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1. RADNET Nuclear Accident Radiation Protection Guidelines (draft)

Introduction:  Types of Nuclear Accidents
A. Exposure Pathways
1. Deposition Mechanisms
2. Exposure Pathway Types
B. Accident Exposure Timetable
C. Protection Actions
D. Ingestion Pathway Bioaccumulation Alert
E. General Notes
F. Other types of Nuclear Accidents
1. Nuclear weapons tests or accidental detonations
2. Chronic weapons production facility and fuel reprocessing facility discharges
3.  Lost licensed devices and medical sources
4.  Uranium-tipped weapons
5.  Nuclear power plants as small nuclear accidents-in-progress
G. Verities of Nuclear Accidents
2. Federal Radiation Protection Guideline Updates 1997-1998 3. Historical Overview of Radiation Protection Guidelines: 1961 - 1980 4. Radiological Monitoring Programs and Remediation Guides
A. USA Programs
5. Bibliography of Radiation Protection Guidelines 6. MARSSIM Appendix

1. RADNET Nuclear Accident Radiation Protection Guidelines (draft)

This is a draft.. in progress, and we solicit any corrections, comments, criticisms or additions.  We will be adding the marked links next week and finishing proofreading the newest sections.
Introduction:  Types of Nuclear Accidents

Accidental Radioactive Contamination of Human Food And Animal Feeds:  Recommendations for State and Local Agencies by the United States Food and Drug Administration lists five different types of nuclear accidents and the types of radionuclides which are dispersed by these accidents.

"The types of accidents and the principal radionuclides for which the DILs were developed are:

The FDA neglects to mention a number of other types of accidental or deliberate discharges of anthropogenic radioactivity which constitute defacto nuclear accidents.  See Section F for further description of the following categories of other types of nuclear accidents.
A. Exposure Pathways

1. Deposition Mechanisms:

In any nuclear accident, the radioactive plume results in two types of ground deposition:  dry deposition and wet deposition. Some types of nuclear accidents can result in only the slow, chronic release of liquid effluent contamination, e.g. fuel reprocessing activities at the Sellafield (UK) and Marcoule (FR) where liquid effluent dispersal is more important than the airborne plume.  In this situation, the primary exposure pathway will be the ingestion pathway.

The highest levels of ground deposition are associated with rain and snowfall events (wet deposition). 

During the Chernobyl nuclear accident, locations over which the accident plume passed that did not experience rain or snowfall events had much less total ground deposition than those locations at which plume passage and rain and snowfall events coincided.  For more information about the widely varying patterns of ground deposition which resulted from the Chernobyl accident, see RAD 10:  Chernobyl fallout data.

2. Exposure Pathway Types:

There are four basic pathways of human exposure to contamination resulting from nuclear accidents of any kind.

a.  External Exposure
(1.)  Facility (accident location) radiation shine
(2.)  Plume cloud shine
(3.)  Ground shine
b.  Absorption (Dermal Deposition)
c.  Inhalation
(1.)  Plume inhalation
(2.)  Resuspended ground deposition inhalation
d.  Ingestion
(1.)  Primary:  Ingestion from foliar and surface contamination
(2.)  Secondary:  Ingestion of contamination via pathways to human consumption such as the forage - cow - milk pathway
(3.)  Tertiary:  Ingestion of contamination via indirect pathways to human consumption, e.g. the incorporation of contaminated whey into processed foods and their redistribution to markets in areas unaffected by ground deposition
B. Accident Exposure Timetable
Accident Phases
Pathway Exposure Mechanism
Early - as long as criticality is maintained or uncontrolled dispersion is occurring, e.g. the early phase of active release during the Chernobyl accident lasted about 10 days. Inhalation of plume.
External exposure from the facility.
External exposure from the plume.
Absorption due to contamination of skin and clothes.
Intermediate - a rather indefinite period of time which would correlate with the decay of most of the short-lived radionuclides which accumulate as a component of ground deposition:  one week to six months. External exposure from ground deposition.
Primary and secondary ingestion of contaminated  food and water.
Absorption due to contamination of clothes and recontamination of skin from ground contamination.
Inhalation of resuspended ground deposition.
Late - long-term exposure to biologically significant radionuclides that accumulate via ground deposition and that have half-lives of six months to 100 years, e.g. 137Cs, 90Sr. Secondary ingestion of contaminated food.
Tertiary ingestion of contaminated processed foods.
External exposure from ground deposition.
Inhalation of resuspended ground deposition.
External exposure from contaminated consumer products.
Very late - Long term exposure to biologically significant radionuclides that accumulate via ground deposition and that have half-lives in excess of 100 years, e.g. 241Am, 239Pu, 99Tc. Inhalation of resuspended ground deposition.
Tertiary ingestion of contaminated processed foods.
External exposure from contaminated consumer products.
C. Protection Actions

