ML19309A145
| ML19309A145 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 12/09/1971 |
| From: | Rich Smith US ATOMIC ENERGY COMMISSION (AEC) |
| To: | Mattimoe J SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| References | |
| NUDOCS 8003260860 | |
| Download: ML19309A145 (2) | |
Text
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UNITED STATES ATOMIC ENERGY COMMISSION t
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DIVISION OF COMPl.!ANCE d
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REGION V 2181 BANCROFT WAY BERxst.EY, CAI.IFoRNIA 94704 Tsim
- s. sai-sian Eur. ss December 9, 1971 Sacramento Municipal Utility District Docket No. 050-0312 P. O. Box 15830 Sacramento, California 95813 Attention:
Mr. John J. Mattimoe Chief Engineer Gentlemen:
This office received information from two licensees operating Ems which may relate to the future performance of reactor scram circuit breakers in your facility.
This letter provides you with a copy of the body of the letter that was O
forwarded to the licensees of operating FWRs by cognizant Regional Offices of the Division of Compliance.
No action on your part is required; however, we will review this matter during our continuing inspection program.
Should you have any questions concerning this matter, we will be pleased to discuss them with you.
Sincerely, ww
,7p R. W. Smith Director
Enclosure:
Body of Ler to Licensees of Operating PWRs
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e ENCLOSURE Body of Letter to Lfcennees of Ooeratinn PWs We recently received information relating to the performance of reactor scram circuit breakers from two licensees operating PWRs. The reactor scram circuit breakers are Westinghouse Type DB 50. The information is as follows:
Three failures to operate occurred at this facility.
Plant A Each failure involved the undervoltage trip attachment. No common mode of failure could be identified. One failure was attributed to a broken latch pin, the second to mechanical binding of the trip level, and the cause of the third was not cpecifically identified.
Plant B Two of the reactor scram circuit breakers failed to trip on undervoltage during surveillance testing. The failure to trip was attributed to dirt accumulation on exposed linkages.
This failure occurred after completion of inspection of the scram breakers to determine the applicability of the problems observed at Plant A.
It is requested that you inform this office within 10 days, in writing, whether reactor scram circuit breakers ' the described make and model are installed in your facility.
If the ar to this question is in the affirmative, provide the date when e a r: of your reactor scram circuit breakers will be inspected and tested.
In addition, it is requested that you infore this office within 10 days in writing, following completion of your inspection and tests of your specific findings including a description of corrective actions taken or planned and the scheduled i
completion date of planned actions.
Should you have any questions concerning this matter, we will be pleased
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to discuss them with you.
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