ML19319D813
| ML19319D813 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 01/27/1978 |
| From: | Mattimoe J SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| To: | |
| Shared Package | |
| ML19319D814 | List: |
| References | |
| NUDOCS 8003250806 | |
| Download: ML19319D813 (1) | |
Text
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Y SACRAMENTO MUNICIPAL UTILITY DISTRICT Q 6201 S Street, Bos 15830, Sacramento, Califomia 95813; (916) 452 3211
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January 27, 1978 i
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' Director of Regulatory Operations ATTN: Mr. R. H. Engelken NRC Operations Office, Region V
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g.u.g 1990 N. California Boulevard
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Walnut Creek Plaza, Suite 202 d
Walnut Creek, California 94596
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Re: Operating License DPR-54 q' g- 00FJJ Docket No. 50-312
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Followup Report: RO-77-16 z
Gentlemen:
l The Sacramento Municipal Utility District reported the discovery of a dry, fluid accumulator on a safety system hydraulic snubber in Reportable Occurrenge Report 77-16 dated November 29, 1977. Since the submittal of that report, o/
additional information relating to the cause of that failure has 'become available, leading to this followup report.
In the original report, it was mentioned that the 0-ring that had failed
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f and permitted the fluid leakage did not appear to be made of the proper i
material. This speculation was based on the fact that the 0-ring was not the same color as other 0-rings and seals.
Further testing has shown that the i
questionable 0-ring was made of polyurethene rather than the proper ethylene,
propylene.
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The snubber in which the 0-ring was installed was originally deliveredd,
to the District with polyurethene seals. The unit was one of many that were returned for replacement of these seals with ethylene propylene. Apparently this one 0-ring was overlooked out of all the seals in all of the units that were rebuilt.
During the functional testing program carried out during the last refueling, some 81 units were disassembled and rebuilt, and no seals of improper materf al were detected. The Disr.rict feels that the current sur-vaillance program, which automatically increases the surveillance frequency upon discovery of any failures, is adequate to detect any other seals that 1
_l may have been overlooked. The failed unit has been rebuilt with proper seal material and has been returned to operation.
1 Respectfully submitted,
.b J. J. Mattimoe Assistant General Manager and Chief Engineer h
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Attachment s o os u s o )*O{R
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i THE HEART OF C A LIF
'AN. ELECTRIC SYSTE M S E RVIN G MORE THAN 600,000 IN
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