In any nuclear accident, there are two fundamental protective action options:  evacuation or sheltering.  Persons living in the vicinity of any nuclear facility during a major nuclear accident have only one viable option:  evacuation to an unimpacted area.  This is easier said than done because, in most accident situations, including Chernobyl, the authorities, whether the NRC or any other governmental authority, had or will have minimal information about the amount of contamination (source term) in and direction of the plume passage.  The Chernobyl accident illustrates the possibility that population groups could be evacuated from the immediate area of the accident (+/- 10 km) and moved to distant areas (+/- 200 km) and actually be entering areas with greater amounts of ground contamination than occurred in the immediate vicinity of the accident.  Governmental agencies responsible for nuclear accidents can almost always be relied upon to provide inaccurate or insufficient information with respect to plume pathways and deposition activity.  Unless you are sure you are close to and downwind from a major nuclear accident, immediate sheltering to avoid the most intense short-lived activity in the passing plume is usually your safest option.


All situations requiring evacuation are characterized by the following safety precautions:

D. Ingestion Pathway Bioaccumulation Alert

Know your bioaccumulators.  If you can avoid the primary ingestion pathway, including foods such as leafy green vegetables, berries, broccoli and cauliflower contaminated with surface deposition (foliar contamination,) the principle ingestion exposure pathway would likely result from secondary contamination of the following foods which are quickly contaminated after a nuclear accident:

Remember that during and after a nuclear accident:
E. General Notes

Know your biologically significant radionuclides.

(1/2 T = the radiological half-life, that is the time it takes for one half of the radioactivity to decay in any radioactive substance)

Know your basic volumetric contamination guidelines.

(1 Bq = one becquerel = 1 disintegration per second = 27 pCi = 27 picocuries.  One picocurie = 2.2 disintegrations per minute)

Radionuclide Bq/l
  • Generic action levels for contaminated foodstuffs (implemented after the Chernobyl accident):
  • Foods destined for general consumption and also for infant milk and drinking water
    134Cs, 137Cs, 103Ru, 106Ru, 89Sr
    241Am, 238Pu, 239Pu
  • FDA derived intervention levels (DILs) August 13, 1998, for all components of the diet:
  • Emergency Protection Action Guideline (PAG)
    131I 134Cs 137Cs
    Infant Adult Infant Adult Infant Adult
    Initial Deposition
    (picocurie/square meter)
    1,300,000 18,000,000 20,000,000 40,000,000 30,000,000 50,000,000
    Forage Concentration
    500,000 7,000,000 8,000,000 17,000,000 13,000,000 19,000,000
    Peak Milk Intake
    150,000 2,000,000 1,500,000 3,000,000 2,400,000 4,000,000
    Total Intake
    (picocurie/accident, 1-30 days)
    900,000 10,000,000 40,000,000 70,000,000 70,000,000 80,000,000
    RADNET has included this older protection action guideline in our current radiation protection guidelines because, in the event of a serious nuclear accident at an NRC licensed facility, the above 1982 guideline is the one likely to be used by the NRC and its licensees in informing the public about the relative risks of the resulting contamination.  The NRC and its licensees have not acknowledged the publication of the 1998 FDA guidelines for contaminated food, nor is it likely that the FDA guidelines for contaminated food will be of any interest to the NRC and its licensees in an accident situation.
    F. Other Types of Nuclear Accidents

    1. Nuclear weapons tests or accidental detonations

    Each and every nuclear weapons test explosion, whether by Russia, France, England, China, India, Pakistan or the United States constitute a defacto nuclear accident.  In the case of an accidental or deliberate detonation of one or more nuclear warheads, all of the isotopes, except Pu-238, that are listed by the FDA for all types of nuclear accidents, would be the principle radionuclides of concern.  Other important radionuclides associated with the detonation of nuclear weapons include barium-140, lanthanum-140, niobium-95, tellurium-132, and zirconium-95.

