ML20055D309
| ML20055D309 | |
| Person / Time | |
|---|---|
| Issue date: | 06/27/1990 |
| From: | Novak T NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD) |
| To: | Groth J INSTITUTE OF NUCLEAR POWER OPERATIONS |
| References | |
| NUDOCS 9007060146 | |
| Download: ML20055D309 (3) | |
Text
JUN 2 71990
~
Mr. John Groth,. Vice President Analysis Division Institute of Nuclear Power Operations 1100 Circle Parkway Suite 1500 Atlanta, Georgia 30339
Dear Mr. Groth:
Subject:
Preliminary Case Study Report on Solenoid Valve Problems at U.S. Light Water Reactors A preliminary AEOD case study report, " Solenoid Valve Problems at U.S. Light Water Reactors," is enciesed. The study analy:es and evaluates operational experience and safety imp (lications associated with failures and degradations ofIt fo solenoid-operated valves SOVs) at U.S. LWRs.
of safety-related equipment to comon-mode failures or degradations of SOVs.
The report presents information on more than 25 events in which common-mode failures or degradations of over 600 SOVs were affected or had the potential to affect, multiple safety systems or multiple trains of individual safety systems. Although plant safety analyses do not address such comon-mode failures or degradations of safety systems, operating experience presented in the report indicates that they have occurred and are continuing to occur.
A number of events in which safety systems have been adversely affected by degradations or failures of SOVs are considered significant precursors. The-case study notes that S0Y problems permeate almost all U.S. nuclear power plants, and that they encompass many aspects of the 50Vs' design, maintenance, and operation. The case study also notes that individual 50V manufacturer's practices regarding guidance with respect to testing and maintenance contribute towards the observed problems. The report presents six recomendations which, if implemented, should reduce reactor accident risks by reducing the likelihood for common-mode failure or degradation of SOVs affecting multiple safety systems or multiple trains of individual safety systems.
In accordance with our " peer review" process, prior to the finalization and
' distribution of our case study reports, we are providing you NSAC, NUMARC, and vendors who provided input to the case study, with a copy of the preliminary report for review and coment. We request that you focus your review primarily on the accuracy and completeness of the technical details (i.e., coments 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 we place on these events and, therefore, obtain a more complete picture of the total report. Changestoth@
pb, PDR ORG EPSINPO Mc RLE cme COPY N
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John Groth -
1 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 ask that comments be provided in writing.
Since we wish to finalize and issue the report shortly, we ask that any i
comments be received by us within 30 days from receipt of this preliminary-report.
If you require additional time beyond that point, please let us know.
to contact me or Dr. Hal Ornstein at (301)garding this study, please feel free If ydu or your staff have any questions re 492 4439.
Sincerely, Original signed by:
ThemanM. Novak i
Thomas M. Novak, Director Division of Safety Programs Office for Analysis and Evaluation of Operational Data
Enclosure:
As stated cc w/ enclosure:
R. Bauman, NPRDS Program J. Cowan, Events Analysis Division R. Thorsteinson Distribution:
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John Sroth '
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4 findings, conclusions, and recommendations will be considered only if the underlying information concerning the details of plant design or systems i
operation is in error. We ask that comments be provided in writing.
Since we wish to finalize and issue the report shortly, we ask that any consnents be received by us within 30 days from receipt of this preliminary report.
If you require additional time beyond that point, please let us know.
to contact me or Dr. Hal Ornstein at (301)garding this study, please feel free If you or your staff have any questions re 492-4439.
Sincerely.
1 i
Thomas M.
ovak, Director Division Safety Programs Office f r Analysis and Evaluation of 0 rational Data
Enclosure:
As stated cc w/ enclosure:
R. Bauman, NPRDS Program J. Cowan, Events Analysis Division R. Thorsteinson 1
Distribution:
PDR Central File ROAB R/F i
DSP R/F AEOD R/F H0rnstein i
SIsrael Plam JRosenthal MW1111ams KBlack TNovak Dross
'EJordan MTaylor EDO l
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