Regulatory Guide 8.29
ML003739401 | |
Person / Time | |
---|---|
Issue date: | 07/31/1981 |
From: | Office of Nuclear Regulatory Research |
To: | |
References | |
RG-8.29 | |
Download: ML003739401 (17) | |
SAat
"REQUo(U.S. NUCLEAR REGULATORY COMMISSION July lU16 R EGULT GUIDE
- OFFICE OF NUCLEAR REGULATORY RESEARCH
REGULATORY GUIDE 8.29 (Tusk OH 9024)
RADIATION EXPOSURE
INSTRUCTION CONCERNING RISKS FROM OCCUPATIONAL
Concerns about these biological effects have resulted in
A. INTRODUCTION
controls on doses to individual workers and in efforts to control the collective dose (person-reins) to the worker Section 19.12 of 10 CFR Part 19, "Notices, Instructions population.
and Reports to Workers; Inspections," requires that all persons working in or frequenting any portion of a restricted NRC-licensed activities result in a significant fraction of area be instructed in the health protection problems asso the total occupational radiation exposure in the United ciated with exposure to radioactive materials or radiation. States. Regulatory action has recently focused more atten This guide describes the instruction that should be provided tion on maintaining occupational radiation exposure at to the worker concerning biological risks from occupational levels that are as low as is reasonably achievable (ALARA).
radiation exposure. Additional guides are being or will be Radiation protection training for all workers who may be developed to address other aspects of radiation protection exposed to ionizing radiation is an essential component of training.
any program designed to maintain exposure levels ALARA.
A clear understanding of what is presently known about the
B. DISCUSSION
biological risks associated with exposure to radiation will result in more effective radiation protection training and It is generally accepted by the scientific community that should generate more interest on the part of the worker in exposure to ionizing radiation can cause biological effects minimizing both individual and collective doses. In addition, that are harmful to the exposed organism. These effects are radiation workers have the right to whatever information classified into three categories:
on radiation risk is available to enable them to make informed Effects occurring in the exposed decisions regarding the acceptance of these risks. It is intended Somatic Effects: that workers who receive this instruction develop a healthy person that, in turn, may be divided into two classes:
respect for the risks involved rather than excessive fear or indifference.
Prompt effects that are observable soon after a large or acute dose (e.g., 100 remsi or more to the whole At the relatively low levels of occupational radiation body in a few hours), and exposure in the United States, it is difficult to demonstrate a relationship between exposure and effect. There is con Delayed effects such as cancer that may occur years siderable uncertainty and controversy regarding estimates after exposure to radiation.
of radiation risk. In the appendix to this guide, a range of Genetic Effects: 2 Abnormalities that may occur in the risk estimates is provided (see Table 1). Information on radiation risk has been included from such sources as the future children of exposed individuals and in subsequent generations. 1980 National Academy of Sciences' Report of the Committee on the Biological Effects of Ionizing Radiation (BEIR-80),
TeratogenicEffects: Effects that may be observed in the International Commission on Radiological Protection (ICRP) Publication 27 entitled "Problems in Developing an children who were exposed during the fetal and embryonic stages of development. Index of Harm," the 1979 report of the science work group of the Interagency Task Force on the Health Effects of
1In the International System of Units (SI) the rem is replaced Ionizing Radiation, the 1977 report of the United Nations by the sievert. 100 reins is equal to I sievert (Svi). Scientific Committee on the Effects of Atomic Radiation
2 (UNSCEAR report), and numerous published articles (see Genetic effects exceeding normal incidence have not been the bibliography to the appendix).
observed in any of the studies of exposed humans.
USNRC REGULATORY GUIDES Comments should be sent to the L..cretary of the Commission, U.S. Nuclear Regulatory Commission, Washington, D.C. 20555, Attention: Docketing and Service Branch.
Regulatory Guides are issued to describe and make available to the public methods acceptable to the NRC staff of Implementing The guides are Issued In the followlhg ten broad divisions:
specific parts of the Commission's regulations, to delineate tech niques used by the staff in evaluating specific problems or postu 1. Power Reactors 6. Products lated accidents, or to provide guidance to applicants. Regulatory 2. Research and Test Reactors 7. Transportation Guides are not substitutes for regulations, and compliance with 3. Fuels and Materials Facilities 8. Occupational Health them is not required. Methods and solutions different from those set 4. Environmental and Siting 9. Antitrust and Financial Review out in the guides will be acceptable If they provide a basis for the 5. Materials and Plant Protection 10. General findings requisite to the issuance or continuance of a permit or license by the Commission.
Copies of Issued guides may be purchased at the current Government Printing Office price. A subscription service for future guides In spe This guide was issued after consideration of comments received from cific divisions Is available through the Government Printing Office.
the public. Comments and suggestions for Improvements In these Information on the subscription service and current GPO prices may guides are encouraged at all times, and guides will be revised, as be obtained by writing the U.S. Nuclear Regulatory Commission, appropriate, to accommodate comments and to reflect new informa Washington, D.C. 20555, Attention: Publications Sales Manager.
tion or experience.
C. REGULATORY POSITION
sessions. Each individual should be given an opportunity to ask questions and should be asked to acknowledge in writing Strong management support is considered essential to an that the instruction has been received and understood.
adequate radiation protection training program. Instruction to workers performed in compliance with § 19.12 of 10 CFR
D. IMPLEMENTATION
Part 19 should be given prior to assignment to work in a restricted area and periodically thereafter. In providing The purpose of this section is to provide information to instruction concerning health protection problems associated applicants regarding the NRC staff's plans for using this with exposure to radiation, all workers, including those in regulatory guide.
supervisory roles, should be given specific instruction on the risk of biological effects resulting from exposure to Except in those cases in which an applicant or licensee radiation. proposes an acceptable alternative method for complying with specified portions of the Commission's regulations, the The instruction should be presented both orally and in methods described in this guide will be used in the evalua printed form to all affected workers and supervisors. It should tion of the training program for all individuals working in include the information provided in the appendix to this or frequenting any portion of a restricted area and for all guide. 3 The information should be discussed during training supervisory personnel after December 15, 1981.
3 Copies of the appendix to this gulde are available at the current If an applicant or licensee wishes to use the material pro Government Printing Office price, which may be obtained by writing vided in this guide on or before December 15, 1981, the to the U.S. Nuclear Regulatory Commission, Washington, D.C.
20SS, Attention: Publications Sales Manager. This appendix is not pertinent portions of the application or the licensee's perfor copyrighted, and Commission approval is not required to reproduce it.
mance will be evaluated on the basis of this guide.
8.29-2
U.S. NUCLEAR REGULATORY COMMISSION
APPENDIX TO REGULATORY GUIDE 8.29 INSTRUCTION CONCERNING RISKS FROM OCCUPATIONAL RADIATION EXPOSURE
This instructional material is intended to provide the The biological effects that are known to occur after user with the best available information concerning what is exposure to high doses (hundreds of rems2 ) of radiation are currently known about the health risks from exposure to discussed early in the document; discussions of the esti ionizing radiation. 1 A question and answer format has been mated risks from the low occupational dose (<5 rams per used. The questions were developed by the NRC staff in year) follow. It is intended that this information will help consultation with workers, union representatives, and develop an attitude of healthy respect for the risks asso licensee representatives experienced in radiation protection ciated with radiation, rather than unnecessary fear or lack training. Risk estimates have been compiled from numerous of concern. Additional guidance is being or will be devel sources generally recognized as reliable. A bibliography Is oped concerning other topics in radiation protection included for the user interested in further study. training.
- *
1. What is meant by risk? assume that some health effects do occur at the lower expo sure levels.
Risk can be defined in general as the probability (chance)'
3. What is meant by prompt effect, delayed effects. and of injury, illness, or death resulting from some activity. genetic effects?
