ML20043C220
| ML20043C220 | |
| Person / Time | |
|---|---|
| Issue date: | 04/18/1988 |
| From: | Thompson H NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| To: | |
| Shared Package | |
| ML20042C963 | List:
|
| References | |
| FRN-53FR49886, RULE-PR-CHP1 NUDOCS 9006040246 | |
| Download: ML20043C220 (11) | |
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CONTROL OF LOW-LEVEL RADIDACTIVE MATERIAL:
EXEMPTION OF PRACTICES HUGH L. THOMPSON, JR.
OFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDS
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UNITED STATES NUCLEAR REGULATORY COMMISSION IAEA International Conference on Radiation Protection in Nuclear Energy 18-22 April, 1988 Sidney, Australia l
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The radiation protection comunity has, for years, been seeking a consistent, straightforward way to exempt small quantities or low concentrations of radioactivity from regulatory control. The reasons for estabitshing exemptions are simple. Regulatory control imposes the economic and administrative burden of a system of licensing, registration, and/or notification upon the controlled activity and upon society as a whole.
It also imposes regulatory requirements such as disposal in licensed radioactive waste disposal facilities.
In the United States, as elsewhere, there are a number of issues which could be dealt with within a framework of exemption rules. Some of these include contaminated sites and facilities, low level waste streams, and slightly contaminated recycled materials.
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The technical anc policy issues in dealing with exemptions, however, have not been simple. The conservative, long held assumption, for radiation protection planning purposes, that stochastic risk is linearly proportional to dose gives rise to questions about risk acceptability on the part of the public when radioactivitiy is introduced into their environment without control. Next, the public perception of radiation risk and the actual risk from radiation exposure.can be ouite different.
Further, the definition of radioactivity itself is a problem since just about everything is radicactive to some extent.
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gives rise to questions about what is considered to be not radioactive and what is radioactive but can be treated as though it is not radioactive. Then there are questions about hcw many exemptions can be granted before the total begins to impose unacceptable risks to the public. These and similar issues lead to the ultimate challenge of dealing with risk in an_ appropriately conservative way while providing practical exemption levels that have some utility.
I While technical in nature, exemptions encompass broad public policy issues about how far regulatory controls should extend. They are coupled with the public's desire to live in as risk free environment as possible.
In the past there have been few incentives for the policy makers in regulatory agencies to expend the resources needed to address the issues. This has resulted in the continuing lack of a national and internaticnal technical policy umbrella under which exemptions 2
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can be granted while assuring adequate protection of the public. The exception to this general condition is the use of radioisotopes in consumer products such as luminous dial watches and smoke detectors. There has been a clear benefit to, and desire by the public to have such products and both international guidelines and national policies for exemption of some products have been established. Today we need a sound technical basis and public policy to deal with larger issues of adequate management of very low-level waste streams, recycling of slightly contaminated materials and decommissioning of sites.
Thus far, these have been treated on an ad hoc basis and, because of the lack of a broad policy, the derivation of exemption levels can result in misallocation of resources.
As the need for policy guidance in this area becomes larger, the support for reaching a consensus on the broad policy issues and analytical procedures related to exemptions becomes more evident. The public is becoming more aware of and sophisticated about radiation in its environment and our improving ability to detect small quantities of radiation has resulted in a perception that the risks from certain materials is increasing.
Issues, such as radon in l
houses, have helped the public understand that its environment is neither free
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J cf radiatien or risk.
Furthermore, in the case of nuclear power production, sophisticated instrumentation has made the detection of small quantities of radioactive material possible, thereby increasing the quantities of items and l
material that must, at the present time, be controlled as radioactive. These
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factors add to the pressure for us to come to grips with the issues and develop l
policies that allow release of certain materials.
In the United States, for example, the Congress passed the Low Level Radioactive Waste Policy Act of 1985 which required the Nuclear Regulatory Commission (NRC) to develop establish standards and procedures so that it l
could act on petitions to exempt specific radioactive waste streams regulated by the Commission. Subsequently, the Commission published procedures which definehowitwouldtreatsuchpetitions(NUREG1213,Rev.1).
The NRC expects to receive petitions for exemptions from the nuclear power industry in accordance with the published procedures quite soon. More recently, the Commission has directed the NRC staff to develop a broad based policy and f ramework under which exemptions can be granted.
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1 Meanwhile, the radiation protection community appears to be drawing closer to a consensus on how to treat exemptions. The consensus is the result of numerous papers and scientific debate on what is acceptable and unacceptable, what has utility ar.d what does not have utility, and how an overall system of exemptions might operate while providing adequate protection of the public. As i
recently as last month, the joint IAEA/NEA expert group developed draft guidance which could serve as guidance on the subject.
The purpose of this paper is to describe some of the issues and problems associated with the development and implementation of exemption rules in the United States. These comments and observations are based upon current experienceswithintheU.S.NuclearRegulatoryCommission(NRC). The NRC regulates a broad spectrum of nuclear activities including comercial nuclear power reactors, the nuclear fuel cycle, and the use of radioisotopes in inoustry, research, and medicine. Some of the topics I will be touching on l
briefly include the terms used to describe the exemption concepts, the framework within which exemptions should be considered, examples of specific actions currently being undertaken in the United States, and some of the l
fundamente1 policy issues upon which a consensus should be reached that must I
still be addressed.
