drinking water regulatory agency (e.g., state) prior to taking 

protective actions.

Options available to water systems to reduce radiation dose to drinking water customers include applying 

treatment technologies, relying on back-up storage, blending water, accessing alternative water sources, 

and rationing of uncontaminated water or a combination of these actions. Examples of these options are 

described briefly below. Technical and economic burden on smaller systems may be reduced by pooling 

resources with other water systems (e.g., establishing interconnections, sharing technical and operator 

staff, and sharing of supplies and equipment). As part of emergency planning efforts, local officials 

should consider the possibility of temporary rationing of uncontaminated or treated water if supplies are 

inadequate to meet normal demand. 

All of these options require advanced planning and should be evaluated and included in state plans as 

appropriate. Guidance on developing emergency drinking water supplies is available from EPA (EPA 

2011b). The CDC also provides resources and guidance for establishing emergency water supplies and 

communicating water advisories to the public (CDC 2014a).

49

• Treating Contaminated Water 

Systems with the appropriate technology in place can treat contaminated water to reduce elevated 

radionuclide levels. Four treatment technologies are classified by EPA as Best Available Technologies 

(BATs) for removing radionuclides from drinking water: coagulation/filtration, ion exchange, lime 

softening and reverse osmosis. EPA has also listed these BATs as Small System Compliance 

Technologies (SSCTs) for radionuclides treatment, along with less commonly used techniques such as 

green sand filtration, co-precipitation with barium sulfate, electrodialysis/electrodialysis reversal, preformed hydrous manganese oxide filtration and activated alumina. Further information on radionuclide 

treatment options is available from EPA (EPA 2015, EPA 2002c).50

Removal efficiency for specific radionuclides will vary across available technologies and may depend on 

technology-specific parameters (e.g., ion exchange effectiveness depends on pH, resin selected and 

presence of other ions). In addition, liquid and solid treatment residuals with elevated radiation levels may 

have special disposal requirements. Disposal options may vary from one jurisdiction to another, and may 

depend on the type, concentration and volume of residuals. Further information on residual disposal 

considerations is available from EPA (EPA 2006a, EPA 2006b). 

• Temporarily Closing Intake Valves 

If the deposition of radionuclides into a river is limited in duration, only a portion of the water may 

become contaminated. A water system with enough storage capacity can temporarily close its intake 

valves and allow the contaminants to flow past the intake to prevent contamination from entering the 

distribution system. 

 

49 See: http://www.cdc.gov/healthywater/emergency/drinkingwateradvisory.html. (CDC 2014a) 50 See: http://cfpub.epa.gov/safewater/radionuclides/radionuclides.cfm (EPA 2015); Also see: 

http://www.epa.gov/safewater/radionuclides/pdfs/guide_radionuclides_smallsystems_compliance.pdf. (EPA 2002c)
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If stored water supplies are not sufficient to meet community fire suppression and sanitation needs while 

intake valves are closed, the system could take other actions discussed in this section, including 

supplementing water supplies with alternate sources or implementing water use restrictions.

• Establishing Interconnections to Neighboring Systems 

If the water system is part of a larger, regional supply system, existing interconnections to 

uncontaminated neighboring water supplies could be activated. It might also be possible to construct 

temporary pipelines on an impromptu basis. 

If this option is implemented, steps should be taken to prevent backflow from the contaminated system. 

Care will also need to be taken to ensure that the supply of water and treatment capacity at the 

uncontaminated system will adequately serve the larger population. 

• Blending Water Sources

If a source of uncontaminated water is available, a water system may choose to blend water from 

contaminated and uncontaminated sources of drinking water to minimize radiation doses from drinking 

water. The water may be blended using storage tanks or a common header to allow for complete mixing 

prior to distribution to customers. 

• Importing Water in Tanker Trucks 

Under some circumstances (e.g., difficult terrain, urgent need), it may be more efficient or expedient to 

temporarily transport clean water by truck, rail or barge to distribution centers in the affected community 

than to lay down pipelines. State and local departments of public health, as well as emergency 

management agencies, typically have standards and requirements related to hauling water. Water systems 

would benefit from having procedures for importing water in tanker trucks documented in an emergency 

response plan. All water systems importing water by tanker should verify that their plan adheres to state 

and local requirements. If the water system’s distribution system is not being used to provide the imported 

water, the needs of residents with limited transportation options and physical disabilities should be taken 

into account when selecting locations for distribution centers. The availability of suitable transport 

vehicles may limit use of this option. 

• Importing Bottled Water 

Providing bottled water to the affected community is another possible option during an emergency 

situation. The water may come from a nearby water system or from a water bottling company. This option 

may be cost-effective during an emergency if water is needed quickly and if the length of the emergency 

does not require long-term action, such as the construction of an interconnecting pipe. 

4.6.6 Derived Response Levels (DRLs)

Once the incident characteristics have been assessed, information regarding duration of the radiological 

release and the half-life of nuclides involved as well as other factors may be considered by local decision 

makers in projecting doses and adapting mitigation measures. All radionuclides are covered by the 

assessment tools provided by FRMAC. For instance, if an alpha emitting isotope was of concern 

following a radiation contamination incident, it would be included in any calculations regarding 

protective actions for drinking water. As such, local officials may choose to work with FRMAC to 

calculate situation-specific DRLs that are based on information gained during the intermediate phase, 

including identification of specific isotopes, release patterns, and associated decay functions.

In the unlikely scenario where radioactive isotopes are continuously replenished, EPA recommends using 

the conservative assumption that radionuclide levels will remain constant over the course of one year. 
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Such an assumption provides an added level of protection in light of the many unknowns involved in an 

emergency. In fact, after the initial deposition event has occurred, concentrations usually decline at rates 

determined by the half-lives of individual isotopes, or decline faster due to dilution with uncontaminated 

water, or could even increase after rainfall or subsequent deposition events. Some nuclides, like I-131, 

have half-lives measured in days, while others, like Cs-137, have half-lives measured in years. 

Table 4-3 provides default DRLs for those unlikely scenarios. These default DRLs provide for 

convenience to allow local entities to make quick decisions about drinking water provided by public 

water systems in the event of a radiological emergency. 

Early exceedance of the default DRL does not suggest that doses will stay at that level. In most cases, 

levels will drop below PAGs as radionuclide concentrations in water decline by a combination of 

radioactive decay and natural attenuation. If the concentrations of radionuclides do not exceed DRLs over 

the course of one year, doses will remain below the PAG.

Table 4-3. Default Derived Response Levels (DRLs)51 – Drinking Water Concentrations 

Corresponding to Specified Doses (mrem) of Select52 Radionuclides, Assuming One Year of 

Exposure at Constant Levels53

Isotope

DRLs for pregnant women, nursing 

women and children age 15 and 

younger – 100 mrem dose

DRLs for the general population – 

500 mrem dose

Sr-90/Y-9054 1,000 pCi/L 7,400 pCi/L

Cs-137 6,200 pCi/L 17,000 pCi/L

I-131 820 pCi/L 10,000 pCi/L

The DRLs provided in Table 4-3 were derived by calculating life-stage-specific DRLs (as described in 

section 4.6.6.2) for eight different ages (fetus, breastfed infant, infant, 1, 5, 10, 15, and adults). For the 

most sensitive life-stages, concentrations of individual radionuclides yielding a 100 mrem dose were 

calculated for each age group, then the most protective/lowest radioactivity concentration was selected as 

the DRL for the entire sensitive life-stage group, including pregnant and nursing women. The calculated 

values differ across individual life-stages because each age group has a different dose conversion factor 

and drinking water ingestion rates. 

For example, the sensitive life-stage group DRL for I-131 was derived by calculating the concentration of 

I-131 which yields a 100 mrem dose for each age group. In this case the resulting concentrations were: 

fetus (2,500 pCi/L), breastfed infants (820 pCi/L), infants (2,100 pCi/L), 1 year (1,900 pCi/L), 5 years 

 

51 The DRLs in Table 4-3 indicate the concentration of each radionuclide which results in the corresponding radiation dose value 

if such radionuclide was the radiation emitter in drinking water. Values provided in this table have been rounded to two 

significant figures.

52 Table 4-3 does not present DRLs for all radionuclides that may occur in drinking water following a contamination incident; 

however, DRLs can be calculated for any isotope of interest by using the provided reference documents and calculation 

methodology.

53 The calculated values provided in Table 4-3 are intended to illustrate the methodology and conservative assumptions EPA 

believes are adequate to provide a reasonable level of protection to sensitive populations. Dose conversion factors, calculation 

methodologies as well as other comprehensive information regarding DRL development will be available and updated as needed 

in the FRMAC Assessment Manual.

54 Y-90 is a radioactive decay product of Sr-90 and will normally be found alongside Sr-90 in the case of a Sr-90 release; 

therefore, they are treated together. Solubility differences may cause less yttrium to be present; however, it is a conservative 

assumption to include both in DRLs. When calculating the combined DRL, note that the dose coefficients (see Table 4-5) are 

additive.
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(1,300 pCi/L), 10 years (2,000 pCi/L), and 15 years (2,400 pCi/L). Since the lowest calculated 

concentration is that of the breastfed infant (820 pCi/L), this value is the DRL that will be applied to be 

the most protective for the entire sensitive life-stage group. 

4.6.6.1 Calculation of Default DRLs

DRLs may be calculated with the help of the following equations. 

The dose (mrem or Sv) due to the ingestion of radionuclide i to age group a over time period T is 

calculated as follows:

DiaT = IiaT × DCFia

Where:

DiaT = Dose (in mrem or Sv) due to the ingestion of radionuclide i to age group a

over time period T.

IiaT = The total intake of radionuclide i for age group a (in pCi or Bq) over time 

period T.

DCFia = The dose conversion factor (also referred to as dose coefficient) for the 

ingestion of radionuclide i in drinking water and age group a (in mrem/pCi or 

Sv/pCi, or mrem/Bq or Sv/Bq). See below for guidance on dose conversion 

factors (DCFs). 

The quantity of radionuclide i ingested by age group a over a given time period, T, is calculated as 

follows: 

IiaT = Ci × Inga × T

Where:

IiaT = The total intake of radionuclide i for age group a (in pCi or Bq) over time 

period T. 

Ci = The concentration of radionuclide i in drinking water (in pCi/L or Bq/L). A 

simplifying assumption is made that the concentration of the radionuclide is 

constant over the time period T. 

Inga = The daily ingestion rate of water for age group a, in L/day. See below for 

guidance on daily water ingestion rates.

T = The time period that the population is drinking contaminated water (days). In 

this analysis, the time period of interest for fetus exposure is 280 days, for all 

other age groups the exposure timeframe is 365 days.

For each age group a and radionuclide i, substituting the applicable PAG for the dose DiaT and then 

solving for Ci yields the applicable DRL.

For example, the DRL for iodine-131 for an adult is calculated as follows: 

DRL = PAG / (Inga × T × DCFia) 

DRL = 500 mrem / (1.643 L/day × 365 days × 8.05 E-05 mrem/pCi) 
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= 500/4.83 E-02 

= 10,352 pCi/L

Which is rounded to 10,000 pCi/L (two significant figures) in consideration of the 

uncertainties involved. 

4.6.6.2 Combining Default DRLs for Multiple Radionuclides 

If multiple radionuclides are present in the water supply, the measured concentrations of each 

radionuclide should be divided by the provided DRL values and summed. Each quotient represents a 

fraction of the allowed concentration (the radionuclide-specific DRL) and the permissible dose (the 

PAG). If the sum of the fractions is less than 1, the total dose does not exceed the PAG value. Emergency 

response personnel may need to calculate the sum of fractions on an ongoing basis, as the concentrations 

of individual radionuclides may change over time. 

The sum of the fractions is expressed as follows:

F = ∑ (Ci / DRLi) 

Where: 

F = sum of the fractions 

Ci = the concentration of radionuclide i in the water supply (pCi/L or Bq/L) 

DRLi (100 or 500 mrem); = derived response level for the i

th radionuclide (pCi/L or Bq/L) 

For example, if Sr-90/Y-90 and Cs-137 are the only radionuclides present in the drinking water, and Sr90/Y-90 are present at 900 pCi/L and Cs-137 is present at 4,500 pCi/L, the combined dose exceeds the 

PAG of 100 mrem for fetuses, infants, and children: 

F = ∑ (Ci / DRLi) 

= (900 pCi/L / 1,000 pCi/L) + (4,500 pCi/L / 6,200 pCi/L) 

= 0.90 + 0.73 

= 1.63 

1.63 > 1, so the PAG is exceeded. 

The same concentrations do not exceed the PAG of 500 mrem for the general population: 

F = ∑ (Ci / DRLi) 

= (900 pCi/L / 7,400 pCi/L) + (4,500 pCi/L / 17,000 pCi/L) 

= 0.12 + 0.26 

= 0.38 

0.38 < 1, so the PAG is not exceeded. 
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4.6.6.3 Water Ingestion Rates

Table 4-4 presents mean values for tap water consumption taken from the CD supplement to Federal

Guidance Report #13 (EPA 2002a). Other sources of estimated drinking water ingestion rates are 

available (e.g., EPA’s Exposure Factors Handbook (EPA 2011a)), but the ingestion rates presented in 

Federal Guidance Report #13 (EPA 1999) were specifically designed with corresponding age ranges to be 

used in conjunction with other data from Federal Guidance Report #13 (EPA 1999). 