    The early phase of this type of accident would only last as long as detonation and plume passage, often as little as 24 hours.  The intermediate phase of a nuclear weapons detonation as a nuclear accident would begin as 131I is quickly taken up in forage pathways.  The late phase would begin soon after the intermediate phase with secondary ingestion of contaminated food as well as continued external exposure from ground deposition.  The very late phase of nuclear weapons detonations-as-accidents, which reach their peak during the early 1960's with intensive Russian and American nuclear weapons tests, continue today with the inhalation of re-suspended ground deposition (e.g. 239Pu).

    2. Chronic weapons production facility and fuel reprocessing facility discharges

    The following principal weapons production and fuel reprocessing chronic accidents-in-progress can best be evaluated by linking to the many bibliographic citations which provide descriptions of the effluent discharges from these facilities.

    3.  Lost licensed devices and medical sources

    This section is under research and construction

    4.  Uranium-tipped weapons

    This section is under research and construction

    5.  Nuclear power plants as small nuclear accidents-in-progress

    RADNET has used the Maine Yankee Atomic Power Company (MYAPC) in Wiscasset, Maine as a case study for analysis of safety, legal, economic and decommissioning issues pertaining to nuclear power plant operation.  This facility may also be used as an example of a nuclear power plant as a small nuclear accident-in-progress.  MYAPC began operation in 1972 and was closed in 1997.  Operational and decommissioning discharges of anthropogenic radioactivity may be divided into the following categories:

    As a consequence of the many components of a nuclear power plant as a small nuclear accident-in-progress, there is no practical usefulness in attempting to divide these incidents into "early, intermediate, late" and very late episodes since each overlaps with the next.  The health physics significance  of these accidents-in-progress can only be documented and unraveled with painstaking radiological surveillance in detailed laboratory radiochemical and spectroanalyses.  For political, economic, psychological and sociological reasons, the detailed analyses of MYAPC as a small nuclear accident-in-progress is not possible.  MYAPC as a small nuclear accident-in-progress is the subject of an elaborate ritual of aversion, as is the environmental and health physics impact of all operating nuclear power plants.

    Note:  The greatest hazard of a normally operating nuclear power plant occurs during reactor containment purging, just prior to removal of spent fuel.  For persons living immediately down wind of the reactor containment (< 5 miles), use of a particulate respirator, which can provide some protection against inhalation of particulates during the plume passage in any kind of nuclear accident may also be a prudent protective action.  Obviously, sheltering during reactor containment purging is the most preferable protection action, but for persons who must be outside, use of the particle respirator is an excellent protective action to avoid accidental inhalation of particulates released during containment purging.

    Particulate respirators can be purchased from Northern Safety Co., Inc., (800) 631-1246.  They offer several styles of design in price ranges from $10 to $50.
    G. Verities of Nuclear Accidents

    2. Federal Radiation Protection Guideline Updates 1997-1998

    Introduction: General Radiation Protection Guidelines

    Sometime in 2002, the US Federal government posted on the internet some general information:
    Fact Sheet: Guidance for Responding to Radiological and Nuclear Incidents. U.S. Department of State, Washington, D.C.
    December 23, 1997: Radiation Protection Guideline Update

    In 1997, the United States Government issued three important publications that contain important information pertaining to radiation protection. None of these publications constitute the comprehensive radiation protection guideline so urgently needed, but, when combined, these three publications provide the most up-to-date summary of the paradigms of federal agencies involved with radiation protection (NRC, DOE, FDA, EPA). The three radiation protection guidelines cited and reviewed in this section of RADNET are, in the order in which they are listed, 1997 Revised FDA Radioactive Contamination Guideline, ASTDR Toxicological Profile for Ionizing Radiation, and the MARSSIM draft Multi-Agency Radiation Survey and Site Investigation Manual.

    The ATSDR Toxicological Profile for Ionizing Radiation may be ordered by visiting the ATSDR site (see RAD 13: RADLINKS for a link to this site.)