However, the perception of risk is affected by how the individual views its probability and its severity. The intent a. Prompt effects are observable shortly after receiving of this document is to provide estimates of and explain the a very large dose in a short period of time. For example, a basis for possible risk of injury, illness, or death resulting whole-body 4 dose of 450 rems (90 times the annual dose from occupational radiation exposure. (See Questions 9 and limit for routine occupational exposure) in an hour to an
10 for estimates of radiation risk and comparisons with average adult will cause vomiting and diarrhea within a few other types of risk.) hours; loss of hair, fever, and weight loss within a few weeks; and about a 50 percent chance of death within
2. What are the possible health effects of exposure to 60 days without medical treatment.
radiation?
b. Delayed effects such as cancer may occur years Some of the health effects that exposure to radiation after exposure to radiation.
may cause are cancer (including leukemia), birth defects in3 c. Genetic effects can occur when there is radiation the future children of exposed parents, and cataracts. damage to the genetic material. These effects may show up These effects (with the exception of genetic effects) have as birth defects or other conditions in the future children of been observed in studies of medical radiologists, uranium the exposed individual and succeeding generations, as miners, radium workers, and radiotherapy patients who demonstrated in animal experiments. However, excess have received large doses of radiation. Studies of people genetic effects clearly caused by radiation have not been exposed to radiation from atomic weapons have also observed in human populations exposed to radiation. It has provided data on radiation effects. In addition, radiation been observed, however, that radiation can change the effects studies with laboratory animals have provided a genes in cells of the human body. Thus, the possibility large body of data on radiation-induced health effects, exists that genetic effects can be caused in humans by low including genetic effects. doses even though no direct evidence exists as yet.
The observations and studies mentioned above, hovever, 4. In worker protection, which effects are of nwst concern involve levels of radiation exposure that are much higher to the NRC?
(hundreds of rems) than those permitted occupationally today ( <5 rems per year). Although studies have not shown a The main concern to the NRC is the delayed incidence cause-effect relationship between health effects and current of cancer. The chance of delayed cancer is believed to depend levels of occupational radiation exposure, it is prudent to
3
1 Cataracts differ from other radiation effects in that a certain lIonizing radiation consists of energy or small particles such as level of dose to the lens of the eye (-_200 rems) is required before gamma, beta, or alpha radiation emitted from radioactive materials they are observed.
which, when absorbed by living tissue, can cause chemical and physical damage. 41t is important to distinguish between whole-body and partial
2 The rem is the unit of measure for radiation dose and relates to body exposure. 100 rems to the whole body will have more effect than 100 to a hand. For example, exposure of a hand would affect a the biological effect of the absorbed radiation. small fraction of the bone marrow and a limited portion of the skin.
8.29-3
on how much radiation exposure a person gets; therefore, One theory is that radiation can damage chromosomes in a every reasonable effort should be made to keep exposures cell, and the cell is then directed along abnormal growth low. patterns. Another is that radiation reduces the body's Immediate or prompt effects are very unlikely since large exposures would normally occur only if there were a normal resistance to existing viruses which can then multiply and damage cells. A third is that radiation activates an existing virus in the body which then attacks normal I
serious radiation accident. Accident rates in the radiation cells causing them to grow rapidly.
industry have been low, and only a few accidents have resulted in exposures exceeding the legal limits. The probabil What is known is that, in groups of highly exposed ity of serious genetic effects in the future children of people, a higher than normal incidence of cancer is observed.
workers is estimated in the BEIRs report, based on animal Higher than normal rates of cancer can also be produced in studies, at less than one-third that of delayed cancer (5-65 laboratory animals by high levels of radiation. An increased genetic effects per million reins compared to 160-450 incidence of cancer has not been demonstrated at radiation cancer cases). A clearer understanding of the cause-effect levels below the NRC limits.
relationship between radiation and human genetic effects will not be possible until additional research studies are 7 If I receive a radiation dose, does that mean I am completed. certain to get cancer?
5. What is the difference Oetween acute and chronic Not at all. Everyone gets a radiation dose every day (see exposure? Question 25), but most people do not get cancer. Even with doses of radiation far above legal limits, most individuals Acute radiation exposure, which causes prompt effects will experience no delayed consequences. There is evidence and may also cause delayed effects, usually refers to a large that some radiation damage can be repaired. The danger dose of radiation received in a short period of time; for from radiation is much like the danger from cigarette smoke.
example, 450 rems received within a few hours or less. The Only a fraction of the people who breathe cigarette smoke effects of acute exposures are well known from studies of get lung cancer, but there is good evidence that smoking radiotherapy patients, some of whom received whole-body increases a person's chances of getting lung cancer. Similarly, doses; atomic bomb victims; and the few accidents that there is evidence that the larger the radiation dose, the have occurred in the early days of atomic weapons and larger the increase in a person's chances of getting cancer.
reactor development, industrial radiography, and nuclear fuel processing. There have been few occupational incidents Radiation is like most substances that cause cancer in that have resulted in large exposures. NRC data indicate that the effects can be seen clearly only at high doses that, on the average, 1 accidental overexposure in which Estimates of the risks of cancer at low levels of exposure any acute symptoms are observed occurs each year. Most are derived from data available for exposures at high dose of these occur in industrial radiography and involve exposures levels and high dose rates. Generally, for radiation protection of the hands rather than the whole body. purposes these estimates are made using the linear model (Curve 1 in Figure 1). We have data on health effects at high Chronic exposure, which may cause delayed effects but doses as shown by the solid line in Figure 1. Below about not prompt effects, refers to small doses received repeatedly 100 reins, studies have not been able to accurately measure over long time periods; for example,20-100 mrem (a the risk, primarily because of the small numbers of exposed mrem is one-thousandth of a rem) per week every week for people and because the effect is small compared to differences several years. Concern with occupational radiation risk is in the normal incidence from year to year and place to place.
primarily focused on chronic exposure to low levels of Most scientists believe that there is some degree of risk no radiation over long time periods. matter how small the dose (Curves I and 2). Some scientists believe that the risk drops off to zero at some low dose
6. How does radiationcause cancer? (Curve 3), the threshold effect. A few believe that risk levels off so that even very small doses imply a significant risk How radiation causes cancer is not well understood. (Curve 4). The majority of scientists today endorse either It is impossible to tell whether a given cancer was caused by the linear model (Curve I) or the linear-quadratic model radiation or by some other of the many apparent causes. (Curve 2). The NRC endorses the linear model (Curve I),
However, most diseases are caused by the interaction of which shows the number of effects decreasing as the dose several factors. General physical condition, inherited traits, decreases, for radiation protection purposes.
age, sex, and exposure to other cancer-causing agents such as cigarette smoke are a few possible contributing factors. It is prudent to assume that smaller doses have some chance of causing cancer. This is as true for natural cancer causers such as sunlight and natural radiation as it is for those that are man made such as cigarette smoke, smog, and
5 man-made radiation. As even very small doses may entail The National Academy of Sciences established a committee on the Biological Effects of Ionizing Radiation (BEIR) whose 1980 some small risk, it follows that no dose should be taken report on the effects ondpopulations of exposure to low levels of without a reason. Thus, a principle of radiation protection ionizing radiation provides much of the background for this guide. is to do more than merely meet the allowed regulatory
8.29-4
LU
Ca, LuI
U.
U
LU
100
DOSE (REMS)
Figure 1. Some proposed models for how the effects of radiation vary with doses at low levels.
limits; doses should be kept as low as is reasonably achievable 1000 draws. We can say that if you receive a radiation dose, (ALARA). you will have increased your chances of eventually developing cancer. It is assumed that the more radiation exposure you We don't know exactly what the chances are of getting get, the more you increase your chances of cancer.
cancer from a low-level radiation dose, but we can make estimates based on extensive scientific knowledge. The estimates of radiation risks are at least as reliable as estimates Not all workers incur the same level of risk. The radia for the effects from any chemical hazard. Being exposed tion risk incurred by a worker depends on the amount of to typical occupational radiation doses is taking a chance, dose received. Under the linear model explained above, a but that chance is reasonably well understood. worker who receives 5 rems in a year incurs 10 times as much risk as another worker (the same age) who receives It is important to understand the probability factors only 0.5 rem. The risk depends not only on the amount of here. A similar question would be: If you select one card dose, but also on the age of the worker at the time the dose is from a full deck, will you get the ace of spades? This received. This age difference is due, in part, to the fact that question cannot be answered with a simple yes or no. The a young worker has more time to live than an older worker, best answer is that your chances are 1 in 52. However, if and the risk is believed to depend on the number of years
1000 people each select one card from full decks, we can of life following the dose. The more years left, the larger predict that about 20 of them will get an ace of spades. the risk. It should be clear that, even within the regulatory Each person will have I chance in 52 of drawing the ace of dose limits, the risk may vary a great deal from one worker spades, but there is no way that we can predict which persons to another. Fortunately, only a very few workers receive will get the right card. The issue is further complicated by the doses near 5 rems per year; as pointed out in the answer to fact that in 1 drawing by 1000 people, we might get only Question 19, the average annual dose for all radiation
15 successes and in another perhaps 25 correct cards in workers is less than 0.5 rem.