Values are provided for males and females in various age groups. Since the ingestion rates for males are 

higher (and therefore more conservative) than those for females, EPA elected to use the intake values for 

males to represent each age group in the calculation of DRLs in Table 4-3. In addition, for the calculation 

of the DRLs for the pregnant women (fetus), nursing women (breastfed infant) and adult, EPA made the 

conservative choice of assigning the drinking water ingestion rate within the adult category, at an 

estimated 1.643 L/day. 

Table 4-4. Mean Drinking Water Ingestion Rates from Federal Guidance 

Report #13 

Age (years)

Tap Water (L/day)

Male Female

0 0.191 0.188

1 0.223 0.216

5 0.542 0.499

10 0.725 0.649

15 0.900 0.712

20 1.137 0.754

50 1.643 1.119

75 1.564 1.179

Source: CD Supplement to Federal Guidance Report #13 (EPA 2002a), Table 3.1.

4.6.6.4 Dose Coefficients, or Dose Conversion Factors (DCF) (Sv/Bq Ingested)

The effective whole body dose per Bq ingested of various radionuclides in water, for various age groups, 

can be found on the CD supplement to Federal Guidance Report #13 (EPA 2002a). These DCF values 

apply to both males and females. In addition, DCFs used to calculate DRLs for the fetus55 and the 

breastfed infant56 are taken from ICRP Publication 88 (ICRP 2002) and ICRP Publication 95 (ICRP 2005) 

respectively. Table 4-5 presents DCFs for a few representative radionuclides of interest, converted to U.S. 

units for convenience.

 

55 ICRP Publication 88, Doses to the Embryo and Fetus from Intakes of Radionuclides by the Mother. (ICRP 2002) 56 ICRP Publication 95, Doses to Infants from Ingestion of Radionuclides in Mother’s Milk. (ICRP 2005)
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Table 4-5. Dose Conversion Factors57

Age

DCFs (mrem per pCi ingested), from Federal Guidance Report #13

Sr-90 Y-90 Cs-137 I-131

Infant (100 day old) 8.40E-04 1.16E-04 7.79E-05 6.82E-04

1 year old 2.68E-04 7.41E-05 4.58E-05 6.62E-04

5 year old 1.73E-04 3.69E-05 3.58E-05 3.83E-04

10 year old 2.21E-04 2.18E-05 3.75E-05 1.94E-04

15 year old 2.92E-04 1.24E-05 4.95E-05 1.27E-04

Adult 1.02E-04 9.94E-06 5.02E-05 8.05E-05

Source: CD Supplement to Federal Guidance Report #13 (EPA 2002a). 

4.7 BASIS FOR INTERMEDIATE PHASE PAGs

For a full description of the risk-benefit analysis used to set the PAG levels, refer to the 1992 PAG 

Manual, Appendices B, C and E. The 1992 PAG Manual is available online in a searchable format. Below 

is a short summary of the basis for the intermediate phase relocation PAGs.

In a prior section (see Section 2.5) for early phase (evacuation) PAGs, analysis was provided for the risks 

of health effects as a function of dose (Principles 1 and 2). Considerations for selection of PAGs for the 

intermediate phase of a radiological incident differ from those for selection of PAGs for the early phase 

primarily with regard to implementation factors (i.e., Principles 3 and 4). Specifically, they differ with 

regard to cost of avoiding dose, the practicability of leaving infirm people and prisoners in the restricted 

zone, and avoiding dose to fetuses. Although sheltering is not generally a suitable alternative to 

relocation, other alternatives (e.g., decontamination and shielding) are suitable. 

For several assumed cumulative annual doses, the cost per day divided by the risk of fatality avoided by 

relocation was plotted for a radionuclide mixture from a hypothetical NPP accident. The cost per day of 

relocation is assumed to be constant, but with some nuclides decaying rapidly, the cost-effectiveness of 

relocation diminishes over time. Drawing only general trends from this, the cost analysis supports 

relocation at doses as low as 1 rem (10 mSv) for the first week and 2 rem (20 mSv) for up to 25 days after 

an accident. 

Based on the avoidance of acute effects alone (Principle 1), relocation of the general population and 

fetuses at 50 rem and 10 rem (500 and 100 mSv), respectively, is justified. However, on the basis of 

control of chronic risks (Principle 2), a lower upper bound is appropriate. Five rem (50 mSv) is taken as 

an upper bound on acceptable risk for controllable lifetime exposure to radiation, including avoidable 

exposure to accidentally deposited radioactive materials. 

Analyses based on Principle 3 (cost/risk) indicate that considering cost alone would not drive the PAG to 

values less than 5 rem (50 mSv). Analyses in support of Principle 4 (risk of the protective action itself) 

provide a lower bound of 0.15 rem (1.5 mSv) for the relocation PAGs. Based on the above, 2 rem (20 

 

57 The DCFs in this table show the variation across age groups and nuclides and are provided to illustrate the conservative 

methodology and assumptions EPA believes are adequate to provide a reasonable level of protection to sensitive populations. 

Additional information including updated dose conversion factors, calculation methodologies and other comprehensive information 

regarding DRL development, will be appended to the FRMAC Assessment Manual.
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mSv) projected committed effective dose equivalent from exposure in the first year is selected as the PAG 

for relocation. Implementation of relocation at this value will provide reasonable assurance that, for a 

reactor accident, a person relocated from the outer margin of the relocation zone will, by such action, 

avoid an exposure rate which, if continued over a period of one year, would result in a dose of about 1.2 

rem (12 mSv). This assumes that 0.8 rem (8 mSv) would be avoided without relocation through normal 

partial occupancy of homes and other structures. 

Contrary to the situation for evacuation during the early phase of an incident, it is generally not practical 

to leave a few people behind when most members of the general population have been relocated from a 

specified area for extended periods of time. It will usually be practicable to reduce these risks by 

establishing a high priority for efforts other than relocation to reduce the dose in cases where pregnant 

women reside near the boundary of the restricted zone. 

The implementation of simple dose reduction techniques will further reduce dose to people who are not 

relocated from contaminated areas. In the case of non-reactor accidents, decay and weathering effects 

differ, and it may be necessary to base relocation decisions on the second and subsequent year dose 

projections.
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KEY POINTS IN CHAPTER 4 – INTERMEDIATE PHASE

 The principal protective actions for reducing exposure of the public to deposited radioactive 

materials are relocation, decontamination and time limits on exposure. The PAG for relocation is 2 

rem (20 mSv) over the first year of exposure. After the first year, the PAG for relocation is 0.5 rem 

(5 mSv) per year.

 Boundaries of relocation areas should be established based on the relocation PAGs and sitespecific geographical features such as rivers, mountains or roadways.

 Projections should be based on incident-specific monitoring and modeling, taking into account 

realistic dose assessment factors.

 Exposure limits must be set for people who must enter the relocation area to perform vital services.

 Other protective actions, such as focused decontamination and time limits on exposure, are applied 

to people in areas where levels of deposited radioactivity are not high enough to warrant 

relocation.

 Protective action guidance for food is contained in FDA’s “Accidental Radioactive Contamination 

of Human Food and Animal Feeds: Recommendations for State and Local Agencies” (FDA 1998). 

 Drinking water guidance is based on a two-tiered approach to help officials prioritize potentially 

scarce water resources:

• 500 mrem (5 mSv or 0.5 rem) projected dose, for one year, to the general population. 

• 100 mrem (1 mSv or 0.1 rem) projected dose, for one year, to the most sensitive 

populations (e.g., infants, children, pregnant women and nursing women). 

 To inform temporary reentry into relocation areas, use the Operational Guidelines (DOE 2009).
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CHAPTER 5. PLANNING GUIDANCE FOR THE LATE PHASE

This chapter provides planning guidance for the long-term cleanup process for the late phase. As used in 

this Manual, the late phase is the period beginning when cleanup and recovery actions have begun and 

ending when all recovery actions have been completed. This phase may extend for months to years. This 

chapter also provides brief planning guidance and discusses options for radioactive waste disposal for a 

large-scale radiological incident. 

5.1 LATE PHASE CLEANUP PROCESS

This section describes the remediation cleanup process for the late phase of a nationally significant 

radiological incident, such as a disaster at an NPP, an RDD or an IND. It should be noted that the extent

and scope of contamination as a result of an NPP, RDD or IND incident may be at a much larger scale 

than a site or facility decommissioning or remedial cleanup. This process identifies the late phase 

remediation or cleanup process steps, including factors for decision-makers to consider in determining 

final cleanup actions while emphasizing opportunities to involve key stakeholders in providing sound, 

cost-effective cleanup recommendations. For information on roles, responsibilities and authorities during 

emergency response and recovery, please refer to— 

 National Response Framework: http://www.fema.gov/national-response-framework (FEMA 

2008a), and 

 Nuclear Radiological Incident Annex, specifically for radiological incidents: 

http://www.fema.gov/pdf/about/divisions/thd/IncidentNucRad.pdf (FEMA 2008b). 

5.1.1 Transitioning from Intermediate to Late Phase Cleanup

The late phase cleanup process begins sometime after the commencement of the intermediate phase and

proceeds independently of intermediate phase protective action activities. The transition is characterized 

by a change in approach, from strategies predominantly driven by urgency, to strategies aimed at both 

reducing longer-term exposures and improving interim living conditions. At this point, the extent of 

radiological contamination will be very well characterized. The late phase involves the final cleanup of

areas and property at which contamination directly attributable to the incident is present. It is in the late 

phase that final cleanup decisions are made and final recovery efforts following a radiological incident 

are implemented.

Unlike the early and intermediate phases of a radiological incident, decision-makers will have more time 

and information during the late phase to allow for better data collection, stakeholder involvement and 

options analysis. Generally, early (or emergency) phase decisions will be made directly by elected public 

officials, or their designees, with limited stakeholder involvement due to the need to act within a short

timeframe. Longer-term decisions should be made with stakeholder involvement and can also include 

incident-specific technical working groups to provide expert advice to decision-makers on impacts, costs

and alternatives. Community members will influence decisions such as if and when to allow people to 

return home to contaminated areas. There will be people living in contaminated areas, outside the

evacuation and relocation zones, where efforts to reduce exposures will be ongoing.

Because of the extremely broad range of potential impacts that may occur from NPP incidents, RDDs and 

INDs (e.g., light contamination of one building to widespread destruction of a major metropolitan area), a 

process should be used to determine acceptable cleanup criteria based on the societal objectives for 

expected land uses and the options and approaches available. Implicit in these decisions is the ability to 

balance health protection with the desire of the community to resume normal life. Radiation protection 

considerations should be addressed in concert with health, environmental, economic, social, 

psychological, cultural, ethical, political, and other considerations. It is recognized that experience from

existing programs, such as the EPA’s Superfund program, the NRC’s process for decommissioning and 
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decontamination to terminate a nuclear facility license, and other national recommendations may be 

useful in planning cleanup and recovery efforts.

Consistent with the “Framework for Environmental Health Risk Management,” mandated by the 1990 

Clean Air Act Amendments and published by the Commission on Risk Assessment and Risk 

Management in 1997 (CRARM 1997), the late phase cleanup process consists of multiple steps, 

including: 1) characterization and stabilization; 2) development of goals and strategies; and 

3) implementation and reoccupancy. Stakeholder involvement should be integrated throughout the 

process. Characterization in this phase consists of delineation, in detail, of the nature and extent of 

contamination in areas impacted by the incident. Stabilization is intended to reduce the spread of

contamination to clean areas, the airborne inhalation hazards, and the volume of radioactive waste 

generated. Establishment of cleanup goals and strategies should consider overall community health, 

along with a variety of factors described further below; they are based upon anticipated land use and a 

variety of selection criteria. Key to these steps is the involvement and acceptance of the impacted state 

and local community. These steps are discussed in more detail below.58

5.1.2 Characterization and Stabilization

The first step in the late phase remediation or cleanup process is characterization, or the comprehensive 

mapping and monitoring of the distribution and level of radioactive contamination. Characterization 

activities are necessary in the preparation for and verification of a successful remediation or cleanup

effort. The late phase characterization work is designed to define, in detail, the nature and extent of the 

contamination and to provide information needed to develop and evaluate cleanup alternatives.

The characterization performed in support of the late phase will be much more detailed and 

comprehensive than the earlier characterization work to support PAG decisions made during the early and 

intermediate phases. It delineates the nature of any actual threat posed to human health or the 

environment and defines the extent of that threat.

Stabilization techniques are designed to immobilize radioactive contamination on soils, buildings, roads 

and equipment. This becomes paramount in a large-scale radiological incident where the spread of 

contamination can occur from natural weathering effects to human and animal interactions with the

environment. Stabilization reduces chronic low-level exposures to residual radiation, airborne hazards, 

and volumes of secondary waste. These reductions can result in significant benefits to the long-term

recovery in terms of time-to-normalcy and economic recovery.

