ML19319E177
| ML19319E177 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 10/18/1977 |
| From: | Mattimoe J SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| To: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| Shared Package | |
| ML19319E171 | List: |
| References | |
| NUDOCS 8003310694 | |
| Download: ML19319E177 (2) | |
Text
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IEFILE COPY
$ SMUD SACRAMENTO MUNIC! PAL UTILITY DISTRICT C 6201 S Street, Box 1230. Sacramerto. Califomia 95813; (916) 452 3211 October 18, 1977 9@7 0
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Director of Regulatory Operations ATTN:
Mr. R. H. Engelken t
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NRC Operations Office, Region V 4
1990 N. California Boulevard g
Walnut Creek Plaza, Suite 202
/D d Walnut Creek, California 94596 e
Re: Operating License DPR-54 Docket No. 50-312 6'
Reportable Occurrence 77-11 yf p
Dear Mr. Engelken:
i fg In accordance with Technical Specifications for Rancho Seco
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j Nuclear Cenerating 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 R0-77-ll.
On September 21,.1977, local leak rate testing (LLRT) was being perfor=ed in accordance with Surveillance Procedure SP 205.02.
Testing of the Reactor Building Purge Inlet penetration revealed a leakage race of 9.040 cubic feet per minute while the Purge Outlet pene-tration was leaking at 64.625 cubic feet per minute. Recognizing the Technical Specifications allowable leakage from all penetrations subject i
to LLRT of 0.06 percent of the cone tinment building atmosphere per 24-hour period (3.743 cubic feet per minute), the leakage from the two penetrations
<l was clearly unacceptable. The plant was in cold shutdown for refueling j
during this surveillance, j
When maintenance personnel atte=pted to reduce the leakage, they -found it necessary to replace the seats on the two isolation valves inside containment. After these were replaced and the seats on the two isolation valves outside containment were adjusted, the penetrations were tested. The purge inlet duct showed a leakage rate of 0.028 cubic feet per_ minute while the outlet duct leakage was.016 cubic feet per minute.
Adding these new leakage rates to the leakage rates from all other pene-l trations subject.to LLRT, a total leakage rate of 0.490 cubic feet per minute was measured.
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Mr. R'..- H. '.Engelken.
P&ge 2 October-18, 1977
~. ' AIReactorBuildingIntegracedLeakageRatetestwas;runfrom i
October 2 through 6 in.accordance with Technical: Specifications, Section 4.4.1.1.4. 'The results'of this1 test were. satisfactory, assuring that
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leakage ~ througli the purge isolation valves was acceptable.- The outlet penetration previously failed the LLRT in a similar manner in-August,
.1975, as reported in A0-75-12.
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All four valves are 66-inch butterfly, Model 60WR,' manufactured -
- by 'Allis Chalmers. ; There was no plant transient or shutdown as a result of'this occurrence.
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Respectfully submitted, i
W J. J. Mattimoe Assistant General Manager
=and Chief Engineer JJM:FTE:nn-
. 2 cs: Director, MIPC'(3)
V Director, IE (30) 4 0
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