ML20033D959
| ML20033D959 | |
| Person / Time | |
|---|---|
| Issue date: | 09/08/1988 |
| From: | Bernero R NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| To: | Stello V NRC OFFICE OF THE EXECUTIVE DIRECTOR FOR OPERATIONS (EDO) |
| Shared Package | |
| ML20033D930 | List: |
| References | |
| NUDOCS 8809150077 | |
| Download: ML20033D959 (4) | |
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k UNITED STATES NUCLEAR REGULATORY COMMISSION e
es.nwovow. o. c. ros55 k....+.
September 8,1988 l
MEMORANDUM FOR:
Victor Stello, Jr.
i Executive Director for Operations j
FROM:
Robert M. Bernero Acting Director Office of Nuclear Material Safety and Safeguards J
SUBJECT:
BASIS FOR NONCONCURRENCE BY NMSS ON THAT PORTION OF THE BRC POLICY STATEMENT WHICH DISCUSSES THE APPLICATION OF A 10 MREM PER YEAR DOSE LEVEL t
The Of fice of Nuclear Material Safety and Safeguards does not concur with that portion of the Below Segulatory Concern (BRC) Policy Statement which selects 10 mrem per year as the dose level for which exemptions could be granted without further-onalysit.
Such a decision assumes that a dose of 10 man per year is insignificant," 1.c. below cercern, and that there is ne need to furthel' cotsider the ALAM f,rincipic, The Policy Statownt, which covers L
matters such as consuwt products, recycled conteminittad materials, and waste disposal, as well as decomissioring actions, is simply too broad for a racse level of 10 mrw to be dismissed without more detailed analysis o
There is a widely held view, although speculative, that few geople wguld ccmmit tntir own resources to reduce an annual risk of death of 10~ to 10".
This translates to a radiation dose of 10 mrem per year and represen(s the su'n of radiation doses which might be dismissed as insignificant.
There is not an l
evident basis, however, to conclude that people would dismiss an accumulated radiation dose greater than 10 mrem as insignificant simply because the dose results from multiple practices, each of which is no more than 10 mrem.
I The National Council on Radiation Protection and Measurements (NCRP), Nuclear Energy Agency of the Organization for Economic Cooperation and Cevelopment (NEA), and the International Atomic Energy Agency (IAEA) have recognized the potential for multiple exposures and, accordingly, have selected a lower value of 1 mrom as the " insignificant" cose with the expectation that individuals could be subject to many exemptions granted under the 1 mrem criteria.
l While other countries and U.S. agencies have selected values between 10 mrem and 1 mrem for certain situations, e.g. Canada (5 mrem for certain waste streams) and EPA (4 mrem for drinking water), these have been for rather specific applications, not for broad policy as is proposed by the NRC Policy Statement. The United Kingdom National Radiological Protection Board (NRPB) recommends a value of 0.5 mrem for individual dose in a context similar to the NRC Policy Statement.
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Victor Stello, Jr.
-2 September 8, 1988
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IMSS recognizes that the collective dose criteria of 100 person-rem is an
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additional limiting factor when determining if exemptions could be granted without further analysis, but notes that the 1,imila.t_ig_n_ottoJlective dose does i
_not afford a reason.abJtals_ura,nce thaffsfivTdual. doses will not accumulate as a result g CmWB illt pr3c.tices.
The main purpose served by the 100 person-rem c7fferf6E is to prevent extensive environmental contamination through the exempt disposal of large quantities of radioactive material, either in dilute fom or in small portions over extended periods of time.
Heretofore, the staff has applied the ALARA principle in approval of consumer i
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products, resulting in most doses being 1 mrom or less, and has taken a conservative view on what is a justified practice. However, exemption dose criteria of 10 arem/100 person-rem as evidently ALARA, coupled with a more liberal view on justified practices, e.g., gemstones, could open new approaches for radioactive consumer products. The staff can only speculate on what these f.cnsumer products might be.
In the past, for exas.ple, we have turned down or discouraged radioactive fish lures,10 curfe tritium batteries for wristwatches, J
r,eptunium timers in watches, and uranium pellets in shotgun shells. Possibil-ities range from large light sources using substantial quantities v trittum or Mgher energy radioisotopes to perttps SN,Il radioisotope poutred batteries similar to those originally designed for pacemakers. Many of these could involve specia?ized uses wMch wocid not necessarily cer. ult in e collective dose of 100 person-rem.
If a sm611 comunity (less than 1.00,000 people) located near a reactor station is examined, assuming candidate waste streams are authorized with the 10 mrem /103 person-rem criteria, as well as takir.g into account present NRC authorized exemptions, some members of the population could be in Gsversi critical groups simultaneously.
