ML20073P867
| ML20073P867 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 02/08/1991 |
| From: | Sullivan H LOS ALAMOS NATIONAL LABORATORY |
| To: | Catton J Advisory Committee on Reactor Safeguards |
| References | |
| ACRS-CT-1991, NUDOCS 9105230231 | |
| Download: ML20073P867 (3) | |
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wt-January 30,1991 Los Alamps National Laboratory e,rwern e N-6 91-242 Los Alamas, New thm AWC w.sw MS K557 nom (505) 667-6231 ITS: 843 6231 Engineering & Safety Analysis Dr.1. Catton US Nuclear Regulatory Commission Advisory Committee on Reactor Safeguards Washington, DC 20555
Dear Ivan:
Subject:
Consultant Report for Interfacing System LOCA Program Meeting on December 12,1990
.\\1y comments on the review of the NRC (both NIUR and RES) program to rero!ve the Interfacing System LOCA Issue are given below. It should be noted that I am currently in conflict of interest with INEL and much of he work was performed t
by them.
The use of Davis-Besse as a generic plant is not addressed clearly in the draf t report. It is not the Davis-Besse plant because of assumptions used in the PRA (i.e., the meterology data and other assumptions). It appears that the interfacing system LOCA is highly plant dependent and should be considered as such.
There appears to be a diversity of opinions on whether plant procedures should be specific vs symptom-oriented and operators' knowledge of what is going on vs following plant procedures. I believe this should be resolved within NRC.
It is not clear that NRR feels the intent of the Standard Review Plan (Sec. 6.3) is being fully satisfied with the single-failure analysis being performed. If it is not being satisfied, then the NRR should specify what is required.
i 1105230231 910208 PDR ACRS PDR CT-1991
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I Dr. II Catton January 30,1991 N-6 91-242 a.
Although I realize that the LER database is hard to use for interfacing system 1.OCA precursors.1 am not convinced that the Level 1 PRA analysis is consistent with the LER data. I believe this would warrant future work and explanation in the report.
The accident environmental issues that will be a part of any break in an interfacine system LOCA appear not to be consider (.d or adequately considered.
Increased risk from common-cause failure needs to be addressed in detail to evaluate these effects.
I believe that human factors are an important part of the interfacing system LOC A issues. The work that INEL presented is a step forward but an unproven method. This should not be considered as a comment against research in this-area because I believe it is clearly needed. However,if it is an important part of the interfacing system LOCAs, then NRR should focus on their work in this area.
11 appeared from the presentation that the need for improved instrumentation
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and/or improved procedures comes from the human factors analysis. I beheve that if this is the case a more careful and detailed analysis of human factors needs to be performed.
Currently, the plant comparisons are not using overall plant risk. By not doing this, the overall effect of changes being considered cannot be evaluated against overall risk changes. I believe this is a serious drawback to the studies being performed on the interfacing system LOCA issues.
Currently, PWRs ar' the only type of reactor being considered. I believe that BWRs also should be included in the Interfacing System LOCA Program. When I asked about including BWRs,it was not clear that NRR and RES were going to Mclude the BWR to the extent that PWRs were studied.-
l Interfacing system LOCAs represent a relatively high-probability event with a 1
relatively high probatility of recovery, much of which is largely dependent on human intervention. I-luman factor onalysis is one of the weakest areas in PRA, l
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January 30,1991 I'rJ1 Catton N.n.91 -24 2 and now we find our analyses depend on this area. I believe that additional focus and work should be given to this area in future analysis and particularly where decisions on suggested changes to plants are involved.
If you or the ACRS members or staff have any questions about my comments please do not hesitate to call me at (505')667 6231 or FTS S43-6231.
Sincerely, 7/sJ AutL-L H. Sullivan 1.HS /is y,
A. S. Neuls, N-6, h!S K557 CRht-4, N15 A150 N-6 File r
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