8.29-5
A reasonable comparison involves exposure to the sun's rays, Frequent short exposures provide time for the skin to TABLE 1 repair. An acute exposure to the sun can result in painful burning, and excessive exposure has been shown to cause Estimates of Excess Cancer Incidence from Exposure to Low-Level Radiation skin cancer. However, whether exposure to the sun's rays is short term or spread over time, some of the injury is not repaired and may eventually result in skin cancer. Number of Additionala Cancers Estimated I
Source to Occur in I Million People After The effect upon a group of workers occupationally Exposure of Each to I Rem of Radiation exposed to radiation may be an increased incidence of cancer over and above the number of cancers that would normally be expected in that group. Each exposed individual BEIR, 1980
has an increased probability of incurring subsequent cancer.
We can say that if 10,000 workers each receive an additional ICRP, 1977 200
I rem in a year, that group is more likely to have a larger incidence of cancer than 10,000 people who do not receive UNSCEAR, 1977 150-350
the additional radiation. An estimate of the. increased probability of cancer from low radiation doses delivered to large groups is one measure of occupational risk and is aAdditional means above the normal incidence of cancer.
discussed in Question 9. bAll three groups estimated premature deaths from radiation induced cancers. The American Cancer Society has recently stated that only about one-half of all cancer cases are fatal. Thus,
8. What groups of expert scientists have studied the risk estimate incidence of cancer, the published numbers were multiplied to from exposure to radiation? by 2. Note that the three groups are in close agreement of radiation-induced cancer. on the risk In 1956, the National Academy of Sciences established advisory committees to consider radiation risks. The fixst of I rem, we could estimate that three would develop cancer these was the Advisory Committee on the Biological Effects because of that exposure, although the actual number could of Atomic Radiations (BEAR) and more recently it was be more or less than three.
renamed the Advisory Committee on the Biological Effects of Ionizing Radiation (BEIR). These committees have The American Cancer Society has reported that approxi periodically reviewed the extensive research being done on mately 25 percent of all adults in the 20- to 65-year age the health effects of ionizing radiation and have published bracket will develop cancer at some time from all possible estimates of the risk of cancer from exposure to radiation causes such as smoking, food, alcohol, drugs, air pollutants and natural background radiatio
n. Thus in any group
(1972 and 1980 BEIR reports). The International Commission ot on Radiological Protection (ICRP) and the National Council 10,000 workers not exposed to radiation on the job, we can on Radiation Protection and Measurement (NCRP) are two expect about 2,500 to develop cancer. If this entire group other groups of scientists who have studied radiation effects of 10,000 workers were to receive an occupational radiation and published risk estimates (ICRP Publication 26, 1977). dose of I rem' each, we could estimate that three additional These two groups have no government affiliation. In cases might occur which would give a total of about 2,503.
This means that a I-rem dose to each of 10,000 workers addition, the United Nations established an independent study group that published an extensive report in 1977, might increase the cancer rate from 25 percent to 25.03 percent, an increase of about 3 hundredths of one percent.
including estimates of cancer risk from ionizing radiation (UNSCEAR, 1977).
As an individual, if your cumulative occupational radia Several individual research groups or scientists such as tion dose is 1 rem, your chances of eventually developing Alice Stewart, E.S. Gilbert, T.F. Mancuso, T.W. Anderson, cancer during your entire lifetime may have increased from to name a few, have published studies concerning low-level. 25 percent to 25.03 percent. If your lifetime occupational radiation effects. The bibliography to this appendix includes dose is 10 rems, we could estimate a 25.3 percent chance of several articles for the reader who wishes to do further developing cancer. Using a simple linear model, a lifetime study. The BEIR-80 report includes analysis of the work of dose of 100 rems may have increased your chances of cancer from 25 to 28 percent.
many independent researchers.
9. What are the estimates of the risk of cancerfrom radia The normal chance of developing cancer if you receive no occupational radiation dose is about equal to your chance tion exposure?
of getting any spade on a single draw from a full deck of playing cards, which is one chance out of four. The addi The cancer risk estimates (developed by the organiza tional chance of developing cancer from an occupational tions identified in Question 8) are presented in Table 1.
exposure of I rem is less than your chances of drawing an ace from a full deck of cards three times in a row.
In an effort to explain the significance of these estimates, we will use an approximate average of 300 excess cancer cases per million people, each exposed to I rem of ionizing Since cancer resulting from exposure to radiation usually occurs 5 to 25 years after the exposure and since not all I
radiation. If in a group of 10,000 workers each receives cancers are fatal, another useful measure of risk is years of
8.29-6
TABLE2 life expectancy lost on the average from a radiation-induced cancer. It has been estimated in several studies that the Estimated Low of Life Expectancy from Health RUWks
1 to radiation Is average loss of life expectancy from exposure of exposure. In other words, a person about I day per rem to 1 rem of radiation may, on the average, lose Estimates of Days of exposed important, Life Expectancy Lost,
1 day of life. The words "on the average" are who gets cancer from radiation however, because the person Health Risk Average years of life expectancy while his coworkers may lose several average number suffer no loss. The ICRP estimated that the Smoking 20 cigarettes/day 2370
985 (6.5
(2.7 years)
industrial accidents is 30 Overweight (by 20%)
of years of life lost from fatal 435 (1.2 years)
of years of life lost from a fatal All accidents combined while the average number 200
cancer is 10, The shorter loss of life Auto accidents radiation-induced 130
expectancy is due to the delayed onset of cancer. Alcohol consumption (U.S. average) 95 Home accidents 41 are It is important to realize that these risk numbers Drowning 8 Many difficulties are involved in designing Natural background radiation, only estimates.
the small research studies that can accurately measure calculated increases in cancer cases due to low exposures to radiation Medical diagnostic x-rays (U.S. 6 normal rate of cancer. There is still average), calculated as compared to the 3.5 and a great deal of controversy with regard to All catastrophes (earthquake, etc.)
uncertainty here result estimates of radiation risk. The numbers used 1 rem occupational radiation dose, 1 and high dose rates, and calculated (industry average for from studies involving high doses they may not apply to doses at the lower occupational the higher-dose job categories is in the levels of exposure. The NRC and other agencies both 0.65 rem/yr) 30
United States and abroad are continuing extensive long-range 1 rem/yr for 30 years, calculated research programs on radiation risk.
Some members of the National Academy of Sciences BEIR Advisory Committee and others feel that risk estimates aAdapted Physcs, from Vol. 36, Cohen June and Lee, "A Catalogue of Risks," Health
1979.
in Table 1 are higher than would actually occur and represent an upper limit on the risk. Other scientists believe that A second useful comparison is to look at estimates of higher.
the estimates are low and that the risk could be the average number of days of life expectancy lost from NRC staff However, these estimates are considered by the exposure to radiation and from common industrial accidents to make an to be the best available that the worker can use at radiation-related facilities and to compare this number asso with days lost from other occupational accidents. Table 3 informed decision concerning acceptance of the risks to ciated with exposure to radiation. A worker who decides shows average days of life expectancy lost as a result of keep exposure accept this risk should make every effort to fatal work-related accidents. Note that the data for occupa to radiation ALARA to avoid unnecessary risk. The worker, tions other than radiation related do not include death risks after all, has the first line responsibility for protecting himself from other possible hazards such as exposure to toxic chem from radiation hazards. icals, dusts, or unusual temperatures. Note also that the unlikely occupational exposure at 5 rems per year for 50
10. How can we compare radiation risk to other kinds of years, the maximum allowable risk level, may result in a health risks? risk comparable to the average risks in mining and heavy construction.