5.1.3 Goals and Strategies

After late phase characterization and stabilization activities are accomplished, areas impacted by 

radioactive contamination are documented and defined to the best extent possible. At this point, decisionmakers should establish cleanup goals and strategies for moving forward. The development of goals and 

strategies marks the second step in the late phase remediation or final cleanup process. As part of an

ongoing iterative process, cleanup goals are informed by the feasibility of cleanup strategies and specific

cleanup strategies adjust as experience is gained. That is, risk management goals may be refined as

decision-makers and stakeholders gain appreciation for what is feasible, the costs and benefits of 

alternative strategies, and the effectiveness of such strategies in reducing exposures and risks to human 

and ecological health. 

 

58 This cleanup process does not rely on and does not affect any authority, including the Comprehensive Environmental

Response, Compensation and Liability Act (CERCLA), 42 U.S.C. 9601 et seq. and the National Contingency Plan (NCP), 40 CFR

Part 300. This document expresses no view as to the availability of legal authority to implement this process in any particular 

situation.
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As cleanup levels for areas are determined, many factors come into play in decision-making, such as 

balancing risk reduction with other societal goals and tolerance for voluntary versus involuntary risk. 

Determining these levels will require consideration of a number of factors— 

 The types of contamination including nuclide mix and chemical form, as well as risk from nonradiological hazards. 

 The technical feasibility, cost, timeliness and effectiveness of decontamination measures; and the 

availability and cost of options for the disposal of wastes.

 The size and character of the areas that are contaminated; past and projected future uses for these 

areas; and the preservation or destruction of places of historical, economic, national, or regional 

significance.

 Site-specific natural and anthropogenic background levels of radioactivity.

 Estimates of the impacts of both contamination and options for decontamination, on human health, 

communities, the economy, ecosystems and ecosystem services.

 Public acceptability and intergenerational equity.

Community involvement and sentiment are vital to this process. The stress from both the incident itself as 

well as the longer-term effects of separation from home will be important factors as overall community 

health is considered. In the United States, a range of one in a population of ten thousand (10-4) to one in a 

population of one million (10-6) excess cancer incidence outcomes is generally considered protective for 

both chemical and radioactive carcinogenic contaminant exposures. This range is the regulatory standard 

generally used in the context of EPA Superfund response actions. The NRC’s decommissioning and 

decontamination process outcomes are usually in or near this range as well. A similar risk range may be 

an appropriate goal for radiological events that affect areas of comparable size. However, such risk ranges 

may not be practically achievable for major incidents that result in the contamination of very large 

geographical areas or impacts on the economy. Every incident is unique. In making decisions about

cleanup goals and strategies for a particular event, decision-makers should balance the desired level of

exposure reduction with the technical feasibility, timing and cost of the measures that would be necessary

to achieve it, in an effort to maximize overall human welfare.

While it may take many years to achieve final cleanup levels, a timely return to normalcy, including 

reoccupancy and a viable community, will require a cleanup process that is flexible, iterative and

inclusive. Decisions should be made on a site-specific basis and should reflect the interim risks that are 

reasonable and acceptable to the affected community while active remediation, radioactive decay, and 

natural weathering move the site toward long-term cleanup goals.

Cleanup strategies are adopted as decision-makers and stakeholders gain an understanding of all relevant

factors. Tradeoffs between alternatives should be considered and balanced so that the best options are 

chosen. Local acceptance will be a key component of a fully transparent approach to long-term 

remediation and cleanup. Factors to consider in determining cleanup actions include evaluating:

 Areas impacted (e.g., size, location relative to population);

 Actions already taken during the early and intermediate phases;

 Ability of a remedy to maintain reliable protection of overall human health and the environment 

over time;

 Assessing the relative performance of treatment technologies on the toxicity, mobility or volume of 

contaminants; 

 Success or effectiveness of the cleanup or remediation as the cleanup progresses (contaminant

removal);

 Adverse impacts on human health and the environment that may be posed in the time it takes to

implement the remedy and achieve the community-based remediation goals; 
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 Impacts of alternative cleanup levels on the local and regional economy (e.g., job loss due to 

closed businesses, job creation due to decontamination and waste handling operations) and on 

residents’ sense of place (e.g., continued limited access to one’s home and community until

cleanup levels have been reached); 

 Preservation or destruction of places of historical, national or regional significance;

 Technical and administrative feasibility of the remedy, including the availability of materials and

services needed to implement each component of the option in question; 

 Cost of each alternative, including the estimated capital and operation and maintenance costs and 

net present value of capital and operation and maintenance costs;

 State concurrence with the remedy; and

 Community support for the remedy.

This may be an iterative process. As experience is gained, adjustments may be required to achieve 

long-term goals.

5.1.4 Implementation and Reoccupancy

To implement cleanup actions in each community, measurable quantities associated with cleanup goals 

should be derived taking into account exposures from all potential pathways and through all 

environmental media (e.g., soil, ground water, surface water, sediment, air, animals or plants). These 

values typically are derived considering reasonably anticipated future land use, dietary habits, and 

commerce patterns. If meeting acceptable cleanup levels based upon the reasonably anticipated postincident land use is not practicable and cost-effective, decision-makers can look to more restrictive land 

uses through institutional and engineering controls. This approach is based on the belief that early

community involvement focusing on desired post-incident uses of the property will result in expedited, 

cost-effective and publicly-supported cleanups. Overall community health, including stress factors from

the initial event and separation from home or family is a necessary consideration. 

In some situations, a site or area may reasonably be anticipated to support a range of uses, so cleanup 

goals may be different for different subareas of the impacted area. Although it may take years to achieve 

the final cleanup goals for all land uses, reoccupancy of the affected area will be possible when interim 

cleanup can reduce short-term exposures to acceptable levels during the time it takes to achieve the longterm goals. There may be institutional or engineering controls placed on some portions of the site to 

prevent excessive exposures until further active remediation, radioactive decay, or natural weathering 

allow the site to meet cleanup goals. An example of an institutional control might be a restriction on 

planting vegetable gardens to avoid ingesting radionuclides that may be taken up by the plant roots from 

the soil. An example of an engineering control to limit exposures might be adding a layer of pavement or 

cement over gamma emitting radionuclides that have become fixed in place by sorbing onto the street and 

sidewalks.

In complex cases such as the situation represented by a wide-area NPP, RDD or IND event, cleanup and 

reoccupancy are likely to occur subarea by subarea in order of priority and community assessments.

Critical infrastructure is likely to have been restored to some level of functionality and further

remediation of the infrastructure should be evaluated against the cleanup goal. A community-based and 

transparent development of priorities would follow, resulting in sequential actions, whereby areas (e.g., 

residential, commercial) would be remediated and reoccupied utilizing temporary cleanup levels that 

would be considered acceptable for an interim period of time prior to final cleanup goals being achieved.

Land use may need to be changed in a subarea where it is not feasible with a combination of remediation 

with engineering and institutional controls to support the pre-incident land use in a manner that protects

human health. In all cases, an appropriate population health monitoring program should be implemented

proportionate to the potential or estimated health risk.
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5.1.5 Stakeholder Involvement

Generally, early (or emergency) phase decisions will be made directly by elected public officials, or their 

designees, with limited stakeholder involvement due to the need to act within a short timeframe. With 

additional time and an increased understanding of the situation, there will be opportunities to involve key

stakeholders in providing sound, cost-effective cleanup recommendations that are protective of human 

health and the environment. 

Affected citizens should be involved in all phases of cleanup planning and long-term remediation of their 

communities. Early in the process, decision-makers should bring together a broad group of stakeholders

(e.g., residents, local business owners, local government officials and others) interested in the processes

that will be required to restore their communities. The credibility of a community group is a function of

its inclusiveness. It should represent all stakeholder interests to ensure it is a voice for the entire

community rather than a few interested parties. Empowering individuals to assist in the process is

important and effective. The affected local community will need to be involved until the site remediation

activities are complete and possibly beyond that if institutional and engineering controls are placed on 

some subareas of the site.

5.1.6 Cleanup Process Implementation and Organization: An Example

This example, adapted closely from the “Planning Guidance for Protection and Recovery Following 

Radiological Dispersal Device (RDD) and Improvised Nuclear Device (IND) Incidents” (DHS 2008), 

describes a hypothetical organization to integrate federal cleanup support activities with state and local

governments and the public. In particular, it addresses a scenario where the federal government is 

expected to be the primary funding entity for cleanup and recovery activities. For some radiological 

scenarios, states might take the primary leadership role in cleanup and contribute significant resources

toward recovery of the site. This example does not address such a scenario, although states may choose to

follow a similar process.

5.1.6.1 Cleanup Implementation

This approach describes how federal departments and agencies may coordinate during a response with 

state and local government counterparts and the public, consistent with the National Response Framework

(NRF) (FEMA 2008a) and the National Disaster Recovery Framework (NDRF) (FEMA 2016a). The

approach does not attempt to provide detailed descriptions of state and local roles and expertise. It is

assumed those details will be provided in state and local level planning documents that address 

radiological/nuclear terrorism incidents.

During the intermediate phase, site cleanup planners should begin the process described below, under the 

direction of the on-site incident command or unified command (IC/UC) and in close coordination with 

federal, state and local officials. After early and intermediate phase activities have come to conclusion and 

only long-term cleanup activities are ongoing, the IC/UC structure may continue to support planning and 

decision-making for the long-term cleanup. The IC/UC may make personnel changes and structural 

adaptations to suit the needs of a lengthy, multifaceted and highly visible remediation process. For 

example, a less formal and structured command, more focused on technical analysis and stakeholder 

involvement, may be preferable for extended site cleanup than what is required under emergency 

circumstances.

Radiological and nuclear incidents cover a broad range of potential scenarios and impacts. This example

assumes that the incident is of sufficient size to trigger a state request for federal assistance and that the

federal government is the primary funding agent for site cleanup. In particular, the process described for 

the late phase cleanup assumes an incident of relatively large size. For smaller incidents, all of the 

elements in this section may not be warranted. The process should be tailored to the circumstances of the

particular incident. Decision-makers should recognize that for some radiological/nuclear incidents, states 
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will take the primary leadership role and contribute significant resources toward cleanup of the site. This

section does not address such a scenario, but states may choose to use the process described here.

5.1.6.2 Cleanup Activities Overview

As described earlier in the document, radiological/nuclear emergency responses are often divided roughly 

into three phases: 1) the early phase, when the plume is active and field data are lacking or not reliable; 

2) the intermediate phase, when the plume has passed and field data are available for assessment and 

analysis; and 3) the late phase, when long-term issues are addressed, such as cleanup of the site. For 

purposes of this example, the response to a radiological or nuclear incident is divided into two separate, 

but interrelated and overlapping, processes. The first is comprised of the early and intermediate phases of

response, which consists of the immediate and near-term on-scene actions of state, local and federal

emergency workers under the IC/UC. On-scene actions include incident stabilization, lifesaving activities, 

dose reduction actions for members of the public and emergency workers, access control and security, 

emergency decontamination of people and property, “hot spot” removal actions, and resumption of basic 

infrastructure functions.

The second process pertains to environmental cleanup, which is initiated soon after the incident (during 

the intermediate phase) and continues into the late phase. The process starts with convening stakeholders 

and technical subject matter experts to begin identifying and evaluating options for the cleanup of the site.

The environmental cleanup process overlaps the intermediate phase activities described above and should 

be coordinated with those activities. This process is interrelated with the ongoing intermediate phase 

activities and the intermediate phase protective actions may continue to apply through the late phase until 

cleanup is complete.

Cleanup planning and discussions should begin as soon as practicable after an incident to allow for 

selection of key stakeholders and subject matter experts, planning, analyses, contractual processes, and 

cleanup activities. States may choose to pre-select stakeholders for major incident recovery coordination. 

These activities should proceed in parallel with ongoing intermediate phase activities and coordination 

between these activities should be maintained. Preliminary remediation activities during the intermediate 

phase—such as emergency removals, decontamination, resumption of basic infrastructure function, and 

some return to normalcy in accordance with intermediate phase PAGs—should not be delayed for the 

final site remediation decisions.

A process for addressing environmental cleanup is presented below. This is a flexible process in which 

numerous factors are considered to achieve an end result that considers local needs and desires, health

risks, costs, technical feasibility and other factors. The general process outlined below provides decisionmakers with input from both technical experts and stakeholder representatives and also provides an 

opportunity for public comment. The extent and complexity of the process for an actual incident should be 

tailored to the needs of the specific incident; for smaller incidents, the workgroups discussed below may

not be necessary.

The goals of the process described below are: 1) transparency—the basis for cleanup decisions should be 

available to stakeholder representatives and to the public at large; 2) inclusiveness—representative

stakeholders should be involved in decision-making activities; 3) effectiveness—technical subject matter 

experts should analyze remediation options, consider established dose and risk benchmarks, and assess

various technologies in order to assist in identifying a final solution that is optimal for the incident; and 

4) shared accountability—the final decision to proceed will be made with input from federal, state and 

local officials.

Under the National Response Framework (NRF) (FEMA 2008a) and the National Disaster Recovery 

Framework (NDRF) (FEMA 2016a), FEMA may issue mission assignments to the involved federal

agencies, as appropriate, to participate in the overall recovery process. Additional funding may be 
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provided to state/local governments to perform response or recovery activities through other mechanisms. 

