ML20245D136
| ML20245D136 | |
| Person / Time | |
|---|---|
| Issue date: | 12/22/1987 |
| From: | Murley T Office of Nuclear Reactor Regulation |
| To: | Tipton T NUCLEAR ENERGY INSTITUTE (FORMERLY NUCLEAR MGMT & |
| References | |
| NUDOCS 8801040597 | |
| Download: ML20245D136 (2) | |
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llNITED STATES 8'
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DEC 2 21937 Mr. Thomas E. Tipton, Director Operations Management and Support Services Division Nuclear Management and Resources Council 1776 Eye Street, N.W.
Washington, DC 20006-2496
Dear Mr. Tipton:
I am replying to your letter dated December 4, 1987, which expressed the concerns of NUPARC members regarding the need for a new interim standard to replace the current NRC staff position on the assessment of skin doses from hot particles for determining compliance with NRC dose limits. We are aware of the concerns of HUMARC members and we agree that an interim standard is desirable.
However, at this time we do not have a suitable basis for such a standard.
- As recognized in your letter, the NRC staff has asked the National Council on Radiation Protection and Measurements (NCRP) to study the health significance of exposure to hot particles and to provide recommendations based on the findings of this study. An NCRP subcommittee has been working on these recom-mendations and we expect them to be available within about six months. As you noted, these recommendations may be used to revise 10 CFR Part 20 as it applies to skin exposure to hot particles; however, formal implementation of a rule change would require additional months. Therefore, upon receipt of these new NCRP recommendations, we will consider development of an interim standard which can be implemented within a relatively short time and used until any needed changes in 10 CFR Part 20 can be made.
l My staff has evaluated and will continue to evaluate both the scientific and regulatory aspects of the hot particle problem.
Information Notice No. 87-39, issued August 21, 1987, included a discussion of the health implications and radiation protection criteria for exposures of skin to hot particles,and called attention to recent reviews of these subjects in the scientific literature.
Furthermore, the NRC staff has been exercising enforcement discretion to i
recognize the lower risk from exposure of skin to a hot particle as compared to the risk for exposure of larger areas of the skin.
You suggested using International Comission on Radiological Protection (ICRP)
Publication 26, NCRP Report 91, and the proposed major revision of 10 CFR 20 as a basis for an interim standard that could be used by the NRC staff until the hot particle recomerdations by NCRP could be implemented. All three of these documents contain an annual limit of 50 rem for dose to skin. Although this limit is somewhat greater than the corresponding current NRC skin dose limits of 7.5 rem and 18.75 rem per calendar quarter, we do not believe that simply adopting the 50-rem annual limit would alleviate the concerns of NUMARC members to any significant degree. The recommendations in ICRP-26 (paragraphs 182 and
'j 183) concerning assessment of skin dose from skin contamination are ambiguous y@
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Mr. ' Thomas L. Tipton MU l
and provide ro clear recommendation on how to assess dose from a hot particle l
nor how to rate the significance of the dose. NCRP Report 91, although provid-1 ing the 50-rem limit for skin, gives no indication of how one is.to assess skin i
dose from any type of skin contamination for comparison with this limit. The L
dose limit for skin in the proposed major revision of 10 CFR 20 is said to apply "to the dose equivalent average over 10 square centimeters in the region of highest exposure." However, subsequent discussions within the NRC have determined that there is no scientific basis for this 10-cmr value, it appears-the value was selected as being the crea of a typical detector of a survey instrument used to measure contamination. Consequently, this section of the i
proposed revision to Part 20 is presently being reconsidered. Therefore, we do I
not believe that ICRP Publication 26, NCRP Report 91, or the published proposed revision of 10 CFR 20 pro"ide an acceptable basis for a new interim standard.
In summary, we agree there is a need for a new interim standard on skin expo-sure to hot particles, we hope that the forthcoming NCRP recommendations will provide a basis for such a standard, and we do not think it is feasible to develop and implement an interim standard before the NCRP provides its recommendations.
We icok forward to receiving the technical report being prepared by the Edison Electric Institute Health Physics Committee's skin contamination group and will be pleased to discuss this issue with representatives of NUMARC and the Edison Electric Institute Health Physics Committee skin contamination group. The NRR contact for 'his issue is Mr. LeMoine J. Cunningham, Chief, Radiation Protec-tion Branch. Mr. Cunningham's teltphone number is (301) 492-4734.
Sincerely,
. ;." Ly or n i ~ t ;.
T Thomas E. Murley, Director Office of Nuclear Reactor Regulation Distribution:
TEMurley, YRR JH5nierek, NRR ADT/P-415 FJMiraglia, NRR FGillespie, NRR C0 Thomas, hRR JLBlaha, NRP FJCongel, NRR LJCunningham, hRR JEWiscioton, NRR CDLynch, NRR JDBuchanan, NRR RJBarrett, NRR DBMatthews, Ni'R REAlexander, RLS DFMossburg, NRR - 879384 JLieberman, OE TOMartin, EDO MECoons, NRR 87-105 FRBellamy, R1 DMCollins, R11 KD5hofer, Ril' LAYandell, RIV FAWenslawski, RV Central files PDP RPB R/F EBeckjord, RES JMTaylor, EDO M/ER
- See Previous Concurrence 1
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- DREP:NRR D:DREP:hkR A[l1 NRR JDBuchanan:bt JEWigginten R5anders LJCunningham FJCongel JHS "szek
'12/16/87 12/16/87 12/16/87 12/16/87 12/(\\/87 12/,) /87
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