ML20197G954
| ML20197G954 | |
| Person / Time | |
|---|---|
| Issue date: | 04/17/1986 |
| From: | Heltemes C NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD) |
| To: | Rossin A NUCLEAR SAFETY ANALYSIS CENTER |
| References | |
| NUDOCS 8605190012 | |
| Download: ML20197G954 (2) | |
Text
o .
APR 171986 Dr. A. David Rossin, Director Nuclear Safety Analysis Center 3412 Hillview Avenue P. O. Box 10412 Palo Alto, California 94303
Dear David Rossin:
Subject:
Request for Peer Review Comments--Preliminary Case Study Report--A Review of Motor-0perted Valve Performance A preliminary case study on a review of motor-operated valve performance in LWRs is enclosed. The review brings together previous NRC studies and documents (AE0D reports and IE bulletins, circulars, and information notices),
reviews over 1100 valve operator events (SCSS and NPRDS) from 1981 to the present, and incorporates new data from an NRC valve testing program that utilized signature tracing techniques on valves in operating plants. This report also responds to item 6(1) of the actions directed by the Executive Director for Operations to respond to the NRC staff investigations of the June 9, 1985 Davis-Besse event.
Our case study report concludes that current methods and procedures at many operating plants are not adequate to assure that valves will operate when needed. Furthermore, the deficiencies would generally not be detected by existing (plant procedures plant technical intendedand specifications to assure operability, ASME Code, Sectionsuch as surveillance XI inservice testing) or plant operator observations. Thus, assurance of valve operability testing appears to be strongly dependent upon diagnostic capability to assess and evaluate failures to operate so that root causes of failure--including switch setpoints--are correctly determined and proper changes implemented. The issue of valve performance and reliability is a complex subject that involves several technical disciplines. The report makes three recommendations.
In accordance with our " peer review" process prior to the finalization and distribucion 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, particularly regarding accuracy and completeness of the technical details. 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. Therefore, 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 AEOD places on these events and, therefore, obtain a more complete picture of the total report. We would welcome comments either informally by telephone or formally by memorandum.
s f
/l S605190012 pDR ore B60417 / J NER PDR
Dr. A. David Rossin 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 the preliminary copy. Should your office require some additional time beyond that point, please let us know; otherwise, it will be assumed that there are no comments.
As you may know, AE00 reports do not represent an official NRC position or the position of the responsible NRC program office. Our reports are one input to an ongoing review and evaluation process, and any recommendation contained in our final report will be considered ar.d perhaps modified or eliminated by the responsible NRC office.
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 have any questions regarding this study, please feel free to contact Earl J. Brown of my staff. Dr. Brown can be reached at (301) 492-4437.
Sincerely, 9/
C. J. Heltemes, Jr. , Director Office for Analysis and Evaluation of Operational Data
Enclosure:
As Stated DISTRIBUTION:
PDR AE0D CF ROAB CF ROAB SF EBrown MChiramal SRubin KBlack WLanning FHebdon CJHeltemes, Jr.
OFC : ROAB : SC:R0AB g : AC:R0AB : DD:A : D:AE : :
NAME : EBrown:as : MChirama : SDRubin : FJ f_,__:_CJHel or : s: :
DATE : 4//f /86 : 4//6/86 : 4//6/86 : 4/ig/86 : 4/ 6 /86 : :
OFFICIAL RECORD C0fT