The components of the process are described below: 

5.1.6.3 General Management Structure

Planning for the long-term cleanup should begin during the intermediate phase and at that time, a 

traditional National Incident Management System (NIMS) response structure should still be in place. 

However, NIMS was developed specifically for emergency management and may not be the most

efficient response structure for long-term cleanup. If the cleanup will extend for years, the IC/UC may 

decide to transition at some point to a different long-term project management structure.

Under the National Response Framework and NIMS, incidents are managed at the lowest possible 

jurisdictional level. In most cases, this will be at the level of the IC/UC. The IC/UC directs on-scene 

tactical operations. Responding local, state and federal agencies are represented in the IC/UC and Incident 

Command Post (ICP) in accordance with NIMS principles regarding jurisdictional authorities, functional 

responsibilities, and resources provided. For a wide-area radiological incident, multiple ICPs may be 

established to manage the incident with an Area Command or Unified Area Command supporting the 

ICPs and prioritizing resources and activities among them. If the incident happens on a federal facility or 

involves federal materials, the representatives in the UC may change appropriately and the response will 

be conducted according to the applicable federal procedures. 

Issues that cannot be resolved at the IC/UC or Unified Area Command level may be raised with the Joint 

Field Office (JFO) and JFO Unified Coordination Group for resolution. The JFO coordinates and 

prioritizes federal resources and when applicable, issues mission assignments to federal agencies under 

the Stafford Act. Issues that cannot be resolved at the JFO level may be raised to the DHS National 

Operations Center senior-level interagency management groups and the White House Homeland Security 

Council and National Security Council. 

Day-to-day tactical management, planning and operations for the cleanup process will be managed at the

IC/UC level, but for large-scale cleanups involving significant federal resources, it is expected that the 

JFO Unified Coordination Group and national level federal officials will review proposed cleanup plans 

and provide strategic and policy direction. The federal agency(s) with primary responsibility for site 

cleanup should be represented in the JFO Unified Coordination Group. The IC/UC will need to establish

appropriate briefing venues as the cleanup process proceeds, including the affected mayor(s) and 

governor(s).

The discussion below assumes a traditional NIMS IC/UC structure; if the IC/UC transitions later to a

different management structure for a longer-term cleanup, the IC/UC would need to determine the 

appropriate way to incorporate the workgroups described below into that structure.

This environmental cleanup process will be managed by the IC/UC, who ultimately determines the 

structure and organization of the ICP, but the discussion below provides one recommended approach for 

managing the cleanup process within a NIMS Incident Command System (ICS) response structure. The 

ICP Planning Section has the lead for response planning activities, working in conjunction with other 

sections and would have the lead for development of the cleanup options analysis, working closely with

the Operations Section. The NIMS describes the units that make up the Planning Section and allows for 

additional units to be added depending on site-specific needs. NIMS states that for incidents involving the 

need to coordinate and manage large amounts of environmental sampling and analytical data from

multiple sources, an Environmental Unit may be established within the Planning Section to facilitate

interagency environmental data management, monitoring, sampling, analysis, assessment and site

cleanup, and waste disposal planning. Radiological incidents would involve the collection of not only

large amounts of radiological data, but also data related to other environmental and health and safety

hazards and therefore would likely warrant the establishment of an Environmental Unit in the Planning
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Section. Planning for FRMAC radiological sampling and monitoring activities will be integrated into the 

Planning Section and coordinated with other Situation and Environmental Unit data management

activities.

The IC/UC may assign the Environmental Unit the responsibility for coordinating the development of the 

cleanup options analysis. For large incidents requiring more complicated tradeoffs or the evaluation of 

cleanup goals with broad implications, the IC/UC may choose to establish a separate unit in the Planning 

Section (e.g., a Cleanup Planning Unit) to coordinate the development of the cleanup options analysis.

The IC/UC may then convene a technical working group and a stakeholder working group, managed by 

the Environmental or Cleanup Planning Unit, to analyze cleanup options and develop recommendations. 

The Environmental or Cleanup Planning Unit would coordinate working group processes and interactions 

and report the results of the cleanup options analysis and workgroup efforts to the IC/UC through the 

Planning Section Chief.

The development and completion of the cleanup options analysis is expected to be an iterative process

and for large incidents, the cleanup will likely proceed in phases, (e.g., from the periphery of the 

contamination toward the most contaminated areas). The extent of the cleanup options analysis and 

process used to develop it would be tailored to the needs of the specific incident, but the following

working groups may be convened by the IC/UC to assist decision-makers in the cleanup options analysis

process, particularly for large or complex cleanups. 

5.1.6.4 Technical Working Group

A technical working group should be convened as soon as practicable, ideally within days or weeks of the 

incident. The technical working group would be managed by the Planning Section Unit that is assigned

responsibility for the cleanup options analysis. The technical working group may or may not be physically

located at the ICP. The group may review data and documents, provide input electronically, and meet 

with incident management officials. The group may also be asked to participate in meetings with the JFO

Unified Coordination Group if needed.

Function: The technical working group provides multi-agency, multi-disciplinary expert input on the 

cleanup options analysis, including advice on technical issues, analysis of relevant regulatory 

requirements and guidelines, risk analyses, and development of cleanup options. The technical working 

group would provide expert technical input to the IC/UC; it would not be a decision-making body. 

Makeup: The technical working group should include selected federal, state, local and private sector 

subject matter experts in such fields as environmental fate and transport modeling, risk analysis, technical 

remediation options analysis, cost, risk and benefit analysis, health physics and radiation protection, 

construction remediation practices, and relevant regulatory requirements. The exact selection and balance 

of subject matter experts is incident-specific. The Advisory Team for Environment, Food and Health is

comprised of federal radiological experts in various fields that may warrant representation on the 

technical working group, therefore, the Team or some of its members may be incorporated into this group

as appropriate.

5.1.6.5 Stakeholder Working Group

The stakeholder working group should be convened as soon as practicable, ideally within days or weeks 

of the incident. The stakeholder working group would be managed by the Planning Section Unit that is 

assigned responsibility for the cleanup options analysis. The IC/UC may direct the Public Information 

Officer (PIO) (who would coordinate with the Joint Information Center (JIC)) to work with the group, 

including establishing a process for the group to report out its recommendations. How and where the 

stakeholder working group would meet to review information and provide its input would need to be 

determined in conjunction with the group members. The stakeholder working group may also be asked to 

participate in meetings with the JFO Unified Coordination Group, if needed. 
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Function: The function of the stakeholder working group is to provide input to the IC/UC concerning local

needs and desires for site recovery, proposed cleanup options, and other recommendations. The group 

should present local goals for the use of the site, prioritizing current and future potential land uses and 

functions, such as utilities and infrastructure, light industrial, downtown business and residential land 

uses. The stakeholder working group would not be a decision-making body. 

Makeup: The stakeholder working group should include selected federal, state and local representatives, 

and local non-governmental representatives as well as local and regional business stakeholders. The exact 

selection and balance of stakeholders is incident-specific.

5.1.6.6 Activities: Cleanup Planning and Recommendations 

The IC/UC directs the management of the cleanup options analysis through the Planning Section. 

Technical and stakeholder working groups assist in performing analyses and developing cleanup options 

and provide input to the IC/UC and may be asked to participate in meetings with the JFO Unified 

Coordination Group. The IC/UC reviews cleanup options analyses and selects a proposed approach for 

site cleanup in close coordination with federal, state and local officials. Again, depending on the incident 

size, it may be necessary to conduct the cleanup in phases. Thus, decisions on cleanup approaches may 

also be made in phases. As appropriate for the magnitude of the cleanup task, the IC/UC would brief 

relevant federal, state and local government officials on proposed cleanup plans for approval. This may 

involve the office of the affected mayor and governor. At the federal level, it may involve the JFO Unified 

Coordination Group and higher-level officials.

5.1.6.7 Public Review of Decision

The IC/UC should work with the PIO and JIC to publish a summary of the process, the options analyzed, 

and the recommendations for public comments. Public meetings should also be convened at appropriate 

times. Public comments should be considered and incorporated as appropriate. A reconvening of the 

stakeholder or technical working group may be useful for resolving particular issues.

5.1.6.8 Execution of Cleanup and Peer Review

Assuming a Presidential declaration of a major disaster or emergency, FEMA may issue mission

assignments to the federal departments and agencies that have the capability to perform the required

cleanup, remediation, or debris removal activities. Cleanup activities should commence as quickly as

practicable and allow for incremental reoccupation of areas as cleanup proceeds. For significant 

decontamination efforts, the IC/UC may choose to employ a technical peer review advisory committee to 

conduct a review of the effectiveness of the cleanup. The technical peer review committee would evaluate 

pre- and post-decontamination sampling data, the decontamination plan, and any other information key to 

assessing the effectiveness of the cleanup. 

5.2 DISPOSAL OF LARGE VOLUMES OF RADIOLOGICAL WASTE

If a large-scale radiological incident were to occur in the United States, the complexity of radiological 

waste disposal would depend on the magnitude of the release and the decisions related to site cleanup, 

both of which will determine the amount and types of waste requiring disposal. Primary responsibility for 

waste management decisions falls to state and local officials. 

This section provides a short introduction to the issue, a summary of the types of available disposal 

options, a more detailed discussion of each disposal option, including disposal capabilities, and discussion 

of roles and responsibilities. Although not addressed explicitly in this section, the need to prepare for and 

conduct safe and environmentally protective storage of waste generated during remediation will also 

present a significant challenge, as illustrated by the challenges that Japan faced in the aftermath of the

Fukushima accident. Many of the considerations for siting disposal facilities will also be applicable to 

storage sites.
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Planners and decision-makers need to view the long-term remediation and recovery as a comprehensive 

process in which waste management and disposal needs are considered from the earliest stages. For 

example, the selected decontamination and remediation approach should involve consideration of a 

number of viable alternatives with regard to potential treatment and disposal options. The precise mix of 

treatment and disposal options employed would depend on the nature of the specific incident (e.g., 

location, waste volumes). The suitability of using any individual facility would depend on a number of 

factors, including but not limited to the toxicity, mobility and volume of radioactively-contaminated 

wastes (these would be evaluated as part of the characterization process), possible treatment technologies 

(e.g., volume reduction technologies at the incident location, thermal treatment, neutralization), costeffectiveness, and existing federal and state (and possibly local) legal requirements governing waste

disposal. 

5.2.1 General Considerations for Waste Disposal Options and Waste Volumes

As noted above, the complexity of radiological waste disposal decisions would depend on a number of 

factors, including the magnitude of the release and the decisions related to site cleanup. Consideration of 

these factors will determine the amount and types of waste requiring disposal. While disposal in a licensed 

low-level radioactive waste (LLRW) disposal facility may be the preferable first choice, there are a 

limited number of such facilities and not all states have access to all licensed commercial disposal 

facilities. If there is a limited radiological incident with relatively small waste volumes, existing capacity 

is available and may be sufficient to address waste disposal. However, waste resulting from a large-scale

radiological incident, such as the event at the 2011 incident at the Fukushima nuclear facility, would 

likely overwhelm current disposal capacity. For large waste volumes, supplements to existing commercial

radioactive waste disposal facilities would need to be considered, such as a combination of hazardous 

waste landfills, solid waste landfills, DOE disposal facilities, and potentially, the construction of a new 

disposal facility. Organizational and administrative issues related to federal and state government

coordination and preparation are also important.

Discussions of waste disposal options often involve comparisons of estimated waste generation and 

available disposal capacity. The amount of waste generated is related to the cleanup approach, the selected 

approach to decontamination and remediation, as well as the long-term cleanup goals, and can affect the 

volume of waste actually requiring disposal. The projected amounts of wastes for a large-scale 

radiological incident may range from tens to hundreds of million cubic feet (or several million metric

tons). Some of the waste may contain high radioactivity, especially at the incident’s origin; however, most 

of the waste is expected to be only slightly contaminated, though in large quantities. The volume of 

contaminated soil in Japan resulting from the Fukushima incident is estimated to exceed one billion cubic 

feet.

As a point of comparison, roughly 28 million cubic feet of LLRW were disposed of at licensed 

commercial disposal facilities during the period 2002-2011. DOE disposed of approximately twice that 

volume in commercial facilities during the same period, in which it was involved in significant large-scale 

site cleanups.59 Thus, over that ten-year period, an average annual volume of less than ten million cubic 

feet was disposed of in commercial facilities. Volumes from the non-governmental sector are not

expected to increase significantly until the current fleet of NPPs is decommissioned. DOE generated 

additional waste volumes that were disposed of at DOE sites. For example, from 2000-2010, DOE 

disposed of approximately 20 million cubic feet of LLRW at the Nevada National Security Site (NNSS, 

formerly the Nevada Test Site). As it continues site cleanups, DOE projects generation of approximately 

150 million cubic feet of LLRW for the period 2010-2015, most of which will be disposed of at the site of 

origin or other designated DOE sites.

