ML19309A331
| ML19309A331 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 12/09/1977 |
| From: | Mattimoe J SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| To: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| Shared Package | |
| ML19309A332 | List: |
| References | |
| NUDOCS 8003270764 | |
| Download: ML19309A331 (1) | |
Text
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ig BE CTY SMUD SACRAMENTO MUNICIPAL. UTILITY DISTRICT C 6201 S Street. Box 15830. Sacramento. California 95813 -(916) 452-3211 December 9, 1977 W.,
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w % u. u)),b 6.J Director of Regulatory Operations cG.,
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Ei ATTN:
Mr. R. H. Engelken j3;,
NRC Operations Office, Region V i,,
1990 North California Boulevard Walnut Creek Plaza, Suite 202
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Walnut Creek, California 94596
~# 6 Re: Oparating License DPR-54 Docket No. 50-312 Reportable Occurrence 77-19
Dear Mr. Engelken:
t In accordance with Technical Specifications for Rancho $eco Nuclear Generating Station, Section 6.9.1, and Regulatory Guide 1.16, Revision 4,'
Section C.2.b(2), the Sacramento Municipal Utility District is hereby reporting.
the following as Reportable Occurrence 77-19.
An unidentified RCS leak rate of greater than 1 gpm was discovered at 1715 on November 16, 1977. Technical Specifications Section 3.1.6.2 permit.
operation for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> af ter detection of such a leak, providing an unsafe condition does not exist. Indications received from dumping of the Reactor Building Drain Accumulator Tank showed that the leak was confined to the reactor building, from which releases to the environment are controlled.
1' Continued operation was determined to be safe, and the reactor remained at ' '.
power while att mpts were made to locate and correct the leak.
The leak could not be located, and at 1628 on November 17, the reactor was brought to a shutdown condition. The evaluation of the shutdown made in accordance with Technical Specification 3.1.6.4 showed that the 7 MW/ minute shtitdown was normal in all respects.
An inspection following the shutdown identified a vent / sample valve on the pressurizer (HV-21515) as the source of the leakage. The valve was 1,
backseated, stopping the leak. The leak rate was checked and found acceptable, after which the reactor was brought critical and a return to power was begun.
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The leaking valve was a 1-inch Velan globe valve, Model 85-3748-13MS.
Respectfully submitted, A.. %-tC-
- l x
v. J. Mattimoe j
Assistant General Manager 3'
JJM:FTE: jim and Chief Engineer rA 8 0 08 270 7(V DL r~
cc: Director, MIPC (3)
Director, IE (30)
AN ELECTRIC SYSTEM S E RVIN G MORE THAN 600.000 IN THE HEART OF C A LIF 0 R N I A
.