ML20247Q134
| ML20247Q134 | |
| Person / Time | |
|---|---|
| Issue date: | 07/20/1989 |
| From: | Cunningham R Office of Nuclear Reactor Regulation |
| To: | Congel F Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8908070057 | |
| Download: ML20247Q134 (4) | |
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e JUL 2 01989 MEMORANDUM FOR:
Frank J. Congel, Director Division of Radiation Protection and Emergency Preparedness Office of Nuclear Reactor Regulation FROM:
LeMoine J. Cunningham, Chief Radiation Protection Branch Division of Radiation Protection and Emergency Preparedness Office of Nuclear Reactor Regulation
SUBJECT:
SUMMARY
OF A MEETING REGARDING HOT PARTICLES AT NUCLEAR POWER PLANTS At our request, representatives of the Nuclear Management and Resources Council (NUMARC) met with NRC staff on July 10, 1989 to discuss items of mutual inter-est associated with hot particles at nuclear power plants.
This meeting was open to the public.
A list of attendees is enclosed.
NUMARC representatives and the NRC staff briefed the ACRS and an ACRS subcom--
mittee earlier this year on the subject of a proposed interim standard for occupational exposure of skin from hot particles.
At these meetings it became apparent to the NRC staff that NUMARC representatives had misunderstandings concerning the content of the proposed interim standard.
During the meeting on July 10, 1989, the staff provided the following clarifications:
1.
_The interim standard included a l m tat on of one hot particle exposure ii i
per individual per calendar quarter.
This limitation applied to an exposure above the current limits in 10 CFR Part 20; multiple hot particle exposures below the Part 20 limits were not relevant to the interim standard.
The staff noted that no more than one hot particle exposure per individual above Part 20 limits has ever been reported to NRC.
2.
The definition of a " hot particle" in the interim standard included no limitation on the size of the particle or the activity in the particle.
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JUL 2 0 569 Frank J. Congel
-2 NUMARC representatives agreed that they had misunderstood these two points during the ACRS and ACRS subcommittee meetings.
NUMARC representatives were asked to explain their statement that the 50-tad limit in the proposed interim standard would not provide relief from controls that are based on the existing limits of 10 CFR Part 20 (7.5 rad or 18.75 rad).
NUMARC representatives stated that they believed the NCRP draft recommendation of 75 pCi-hrs was technically justifiable and that this limit would provide much more relief that would the NRC staff proposed limit of 50 rads.
The NRC staff summarized the status of scientific data and models concerning hot particles as follows:
1.
The model involving a critical radius and a 2000-rad threshold was not the basis for the recommendations in draf t NCRP Report #101.
2.
The threshold for ulceration when expressed in terms of either beta 2 increases with increasing particle emission or dose averaged over 1 cm size for particles larger than about one millimeter diameter; therefore, the results of the EPRl/PNL studies should not be applied to particle sizes smaller than their test sources.
NUMARC representatives did not agree with these two statements.
The staff informed NUMARC that an ICRP task group recently has proposed a limit of 100 rads averaged over an area of I cm2 and a depth range of 100-150 pm for occupational exposure of skin from a hot particle. This 100-rad limit does not include a safety factor. The staff emphasized that this recommendation is far from final.
NUMARC representatives were also informed that apparent differences in thresh-old values between the Forbes-Mikhail data and.the data of Hopewell et al.
appear to be approaching resolution.
NUMARC representatives briefly summarized some results of a recent survey regarding control of hot particles at nuclear power plants.
As a result of the identification of misunderstandings, discussed above, NUMARC will revise some questions used in the survey.
NUMARC agreed to provide NRC staff with a copy of the revised questionnaire and asked for suggestions for additional ques-tions.
Results of the revised survey will be made available to the NRC.
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. Frank'J.' Congel The NRC staff discussed several examples of statements by NUMARC representa-tives at the ACRS meetings that the staff believed were incorrect or imparted a.
biased perspective.
NUMARC representatives and NRC staff agreed there is a need for more direct discussions, such as this meeting, and that these should lead to improved working relationships.
Original signed by teMoine J.'Cunningham LeMoine J. Cunningham, Chief Radiation Protection Branch Division of Radiation Protection and Emergency Preparedness Office of Nuclear Reactor Regulation
Enclosure:
List of Attendees at Meeting Distribution:
FJMiraglia, NRR FJCongel, NRR LJCunningham, NRR JEWigginton, NRR THEssig, NRR JDBuchanan, NRR WDTravers, NRR RJBarrett, NRR MFWeber, OCM/KC MVFederline, OCM/KC JLieberman, OE JMJohansen, OE BMMorris, RES DACool, RES JMBell,'RES MRKnapp, RI RRBellamy, RI JPStohr, RII DMCollins, RII CENorelius, RIII LRGreger, RIII ABBeach, RIV BMurray, RIV RAScarano, RV GPYuhas, RV FJRemick, ACRS TTipton, NUMARC PDR RLAnderson, TTC
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.... s ENCLOSURE Attendees at the NRC-NUMARC Meeting i
July 10,1989 L. J. Cunningham NRC/NRR/PRPB F. J. Congel NRC/NRR/DREP Tom Tipton NUMARC Michael C. Williams Union Electric Lynne A. Fairobent NUMARC John F. Schmitt NUMARC John D. Buchanan NRC/NRR/PRPB Tom Essig NRC/NRR/PRPB Jim Wigginton NRC/NRR/PRPB Jack Bell NRC/RES/RPHEB Jenny M. Johansen NRC/0E Donald A. Cool NRC/RES/RPHEB Robert C. Lowry NUS Corporation Darlene Calandra BCP&R Michael Weber NRC - Chairman's Office Maria Conover Bechtel
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