05000312/LER-1981-025, Forwards LER 81-025/03T-0.Detailed Event Analysis Also Submitted

Forwards LER 81-025/03T-0.Detailed Event Analysis Also Submitted

ML20004C026
Person / Time
Site:	Rancho Seco
Issue date:	05/19/1981
From:	Mattimoe J SACRAMENTO MUNICIPAL UTILITY DISTRICT
To:	Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML20004C027	List: 05000312/LER-1981-025, Forwards LER 81-025/03T-0.Detailed Event Analysis Also Submitted 05000312/LER-1981-025-03, /03T-0:on 810420 & 0506,pressurizer Liquid Sample Valve Failed to Operate.Caused by Stripped Drive Sleeve Bevel Gear.Operator Removed & Replaced.Valve Tested & Stroked
References
NUDOCS 8106010447
Download: ML20004C026 (2)

LER-1981-025, Forwards LER 81-025/03T-0.Detailed Event Analysis Also Submitted

Event date:
Report date:
3121981025R00 - NRC Website

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( )SrMUa SACRAMENTO MUNICIPAL UTILITY DISTRICT C 6201 S Street, Box 15830, Sacramento, California 95813; (916) 452-3211 May 19, 1981 R. H. ENGELKEN, DIRECTOR REGION V 0FFICE OF INSPECTION & ENFORCEMENT U. S. NUCLEAR REGULATORY COMMISSION 1990 N CALIFORNIA BLVD WALNUT CREEK PLAZA SUITE 202 WALNUT CREEK CA 94596 OPERATING LICENSE DPR-54 DOCKET NO. 50-312 REPORTABLE 0CCURRENCE 81-25

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In accordance with Technical Specifications for Rancho Seco Nuclear Generating Station, Section 6.9.4.2c, and Regulatory Guide 1.16, I

Revision 4, Section C.2.b(2), the Sacramento Municipal Utility District is hereby submitting a thirty-day report of Reportable Occurrence 81-25

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On April 20, 1981, while performing SP 205.07A/B/C, Isolation Valve Surveillance Test, SFV-70001, the pressurizer liquid-samprie-valve -

r-failed to operate.

Maintenance personnel investigated the problem.

l The valve was manually operated and subsequent ^artemptT Et-"remvie" operation were sucessful.

Although no work was-performed on the valve, six successful operations of the valve were determined adequate to assure operability.

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On May 6, 1981, a second unsuccessful attempt E operata tha valv.ftwa encountered.

Since the previous solution (i.e., operating the valve manually to eliminate the possibility of the va4ve sticking'or binding) ' '

was short lived, it was decided to inspect the motor operoiv.

This inspection revealed the drive sleeve bevel gear, which drives the pinion for the limit switch assembly, was s[ trip 7ejd.

Rather than disas-

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semble and repai r the operator at this time, the operator was_ removed I

and replaced with a spare from the warehouse. _J_he replacement operator is the same type and model as the original.

Following replacement and appropriate limit sw+tch torque adjustmen'ts,

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the valve was tested and the stroke times werd steeptabte per - '- ' '- '

Specifications Table 3.6-1.

The defective components irt the original operator will be replaced and the operator placed in the warehouse as

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a spare.

\\ 81060ToiW

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R. H. Engalkan MIY 19, 1981 The particular valve operator is a Limitorque Model SMB-000 manufactured by, Limi torque 03rporation.

There were no plant transients nor power reductions as'sociated with this event.

John J. Mattimoe Assistant General Manager and Chief Engineer cc:

ISE Washington (30)

MIPC.(3)

EPRI-NSAC

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