Potential exposures might be as follows:
5 erem from each reactor's release,10 mrem each from four exempted reactor waste stream practices (i.e., dry active waste, waste oil, contaminated soil, secondary ion exchange resins),10 mrem from incinerated hospital waste (expanded limit over present{ules),and10mremtotalfromacombinationofexistingconsumer These can accumulate to an individual dose that is a significant products.
fraction of the 100 mrem per year dose limit for members of the public. Coupled with new initiatives for consumer products, some individual doses could approach or exceed the 100 mrem per year dose limit. Thus, if 10 mrem is used as the individual dose criterion, then individuals subject to multiple exposures could approach the dose limits, leaving little room for exposures by future sources of much greater societal value.
Such a circumstance would be far less likely if the Policy Statement were limited to 1 mrem per year.
1 The NCRP, in Report No. 93, concluded that the average annual effective dose equivalent to a member of the U.S. population from consumer products ranges from about 6 to 12 mrem per year.
Not all members of the public are exposed to all sources of consumer prooucts, and not all consumer products are regulated by the NRC.
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Victor Stello, Jr. September 8, 1988
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An additional basis for nonconcurrence is the question of need for the 10 mrem 1
criterion. The Policy Statement would allow exemption of practices at levels above the listed individual and collective. dose criteria, so long as an appropriate demonstration of justification and ALARA had been made.
- Further, we anticipate that the use of a 1 mrom individual dose criterion would have broad application.
For example:
1.
NCRP' Report g3 indicates that many consumer products, including smoke detectors, luminous watches and clocks, and thorium products such as fluorescent lamp starters and gas mantles result in average annual i
dose equivalents to the exposed population of less than 1 mrem.
2.
With reasonable dose modeling, it is anticipated that a large fraction of waste streams which are candidates for exemptions would result in doses on the order of magnitude of 1 mrom for critical groups within j
the general population. The present biomedical waste rule was based un estimates that average doses to the critical group would be 1 mrem j
or less.
3.
The distribution of neutron irradiated gemtones t,hich ws recently i
i authorized by the Commissicn has been calculate (. to reselt in l
ftffective whole bocy dose equivalents of less than 1 arem to indiviousls waring such gus as je@y.
2 In M61tinn to these cont.ideraticM, thtre are sey2r 1 technical points th4t stgnal cautirn with respect to the apphcetion of the 10 mrem individual dxe h
criterion.
The scientific community is currently parforming a reekamination of a.
the Hiroshima and Nagasaki atomic bomb dosimetry'and epidemiology.
Alttough not complete, the reexamination indicates that risk t
conversion factors might be low by a factor of two or three.
If so, ""4 4
above the level of risk considered acceptable by most individua this could cause exempted items to produce a level of risk at or I
b.
Once waste streams and products are exempted, it will be difficult t
I to correct problems they create in the environment. While assumptions for modeling are usually conservative, experience has indicated that once an exemption is granted the analyzed situation L
may not remain accurate because of unexpected ways in which the products are handled and disposed of. The Policy Statement provides for opportunities to assess the impact of an exempted practice or combinations of exempted practices. However, in past experience this approach has not provided a practical mechanism for identifying and correcting problems.
The Policy Statement refers to the maximum individual annual dose in t
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reference to the individual dose criterion. We believe that a better regulatory approach is to use the critical group concept rather than the maximum exposed inoividual for applying the individual dose
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threshold criteria because it more accurately reflects the actual
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,e Victor Stello, Jr. September 8, 1988
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impact to those at greatest risk from a practice. A critical group is defined as the group of individuals expected to receive the greatest exposure from the practice. The concept of maximum l
individual dose is subject to differing interpretations, but usually carries with it certain assumptions that could produce a dose considerably greater than that experienced by the critical group, i
Thus, application of the maximum exposed individual concept could result in the reduction of the permissible concentrations and quantities of radioactive material allowed under an exemption to the l
point of being useless.
In summary, if it is necessary to select a single dose level which might be considered as below regulatory concern for the very broad NRC Policy Statement, we believe that 1 mrem per year is the more appropriate dose value. The provisions in the Policy Statement concerning BRC can acconnodate higher doses.
Using this approach, it is also possible to reconcile and amplify previous positions on specific types of practices.
For example, the Commission in its Policy Statement en exemption fer disposal of slightly contaminated radioactive waste materici provided procedures for expeditious handling of petitiens involving individurl done on the order of a few trem per year. Such an apprcach would be consiste% with a broad AC Policy Statemerit using an individual cose l;
c.riteria described as, beinj on the etder of ? wen per year.
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~ ~.s Robert M. Bernero, Acting Director Office of Nuclear Material Safety and Safeguards cc:
E. S. Beckjord, RES T. E. Murley, NRR H. R. Denton, GPA
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