Perhaps the most useful unit for comparison among health risks is the average number of days of life expectancy Industrial accident rates in the nuclear industry and lost per ,unit of exposure to each particular health risk. related occupational areas have been relatively low during Estimates are calculated by looking at a large number of per the entire history of the industry (see Table 4). This is sons, recording the age when death occurs from apparent believed to be due to the early and continuing emphasis on a
causes, and estimating the number of days of life lost as tight safety controls. The relative safety of various occupa number of days of tional areas can be seen by comparing the probability of result of these early deaths. The total life lost is then averaged over the total group observed. death by accident per 10,000 workers over a 40-year working lifetime. These figures do not include death Several studies have compared the projected loss of life from possible causes such as exposure to toxic chemicals or expectancy resulting from exposure to radiation with other radiation.
in health risks. Some representative numbers are presented Table 2. II. Can a worker become sterile orimpotentfrom occupa tional radiationexposure?
These estimates indicate that the health risks from occu pational radiation exposure are smaller than the risks asso Observation of radiation therapy patients who receive ciated with many other events or activities we encounter and localized exposures, usually spread over a few weeks, has accept in normal day-to-day activities.
8.29-7
TABLE 3 shown that a dose of 500-800 reins to the gonads can produce permanent sterility in males or females (an acute Estimated Loss of Life Expectancy from Industrial Hazards& whole-body dose of this magnitude would probably result in death within 60 days). An acute dose of 20 reins to the testes can result in a measurable but temporary reduction in
-1 Estimates of Days of sperm count. Such high exposures on the job could result Life Expectancy Lost, only from serious and unlikely radiation accidents. Although Industry Type Average high doses of radiation can affect fertility, they have no effect on the ability to function sexually. Likewise, exposure All industry 74 to permitted occupational levels of radiation has no observed Trade 30 effect on fertility and also has no effect on the ability to Manufacturing 43 function sexually.
Service 47 Government 55 12. What are the NR C externalradiationdose limits?
Transportation and utilities 164 Agriculture 277 Federal regulations currently limit occupational external Construction 302 wholl-body radiation dose to 1/ 4 reins in any calendar Mining and quarrying 328 quarter or specified 3-month period. However, when there Radiation accidents, death from, <I is d xcumented evidence that a worker's previous occupa exposure tional dose is low enough, a licensee may permit a dose of Radiation dose of 0.65 rem/yr 20 up to 3 reins per quarter or 12 reins per year. The accumulated (industry average) for 30 years, dose may not exceed 5(N - 18) reins 6 where N is the person's calculated age in years, i.e., the lifetime occupational dose may not Radiation dose of 5 rems/yr for 250 exceed an average of 5 rems for each year above the age
50 years of 18.
Industrial accidents at nuclear 58 facilities (nonradiation) An additional whole-body dose of approximately
5 reins per year is permitted from internal exposure. (See Question 28.)
aAdaptod from Cohen and Lee, "A Catalogue of Risk," Health Phyis, Vol. 36, June 1979; and World Health Oripnization, Health 13. What is meant by ALARA?
Implications of NuclearPower Production, December 1975.
In addition to providing an upper limit on a person's permissible radiation exposure, the NRC also requires that I
its licensees maintain occupational exposures as far below the limit as is reasonably achievable (ALARA). This means TABLE 4 that every activity at a nuclear facility involving exposure to radiation should be planned so as to minimize unnecessary Probability of Accidental Death by Type of Occupationa exposure to individual workers and also to the worker population. A job that involves exposure to radiation should be scheduled only when it is clear that the benefit Number of Accidental justifies the risks assumed. All design, construction, and Deaths for 10,000 operating procedures should be reviewed with the objective Occupation Workers for 40 Years of reducing unnecessary exposures.
Mining 252 14. Has the ALARA concept been applied if, iustead of Construction 228 reachingdose limits duringthe first week of a quarter, Agriculture 216 the worker's dose is spreadout over the whole quarter?
Transportation and public 116 utilities No. For radiation protection purposes, the risk of All industries 56 cancer from low doses is assumed to be proportional to the Government 44 amount of exposure, not the rate at which it is received.
Nuclear industry (1 975 data 40 Thus it is assumed that spreading the dose out over time or excluding construction) over larger numbers of people does not reduce the overall Manufacturing 36 risk. The ALARA concept has been followed only when the Services 28 individual and collective doses are reduced by reducing the Wholesale and trade 24 time of exposure or decreasing radiation levels in the
6 The NRC has published a proposed rule change for public comment that would eliminate the 5(N-I 8) formula. This proposal i aAdapted from National Safety Council, Accident Facts, 1979;
currently under consideration by a task force reviewing all of 10 CFR -1, Part 20. Recent EPA guidance recommends eliminating the S(N-l 8)
and Atomic Energy Commission, OperationalAccidents and Radia. formula. If adopted, the maximum allowed annual dose will be 5 reins tion Exposure Experience, WASH-I 192, 1975. rather than 12.
8.29-8
cancer for the worker population. At best, the total risk individual and collective doses are reduced by reducing the remains the same, and it may even be increased. The only time of exposure .or decreasing radiation levels in the way to reduce the risk is to reduce the collective dose; that working environment. can be done only by reducing the radiation levels, the working times, or both.
it
15. What is meant by collective dose and why should be maintainedALARA? 17. Why doesn't the NRC impose collective dose limits?
Nuclear industry activities expose an increasing number Compliance with individual dose limits can be achieved a
of people to occupational radiation in addition to the radia simply by using extra workers. However, compliance with from natural background radiation dose limit (such as 100 person-rems per year for a tion doses they receive collective The collective occupational licensee) would require reduction of radiation levels, and medical radiation exposures, dose (person-reins) is the sum of all occupational radiation working times, or both. But there are many problems exposure received by all the workers in an entire worker associated with setting appropriate collective dose limits.
if 100 workers each receive 2 rems, population. For example, the individual dose is 2 rems and the collective dose is 200 For example, we might consider applying a single a
person-reins. The total additional risk of cancer and genetic collective dose limit to all licensees. The selection of such population is assumed to depend on collective dose limit would be almost impossible because of effects in an exposed the collective dose. the wide variations in collective doses among licensees.
A power reactor could reasonably be expected to have an of risk to It should be noted that, from the viewpoint average annual collective dose of several hundred person be con a total population, it is the collective dose that must reins. However, a small industrial radiography licensee could very well hive a collective dose of only a few person of health trolled. For a given collective dose, the number if a larger number of effects is assumed to be the same even reins in a year.
spreading the dose out people share the dose. Therefore, may reduce the individual risk, but not that of the population: Even choosing a collective dose limit for a group of similar licensees would be almost as difficult. Radiography dose Efforts should be made to maintain the collective licensees as a group had an average collective dose in 1977 of 9 person-reins. However,. the smallest collective dose for increase the overall popula ALARA so as not to unnecessarily tion incidence of cancer and genetic effects. a radiography licensee was less than 1 person-rem, and the largest was 401 person-reins.
risks?
16. Is the use of extra workers a good way to reduce Setting a reasonable collective dose limit for each indi vidual licensee would also be very difficul
t. It would
"no"
There is a "yes" answer to this question and a answer. For a given job involving exposure to radiation, require a record of all past collective doses on which to base the more people who share the work, the lower the average such limits. Setting an annual collective dose limit would lower the dose to an individual. The lower the dose, the then amount to an attempt to predict a reasonable collective is "yes." be risk. So, for you as an individual, the answer dose for each future year. In order to do this, it would necessary to be able to predict changes in each licensed But how about the risk to the entire group of workers? activity that would increase or decrease the collective dose.