 

59 Information on disposal in commercial disposal facilities provided by the Manifest Information Management System (MIMS), 

operated by the DOE at http://mims.apps.em.doe.gov. 
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Managing the large volumes of waste resulting from a large-scale radiological incident, such as with the

Fukushima accident, would likely overwhelm existing capacity in the U.S. and thus require an overall 

strategy employing all available types of disposal facilities and integrating federal, state, local and private 

sector assets. For example, consider the following— 

 At the beginning of 2016, more than 150 million cubic feet of capacity was licensed at commercial

disposal facilities. An incident could consume all remaining licensed commercial LLRW disposal 

capacity, which would affect waste generators in the energy, industrial, research and medical 

sectors for whom the capacity was originally licensed. While there may be remaining property at

the facilities that could be developed, there is no guarantee that additional capacity can be licensed 

or that states will allow all capacity to be consumed. 

 Estimated waste volumes are comparable to projected generation from the entire DOE complex 

over the next several years, which includes DOE’s large-scale site cleanups. While DOE is 

somewhat less constrained than non-DOE disposal sites in adding additional disposal capacity at

its sites, displacement of projected DOE disposal with incident-related waste has the potential to 

interfere with ongoing cleanup activities, leading to extended on-site storage, slower cleanups, and 

controversial efforts to expand disposal capacity at other DOE sites. Further, there is at present no 

mechanism to provide access to DOE disposal sites for disposal of incident-related waste.

5.2.2 Existing Disposal Options

An effective response to a large-scale radiological incident will involve consideration of the entire range

of potential disposal options. The precise mix of disposal options employed will depend on the nature of 

the specific incident (e.g., location, waste volumes). The process selected to plan and conduct the longterm decontamination and remediation should identify and make provisions for using the different 

available disposal options. 

Each of these potential disposal alternatives is discussed in more detail below. There may also be some

remaining wastes that might require special consideration based on factors such as level of contamination, 

waste form, lack of access, or capacity or presence of other hazardous or toxic contaminants. These 

wastes could include those containing both hazardous and toxic constituents (e.g., mercury and PCBs—

polychlorinated biphenyls), animal carcasses, or contaminated vehicles (where dismantling the vehicle 

may represent a greater potential for dispersal of contaminants and exposure of workers).

5.2.2.1 Commercially Licensed LLRW Disposal Facilities

Given that the bulk of the waste resulting from the release of radionuclides from a nuclear facility or a 

deliberate action will contain radionuclides commonly contained in LLRW, licensed commercial disposal 

facilities would be the most appropriate and publicly acceptable option for disposal if the volumes of 

waste from the incident were relatively small. It would be anticipated that the waste would be mostly at 

the lower end of radionuclide concentrations. Thus, these facilities will be capable of handling all but the 

most problematic waste types, if the amounts were limited. At present, all commercial LLRW disposal 

facilities are licensed by states (through agreements with NRC, referred to as “Agreement States”).

As described earlier, available capacity and access are significant concerns in relying on commercial 

LLRW disposal facilities. Further, even if a facility would be generally available to all waste generators 

and it is found that all but a small portion of the waste would meet that facility’s disposal criteria, it is 

possible that there may be objections to accepting all waste from an incident outside the state, even if the 

facility’s capacity was sufficient.

Access to other facilities generally unavailable to the state(s) affected by the incident might be feasible in 

an emergency situation under NRC regulations, but it should not be expected that large volumes of waste 

will be accepted under these provisions. There is also the possibility that the affected state could construct 

a disposal facility to provide additional capacity. Several states conducted extensive studies of their 
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geology in anticipation of constructing disposal facilities and these studies may be of use in such 

situations.

5.2.2.2 Solid and Hazardous Waste Landfills

Most states are authorized by the EPA under the Resource Conservation and Recovery Act (RCRA) to

operate their own hazardous waste management programs in lieu of the federal Subtitle C program.60

Management of non-hazardous solid wastes is governed by RCRA Subtitle D, which is administered 

largely by the states. Compared to the number of licensed LLRW disposal facilities in the U.S., there are a 

greater number of commercial landfills operating under Subtitle C and many more operating under 

Subtitle D of RCRA for disposal of hazardous and solid wastes, respectively. It would not be expected 

that all of these facilities (particularly those operating under Subtitle D) would be appropriate disposal 

options. However, some of the hazardous waste landfills have accepted some radioactive material for 

disposal and a few have received the necessary state approvals to do so on a routine basis. Historically, 

most of the radiological waste streams accepted by hazardous waste landfills contain naturally-occurring 

radionuclides not regulated by NRC, such as wastes from the oil and gas or other resource extraction

industries, as well as water treatment residuals. However, both NRC and DOE, in coordination with state 

regulators and facility operators, have approved disposal of radioactive waste in RCRA landfills on a 

case-by-case basis. Thus, there is reason to believe that one or more hazardous waste landfills could

contribute to the disposal capacity for incident-related waste. The use of any particular RCRA facility for 

the disposal of radioactive contaminants or mixed contamination would require that the unit is well

designed and managed appropriately. The uniform design and engineering requirements applicable to

hazardous waste landfills would facilitate such an evaluation; by contrast, not all solid waste landfills are

constructed to the same specifications. Further, the evaluation would include consideration of the waste

characteristics, site characteristics, waste acceptance criteria, and other facility attributes.

RCRA hazardous and solid waste landfills may also offer the advantage of disposal capacity suitable for

large volumes of lightly-contaminated material (e.g., soil).61 In addition, these facilities are more likely to 

be located near the incident location, which can facilitate their use if deemed appropriate by federal, state 

and local officials. However, use of these facilities for disposal of radionuclides typically found in lowlevel radioactive waste, even if it contains very low concentrations of those radionuclides, may generate 

public concern if the facilities have not been previously approved for this type of disposal. Therefore, 

additional effort by state and local officials would be necessary to ensure the facility can manage the 

waste in a protective manner, including technical modification, if appropriate. 

5.2.2.3 Potential Use of Federal Properties for New Disposal Capacity

DOE facilities could potentially be a disposal alternative that may be most appropriate for limited 

volumes of waste for which there is no other disposal outlet (such as high-activity waste, certain mixed

wastes, or other problematic waste streams). Waste disposed at DOE sites must meet the waste

acceptance criteria for those sites. DOE does not generally accept non-DOE-owned or generated waste for 

disposal at its sites. In addition, DOE has significant ongoing remediation at a number of sites that will 

generate large volumes of waste over the coming years. Diverting DOE disposal capacity to incidentrelated waste may interfere with those efforts. DOE has also utilized commercial LLRW disposal 

facilities, primarily for bulk waste streams from cleanups, and this potential disposal alternative may also 

be affected by a large-scale radiological incident.

 

60 Alaska, Iowa, Puerto Rico, the Virgin Islands, American Samoa and the Trust Territories and Northern Marianas Islands do not

have authorized RCRA programs as of the date of this publication. 61 EPA reports that about 132 million tons of municipal solid waste were landfilled in 2009, comparable to the rate over the past 

two decades. The 2009 figure represents about 54 percent of total generation. (EPA 2010a) 
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DOE’s primary disposal site serving the DOE complex is the NNSS. DOE/NNSS continues to excavate

additional disposal capacity as needed and estimates that significant additional capacity could be 

developed at NNSS.

DOE’s other designated site for complex-wide disposal is Hanford, WA; however, DOE has an agreement

with the State of Washington that it will not bring waste from other sites until certain remediation

milestones have been met. Overall, DOE anticipates that most of its waste generated in the coming years 

will be disposed at the site of generation. Sites other than NNSS and Hanford are designated for disposal 

of waste generated at those sites, although exceptional situations may allow for disposal of waste 

generated off-site and development of some additional disposal capacity. Additional disposal capacity 

would likely be dependent upon agreement from the state in which the facility is located.

In order to provide cleanup managers the use of all potential disposal capacity there are some issues that

would need to be addressed, such as waste acceptance criteria for waste sites that have not been evaluated 

for radioactive material disposal. However, based on an understanding of the types of waste involved and

the capabilities of existing disposal facilities, a generalized discussion of the attributes of the different

disposal options, with qualifiers, can be developed and these attributes are discussed below. 

COMPARISON OF ATTRIBUTES OF EXISTING DISPOSAL OPTIONS

 Licensed Commercial LLRW Disposal Facilities— 

o Can manage most anticipated waste types within license conditions.

o Highest degree of public acceptance.

o Significant bulk disposal volume possible. 

o Access restrictions may require special approval for waste from certain states.

o Management of mixed radioactive and hazardous waste will need to ensure proper 

disposal and long-term groundwater monitoring.

 Solid and Hazardous Waste Landfills— 

o May offer local disposal option for expected large volumes with limited contamination.

o May offer a disposal option at hazardous waste landfills for mixed wastes (mixtures of 

hazardous and radioactive wastes); hazardous waste landfills have specified construction

and engineering requirements.

o Need to consider the location of the units in proximity to large or sensitive populations, 

sensitive ecosystems, and sole source aquifers.

o May require design modifications to ensure that the waste can be managed protectively 

over time.

o Difficulty in obtaining public acceptance, although some hazardous waste landfills have 

accepted waste with limited radionuclide content with state approval.

o Requires additional demonstration of suitability to ensure protectiveness for radiological 

material (e.g., groundwater monitoring, additional engineering controls); many solid 

waste landfills have not been evaluated for disposal of radioactive material and may not 

be suitable for radiological material.

o May require longer-term/special monitoring, as well as institutional controls.

 DOE Disposal Sites— 

o Could potentially handle high-activity waste if insufficient commercial access or capacity.

o May be suitable for some problematic waste types (e.g., whole vehicles).

o DOE disposal facilities generally accept only DOE-owned or DOE-generated waste. 

Disposal of non-DOE waste requires additional review and agreements involving the host 

state, consistent with DOE’s authorities, particularly where existing agreements limit

DOE’s waste disposal activities.
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5.2.3 Planning and Coordination among Federal and State Entities for Disposal 

Options

A number of federal and state agencies may have important roles to play in making decisions on final 

disposal, depending on the extent of the waste. A framework for coordination with these various federal 

and state agencies should be an element of the process selected for long-term decontamination and 

remediation. 

States should be intimately involved ahead of time in planning for a large-scale radiological incident and 

the resulting waste disposal. The following authorities regarding waste disposal may exist within affected

states— 

 All existing commercial LLRW disposal facilities are licensed by Agreement States.

 Many, but not all, states have formed regional compacts (as authorized by Congress) to site and 

operate LLRW disposal facilities; compacts control access to these sites.

 Although statutorily required62 to provide disposal capacity for low-level waste generated within 

the compact boundaries (with certain exceptions), states are under no obligation to accept waste 

from outside their compacts. States that are not members of compacts do not have the statutory

protection to prohibit disposal of out-of-compact waste.

 Many DOE disposal sites have agreements with the host State regarding the extent of long-term

disposal or acceptance of off-site waste. States hosting DOE disposal sites should participate in 

planning for the potential disposal of incident-related off-site waste at DOE sites.

 States regulate hazardous waste landfills (when authorized by EPA) and solid waste landfills that 

may be used for disposal of waste with very low concentrations of radioactivity (see Section 

5.2.2.2). In planning for disposal of incident-related waste, states should take into account any 

restrictions placed on the disposal of radionuclides in these facilities.

 It is anticipated that on-site disposal at a location affected by the incident, where appropriate, will

be one location of choice and that an affected state could approve construction of a new disposal 

facility for that purpose. 

Depending on the circumstances, coordination with numerous federal agencies would be necessary. Of 

particular note:

 EPA is the coordinating agency for long-term remediation and cleanup, as designated by the 

National Response Framework (FEMA 2008a) and has federal authority for hazardous waste 

disposal; 

 DOE is “owner” of federal sites that may be used for waste disposal; 

 NRC is the federal authority for commercial LLRW disposal; and

 USDA provides technical assistance for agricultural materials contaminated by the release, 

including animal carcasses.

5.2.4 Considerations for Modified Use of Existing Disposal Options

Depending on the circumstances, it may be appropriate to create additional disposal capacity. This 

decision would most likely need to involve extensive discussion between the federal government and the 

affected state(s) where an incident occurred. Generally, there are two options for additional disposal 

capacity— 

 On-site disposal. As a result of evaluating available options, it may be advantageous to develop 

disposal capacity on-site (e.g., build a large disposal facility within the property boundaries where 

the facility causing the release is located), if the site is suitable.

 

62 Pursuant to the Low-Level Radioactive Waste Policy Act of 1980 (LLRWPA) and the 1985 LLRWP Amendments Act of 

1985.
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 Off-site disposal. An additional option would be for a state or the federal government to build a 

disposal site on suitable public lands. The federal or state government could use the provisions of 

eminent domain to condemn property contaminated by a radiological incident and subsequently, 

then use it for waste disposal.

