ML20207Q068
| ML20207Q068 | |
| Person / Time | |
|---|---|
| Issue date: | 12/11/1986 |
| From: | Heltemes C NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD) |
| To: | Layman W NUCLEAR SAFETY ANALYSIS CENTER |
| References | |
| NUDOCS 8701220015 | |
| Download: ML20207Q068 (2) | |
Text
- /)bil December 11, 1986 Mr. W. Layman, Acting Director Nuclear Safety Analysis Center 3412 Hillview Avenue P. O. Box 10412 Palo Alto, California 94303
Dear Mr. Layman:
Subject:
Request for Peer Review Comments - Prelimimary Case Study Report on Air Systems Problems at U.S. Light Water Reactors A preliminary AE0D case study report on "A;r Systems Problems at U.S. Light Water Reactors" is enclosed. The study analyzes and evaluates the operational experience related to, and the safety implications associated with fsilures and degradations of air systems at U.S. LWRs.
The report presents aspects of air systems degradations and plant responses to air systems losses which are not addressed in previous studies. It also highlights more than two dozen events in which, contrary to licensing assumptions, a safety-related system failed due to an air system degradation or failure.
Operating events involving the loss or degradation of air systems were judged to De safety significant because they may lead, under different circumstances, to potentially serious events and conditions which have not been analyzed in the FSARs.
The report presents five recommendations which, if implemented, should reduce reactor accident risks by reducing the likelihood for common mode failure of safety systems and by enhancing plant recovery from anticipated and unanticipated transients.
In accordance with our " peer review" process, prior to the finalization and distribution of our case study reports, we are providing NRR, IE, Regional Offices, RES, NSAC and INP0 with a copy of a preliminary report for review and comment. We request that you focus your review primarily on the accuracy and l completeness of the technical details (i.e., comments are being solicited on the technical accuracy of the report). The findings, conclusions, and recommendations are provided for your information in order that you may understand the significance AE0D places on these events and, therefore, obtain a more complete picture of the total report. Changes to the findings, conclusions, and recommendations will be considered only if the underlying information concerning the details of plant design or systems operation is in error. We would welcome comments either informally by telephone or formally by letter.
WN
'\ p l <Qb l 8701220015 861211 l PDR ORG fJEXD PDH l
Mr. William B. Layman Since we wish to finalize and issue the report shortly, we ask that any comments be received by us within 30 days from receipt of this preliminary report. Should your office require additional time beyond that point, please let us know; otherwise, it will be assumed that you have no comments.
A copy of the preliminary report and this letter are being placed in the Public Document Room at 1717 H Street, N.W., Washington, D.C. 20555.
If you or your staff have any questions regarding this study, please feel free to contact me or Dr. Hal Ornstein at (301) 492-4439.
Sincerely, C. J. Hel temes , Jr. , Di rectot Office for Analysis and Evaluation of Operational Data
Enclosure:
As Stated cc w/ enclosure:
G. Vine, NSAC W. Reuland, NSAC DISTRIBUTION:
PDR MWilliams AE0D CF LBell R0AB CF RDennig ROAB SF AE0D SF H0rnstein Plam KBlack WLanning FHebdon CHeltemes SRubin MChiramal P8aranowsky 0FC :ROAB :ROAB SC :ROAB:BC :AE0 :DD :AE00:D : :
_____ A M _:____ J:L__:____________:__ _______:_ .W______:____________:___________
NAME :H0rnstein:nc:Plam 01Tl:SRubin :FH don :C gltemes : : :
DATE :12/P /86 :11/o9/86 :11/04/86 :11/st/86 :17/11/86 : :