Under assumptions used by the NRC for purposes of protec In addition, annual collective doses vary significantly from of tion, the risk of cancer depends on the total amount year to year according to the kind and amount of mainte radiation energy absorbed by human tissue, not on the nance required, which cannot generally be predicted in advance. Following all such changes and revising limits up if number of people to whom this tissue belongs. Therefore, and down would be very difficult if not impossible. However, of 10, and if both
30 workers are used to do a job instead these efforts would be necessary if a collective dose limit the total groups get the same collective dose (person-reins),
for the cancer risk is the same, and nothing was gained were to be reasonable and help minimize doses and risks.
the answer group by using 30 workers. From this viewpoint but simply spread is "no." The risk was not reduced 18. How are radiationdose limits established?
aroun'd among a larger number of persons.
The NRC establishes occupational radiation dose Unfortunately, spreading the risk around often results limits based on guidance to Federal agencies from the in a larger collective dose for the job. Workers are exposed Environmental Protection Agency (EPA) and, in addition, considers NCRP and ICRP recommendations. Scientific to as they approach a job-, while they are getting oriented reviews of research data on biological effects such as the they withdraw from the job. The dose do the job, and as If received during these actions is called nonproductive. BEIR report are also considered.
dose several crew changes are required, the nonproductive of For example, recent EPA guidance recommended can become very large. Thus it can be seen that the use
5 extra workers may actually increase the total occupational that the annual whole-body dose limit be established at dose and the resulting collective risks. reins per year and indicated that exposure, year after year, to 5 rems would involve a risk to a worker comparable to The use of extra workers to comply with NRC dose the average risks incurred by workers in the higher risk jobs limits is not the way to reduce the risk of radiation-induced
8.29-9
such as mining. In fact, few workers ever reach such a limit, there is danger. Exceeding a limit does not imply that you much less year after year, and the risks associated with have suffered an injury. A good comparison is with the actual exposures are considered by the EPA to be comparable highway speed limit, which is selected to limit accident risl to the safer job categories. A 5-rem-per-year limit would allow occasional high dose jobs to be done without excessive risk.
and still allow you to get somewhere. If you drive at mph, you increase your risk of an auto accident to levels I
that are not considered acceptable by the people who set speed limits, even though you may not actually have an
19. What are the typical radiationdoses received by workers? accident. If a worker's radiation dose repeatedly exceeds 3 rems in a quarter, the risk of health effects could eventually The NRC requires that certain categories of licensees increase to a level that is not considered acceptable to the report data on annual worker doses and doses for all workers NRC. Exceeding an* NRC protection limit does not mean who leave employment with licensees. Data were received that any adverse health effects are going to occur. It does on the occupational doses in 1977 of approximately 100,000 mean that a licensee's safety program has failed in some workers in power reactors, industrial radiography, fuel respect and that the NRC and the licensee should investigate processing and fabrication facilities, and manufacturing to make sure the problems are corrected.
and distribution facilities. Of this total group, 85 percent received an annual dose of less than I rem; 95 percent If an overexposure occurs, the regulations prohibit any received less than 2 reins; fewer than 1 percent exceeded additional occupational exposure to that person during the
5 rems in 1 year. The average annual dose of those workers remainder of the calendar quarter in which the overexposure who were monitored and had measurable exposures was occurred. The licensee is required to file an overexposure about 0.65 rem. A study completed by the EPA, using report to the NRC and may possibly be subject to a fine,
1975 exposure data for 1,260,000 workers, indicated that just as you are subject to a traffic fine for exceeding the the average annual dose for all workers who received a speed limit. In both cases, the fines and, in some serious or measurable dose was 0.34 rem. repetitive cases, suspension of license are intended to encourage efforts to operate within the limits. The safest Table 5 lists average occupational exposures for workers limits would be 0 mph and 0 rem per quarter. But then we (persons who had measurable exposure above background wouldn't get anywhere.
levels) in various occupations, based on the 1975 data.
21. Why do some facilities establish administrative limits TABLE 5 that are below the NRC limits?
U.S. Occupational Exposure Estimatesa There are two reasons. First, the NRC regulations stat%
that licensees should keep exposures to radiation ALARA.
IL
Average Whole. By requiring specific approval for worker doses in excess of Occupational Body Dose Collective Dose set levels, more careful risk-benefit analysis can be made as Subgroup (millirems) (person-reins) each additional increment of dose is approved for a worker.
Secondly, a facility administrative limit that is set lower Medicine 320 51,400 than the quarterly NRC limit provides a safety margin Industrial Radiography 580 5,700 designed to help the licensee avoid overexposures.
Source Manufacturing 630 2,500
Power Reactors 760 21,400
Fuel Fabricationi and 560 3,100 22. Several scientists have suggested that NRC limits are Reprocessing too high andshould be lowered Whatare the arguments Uranium Enrichment 70 400 for lowering the limits?
Nuclear Waste Disposal 920 100
Uranium Mills 380 760 In general, those critical of present dose limits say that Department of Energy 300 11,800 the individual risk is higher than is estimated by the BEIR
Facilities Committee, the ICRP, and UNSCEAR. Based on studies of Department of Defense 180 10,100 low-level exposures to large groups, some researchers have Facilities concluded that a given dose of radiation may be more likely Educational Institutions 206 1,500 to cause biological effects than previously thought. Some of Transportation 200 2,300 these studies are listed in the bibliography (Manquso, Archer) and the BEIR-80 report includes a section analyzing
"Adapted from Cook and Nelson, Occupational Exposures to the findings of these and other studies. Scientific opinion IonizingRadiatfon in the United States: A Comprehensive Summary differs on the validity of the research methods used and the for 1975, Draft, Environmental Protection Agency. methods of statistical analysis. The problem is that the expected additional incidence of radiation-caused .effects
20. What happens if a worker exceeds the quarterly expo such as cancer is difficult to detect in comparison with the sure limit?
Radiation protection limits, such as 3rems in 3 months, much larger normal incidence. It cannot be shown withou question that these effects were more frequent in the exposed study group than in the unexposed group used for I
are not absolute limits below which it is safe and above which comparison, or that the observed effects were caused
8.29-10
level radiation according to the linear model explained in by radiation. The BEIR committee concluded that claims Question 7. Based on this approach, the regulations in 10 CFR
of higher risk had "no substance."
Part 20, "Standards for Protection Against Radiation," also state that licensees should maintain all radiation exposures, The NRC staff continually reviews the results of research and releases of radioactive materials in effluents, as low as is on radiation risks. With respect to large-scale studies of reasonably achievable. More recent scientific reviews of the radiation-induced health effects in human populations large body of experimental data, such as the BEIR-80 and exposed to low-level ionizing radiation, the NRC and EPA
the recent EPA guidance, continue to support the view that have recently concluded that there is no one population use of a 5-rem-per-year limit is acceptable in practice.
group available for which such a study could be expected to Experience has shown that, under this limit, the average provide a more meaningful estimate of the low-level radia dose to workers is near 0.5 rem/yr with very few workers tion risk. This is due, in large part, to the observed and consistently approaching the limit.
estimated low incidence of radiation health effects from low doses. However, the results of ongoing studies, such as c. There is little to gain.
that on nuclear shipyard workers, will be carefully reviewed and the development of a radiation-worker registry is Reducing the dose limits, for example, to 0.5 rem/yr being considered as a possible data base for future studies.
has been analyzed by the NRC staff. An estimated 2.6 million person-reins could be saved from 1980 through the year
23. What are the reasons for not lowering the NRC dose limits? 2000 by nuclear power plant licensees if compliance with the new limit were achieved by lowering the radiation Assuming that the 5-rem-per-year limit is adopted, levels, working times, or both, rather than by using extra workers. It is estimated that something like $ 23 billion would there are three reasons:
be spent toward this purpose. Spending $23 billion to save
2.6 million person-reins would amount to spending $30 to a. Health risks are already low.