If it is determined that constructing a new disposal facility is the appropriate action, the proposed site(s) 

should be evaluated for suitability. Although the contemplated disposal actions would be taken in event of

a national emergency, every effort should be made to ensure the protection of public health and the 

environment. Appropriate regulatory standards should be considered in developing a specific disposal 

plan. The disposal plan and site suitability should take into account the radiological characteristics of the 

waste. As discussed above, some slightly radioactive materials may be disposed in hazardous waste

landfills if they are permitted for it. More radioactive materials may be sent to sites licensed as LLRW

disposal facilities, though less contaminated materials may also be sent to LLRW disposal facilities. A 

small amount of waste from a radiological incident may have concentrated radioactivity, but most of the 

waste generated in a large-scale radiological incident would likely be contaminated with low levels of 

radioactivity. The different radiological characteristics of the waste would have a bearing on the 

stringency of containment required of a waste disposal facility. All waste sites would need to have 

appropriate controls to protect public health and the environment for any level of radioactive 

contamination, but more highly radioactive materials would need more robust controls than slightly

contaminated material.

The physical/geographic characteristics of the site and the availability of land will be important in 

determining the appropriateness of a potential disposal site. Sites with limited rainfall, high 

evapotranspiration, deep water tables, and soil characteristics that limit migration of radionuclides have 

been found to be best suited for disposal of radioactive waste, although waste management and 

engineering can be applied to improve performance at sites with less favorable characteristics (e.g., 

controls on the waste form or level of allowable radioactivity, addition of liners, cover requirements, or 

through construction of concrete bunkers or vaults). Other characteristics, such as location in a high risk 

area (e.g., flood plain or seismic zone) or sensitive ecologic area, should also be considered. A disposal 

cell for 1 million cubic feet of waste will occupy 1 acre or more of surface area, assuming disposal to a 

depth of about 30 feet (9 meters). Large-scale disposal operations may also require extensive surface

facilities.

Additional factors to evaluate the advantages and disadvantages among potentially suitable sites may

include: 

 Proximity to the incident: it may be useful to consider sites in different regions of the country to 

limit transportation demands;

 Proximity to residential areas or commercial districts: the potential for disposal activities to affect 

nearby populations or commercial activities, whether located within the site boundaries or on 

adjacent property, should be considered; 

 Proximity to transportation: access to timely and direct transportation that can accommodate large 

shipments is desirable—action to facilitate: construction of transportation infrastructure (e.g., 

direct rail lines);

 Experience in waste disposal: waste disposal sites will have infrastructure, procedures and trained 

personnel that can make most efficient use of the site—action to facilitate: development of 

infrastructure, training, construction of disposal cells and engineered containment (e.g., vaults or 

bunkers); and 

 Level of existing contamination: areas that are unlikely to be remediated in the near future or 

unlikely to be released for public use may be more acceptable for disposal.
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5.2.5 Potential Federal Properties to Develop New Disposal Capacity

In addition to criteria for siting new disposal facilities, the federal government has control of a large 

amount of land throughout the U.S. that could be repurposed, or could offer assistance to support state 

governments in developing new facilities.

5.2.5.1 DOE Sites

DOE has decades of experience in radioactive waste management. In considering the primary selection

criteria described above, DOE sites in the western U.S. generally have more favorable characteristics and

readily available property compared to those in the eastern U.S. However, DOE has successfully 

implemented disposal at the eastern sites, often with some engineering enhancements. DOE has several 

categories of sites for consideration, beginning with the most suitable— 

 Active disposal or cleanup sites in the western U.S.

 Active disposal or cleanup sites in the eastern U.S.

 Closed sites with disposal areas.

 Closed uranium milling sites.

 Other long-term stewardship sites.

Considerations: Some DOE sites have agreements with states or other stakeholders regarding further 

disposal or cleanup activities. Current disposal sites have waste acceptance criteria governed by DOE

policy or statute. Closed and long-term stewardship sites may not have large amounts of additional

property available for disposal.

5.2.5.2 DoD Installations

DoD maintains some installations with large land areas, primarily in the western U.S. Many of these sites 

have been contaminated through extensive training or other activities. DoD likely has more sites in the 

eastern U.S. than does DOE. Categories of sites that could be considered suitable include: 

 Bombing and firing ranges;

 Chemical weapons demilitarization and storage sites;

 Ammunition plants and arsenals; and 

 Surplus properties (e.g., BRAC – base realignment and closure, FUDS – formerly used defense 

site).

Considerations: Section 2692 of title 10, United States Code, “Storage, Treatment and Disposal of

NonDefense Toxic and Hazardous Materials,” generally states that the Secretary of Defense may not 

permit the use of an installation of the DoD for the storage, treatment, or disposal of any material that is a 

toxic or hazardous material and that is not owned either by the DoD or by a member of the armed forces

(or by a dependent of the member) assigned to or provided military housing on the installation.

Radiological waste resulting from either a nuclear accident or a terrorist attack may fall under this

prohibition. The Secretary of Defense may grant exceptions to this restriction when “essential to protect

the health and safety of the public from imminent danger.” A determination of whether or not radiological

waste meets the “imminent danger” threshold would be required. 

Additionally, some DoD properties, including ranges in the western U.S., are on “withdrawn” lands, 

which are part of the public domain supervised by the Bureau of Land Management (BLM). Withdrawn 

land statutes permit DoD to use the property for specific military mission needs. The use of withdrawn 

lands to manage radiological waste would violate those statutes.
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5.2.5.3 Other Federal Properties

Agencies such as the Department of Interior or USDA own large properties that could be considered 

suitable for disposal, many of which are in the western U.S. These properties may be administered by 

discrete entities within the cabinet-level departments, such as the National Park Service, BLM, or Forest

Service. Some properties may be in proximity to DOE or DoD lands.

Considerations: Properties may be designated for public use or for protection (e.g., wilderness areas or 

preserves). Many properties are also in rugged terrain with difficult access or border tribal lands.
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KEY POINTS IN CHAPTER 5 – LATE PHASE

 Numeric PAGs will not be used to guide restoration and recovery of areas impacted by a 

radiological incident; rather, planning activities should include a process to involve stakeholders in 

setting priorities and determining actions. Such a process should be flexible to adapt to a variety of 

situations.

 Planning considerations for worst case scenarios are provided. Smaller radiological incidents may 

be well addressed by existing emergency response and environmental cleanup programs at local, 

state, tribal and federal levels.

 Reoccupying households and businesses should be considered in balance with progress made in 

reducing radiation risks through decontamination, radioactive decay, and managing contaminated 

waste.

 Exposure limits that lead to excess lifetime cancer incidence in a range of one in a population of 

ten thousand (10-4) to one in a population of one million (10-6) are generally considered protective, 

though this may not be achievable after a large-scale radiological incident. In making decisions 

about cleanup goals and strategies for a particular event, decision-makers must balance the 

acceptable level of excess lifetime cancer incidence with the extent of the measures that would be 

necessary to achieve it.

 Incidents that result in large volumes of waste from a large-scale radiological incident would likely 

overwhelm existing radioactive waste disposal capacity in the U.S.

 Following a nuclear accident, the states bear primary responsibility to identify and provide waste 

management options, including disposal capacity; in the event of a terrorist attack, the federal 

government can offer a range of assistance to states to identify and implement waste management 

options. 

 Safely managing and disposing of radioactive waste will require advance planning at all levels of 

government and careful coordination with stakeholders at all stages of the decision-making 

process.
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APPENDIX A – REFERENCES

Aaberg 1989 Aaberg, R. Evaluation of Skin and Ingestion Exposure Pathways. EPA 520/1-89-016. 

U.S. Environmental Protection Agency, Washington, D.C., (1989).

CDC 2014a Centers for Disease Control and Prevention [CDC], Department of Health and 

Human Services. Drinking Water Advisory, Planning, and Emergency Response 

Resources. Centers for Disease Control and Prevention, U.S. Department of Health 

and Human Services, Atlanta, GA, (2014).

CDC 2014b Centers for Disease Control and Prevention [CDC], Department of Health and 

Human Services. Population Monitoring in Radiation Emergencies: A Guide for

State and Local Public Health Planners. Second edition. Centers for Disease Control

and Prevention, Department of Health and Human Services, Atlanta, GA, (2014).

CRARM 1997 The Presidential/Congressional Commission on Risk Assessment and Risk 

Management [CRARM]. Framework for Environmental Health Risk Management. 

Washington, D.C., (1997).

DHS 2008 Department of Homeland Security [DHS], Federal Emergency Management 

Agency. Planning Guidance for Protection and Recovery Following Radiological

Dispersal Device (RDD) and Improvised Nuclear Device (IND) Incidents. Federal

Register, 70, 45029; August 1, 2008.

DoD 2003 Department of Defense [DoD], Military Medical Operations, Armed Forces

Radiobiology Research Institute. Medical Management of Radiological Casualties,

Second Edition. Armed Forces Radiobiology Research Institute, Department of

Defense, Bethesda, MD, (2003).

DOE 1988 Department of Energy [DOE]. External Dose-Rate Conversion Factors for

Calculation of Dose to the Public. DOEIEH-0070, U.S. Department of Energy,

Washington, D.C., (1988).

DOE 1990 Department of Energy [DOE]. Effectiveness of Sheltering-in-place in Buildings and

Vehicles for Plutonium. DOE/EH-0 159, U.S. Department of Energy, Washington,

D.C., (1990).

DOE 2009 Department of Energy [DOE]. Preliminary Report on Operational Guidelines

Developed for Use in Emergency Preparedness and Response to a Radiological

Dispersal Device Incident. DOE/HS-0001; ANL/EVS/TM/09-1. U.S. Department of 

Energy, Washington, D.C., (2009).

DOE 2010 Department of Energy [DOE]. Federal Radiological Monitoring and Assessment

Center (FRMAC) Assessment Manual, Volume 2: Pre-Assessed Default Scenarios.

SAND2010-2575P. Federal Radiological Monitoring and Assessment Center, U.S.

Department of Energy, Washington, D.C., (2010).
Protective Action Guides and Planning Guidance for Radiological Incidents 88

PAG Manual EPA-400/R-17/001

DOE 2012 Department of Energy [DOE]. Radiological Emergency Response Health and Safety

Manual. DOE/NV/11718-440. Federal Radiological Monitoring and Assessment

Center, U.S. Department of Energy, Washington, D.C., (2012).

DOE 2015 Department of Energy [DOE]. Federal Radiological Monitoring and Assessment

Center (FRMAC) Assessment Manual, Volume 1: Overview and Methods.

SAND2013-0184P. Federal Radiological Monitoring and Assessment Center, U.S.

Department of Energy, Washington, D.C., (2015).

EPA 1978a Environmental Protection Agency [EPA]. Protective Action Evaluation Part I: The 

Effectiveness of Sheltering-in-Place as a Protective Action Against Nuclear

Accidents Involving Gaseous Releases. EPA 520/1-78-001A. U.S. Environmental 

Protection Agency, Washington, D.C., (1978).

EPA 1978b Environmental Protection Agency [EPA]. Protective Action Evaluation Part II -

Evacuation and Sheltering-in-place as Protective Actions Against Nuclear Accidents

Involving Gaseous Releases. 520/1-78-001B. U.S. Environmental Protection

Agency, Washington, D.C., (1978).

EPA 1987a Environmental Protection Agency [EPA]. An Analysis of Evacuation Options for 

Nuclear Accidents. EPA 520/1-87-023. U.S. Environmental Protection Agency, 

Washington, D.C., (1987).

EPA 1987b Environmental Protection Agency [EPA]. Radiation Protection Guidance to Federal

Agencies for Occupational Exposure. Federal Register, 52, 2822-2834; 1987. 

EPA 1992a Environmental Protection Agency [EPA]. Implementing Protective Actions for 

Radiological Incidents at Other Than Nuclear Power Reactors. EPA 402-R-92-001. 

U.S. Environmental Protection Agency, Washington, D.C., (1992).

EPA 1992b Environmental Protection Agency [EPA]. Manual of Protective Action Guides and 

Protective Actions for Nuclear Incidents. EPA 400-R-92-001. U.S. Environmental 

Protection Agency, Washington, D.C., (1992).

EPA 1997 Environmental Protection Agency [EPA]. Health Effects Assessment Summary 

Tables, FY 1997 Update. EPA 540-R-97-036. U.S. Environmental Protection 

Agency, Office of Superfund Remediation and Technology Innovation, Washington, 

D.C., (1997). 

EPA 1999 Environmental Protection Agency [EPA]. Cancer Risk Coefficients for

Environmental Exposure to Radionuclides, Federal Guidance Report #13. EPA 402-

R-99-001. U.S. Environmental Protection Agency, Office of Air and Radiation,

Washington, D.C., (1999).

EPA 2001 Environmental Protection Agency [EPA]. Radionuclides Rule: A Quick Reference 

Guide. EPA 816-F-01-003. U.S. Environmental Protection Agency, Office of Water, 

Washington, D.C., (2001).
Protective Action Guides and Planning Guidance for Radiological Incidents 89

PAG Manual EPA-400/R-17/001

EPA 2002a Environmental Protection Agency [EPA]. Cancer Risk Coefficients for 

Environmental Exposure to Radionuclides: CD Supplement, Federal Guidance 

Report #13. EPA 402-C-99-001, Rev. 1. U.S. Environmental Protection Agency, 

Office of Air and Radiation, Washington, D.C., (2002).

EPA 2002b Environmental Protection Agency [EPA]. Implementation Guidance for 

Radionuclides. EPA 816-F-00-002. U.S. Environmental Protection Agency, Office of 

Ground Water and Drinking Water, Washington, D.C., (2002).

