ML16342B457
| ML16342B457 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 06/23/1988 |
| From: | Kirsch D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | Shiffer J PACIFIC GAS & ELECTRIC CO. |
| References | |
| NUDOCS 8806280194 | |
| Download: ML16342B457 (4) | |
Text
Docket Nos.
50-275 and 50-323 Pacific Gas 8 Electric Company 77 Beale Street, Room 1451 San Francisco, California 94106 Attention:
Mr. J.
0 ~ Shiffer, Vice President Nuclear Power Generation Gentlemen:
This letter is to discuss the results of our review of your actions related to Reactor Coolant Pump Motor Upper Oil Reservoir Assemblies degradation.
The actions were described in a telephone conference call on May 12,
- 1988, and documented in Unit 1 Licensee Event Report 88-015 dated June 2, 1988.
Our review of your evaluation and actions taken regarding this matter concluded:
PG8E's justification for continued operation of Unit 2 appears to be acceptable on the basis of (1) the nature of the defects, (2) the possible consequences of the defects should flow chamber failure occur, and (3) actions taken to assure heightened operator awareness and revised procedural instructions to describe operator actions regarding plant shutdown if oil reservoir cracking is suspected.
Further, in the unlikely event of an absence of operator action, the ultimate possible consequences of a bearing failure have been well studied and do not represent an unreviewed safety question.
PG8E's corrective actions for Unit 1 appear to be acceptable based on the operating history of the pumps.
Specifically, the refurbishment of the pumps by replacing and repairing the damaged parts should provide an operable system for at least one refueling cycle which would represent less pump operating time than the pumps had seen through their second refueling osage.
't C
In conversation between Westinghouse representatives and our Senior Resident Inspector at Diablo Canyon on June 9, 1988, it was stated that Diablo Canyon was unique in several aspects.
Specifically, the material used at Diablo Canyon for the flow chamber is a unique high strength material, other pumps of this design have been provided with modification kits for reducing oil flow to alleviate an oil frothing and aging
- problem, and finally only Diablo Canyon has attempted to reduce oil frothing problems by plugging and/or orificing the flow holes, in the pump thrust runner.
Consequently, Mestinghouse does not believe this problem SS062SOi94 SS0623 PDR ADOCK 05000275 P
~ED I
will occur at other plants and does not intend to issue a service bulletin.
- Further, Westinghouse does not consider the problem to be safety significant.
We have completed our review of your evaluation supporting continued operation of Unit 2 and restart of Unit 1, and, with concurrence from NRR, found your assessment acceptable.
If you have any questions please feel free to contact us.
Sincerely, Original signa'd by 0.
F. ki;sdi D.
F. Kirsch; Director Division of Reactor Safety and Projects CC:
G. Knighton, NRR>S.
M. Skidmore, PG&E J.
D. Townsend, Plant Manager, PG8E Co., Diablo Canyon Richard F.
Locke D. Taggart, Supervisor, guality Assurance R. Weinberg, News Services T.
L. Grebel, Regulatory Compliance Supervisor State of California bcc: Project Inspector Resident Inspector G.
- Cook, RV B. Faulkenberry, RV J. Martin, RV T. Foley, NRR M. Smith REGION V Joan/
MMendonca 6/~88 RZimmerman 6/ 0988 DKirsch 6/p/88 AChaffee 6/
/88
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GKnighton 6/~88 EST COPY g
R ESI.COPY REqUEST Y j REQUEST COPY j UEST COPY ]
YES /
NO ES /
NO YES /
NO YES /
NO YES /
NO S
TO PDR j
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NO