ML16253A263
| ML16253A263 | |
| Person / Time | |
|---|---|
| Issue date: | 07/18/1991 |
| From: | Ward D Advisory Committee on Reactor Safeguards |
| To: | Selin I NRC/Chairman |
| References | |
| D910718 | |
| Download: ML16253A263 (2) | |
Text
D910718 The Honorable Ivan Selin Chairman U.S. Nuclear Regulatory Commission Washington, D.C. 20555
Dear Chairman Selin:
SUBJECT:
PROPOSED NUMARC/EPRI FIRE VULNERABILITY EVALUATION METHODOLOGY FOR USE IN THE IPEEE During the 375th meeting of the Advisory Committee on Reactor Safeguards, July 11-13, 1991, we reviewed the Fire Vulnerability Evaluation (FIVE) Methodology developed by the Nuclear Management and Resource Council (NUMARC) and the Electric Power Research Institute (EPRI) for possible application by licensees in perform-ing their individual plant examination of external events (IPEEE) and the NRC staff evaluation of this methodology. This matter was discussed during a meeting of our Subcommittee on Extreme External Phenomena on July 10, 1991. During this review, we had the benefit of discussions with representatives of NUMARC/EPRI and the NRC staff. We also had the benefit of the documents referenced.
The FIVE methodology has been developed and proposed as an alternative to probabilistic risk assessment (PRA) for identifying potential severe accident vulnerabilities that could result from internal fires at nuclear power plants. In its draft evaluation report, the NRC staff has reviewed this methodology and has identified a number of clarifications and enhancements that they believe would improve the methodology. One of these clarifica-tions, which we believe to be of particular importance, deals with the effect of fire suppressants on safety equipment. This same consideration applies to the alternative PRA methods of fire evaluation. A further improvement, to provide guidelines for compartment interaction analysis, has been agreed to by the proponents.
The NRC staff has concluded that the FIVE methodology, if modified to incorporate these clarifications and enhancements, would be adequate for use in the IPEEE. We agree. This agreement is based, in large part, on our belief that the effectiveness of a search for vulnerabilities will depend as much on the competence and dedication of those making the search as on the particular choice of methodology.
Sincerely, David A. Ward Chairman
References:
- 1. Memorandum dated May 8, 1991 from W. Minners, Office of Nuclear Regulatory Research, NRC, for R. Fraley, Advisory Committee on Reactor Safeguards,
Subject:
ACRS Review of NUMARC/EPRI Fire Vulnerability Evaluation (FIVE) Methodology for Use in the IPEEE, with attachments, as follows:
(a) Draft NRC Staff Evaluation Report on Revised NUMARC/EPRI Fire Vulnerability Evaluation (FIVE) Methodology (undated)
(b) Letter dated November 14, 1990 from W. Rasin, NUMARC, to W. Minners, NRC, transmitting the following:
(i) Fire Vulnerability Evaluation Methodology (FIVE) - Plant Screening Guide, Prepared for EPRI by Professional Loss Control, November 2, 1990 (ii) Fire Events Database for U.S. Nuclear Power Plants, Draft Final Report prepared by SAIC for EPRI, November 26, 1990 (Proprietary)
(iii) Letter dated November 20, 1990 from J. P.
Sursock (EPRI) to D. Modeen, NUMARC,
Subject:
Comparison Between FIVE Fire Hazard Analysis Methodology and Experimental Data
- 2. Letter dated May 7, 1991 from R. Ng (NUMARC) to T. King, Office of Nuclear Regulatory Research, NRC,
Subject:
Response
to Draft NRC Evaluation Report
- 3. Draft NRC Staff Evaluation Report on Revised NUMARC/EPRI Fire Vulnerability Evaluation (FIVE) Methodology (Latest Version Provided to ACRS on July 10, 1991) (Predecisional)