A number of terms have been used in discussions of regulatory controls at low levels of dose including exemption levels, below regulatory concern, negligible individual risk levels, and de minimis. As a result, different terms have been used at various times to mean both the general region of low do.e levels which l
an individual would consider to be trivial and the larger region of low dose levels in which regulation to further control dose and risk may be unwarranted.
Although the specific terms have varied somewhat, the concepts being referred to have come to a high degree of agreement. Therefore, for our purposes, the tenns exemption levels and below regulatory concern will be considered as synonymous and to refer to the region of low dose levels at which regulation may be unwarranted.
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The terms " practice" and " source" have also been used in slightly different ways over the last few years, resulting in some confusion. There is now emerging agreement that the term " practice" refers to the continuing or coordinated set of activities utilizing radiation or radioactive material which are aimed at a
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given purpose. The term " source", then, refers to the physical entity (radioactive material) whose use, manipulation, operation, decomunissioning and/or disposal, constitutes the " practice". The relationship between practice and source can be illustrated by the disposal of low level solid radioactive wastes where the " practice" could be defined as the disposal of certain wastes at a given landfill, and the " source" is the waste itself.
it is important, at the outset, to remember the context in which decisions about reducing or eliminating regulatory requirements are made. The framework for radiation protection in the United States, as elsewhere, consists of the three fundamental principles Justification, Dose Lin;its, and Optimization (ALARA).
i The first principle, justification, states that there should be some net benefit l
to be gained from the use of radioactive material, and that the benefit derived should outweigh the detriunt associated with the radiation exposure.
Although the justification requirement is frequently dismissed in regulatory l
agencies where most practices, such as nuclear power generation, have already been justified through national legislation and other means, the concept is still of great importance when considering exemption from regulatory controls.
The tendency of many people is to assume that if the doses are likely to be low, then this is de facto proof that the practice causing thr. exposure is justifico.
However, while justification will encompass many cifferent I
viewpoints and involve many non-radiological criteria, the practice must still be justified, even if the resultant doses are expected to be low. Therefore the radiation protection comunity must be careful to keep those responsible for policy decisions aware of the justification requir.ement.
The second principle, the dose limits, establish the boundary between L
acceptable and unacceptable exposure. Obviously the sum of all exposures l
from all practices and sources must remain within these overriding limits, and the coses from practices considered for exemption from some regulatory control should be within some small fraction of the limits.
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7 The third princip'a, optimization operates in the regions below the dose limits and is the continuing process of balancing reductions in residual levels of radiation doses, both individual and collective, against the economic, social, and political factors present.
In this sense, optimization is the same as the term As low As Reasonably Achievable (ALARA), and the two terms are used synonymously in the United States.
At the lower end of 'the ALARA region of doses, well below the basic dose' limits, lies the region of doses that may be considered as below regulatory concern.
It is here that the opportunities for exemption from some or all regulatory requirements come into play. The relationships between the dose
. limits, ALARA, below regulatory concern, and de minimis or negligible individual risk levels is illustrated by Figure 1.
One of the sticking points has been the distinction between what is acceptable for. exemption-from a regulatory standpoint and a risk which might be considered trivial by an incividual.
Exemption Dom regulatory controls such as licensing, registration, and notification connotes levels of risk or dose that may be considered acceptable from a regulatory standpoint, i.e., individual and collective doses that warrant limited government attention taking into account the cost of further regulation and the likelihood that such regulation would significantly alter the resulting dose. Thus, the authorization of an exemption for a practice in which the doses are consioered by the regulatory authority as below regulatory concern can be made only after sn optimization analysis. A practice could be considered as a candidate for reduced regulatory requirements-if it could be demonstrated that certain specific conditions are' met. The conditions for considering exemption might include requirements such as: (1) the use of edditional controls on the practice or source of exposure does not result in an additional reduction in the dose received; or (2) the costs of the regulatory controls is not balanced by the benefits of dose reduction that could be achieved.
Establishment of an exemption for a particular practice or source of exposure would not imply that the dose would necessarily be considered as trivial by 6
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individuals.
Because decisions on triviality are based upon their subjective j
personal judgments, some individuals might wish to take some further action to reduce or avoid the risk associated with a low level of radiation dose. However.
promulgation of an exemption is appropriate from a regulatory standpoint-because either the degree of risk is too small to justify the burden of additional l
regulstory requirements, or because there would be little gain in risk reduction by the addition of regulatory controls.
I It should be noted that there is, embedded in the range of doses at which exemption may be considered, a level of dose that would likely be taken by most individuals as not warranting further actions to reduce risk. There has.been a L
. great deal of effort devoted to determining such a level, and, although l
speculative, a consensus is emerging among those that have studied the issue, that risk of death on the order of 10'7 to 10-6 would be considered as l
negligible by most people.