$90 million to prevent each potential radiation-induced premature cancer death. Society considers this cost unaccept The estimated health risks associated with current ably high for individual protection.
average occupational radiation doses (e.g., 0.5 tem/yr for
50 years) are comparable to or less than risk levels in other
24. Are there any areas of concern about radiation risks occupational areas considered to be among the safest, if a that might result in changing the NRC dose limits?
person were exposed to the maximum of 5 reins per year for 50 years, which virtually never occurs, he or she might Yes. Three areas of concern to the NRC staff are specifi incur a risk comparable to the average risks in mining and cally identified below:
heavy construction. An occasional 5-remi annual dose might be necessary to allow some jobs to be done without a a. An independent study by Rossi and Mays and other significant increase in the collective dose. If the dose limits biological research have indicated that a given dose of were lowered significantly, the number of people required neutron radiation may be more likely to cause biological to complete many jobs would increase. The collective dose effects than was previously thought. Other recent studies would then increase since more individuals would be cast doubt on the issue. The NCRP is currently studying the receiving nonproductive exposure while entering and data related to the neutron radiation question and is leaving the work area and preparing for the job. The total expected to make recommendations as to whether neutron number of health effects might go up as the collective dose increased. dose .limits should be changed. Although the scientific community has not yet come to agreement on this question, b. The current regulations are considered sound. workers should be advised of the possibility of higher risk when entering areas where exposure to neutrons will occur.
The regulatory standards for dose limits are based b. It has been known for some time that rapidly on the recommendations of ,the Federal Radiation Council.
At the time these standards were developed, about 1960, it growing living tissue is more sensitive to injury from radiation than tissue in which the cells are not reproducing rapidly.
was considered unlikely that exposure to these levels during Thus the embryo or fetus is more sensitive to radiation a working lifetime would result in clinical evidence of injury or disease different from that occurring in the injury than an adult. The NCRP recommended in Report unexposed population. The scientific data base for the No. 39 that special precautions be taken when an occupa standards consisted primarily of human experience (x-ray tionally exposed woman could be pregnant in order to exposures to medical practitioners and patients, ingestion protect the embryo or fetus. In 1975, the NRC issued Regulatory Guide 8.13, "Instruction Concerning Prenatal of radium by watch dial painters, early effects observed in Japanese atomic bomb survivors, radon exposures of Radiation Exposure," in which it is recommended thai uranium miners, occupational radiation accidents) involving licensees instruct all workers concerning this special risk very large doses delivered at high dose rates. The data base The guide recommends that all workers be advised that thi NCRP recommended that the maximum permissible dose tc also included the results of a large number of animal experiments involving high doses and dose rates. The animal the embryo or fetus from occupational exposure of tht experiments were particularly useful in the evaluation of mother should not exceed 0.5 rem for the full 9-montl genetic effects. The observed effects were related to low- pregnancy period. In addition, the guide suggests option
8.29-11
available to the female employee who chooses not to Thus, the average individual in the general population expose her embryo or fetus to this additional risk. receives about 0.2 rem of radiation exposure each year The United States Department of Health and Human Services is similarly concerned about prenatal exposure from sources that are a part of our natural and man-made environment. By the age of 20 years, an individual has accumulated about 4 rems. The most likely target for I
from medical x-rays. In 1979 they published proposed reduction of population exposure is medical uses.
guidelines for physicians concerning abdominal x-rays for possibly pregnant women. The guidelines in effect encourage 26. Why aren 't medical exposures considered as part of a the x-ray staff to make efforts to determine whether a worker's allowed dose?
female patient is pregnant and to defer x-rays if possible until after the child is born. Equal doses of medical and occupational radiation have equal risks. Medical exposure to radiation should be justified c. Also of special interest is the indication that female for reasons quite different, however, from those applicable workers are subject to more risk of cancer incidence than to occupational exposure. A physician prescribing an x-ray male workers. In terms of all types of cancer except leukemia,, should be convinced that the benefit to the patient of the the BEIR-80 analysis indicates that female workers have resulting medical information justifies the risk associated a risk of developing radiation-induced cancer that is approxi with the radiation. Each worker must decide on the accept mately one and one-half times that for males. This increased ance of occupational radiation risk just as each worker must risk is primarily due to the incidence of breast and thyroid decide on the acceptability of any other occupational cancer in women. These types of cancer, however, have a hazard.
high cure rate. Thus the difference between men and women in cancer mortality is not great. Incidence of For another point of view, consider a worker whoreceives radiation-induced leukemia is about the same for both a dose of 2 reins from a series of x-rays or a radioactive sexes. Female workers should be aware of this difference in medicine in connection with an injury or illness. This dose the risks of radiation-induced cancer in deciding whether and the implied risk should be justified on medical grounds.
or not to seek work involving exposure to radiation. If the worker had also received a dose of 2 rems on the job, the combined dose of 4 rems would not incapacitate the
25. How much radiation does the average person who worker. A dose of 4 rems is not especially dangerous and is does not work in the nuclear industry receive? not large compared to the cumulative lifetime dose. Restrict ing the worker from additional job exposure during the We are all exposed from the moment of conception to ionizing radiation from several sources. Our environment, and even the human body, contains naturally occurring remainder of the quarter would have no effect one way or the other on the risk from the 2 reins already received from medical exposure. If the individual worker accepts the risks I
radioactive materials that contribute some of the background associated with the x-rays on the basis of the medical radiation we receive. Cosmic radiation originating in space benefits and the risks associated with job-related exposure and in the sun contributes additional exposure. The use of on the basis of employment benefits, it would be unfair to x-rays and radioactive materials in medicine and dentistry restrict the individual from employment in radiation areas adds considerably to our population exposure. for the remainder of the quarter.
Table 6 shows estimated average individual exposure Some therapeutic medical doses such as those received in millirems from natural background and other sources. from cobalt-60 treatment can range as high as 6000 rems to a small part of the body, spread over a period of several TABLE 6 weeks or months.
U.S. General Population Exposure Estimates (1 9 7 8 )a 27. What is meant by internalexposure?
Average Individual The total radiation dose to the worker is the external Source Dose dose (measured by the film badge and reported as "whole (mrem/yr) body dose") plus the dose from internal emitters. The monitoring of the additional internal dose is difficult.
Natural background (average in U.S.) 100 Because there is the possibility of internal doses occurring, a Release of radioactive material in 5 good air-monitoring program should be established when natural gas, mining, milling, etc. warranted.
Medical (whole-body equivalent) 90
Nuclear weapons (primarily fallout) 5-8 The uptake of radioactive materials by workers is gener Nuclear energy 0.28 ally due to breathing contaminated air. Radioactive materials Consumer products 0.03 may be present as fine dust or gases in the workplace atmosphere. The surfaces of equipment and workbenches Total ,u200 mrem/yr aAdapted from a report by the Interagency Task Force on the 7It is likely that a significant portion of reported L
medical x-ray Health Effects of Ionizing Radiation pubished by the Department exposure is to parts of the body only. An exposure of 100 mrem to of Health, Education, and Welfare. the whole body is more significant than a 100-mrem chest x-ray.
8.29-12
limit. ICRP recommends that the internal and external doses may be contaminated. Radioactive materials may enter the should be appropriately added. This recommendation is body by being breathed in, taken in with food or drink, or currently under study by the staffs of the NRC, the EPA,
being absorbed through the sking pgrticularly if the skin is and the Occupational Safety and Health Administration broke
n. I I I
(OSHA).
After entering the body, the radioactive material will 30. How it a worker's external radiationdose determined?
migrate to particular organs or particular parts of the body depending on the biochemistry of the material. For example, A worker may Wear three types of radiation-measuring uranium will tend to deposit in the bones where it will devices. A self-reading pocket dosimeter records the exposure remain for a long time. It is slowly -eliminated, from the to incident radiation and can be read out immediately upon body, mostly by way of the kidneys. Radium will also tend finishing a job involving external exposure to radiation. A
to deposit in the bones. Radioactive iodine will ,seek out the film badge or TLD badge records radiation dose, either by thyroid glands (located in the neck) and, deposit there. the amount of darkening of the film or by storing energy in the TLD crystal. Both these devices require processing to The dose from these internal emitters cannot be mea determine the dose but are considered more reliable than sured either by the film badge or by other ordinary dosim the pocket dosimeter. A worker's official report of dose eters carried by the worker. This means'that the internal received is normally based on film or TLD badge readings, radiation dose must be separately monitored using other which provide a cumulative total and are more accurate.
detection methods.