EPA 2002c Environmental Protection Agency [EPA]. Radionuclides in Drinking Water: A Small 

Entity Compliance Guide. EPA 815-R-02-001. U.S. Environmental Protection 

Agency, Washington, D.C., (2002).

EPA 2006a Environmental Protection Agency [EPA]. A System’s Guide to the Management of 

Radioactive Residuals from Drinking Water Treatment Technologies. EPA 816-F-06-

012. U.S. Environmental Protection Agency, Washington, D.C., (2006). 

EPA 2006b Environmental Protection Agency [EPA]. A System’s Guide to the Identification and 

Disposal of Hazardous and Non-Hazardous Water Treatment Plant Residuals. EPA

816-F-06-011. U.S. Environmental Protection Agency, Washington, D.C., (2006).

EPA 2010a Environmental Protection Agency [EPA]. Municipal Solid Waste in the United 

States: 2009 Facts and Figures. EPA 530-R-10-012. U.S. Environmental Protection 

Agency, Washington, D.C., (2010).

EPA 2010b Environmental Protection Agency [EPA]. Revised Public Notification Handbook. 

EPA 816-R-09-013. U.S. Environmental Protection Agency, Washington, D.C., 

(2010).

EPA 2011a Environmental Protection Agency [EPA]. Exposure Factors Handbook: 2011 Edition. 

EPA 600-R-09-052F. U.S. Environmental Protection Agency, Washington, D.C., 

(2011).

EPA 2011b Environmental Protection Agency [EPA]. Planning for an Emergency Drinking 

Water Supply. EPA 600-R-11-054. U.S. Environmental Protection Agency, 

Washington, D.C., (2011).

EPA 2014 Environmental Protection Agency [EPA]. Rapid Radiochemical Methods Applicable 

to Selected Radionuclides for Environmental Remediation Following Radiological 

Incidents, Third Edition. U.S. Environmental Protection Agency, Washington, D.C., 

(2014). 

EPA 2015 Environmental Protection Agency [EPA]. Radionuclides in Drinking Water –

Compliance Options: Treatment Technology Descriptions. U.S. Environmental 

Protection Agency, Washington, D.C., (2015).
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FDA 1998 Food and Drug Administration [FDA]. Accidental Radioactive Contamination of

Human Food and Animal Feeds: Recommendations for State and Local Agencies.

U.S. Food and Drug Administration, Center for Devices and Radiological Health, 

Rockville, MD, (1998).

FDA 2001 Food and Drug Administration [FDA]. Notice: Guidance on use of Potassium Iodide

as a Thyroid Blocking Agent in Radiation Emergencies. Federal Register, 66, 64046; 

2001. 

FDA 2002 Food and Drug Administration [FDA]. Guidance for Industry - KI in Radiation

Emergencies – Questions and Answers. Procedural, Revision 1. Food and Drug 

Administration, Center for Drug Evaluation and Research, Rockville, MD, (2002).

FDA 2004 Food and Drug Administration [FDA]. Supporting Document for Guidance Levels 

for Radionuclides in Domestic and Imported Foods, Docket No. 2003D-0558. U.S. 

Food and Drug Administration, Center for Food Safety and Applied Nutrition, 

College Park, MD, (2004).

FEMA 1995 Federal Emergency Management Agency [FEMA]. Contamination Monitoring 

Standard for a Portal Monitor Used for Radiological Emergency Response. FEMA 

REP-21. U.S. Department of Homeland Security, Federal Emergency Management

Agency, Washington, D.C., (1995).

FEMA 2002 Federal Emergency Management Agency [FEMA]. Contamination Monitoring 

Guidance for Portable Instruments Used for Radiological Emergency Response to 

Nuclear Power Plant Accidents. FEMA REP-22. U.S. Department of Homeland 

Security, Federal Emergency Management Agency, Washington, D.C., (2002).

FEMA 2008a Federal Emergency Management Agency [FEMA]. National Response Framework.

U.S. Department of Homeland Security, Federal Emergency Management Agency,

Washington, D.C., (2008).

FEMA 2008b Federal Emergency Management Agency [FEMA]. National Response Framework,

Nuclear Radiological Incident Annex. U.S. Department of Homeland Security, 

Federal Emergency Management Agency, Washington, D.C., (2008).

FEMA 2016a Federal Emergency Management Agency [FEMA]. National Disaster Recovery 

Framework (NDRF), Second Edition. U.S. Department of Homeland Security, 

Federal Emergency Management Agency, Washington, D.C., (2016).

FEMA 2016b Federal Emergency Management Agency [FEMA]. National Response Framework 

and Emergency Support Function #15, External Affairs Annex. U.S. Department of 

Homeland Security, Federal Emergency Management Agency, Washington, D.C., 

(2016).

FRC 1964 Federal Radiation Council [FRC]. Background Material for the Development of 

Radiation Protection Standards, Staff Report of the FRC, Report No. 5. Washington, 

D.C., (1964). 
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FRC 1965 Federal Radiation Council [FRC]. Background Material for the Development of 

Radiation Protection Standards, Protective Action Guides for Strontium-89, 

Strontium-90 and Cesium-137, Report No. 7. Washington, D.C., (1965). 

Hans et al. 1975 Hans, J.M. Jr. and Sell, T.C. Evacuation Risks - An Evaluation. EPA 520/6-74-002.

U.S. Environmental Protection Agency, Washington, D.C., (1975).

IAEA 1991 International Atomic Energy Agency [IAEA]. Principles for Establishing Intervention

Levels for the Protection of the Public in the Event of a Nuclear Accident or

Radiological Emergency. Safety Series No. 72, Revision 1. International Atomic

Energy Agency, Vienna, Austria, (1991).

IAEA 2002 International Atomic Energy Agency [IAEA]. Preparedness and Response for a 

Nuclear or Radiological Emergency. Safety Series GS-R-2. International Atomic 

Energy Agency, Vienna, Austria, (2002).

ICRP 1991 International Commission on Radiological Protection [ICRP]. 1990 

Recommendations of the International Commission on Radiological Protection.

ICRP Publication 60, Annals of the ICRP 21(1-3). Pergamon Press, Oxford (1991).

ICRP 2002 International Commission on Radiation Protection [ICRP]. Doses to the Embryo and 

Fetus from Intakes of Radionuclides by the Mother, ICRP Publication #88, Corrected 

Version. International Commission on Radiation Protection, Ottawa, Ontario, 

Canada, (2002).

ICRP 2005 International Commission on Radiation Protection [ICRP]. Doses to Infants from 

Ingestion of Radionuclides in Mother’s Milk, ICRP Publication #95. International 

Commission on Radiation Protection, Ottawa, Ontario, Canada, (2005).

ICRP 2007 International Commission on Radiological Protection [ICRP]. The 2007 

Recommendations of the International Commission on Radiological Protection, 

Annals of the ICRP, Volume 37, Nos.2-4, 2007, Publication #103. International 

Commission on Radiation Protection, Ottawa, Ontario, Canada, (2007).

NAS 1980 Committee on the Biological Effects of Ionizing Radiation (BEIR) of the National 

Academy of Sciences [NAS], National Research Council. The Effects on Populations 

of Exposure to Low Levels of Ionizing Radiation: BEIR III. NAS/National Research 

Council, Washington, D.C., (1980). 

NCRP 2001 National Council on Radiation Protection and Measurements [NCRP]. Management

of Terrorist Events Involving Radioactive Material, NCRP Report No. 138. National

Council on Radiation Protection and Measurements, Bethesda, MD, (2001).

NCRP 2008 National Council on Radiation Protection and Measurements [NCRP]. Management 

of Persons Contaminated with Radionuclides: Handbook, NCRP Report No. 161, 

Vol. I and Vol. II. National Council on Radiation Protection and Measurements, 

Bethesda, MD, (2008).
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PAG Manual EPA-400/R-17/001

NCRP 2010 National Council on Radiation Protection and Measurements [NCRP]. Responding to 

a Radiological or Nuclear Terrorism Incident: A Guide for Decision Makers, NCRP

Report No. 165. National Council on Radiation Protection and Measurements,

Bethesda, MD, (2010).

NCRP 2011 National Council on Radiation Protection and Measurements [NCRP]. Population 

Monitoring and Radionuclide Decorporation Following a Radiological or Nuclear 

Incident, NCRP Report No. 166, National Council on Radiation Protection and 

Measurements, Bethesda, MD, (2011).

NCRP 2013 Brent, R.L., Frush, D.P., Harms, R.W., and M.S. Linet. Preconception and Prenatal 

Radiation Exposure: Health Effects and Protective Guidance, NCRP Report #174, 

National Council on Radiation Protection and Measurements, Bethesda, MD, (2013).

NRC 1975 Nuclear Regulatory Commission [NRC]. Reactor Safety Study. An Assessment of

Accident Risks in U. S. Commercial Nuclear Power Plants. WASH-1400, NUREG751014. U.S. Nuclear Regulatory Commission, Washington, D.C., (1975).

NRC 1978 and 

EPA 1978 

Nuclear Regulatory Commission [NRC] and Environmental Protection Agency

[EPA]. Task Force Report. Planning Basis for the Development of State and Local

Government Radiological Emergency Response Plans in Support of Light Water

Nuclear Power Plants. NUREG-0396 or EPA 520/1-78-016. U.S. Environmental

Protection Agency, Washington, D.C., (1978).

NRC 1980 Nuclear Regulatory Commission [NRC]. Criteria for Preparation and Evaluation of

Radiological Emergency Response Plans and Preparedness in Support of Nuclear

Power Plants. NUREG-0654, FEMA-REP-1, Rev. l. U.S. Nuclear Regulatory

Commission, Washington, D.C., (1980).

NRC 1983 Nuclear Regulatory Commission [NRC]. Emergency Planning for Research and Test 

Reactors. U.S. Nuclear Regulatory Commission, Washington, D.C., (1983).

NRC 1988 Nuclear Regulatory Commission [NRC]. A Regulatory Analysis on Emergency

Preparedness for Fuel Cycle and Other Radioactive Material Licensees. NUREG1140. U.S. Nuclear Regulatory Commission, Washington, D.C., (1988).

NRC 2005 Nuclear Regulatory Commission [NRC]. Identification and Analysis of Factors

Affecting Emergency Evacuations. NUREG/CR-6864. U.S. Nuclear Regulatory

Commission, Washington, D.C., (2005).

NRC 2008 Nuclear Regulatory Commission [NRC]. Assessment of Emergency Response

Planning and Implementation for Large Scale Evacuations. NUREG/CR-6981. U.S.

Nuclear Regulatory Commission, Washington, D.C., (2008).

NRC 2011 Nuclear Regulatory Commission [NRC]. Standard Format and Content for 

Emergency Plans for Fuel Cycle and Materials Facilities. U.S. Nuclear Regulatory 

Commission, Washington, D.C., (2011).
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NSS 2010 National Security Staff [NSS], Interagency Policy Coordination Subcommittee for

Preparedness and Response to Radiological and Nuclear Threats. Planning

Guidance for Response to a Nuclear Detonation. Second Edition. Interagency

Policy Coordination Subcommittee for Preparedness and Response to

Radiological and Nuclear Threats, Washington, D.C., (2010).

Pasquill, 1961 Pasquill, F. The Estimation of the Dispersion of Windborne Material. Meteorological

Magazine. 90, 33-49, (1961).

SNL 1982 Sandia National Laboratory [SNL]. Technical Guidance for Siting Criteria

Development. NUREG/CR-2239. U.S. Nuclear Regulatory Commission,

Washington, D.C., (1982).
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APPENDIX B – GLOSSARY

Acute health effects: Health problems caused by high radiation doses received in a short period of time. 

Examples of acute effects include erythema (reddening of skin), blistering, epilation (hair loss), and 

vomiting.

ALARA: Acronym for "as low as reasonably achievable" means making every reasonable effort to 

maintain exposures to radiation as far below the dose limits in this part as is practical consistent with the 

purpose for which the activity is undertaken.

Alpha radiation: Alpha radiation comes from the ejection of alpha particles from the nuclei of some 

unstable atoms. An alpha particle is identical to a helium nucleus and consists of two protons and two 

neutrons. Alpha particles are highly energetic, but can only travel a few centimeters in air. They have low 

penetrating power and can be stopped by a sheet of paper. Alpha particles generally cannot even penetrate 

the layer of dead cells on the skin, but can pose a health risk when inhaled or ingested. 

Avoided dose: The radiation dose saved by implementing a protective action.

Best Available Technologies (BAT): BATs are treatment technologies, treatment techniques, or other 

means that the U.S. EPA administrator determines to be available, after examination for efficacy under 

field conditions and not solely under laboratory conditions (taking cost into consideration).

Beta radiation: Beta radiation comes from the emission of beta particles during radioactive decay. Beta

particles are highly energetic and fast-moving. They carry a positive or negative charge and can be 

stopped by a layer of clothing or few millimeters of a solid material. Beta particles can penetrate the skin 

and cause skin burns, but tissue damage is limited by their small size. Beta particles are most hazardous 

when inhaled or ingested.