This level of risk currently translates to doses on the order of 10 to 100 USv (1 to 10 mrem).
L In the United States, there are several examples of exemption from some regulatory requirements that have been promulgated in the past.
These include criteria L
for:.(1) release into sanitary sewerage systems; (2) disposal of limited quantities E
.of tritium and carbon-14 in animal tissue or scintillation fluids without regard to radioactivity; (3) reduction or elimination of licensing requirements for limited concentrations, quantities, or specific products such as smoke detectors; and (4) contamination limits for decommissioning and decontamination of some types of facilities. Along with these exempticns which are already in place, there are several efforts underway in the United States, including some which may result in a more general, generic basis for decisions on future exemptions. These efforts include development of generally applicable guidance for public dose
. levels, development of general residual radioactivity levels for decommissioning, L
and implementation cf the recently enacted Low-Level Radioactive Waste Policy l
Act.
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(E With regard to the last effort, the implementation of the Low-Level Radioactive Waste Policy Act, I.have already mentioned that NRC has published procedures which define how the agency will treat petitions for exemption of certain waste streams. We expect that the NRC will receive petitions for exempted disposal of waste streams in areas such as compactable dry waste, contaminated waste oil, contaminated soil, and secondary resins. Each of these petitions will be-generic in nature, that is, will apply to the specified type of waste as it may occur from any of the facilities in the United States.
In this sense. it will constitute a petition for an exemption for a practice rather than an exemption of a source generated at any specific site. The petitions are also to' include documentation of industry analyses of potential pathways of exposure, levels, concentrations, and types of radionuclides involved, and the expected impact along with cost savings associated with the exemptions. We expect that some of these petitions will be received later this year.
Another issue which the NRC is currently addressing with is the distribution of gemstones, such as topaz, that have been irradiated in a reactor. The resulting gems remain slightly radioactive due to activation products such as tantalium and. scandium for several years. This issue has involved selection of appropriate dose criteria and establishment of reasonable controls. The Commission has directed the NRC sttff to develop a licensing approach for facilities that either irradiate or import the gemstones. Distribution of the
_ gemstones beyond the reactor conducting the irradiation or the initial importer of the gemstones _tc the United States would be exempted from further controls based upon assurance through license controls that' the radionuclide content remaining.at the time they are released as exempt gemstones below selected criteria ~.
In this way, control can be exercised by the NRC to ensure that the gemstones are held for decay for a period of time long enough to reduce the dose to acceptable levels.
As 1-mentioned earlier, the Comission has directed the NRC staff to develop a broad based policy and framework under which exemptions could be considered 8
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gs a-and granted..In this effort, the NRC plans to build upon the work that has already been accomplished in the field, including the recent efforts of IAEA and NEA to establish a framework for exemption.
In the preparation of generalized policy and criteria for exemption, there are a number of fundamental policy issues that must be resolved.
The first of these is whether the " practice" to be defined should be broad, such as is contemplated by the implementation of the Low Level Radioactive Waste Policy Act, or more narrowly, such as the placement rf wte to a specific landfill discussed in an earlier example.
In theory, eitut >f these approaches could be utilized, and each presents unique implementation problems and concerns.
A second issue involves maintaining control and recordkeeping so that regulatory authorities can differentiate between intentionally exempted low level activity and the accidental introduction of activity which might require investigation and remedial action.
It must be remembered that the contamination in steel at Ciudad Juarez, Mexico was detected as low concentrations of radioactive material in items being imported from Mexico to the United States. Detection and differentiation of this type of event from the recycle of small quantities of radicactive material under an exemption will be increasingly difficult unless appropriate controls are developed and instituted. The recycle issue is truly an international issue because slightly contaminated products will be introduced into international trade.
It calls for international guidance which will be consistently followed by countries recycling material.
The solutions to these and other issues are not easy, because they constitute both broad policy and technical challenges which require national and inter-national consensus and cooperation.
There is much work that remains to be done in this field.
In the United States, we recognizs that establishing rules and levels for exemption can only be realistically accomplished if there is an international consensus on the overall policy and direction.
For this reason, we strongly support the efforts tt.at are currently uncerway in the international radiation protection community, such as work recently accomplished by NEA and IAEA.
Further, in cooperation with NEA, the NRC is currently planning to sponsor a workshop on on the subject in an attempt to build on the current framework, come to grips with sorte of the remaining technical and policy issues related to exemption rules and expand the bases for consensus. This workshop is now scheduled for October 17-19, 1988 in Washington, D.C.
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1 the plans for the workshop will soon be sent out by the NRC in cooperation with the NEA.
It is our hope that this will add impetus to the international efforts to establish a well reasoned and socially acceptable framework for exemption from regulatory controls.
In conclusion, I would like to encourage those involved in radiation protection policy to continue the efforts which are now underway to establish an international consensus on exemption of low levels of radioactive material from regulatory control.
It is particularly important that-those responsible for policy decisions become involved and build upon the consensus developing on some of the basic technica'l issues. Although there are significant' issues remaining to be addresses, I believe that a rational approach is emerging and that the further efforts currently being planned should be supported.
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