31. What are my options ifI decide not to acceptthe risks Internal exposure can be estimated by measuring the associated with occupationalradiationexposure?
radiation emitted, from the body or by measuring the radioactive materials contained in biological samples such as If the risks from exposure to radiation that may be urine or feces. Dose estimates can also be made if one. expected to occur during your work are unacceptable to knows how much radioactive material is in the air and the you, you could request a transfer to a job that does not length of time during which the air was breathed.
involve exposure to radiation. However, the risks associated with exposure to radiation that workers, on the average,
28. How are the limits for internalexposure set?
actually receive are considered acceptable, compared to other occupational risks, by virtually all the scientific Standards have been established for the maximum groups that have studied them. Your employer is probably permissible amount of each radionuclide that may be
8 not obligated to guarantee you a transfer if you decide not accumulated in the critical organs of the worker's body. to-accept an assignment requiring exposure to radiation.
Calculations are made to determine the quantity of radioactive material that has been taken into the body and You also have the option of seeking other employment the total dose that would result. Then, based on limits in a nonradiation occupation. However, the studies that established for particular body organs similar to 11/4 reins have compared occupational risks in the nuclear industry to in a calendar quarter for whole-body exposure, the regula those in other job areas indicate that nuclear work is tions specify maximum permissible concentrations of radio relatively safe. Thus, you will not necessarily find signif active material in the air to which a worker can be exposed icantly lower risks in another job.
for 40 hours4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br /> per week over 13 weeks or 1 calendar quarter.
The regulations also require that efforts be made to keep A third option would be to practice the most effective internal exposure ALARA.
work procedures so as to keep your exposure ALARA. Be aware that reducing time of exposure, maintaining distance Internal exposure is controlled by limiting the release of from radiation sources, and using shielding can all lower radioactive material into the air and by carefully monitoring your exposure. Plan radiation jobs carefully to increase the work area for airborne radioactivity and surface con efficiency while in the radiation area. Learn the most tamination. Protective clothing and respiratory (breathing)
effective methods of using protective clothing to avoid protection should be used whenever the possibility of contamination. Discuss your job with the- radiation protec contact with loose radioactive material cannot be prevented.
tion personnel who can suggest additional ways to reduce your exposure.
29. Is the dose a person received fom internal exposure added to that received from external exposure?
32. Where can I get additionalijWormation on radiationrisk?
Exposure to radiation that results from radioactive The following list suggests sources of useful informa materials taken into the body is measured, recorded, and tion on radiation risk:
reported to the worker separately from external dose. The internal dose to the whole body or to specific organs does a. Your Employer not at this time count against the 3-rem-per-calendar-quarter The radiation protection or health physics office
8 Critical organ refers to those parts of the body vulnerable to radia tion damage such as bone, lungs, thyroid, and other systems where in the facility where you are employed.
certain radioactive materials will concentrate if taken into the body.
8.29-13
b. Nuclear Regluklato Commisoion A, Depirtment o Health and Human Service#
Regional Office# Office of the Director King of Pruslia, PA 19406 Atlanta, GA 30303
215-337-5000
404-221-4503 Bureau of Radiological Health (HPX-.)
Department of Health and Human Services
5600 Fishers Lane I
Glen Ellyn, IL 60137 312-932-2500 Rockville, MD 20857 Arlington, TX 76012 817-334-2841 Walnut Creek, CA 94596 415-943.3700 Telephone: 301-443-4690
Headquarters d. Environmental ProtectionAgency Occupational Radiation Protection Branch Office of Radiation Programs Office of Nuclear Regulatory Research U.S. Environmental Protection Agency U.S. Nuclear Regulatory Commission 401 M Street, SW
Washington, D.C. 20555 Washington, D.C. 20460
Telephone: 301.443-5970 Telephone: 703-557-9710
8.29-14
BIBLIOGRAPHY
American Cancer Society, 1979 Cancer Facts and Figures, International Commission on Radiological Protection, Radia
1978. tion Protection, Recommendations of the International Commission on Radiological Protection, ICRP Publication 26, Anderson, T.W., "Radiation Exposure of Hanford Workers: Pergamon Press, January 1977.
A Critique of the Mancuso, Stewart, and Kneale Report,"
Health Physics, Vol. 35, December 1978. Kelsey, C.A., "Comparison of Relative Risk from Radiation Exposure and Other Common Hazards," Health Physics, Archer, V.E., "Effects of Low-Level Radiation: A Critical Vol. 35, August 1978.
Review," Nuclear Safety, Vol. 21, No. 1, January-February
1978. Lapp, R.E., The Radiation Controversy, Reddy Communica tions, Inc., Greenwich, Connecticut, 1979.
Atomic Energy Commission, Operational Accidents and Radiation Exposure Experience, WASH-1192, Fall 1975. Lapp, R.E., A Worker's Guide to Radiation, Atomic Industrial Forum, August 1979.
Barnett, M.H., The BiologicalEffects of Ionizing Radiation:
An Overview, Department of Health, Education, and Welfare Linos, A., et al., "Low Dose Radiation and Leukemia, Mayo Publication (FDA) 77-8004, October 1976. Clinic and Foundation, Rochester, Minn.," New England Journal of Medicine 1980; Vol. 302, pp. 1101-1105.
Cohen, B.L., and Lee, I.S., "A Catalog of Risks," Health Physics, Vol. 36, June 1979. Mancuso, T.F., Stewart, A., and Kneale, G., "Radiation Expo sures of Hanford Workers Dying from Cancer and Other Cook, J., and Nelson, D., OccupationalExposures to Ionizing Causes," Health Physics, Vol. 33, November 1977.
Radiation in the United States: A Comprehensive Summary for 1975, EPA 520/4-80-001, Environmental Protection Mulkie, R., "N'atura' Radiajion Baukground vs. Radiaticn from Agency. Nuclear Power Plants," Journal of Environmental Sciences, August 1972.
Department of Health, Education, and Welfare, Biologic Effects of Ionizing Radiation, Report of the Science Work Najarian, T., and Colton, T., "Mortality from Leukemia and Group of the Interagency Task Force on Radiation, June 1979. Cancer in Shipyard Nuclear Workers," Lancet, I: May 1978.
Dreyer, N.A., et al., The Feasibilityof Epidemiologic Inves National Academy of Sciences, The Effects on Populations tigations of the Health Effects of Low-Level IonizingRadia of Exposure to Low Levels of Ionizing Radiation, Report tion, NUREG/CR-1728, Nuclear Regulatory Commission, of; the Committee on the Biological Effects of Ionizing November 1980. Radiation (BEIR), 1980.
Gilbert, E.S., "Assessment of Risks from Occupational Rossi and Mays, "Leukemia Risk from Neutrons," Health Exposure to Ionizing Radiation," in Energy and Health Physics, Vol. 34, pp. 353-360, 1978.
Proceedings of the Conference on Energy and Health, June
26-30, 1978, SIAM Publication, Philadelphia, 1979. Schottenfeld, D., and Haas, J., "Carcinogens in* the Work place," CA-A Cancer Journal for Clinicians,Vol. 29, No. 3, Gofman, J.W., "The Question of Radiation Causation of May-June 1979.
Cancer in Hanford Workers," Health Physics, Vol. 37, November 1979. United Nations Scientific Committee on the Effects of Atomic Radiation, 1977, Sources and Effects of Ionizing Gotchy, R.L., "Estimation of Life Shortening Resulting Radiation, Report to the General Assembly, UN Publica from Radiogenic Cancer per Rem of Absorbed Dose," tion No. E.77.IX.I, 1977.
Health Physics, Vol. 35, October 1978.
Upton, Arthur C., "Radiation from Nuclear Power Exagger Hall, E.J., Radiation and Life, Pergamon Press, 1976. ated," New EnglandJournalof Medicine, VoL 302, pp. 1205
1206, May 22, 1980.