Centigray (cGy): One cGy is equal to one hundredth of a gray (0.01Gy). See Gray. One cGy is 

equivalent to one rad. See Rad. 

Cloudshine: Gamma radiation emitted from an airborne plume overhead.

Committed effective dose: The sum of the committed equivalent doses following intake (inhalation or

ingestion) of a radionuclide to each organ multiplied by a tissue weighting factor.

Community Water Systems (CWS): A public water system that serves at least 15 service connections 

used by year-round residents or regularly serves at least 25 year-round residents.

Contamination: Radionuclides on a surface or in the environment as a result of an accidental release.

Concentration: Radionuclide activity per unit of mass.

Chronic effects: Health problems caused by radiation doses delivered over a long period. Examples of 

chronic effects include cancer and genetic mutations.

Derived Intervention Level (DIL): Concentration derived from the intervention level of dose at which

introduction of protective measures should be considered. (FDA 1998) 

Derived Response Level (DRL): A level of radioactivity in an environmental medium that would be 

expected to produce a dose equal to its corresponding Protective Action Guide. 
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Dose: The amount of radiation exposure a person has received, calculated considering the effectiveness of

the radiation type (alpha, beta, gamma), the timeframe of the exposure, and the sensitivity of the person or

individual organs.

Dose parameter (DP): Any factor that is used to change an environmental measurement to dose in the 

units of concern. 

Dose projection: A calculated future dose that an individual might receive; also the process of making 

these calculations.

Dose reduction factor: A factor by which a decontamination technique or protective action reduces the

radiation dose to a person. 

Dosimetry: The system for assessing radiation doses from external radiation exposures and from intakes 

of radionuclides using biokinetic models and dosimetric quantities developed by the ICRP and the 

International Commission on Radiation Units and Measurements (ICRU).

Early phase: The beginning of a radiological incident for which immediate decisions for effective use of 

protective actions are required and must therefore be based primarily on the status of the radiological

incident and the prognosis for worsening conditions. This phase may last from hours to days. 

Effective dose: The sum of organ equivalent doses weighted by ICRP organ weighting factors.

Emergency Planning Zone: A designated zone around a commercial nuclear power plant for which

radiological response plans must be maintained under Nuclear Regulatory Commission regulations. 

Emergency worker: Anyone with a role in responding to the incident whether a radiation worker 

previously or not, who should be protected from radiation exposure.

Evacuation: The urgent removal of people from an area to avoid or reduce high-level, short-term 

exposure, from the plume or from deposited radioactivity. Evacuation may be a preemptive action taken in 

response to a facility condition rather than an actual release.

Gamma radiation: Gamma radiation comes from the emission of high-energy, weightless, chargeless

photons during radioactive decay. Gamma photons are pure electromagnetic energy and highly 

penetrating—several inches of lead or a few feet of concrete may be required to attenuate them. External 

exposure to gamma rays poses a health threat to the entire body. Inhalation and ingestion of gamma 

emitters also poses a health threat.

Graves’ disease: An autoimmune disorder that leads to the over activity of the thyroid.

Gray (Gy): International unit of absorbed radiation dose. One Gy is equivalent to 100 rad. See Rad. 

Groundshine: Gamma radiation emitted from radioactive materials deposited on the ground. 

Half-life: The time required for half the atoms of a given radioisotope to transform by radioactive decay.

Hashimoto’s thyroiditis: An autoimmune disorder that leads to underactive thyroid with bouts of over

activity.

Improvised Nuclear Device (IND): A crude, yield-producing nuclear weapon fabricated from diverted 

fissile material.
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Intermediate phase: The period beginning after the source and releases have been brought under control 

(has not necessarily stopped but is no longer growing) and reliable environmental measurements are 

available for use as a basis for decisions on protective actions and extending until these additional 

protective actions are no longer needed. This phase may overlap the early phase and late phase and may 

last from weeks to months. 

Isodose-rate line: A contour line that is used to connect points of equal radiation dose rates.

Late phase: The period beginning when recovery actions designed to reduce radiation levels in the 

environment to acceptable levels are commenced and ending when all recovery actions have been 

completed. This phase may extend from months to years. A PAG level, or dose to avoid, is not 

appropriate for long-term cleanup.

Latency period, cancer: The time elapsed between radiation exposure and the onset of cancer. 

Maximum Contaminant Level (MCL): An enforceable standard established to protect the public against 

consumption of drinking water contaminants that present a risk to human health. A MCL is the maximum 

allowable amount of a contaminant in drinking water that is delivered to the consumer.

Microsievert (μSv): One millionth of a Sievert. See Sievert. One ten-thousandth of a rem. See Rem.

(1 μSv = 0.1 mrem (millirem))

Millirem (mrem): One thousandth of a rem. See Rem.

(1 mrem = 0.00001 Sv (sievert) = 0.01 mSv (millisievert) = 10 μSv (microsievert)) 

Millisievert (mSv): One thousandth of a sievert. See Sievert.

(1 mSv = 100 mrem (millirem) = 0.1 rem) 

Noble gases: A group of elemental gases that are tasteless, odorless, and that do not undergo chemical 

reactions under natural conditions. The noble gases consist of Helium (He), Neon (Ne), Argon (Ar), 

Krypton (Kr), Xenon (Xe), and Radon (Rn). 

Off-site: Areas outside the controlled border of a facility, such as a nuclear power plant. For an incident 

not involving a facility, this term may also be used to refer to areas impacted by contamination. 

On-site: Areas inside the controlled border of a facility, such as a nuclear power plant. For an incident not

involving a facility, this term may refer to areas controlled during a response.

Potassium iodide: A salt of stable, non-radioactive iodine in medicine form. The administration of 

potassium iodide saturates the thyroid with non-radioactive iodine, so it does not absorb radioactive 

iodine released into the environment from a radiological incident.

Projected dose: The prediction of the dose that a population or individual could receive.

Protective actions: An activity conducted in response to an incident or potential incident to avoid or 

reduce radiation dose to members of the public.

Protective Action Guide (PAG): The projected dose to an individual, resulting from a radiological 

incident at which a specific protective action to reduce or avoid that dose is warranted.

Prophylactic: A treatment or medication designed to prevent exposure to radiation.
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Rad (radiation absorbed dose): A basic unit of absorbed radiation dose. It is being replaced by the “gray,” 

which is equivalent to 100 rad. One rad equals the dose delivered to an object of 100 ergs of energy, per 

gram of material.

Radioactive: Quality of a material that emits alpha particles, beta particles, gamma rays, or neutrons. 

Radiological dispersal device (RDD): A device or mechanism that is intended to spread radioactive 

material from the detonation of conventional explosives or other means. An RDD is commonly known as 

a “dirty bomb.” 

Radiopharmaceutical: A radioactive chemical used for diagnosis, cure, treatment, or prevention of 

diseases.

Recovery: The phase after response when efforts focus on remediation, or the process of reducing

radiation exposure rates and concentrations of radioactive material in the environment to levels acceptable

for unconditional occupancy or use.

Reentry: Workers or members of the public going into relocation or radiological contaminated areas on a 

temporary basis under controlled conditions. 

Release: Uncontrolled distribution of radioactive material to the environment. 

Relocation: The removal or continued exclusion of people (households) from contaminated areas to 

avoid chronic radiation exposure. Not to be confused with evacuation. 

Reoccupancy: The return of households and communities to relocation areas during the cleanup process, 

at radiation levels acceptable to the community. 

Rem (roentgen equivalent man): The product of the absorbed dose in rads and a weighting factor which

accounts for the effectiveness of the radiation to cause biological damage; a conventional unit for 

equivalent dose. One rem equals 0.01 Sv. 

Release rate: The measure of the amount of radioactive material dispersed per unit of time.

Return: Permanent resettlement in evacuation or relocation areas with no restrictions, based on 

acceptable environmental and public health conditions. 

Roentgen (R): A conventional unit for exposure. For x-ray and gamma radiation, Rad ~ rem ~ Roentgen 

(R). A handheld survey meter that reads in R/hr can be used to measure exposure rates. 

Shelter-in-place: The action of staying or going indoors immediately. 

Sievert (Sv): International unit of equivalent dose. One sievert equals 100 rem. 

(1 Sv = 1,000 mSv (millisieverts) = 1,000,000 μSv (microsieverts) = 100 rem = 100,000 mrem (millirem))

Small System Compliance Technologies (SSCT): Treatment technologies that achieve compliance with 

Maximum Contaminant Levels and which have been identified by EPA as being affordable for small 

drinking water systems serving fewer than 10,000 persons.

Source term: The amount of a contaminant available in a scenario or actually released to the 

environment. 
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Stay time: Term of art used in the radiation safety field. Stay times are the amount of time a person may 

access the contaminated area. These times vary based upon site-specific factors or incident characteristics 

such as indoor or outdoor work, sensitive populations, and level of radioactivity.

Total Effective Dose (TED): The sum of the effective dose (for external exposures) and the committed 

effective dose; also referred to in this Manual as whole body dose. See Section 2.3. 

Whole Body Dose: See Total Effective Dose. 
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APPENDIX C – LIST OF ACRONYMS

AEA Atomic Energy Act

ALARA As Low as Reasonably Achievable 

ANS American Nuclear Society

BAT Best Available Technology

BEIR Committee on the Biological Effects of Ionizing Radiation (BEIR) of the 

National Academy of Sciences

BLM Bureau of Land Management

Bq Becquerel (measurement unit)

CDC Centers for Disease Control and Prevention 

CERCLA Comprehensive Environmental Response, Compensation and Liability Act

CFR Code of Federal Regulations

cGy Centigray (measurement unit)

Ci Curie (measurement unit)

cpm Counts per minute (measurement unit) 

CRARM Presidential/Congressional Commission on Risk Assessment and Risk 

Management

CWS Community Water System

DCF Dose Conversion Factor 

DHS Department of Homeland Security 

DIL Derived Intervention Levels

DoD Department of Defense

DOE Department of Energy 

DOL Department of Labor 

DP Dose Parameter

DRL Derived Response Level

DTPA Diethylenetriaminepentaacetic acid or Pentetic acid

EAL Emergency Action Level

EPA Environmental Protection Agency

EPZ Emergency Planning Zone 

FDA Food and Drug Administration

FEMA Federal Emergency Management Agency

FRC Federal Radiation Council 

FRMAC Federal Radiological Monitoring and Assessment Center

FRPCC Federal Radiological Preparedness Coordination Committee

hr Hour 

Gy Gray (measurement unit)
Protective Action Guides and Planning Guidance for Radiological Incidents 100

PAG Manual EPA-400/R-17/001

HAZWOPER Hazardous Waste Operations and Emergency Response 

HHS Department of Health and Human Services

HPS Health Physics Society

IAEA International Atomic Energy Agency

ICP Incident Command Post

ICRP International Commission on Radiological Protection 

ICRU International Commission on Radiation Units and Measurements

IC/UC Incident Command/Unified Command 

ICS Incident Command System 

IND Improvised Nuclear Device

JFO Joint Field Office

JIC Joint Information Center

KI Potassium Iodide 

km Kilometer

L Liter

LLRW Low-level radioactive waste

LLRWPA Low-Level Radioactive Waste Policy Act 

MCL Maximum Contaminant Level

mg Milligram (measurement unit)

MIMS Manifest Information Management System

mL Milliliter (measurement unit)

μR Microroentgen (measurement unit)

μSv Microsievert (measurement unit)

mSv Millisievert (measurement unit)

mrem Millirem (measurement unit)

mR Milliroentgen (measurement unit)

NAS National Academy of Sciences

NCP National Contingency Plan

NCRP National Council on Radiation Protection and Measurements

NIMS National Incident Management System

NNPP Naval Nuclear Propulsion Program

NNSS Nevada National Security Site

NPDWR National Primary Drinking Water Regulation

NPP Nuclear Power Plant 

NRC Nuclear Regulatory Commission

NRF National Response Framework 

NDRF National Disaster Recovery Framework
Protective Action Guides and Planning Guidance for Radiological Incidents 101

PAG Manual EPA-400/R-17/001

NSS National Security Staff

NUREG NRC technical report designation (Nuclear Regulatory Commission) 

OSHA Occupational Safety and Health Administration 

PAG Protective Action Guide 

pCi Picocurie (measurement unit)

PIO Public Information Officer 

PPE Personal Protective Equipment 

R Roentgen (measurement unit)

RASCAL Radiological Assessment System for Consequence Analysis 

Rem Roentgen equivalent man (measurement unit)

REMM Radiation Emergency Medical Management

RESRAD RESidual RADioactivity (computer code developed by Argonne National 

Laboratory)

RCRA Resource Conservation and Recovery Act

RDD Radiological Dispersal Device

SDWA Safe Drinking Water Act

SSCT Small System Compliance Technology

SNL Sandia National Laboratories

Sv Sievert (measurement unit)

TED Total Effective Dose 

USDA United States Department of Agriculture
United States

Environmental Protection Agency

Office of Air and Radiation

1200 Pennsylvania Avenue, N.W. (6101A)

Washington, DC 20460

Official Business

Penalty for Private Use $300

EPA-400/R-17/001

January 2017

www.epa.gov/radiation/protective-action-guides-pags