05000312/LER-1981-022, Forwards LER 81-022/03L-0.Detailed Event Analysis Also Submitted

Forwards LER 81-022/03L-0.Detailed Event Analysis Also Submitted

ML19347F631
Person / Time
Site:	Rancho Seco
Issue date:	05/12/1981
From:	Mattimoe J SACRAMENTO MUNICIPAL UTILITY DISTRICT
To:	Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML19347F632	List: 05000312/LER-1981-022, Forwards LER 81-022/03L-0.Detailed Event Analysis Also Submitted 05000312/LER-1981-022-03, /03L-0:on 810416,safety Sys Hydraulic Snubbers SS-16,SS-17 & 71(MS-20522-SW2) Were Found Low on Fluid Level.Cause Not Stated.Assemblies Reworked
References
NUDOCS 8105220272
Download: ML19347F631 (2)

LER-1981-022, Forwards LER 81-022/03L-0.Detailed Event Analysis Also Submitted

Event date:
Report date:
3121981022R00 - NRC Website

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' ' SACRAMENTO MUNICIPAL UTILITY DISTRICT C 6201 S Street, Box 1583, Sacramento, California 95813; (916) 452-3211 May 12, 1981 6 N.s 9

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MAY 01193W 5 R. H. ENGELKEN, DIRECTOR

" E s Y REGION V 0FFICE OF INSPECTION t. ENFORCEMENT g.

1 U. S. NUCLEAR REGULATORY COMMISS10N

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1990 N CALIFORNIA BLVD WALNUT CREEK PLAZA SUITE 202 WALNUT CREEK CA 94596 OPERATING LICENSE DPR-54 DOCKET NO. 50-312 REPORTABLE OCCURRENCE 81-22 In accordance with Tecnnical Specificatir for Rancho Seco Nuclear Generating Station, Section 6.9.4.2b and Regulatory Guide 1.16, Revision 4, Section C.2.b.2, the Sacramento Municipal Utility District is hereby submitting a thirty-day report of Reportable Occurrence 81-22.

In compliance with Technical Specifications, Section 4.14.1, the visual inspection of " inaccessible" safety system hydraulic saubbers was being performed on April 16, 1981.

During that inspection, three of the 77 snubbers in the " inaccessible" category were found to be low on fluid. All three units were determined as inoperable since two of the units are, per Technical Specification Section 4.14.4, exempt from functional testing and the third was refilled prior to being removed and tested in the "as found" condi tion.

The two units exempt from functional testing were Snubber No. SS-16, exempt due to a ratei capacity greater then 50,000 pouads, and Snubber No. SS-17, exempt due to being difficult to remove or in a high radiation area.

Since the cause of the low fluid I

8105220 d AN E L E C T R I C S Y S T E li S E RVIN G MORE THAN 600,000 IN THE HEART OF C A LI F O R N I A j

.T. H. Engelken May 12, 1981 level was either due' to the accumulators or the valve bodies, both of these assemblies were removed from the snubbers and reworked.

.The' reworked accumulators and valve bodies.were then reinstalled and the units' filled a

to the proper levels.

The unit which was, inadvertently refilled, prior to-

+

being tested ' to veri fy operabili ty, Snubber. No.

MS-20522-SW2, was determined to be leaking fluid from the accumulator. The unit was' removed, the accumulator rebuilt, the unit successfully tested and then reinstalled.

in accordance with the schedule in Technical Specifi-cations Section 4.14.1, the inspection tirce interval has been -reduced to _four months + 25%.

All three snubber units are manufactured by Bergen -

Patterson Pipe Support Corporation.

Since the unit was shutdown for refueling, there were no transients nor power reductions associated with this event.

l John

. Mattimoe Assistant General Manager and Chief Engineer cc:

l&E Washington (30)

MIPC (3)

EPRl-NSAC I