International Commission on Radiological Protection, Problems Involved in Developingan Index of Harm, Annals World Health Organization, Health Implications of Nuclear of the ICRP, ICRP Publication 27, Pergamon Press, May 1977. Power Production, Report of a %orking Group, December 1975.
8.29-15
VALUE/IMPACT STATEMENT
1. PROPOSED ACTION from the availability of an NRC guide on radiation risk
-1 suitable for inclusion in those training program
s. The guide
1.1 Description was reviewed and distributed to agreement states by the Office of State Programs. Comments have been received All NRC licensees are required to provide appropriate radia from the EPA and the Bureau of Radiological Health.
tion protection training for all permanent and transient person nel who work in restricted areas (§ 19.12 of 10 CFR Part 19). 1.3.3 Industry A clear and reasonable assessment of the biological risks asso ciated with occupational radiation exposure is essential to Providing a reasonable and understandable statement on effective radiation protection training. The proposed action is worker risk should facilitate industry efforts to provide to provide instructional material in a suitable form describing effective safety training and to better achieve as low as is and estimating the risks from exposure to radiation. The reasonably achievable (ALARA) objectives. Minimal impact instructional material will be suitable for use in licensee is expected in the form of additional cost of training training programs and will represent an acceptable method of programs since training requirements already exist. Comments complying with part of the existing training requirements. from unions and industry in the development of instructional material on risk were encouraged. Numerous public comment
1.2 Need for Proposed Action letters were received from industry and three meetings were held with worker groups to review the draft guide.
One common element of those occupational areas encom passed by NRC licensing activity is worker exposure to ionizing 1.3.4 Workers radiation and the biological risks from exposure. Union repre sentatives have expressed a dissatisfaction with the way in The proposed action should improve worker protection which these risks have been explained to the worker by the in that reasonable understanding of radiation risk is essential licensee. In addition, they feel the NRC has a responsibility to the development of safe working practices. The staff to make its position on the controversial issue of radiation believes that an objective discussion of radiation risk may in risk clear to the worker and the public. A meeting of NRC fact reduce "over concern" and also eliminate "under staff and union representatives was held on November 28, concern" on the part of some worker
s. If improved training
1978, during which this matter was discussed. A transcript results in a wider recognition and respect for radiation aL
of the meeting is available from the Public Document Room. an industrial hazard, more attention will be given to protective procedures and a. reduction in individual and collective dose The Environmental Protection Agency (EPA) has should result.
published recommendations concerning radiation protection for public comment and, in conjunction with other govern 1.3.5 Public ment agencies, will be holding public hearings on radiation risk and dose limits. This guide reflects current and proposed Nuclear workers are also members of the public and are EPA guidance and will be helpful to workers and worker generally residents of the area where facilities are located.
groups interested in understanding current discussion on Having a better-informed public should result in a wider the issues of risk-and dose limits. range of participation in local decisionmaking concerning nuclear development. Improved training implies the added
1.3 Value/Impact of Proposed Action benefit of increased plant safety, thereby decreasing the probability of accidents that could involve the public.
1.3.1 NRC Operations
1.3.6 Decision on Proposed Action Instructional material on radiation risk written at a level and scope understandable to the worker should contribute The NRC should develop and provide instructional to increased confidence, on the part of the worker, in the material concerning risk from occupational radiation NRC in general. A better understanding of the risk should exposure.
elicit more worker cooperation with NRC-enforced safety programs. Impacts of the development of instructional
2. TECHNICAL APPROACH
material on risk include task completion manpower cost, estimated to be 0.2 person-year, and printing costs of The technical approach proposed is to develop instruc approximately $400.00. tional material concerning risks to the worker from occupa tional radiation exposure and to publish the material in a
1.3.2 Other Government Agencies form that will receive the widest dissemination among NRC-licensed facilities. An alternative is to publish the Agreement States whose licensing regulations include findings of the proposed hearing on dose limits and assume I
radiation protection training requirements may benefit the relevant information will filter down to the worke
r. It is
8.29-16
- the feeling of the staff that a direct approach is required 3.2 Decision on Procedural Approach here.
The staff concludes that a regulatory guide similar to
3. PROCEDURAL APPROACH Regulatory Guide 8.13 on the subject of worker instruction concerning risks from occupational radiation exposure The proposed action, to publish training material concern should be published at this time.
ing risks from occupational radiation exposure, the use of which would be recommended to all licensees, could be 4. STATUTORY CONSIDERATIONS
accomplished by several alternative methods. These include an NRC regulation requiring that specific training materials 4.1 NRC Regulatory Authority be used, a regulatory guide based on the existing § 19.12 that would provide an acceptable method for training on Section 19.12 of 10CFR Part 19 establishes a legal risks, an ANSI standard on training that could be adopted requirement that all NRC licensees provide radiation by a regulatory guide, and a NUREG report or a branch protection training to personnel and that the training be position paper. commensurate with the potential risks from radiation exposure encountered by those personne
l. The NRC is thus
3.1 Value/Impact of Procedural Alternatives authorized to provide criteria for acceptable levels of training and to inspect for compliance with training require An NR C regulation establishes general legal requirements, ments.
is costly and time consuming to prepare, and is not an appropriate vehicle for the specific and narrow objective 4.2 Need for NEPA Statement proposed here. A regulation would be difficult to modify as new information on radiation risk is .developed. One The action proposed here is to publish an instructional advantage is that a regulation legally requires compliance. document on risks. This will occur after, and be in addition In general, this approach is not considered cost effective in to, any major NRC action on retaining or modifying view of the objectives of the proposed action. existing dose limits, based on planned public hearings.
Since at that time it would not constitute a major addition ANSI standards are generally intended as highly technical or change and would entail no effect on the environment, and advanced treatments of specialized areas of concern *to an environmental impact statement is not considered industry. A comprehensive technical review of risks from necessary.
radiation would be of value but would not be suitable as instructional material at an introductory level for worker 5. RELATIONSHIP TO OTHER EXISTING OR PROPOSED
radiation protection training. Completion of an ANSI REGULATIONS OR POLICIES
standard and an endorsing regulatory guide would require several years and would be too costly. This approach is not Regulatory Guide 1.70, "Standard Format and Content considered cost effective in view of the proposed objectives. of Safety Analysis Reports for Nuclear Power Plants,"
requires a commitment to appropriate radiation protection A NUREG document would be an appropriate vehicle training. When next revised, it should include reference to for a comprehensive discussion of radiation risk beyond the this proposed action as an acceptable element of a licensee's scope of what is proposed here. A regulatory position, training program.
however, is not established through publication of a NUREG
report. Since this proposal includes establishing an accept This proposed guide is consistent with Regulatory able method for compliance with elements of required Guide 8.8, "Information Relevant to Ensuring That Occupa training programs, a NUREG report is not suitable. tional Exposures at Nuclear Power Stations Will Be As Low As Is Reasonably Achievable." When next revised, Regulatory Branch position statements are intended as interim Guide 8.8 should include cross-reference to this proposed measures to be used when an immediate response is required. action.
They are usually superseded when a more permanent mode of guidance is developed. This proposed action directly supplements Regulatory Guide 8.27 and will supplement and be referenced in other A regulatory guide can be prepared at reasonable cost planned guides on training at other types of licensed facil within a reasonable time period. The staff does not consider ities, e.g., uranium fuel fabrication plants, uranium mills, that revision of any existing regulatory guides could provide medical institutions.
the instructicnal material intended here. Regulatory guides on training requirements are being developed but are specific to 6. SUMMARY AND CONCLUSIONS
types of licensees such as Regulatory Guide 8.27, "Radiation Protection Training for Personnel at Light-Water-Cooled In summary, it is proposed that this regulatory guide be Nuclear Power Plants." The action proposed here has broad prepared and issued for the purpose of providing instruc application to all licensees, as does Regulatory Guide 8.13, tional material concerning assessment of risk from occupa
"Instruction Concerning Prenatal Radiation Exposure." tional radiation exposure.
8.29-17