    The MARSSIM was announced in the Federal Register on 1/6/97 (Vol. 62, no. 3, pg. 736) and may be requested by Fax from the US NRC at 301 015-2260 or downloaded from the Internet at http://www.epa.gov/radiation/cleanup. This document is particularly important because it forms the basis for site characterization and consequent decommissioning of NRC licensed nuclear facilities such as the Maine Yankee Atomic Power Company facility at Wiscasset, Maine. RADNET readers please note that the long citations from MARSSIM can be found in RAD 6: Section 5.


    United States Food and Drug Administration. (March 5, 1997). Draft: Accidental radioactive contamination of human food and animal feeds: Recommendations for state and local agencies. Center for Devices and Radiological Health, U.S. FDA, Washington, D.C.

    B. ATSDR Toxicological Profile for Ionizing Radiation

    United States Department of Health & Human Services. (September 1997). Draft for public comment: Toxicological Profile for Ionizing Radiation. Prepared by: Research Triangle Institute for the US Dept. of Health & Human Services, Public Health Service, Agency for Toxic Substances and Disease Registry, Atlanta, Georgia.IS.

    The Agency for Toxic Substances and Diseases Registry developed this toxicological profile as a component of the CERCLA, also known as the Superfund Act. This toxicological profile is probably the most important publication issued by the federal government pertaining to ionizing radiation. The editor of RADNET will make a number of critical comments about this draft in the following review. These criticisms should in no way detract from the importance of the publication of this toxicological profile since it is the first attempt at a comprehensive analysis of the health physics significance of ionizing radiation in the United States. Despite the deficiencies discussed below, this draft ushers in a new era in government publications due to its innovative inclusion of Internet URL addresses for links to important information sources pertaining to ionizing radiation. These addresses are included in the references in Section 10 of this report both as a component of some citations which can be accessed electronically as well as separately under the heading http: in the bibliography.

    In our opinion this toxicological profile for ionizing radiation raises the following central issue: how can dosimetric models documenting the health physics impact of ionizing radiation be used to estimate doses from radioactive substances taken into the body without a much more complete knowledge of actual media specific, nuclide specific levels of contamination? The credibility of the dosimetric models used in this and other reports is undercut by a lack of pathway analyses for all radionuclides in all pathways in all ecosystems - a Herculean task not discussed in this profile. Current NRC criteria for decommissioning nuclear facilities such as the Maine Yankee Atomic Power Company are based on the effective use of radiological dose as the appropriate measure for the decommissioning of radiologically contaminated areas. In the case of the NRC, the primary decommissioning guideline is 25 mrem/yr TEDE (total effective dose equivalent) from all radionuclides in all pathways. Both the NRC and the ATSDR profile fail to emphasize the significance of comprehensive a priori pathway analyses as a basis for credible dosimetric evaluation. Concurrent unresolved issues which further undercut the credibility of current dosimetric models include the problem of exposure to ionizing radiation not high enough to evaluate statistically and the lingering controversies pertaining to the delayed effects of exposure to low levels of ionizing radiation. The general problem of insufficient data with respect to nuclide-specific, media-specific analyses within particular pathways and ecosystems is not discussed in detail in this publication but is occasionally referenced as in the following quotation under the heading "Identification of data needs": (4.10, pg. 189) "Some human data do exist on the health effects associated with acute exposure to ionizing radiation (see Chapters 3 and 5); however, most of the potential effects have been derived from laboratory animal data. It would be helpful to estimate the dose of radiation each of these individuals was exposed to and monitor these people over the long term to determine what health effects (if any) these doses of ionizing radiation had on lifespan, cancer rates, and reproductive effects. There is ongoing research in these areas."

    The publication of this profile is a giant step in the direction of federal sponsorship of a comprehensive protection action guideline for ionizing radiation, the criticisms made in the following annotation notwithstanding.

    C. MARSSIM Draft Multi-Agency Radiation Survey and Site Investigation Manual (EPA, NRC, DOE)

    United States Department of Energy, Environmental Protection Agency, Nuclear Regulatory Commission and Department of Defense. (December 6, 1996). Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM): Draft for public comment. NUREG-1575. EPA 402-R-96-018. NTIS-PB97-117659. Washington, D.C. http://www.epa.gov/radiation/cleanup.

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