05000312/LER-1981-033, Forwards LER 81-033/03L-0.Detailed Event Analysis Submitted

Forwards LER 81-033/03L-0.Detailed Event Analysis Submitted

ML20009B948
Person / Time
Site:	Rancho Seco
Issue date:	07/03/1981
From:	Mattimoe J SACRAMENTO MUNICIPAL UTILITY DISTRICT
To:	Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML20009B949	List: 05000312/LER-1981-033, Forwards LER 81-033/03L-0.Detailed Event Analysis Submitted 05000312/LER-1981-033-03, /03L-0:on 810611,investigation of Diesel Trouble Alarm Revealed Open Relay Which Would Have Prevented Operation of Diesel Generator A.Relay Reset.Alarm to Be Modified
References
NUDOCS 8107200061
Download: ML20009B948 (1)

LER-1981-033, Forwards LER 81-033/03L-0.Detailed Event Analysis Submitted

Event date:
Report date:
3121981033R00 - NRC Website

text

.

esuuo SACRAMENTO MUNICIPAL UTILITY DISTRICT O 6201 S Street, Box 15830, Sacramento, California 95813; (916) 452-3211 July 3, 1981

,,g,g

.h

,7:

..+< %

{p', Jgt I?. K21 1

. n. t

- g E.d

,, vi v

/3j V'y, w; 203 ;

e t

m R H ENGELKEN, DIRECTOR xy ge-%((p REGION V 0FFICE OF INSPECTION f, ENFORCEMENT

' @N U S NUCLEAR REGULATORY COMMISSION L ' db.N \\gQ.Nl 1990 N CALIFORNIA BLVD

( h,,,

yh NLdll'/ith I WALNUT CREEK PLAZA SUITE 202 SY WALNUT CREEK CA 94596

- 7 a

~

? JUL 17 ISSiw f OPERATING LICENSE DPR-54

" Mag (**,A DOCKET NO. 50-312 y;,\\

REPORTABLE OCCURRENCE 81-33 xA 3

(/

In accordance with Technical Specification Section 6.9.4.2.b, the Sacramento Municipal Utility District hereby submits a thirty-day report of Reportable Occurrence 81-33 On June 11, with the reactor at hot standby, investigation of a

" Diesel Trouble" alarm revealed an open relay in the "A" Diesel Generator circuit. The diesel could not have started in this condition.

The relay was immediately reset.

It was not known how long the relay had been open. The open-relay condition will be moved to the " Diesel Not Ready for Auto Start" alarm, which indicates disabling conditions. This will insure immediate control room response.

A further indication of the open relay was a dropped relay target.

This is checked every shift.

Since the previous shift did not report a dropped target, and since there is no knowledge of an event, just prior to finding the open relay, which could have opened the relay, the possibility exists that the dropped target had been over-looked.

To preclude this in the future, different relay marking techniques will be investigated, to find the best available.

There were no transients or power reductions associated with this event.

3

-)

a,j[ fl /]Lai x

JJohn J'5. Mattimoe Assistant General Manager and Chief Engineer j

8107200061 810703 PDR ADOCK 05000312

.ER<in, vor. < NAN c0;,ac_

i, nf :

,r

4 ii

--[

S PDR