ML20213A514
| ML20213A514 | |
| Person / Time | |
|---|---|
| Issue date: | 01/08/1987 |
| From: | Michael Corradini Advisory Committee on Reactor Safeguards, WISCONSIN, UNIV. OF, MADISON, WI |
| To: | Kerr W MICHIGAN, UNIV. OF, ANN ARBOR, MI, Advisory Committee on Reactor Safeguards |
| References | |
| ACRS-CT-1880, NUDOCS 8702030319 | |
| Download: ML20213A514 (2) | |
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-[f Department of Nuclear Engineering and Engineering Physics ggf E
University of Wisconsin
% oi 153 Engineering Research Building 1500 Johnson Drwe Madisort WI 53706 1687 Phone (608) 2631646 January 8,1987 J
Prof. W. Kerr Nuclear Engineering Department University of Michigan Ann Arbor MI 48104
Dear Bill,
Through the holiday season I have been considering the NRC staff position on the use of the IDCOR methdology for the planned individual ' plant examinations for severe accident vulnerabilities.
I am still convinced of its positive qualitative value in determining if a particular plant is significantly more prone to core melt than the IDCOR surrogate plant, or if it may release signi-ficantly more fission products.
I also recognize that modifications are still needed in the IDCOR IPEM to satisfy many of our real concerns about accuracy and uncertainties.
However, these I feel can be eventually resolved. I would like to discuss two other concerns I have:
i) Ability and willingness of utilities to perform the IRE by themselves, ii)
Consistent review of each IPE by NRC staff.
First, the original intent of the NRC individual plant examination was to ful-fill the final provisions of the Severe Accident Policy Statement.
In doing this the NRC along with the efforts of IDCOR have tentatively adopted the IDCOR have tentatively adopted the IDCOR IPEM as one way to fullfill this re-quirement.
From the very beginning of this endeavor the NRC has stated its intent and the IDCOR group has supported the idea that the licensee should l
p(rform this analysis or at least the primary part of the analysis.
In this way the licensee will probably gain a greater knowledge of the nuclear plant and containment system, particularly in terms of the system interactions dur-ing a possible emergency conditions such as a severe accident. My concern is that the IPEM is complex enough that many utilities may choose to hire consul-tants to perform the whole task.
This would defeat one of the primary pur-poses of the effort.
I would urge the NRC staff to impress upon the licensee the need to primarily perform these tasks 'in-house' for their own benefit of l
possible greater insight into the plant and enhance safety.
l The NRC staTf has tentatively set a tight schedule to have these IPE's per-formed and reviewed.
This leads to my second concern, that the review of the licensee IPE by the NRC staff is done in a consistent and complete manner. My concern is based on the fact that currently there are only a few NRC staff that are intimately involved with the development of the Severe Accident IPE Generic Letter and associated screening criteria and guidelines; therefore, it 8702030319 70108
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f seems impossible for these informed staff to become involved in all the li-censee reviews.
The transfer of this ' technology' to other NRC staff in li-censing by these key individuals takes time and I cannot envision the review being done rapidly if consistency and completeness are important.
Therefore, 1
either the current key staff should get' more of the NRC licensing branch in-volved now early in the IPE process, or a more realistic schedule should be drawn up for the review.
I would appreciate your comments on these topics.
I hope you ardhpot mourning the Michigan Rose Bowl loss too mtrch.
Si ncerely,
M. L. Corradini Professor Nuclear Engineering and Engineering Physics Mechanical Engineering
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