05000312/LER-1981-057, Forwards LER 81-057/03L-0.Detailed Event Analysis Submitted

Forwards LER 81-057/03L-0.Detailed Event Analysis Submitted

ML20039F007
Person / Time
Site:	Rancho Seco
Issue date:	12/23/1981
From:	Mattimoe J SACRAMENTO MUNICIPAL UTILITY DISTRICT
To:	Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML20039F008	List: 05000312/LER-1981-057, Forwards LER 81-057/03L-0.Detailed Event Analysis Submitted 05000312/LER-1981-057-03, /03L-0:on 811208,reactor Protection Channel C Found Indicating 15 Psi Higher than Channels A,B & D. Apparently Caused by Transmitter Failure.Investigation Continuing & Channel C Bypassed
References
NUDOCS 8201110715
Download: ML20039F007 (1)

LER-1981-057, Forwards LER 81-057/03L-0.Detailed Event Analysis Submitted

Event date:
Report date:
3121981057R00 - NRC Website

text

r-F.4suun SACRAMENTO MUNICIPAL UTILITY DISTRICT O 6201 S Street. Box 15830, Sacramento, California 95813; (916) 452-3211 December 23, 19P1 c

s.3 s/.

y, s R H ENGLEKEN, ADMINISTRATOR

^ '

I/]

j REGION V 0FFICE OF INSPECTION & ENFORCEMENT U S NUCLEAR REGULATORY COMMISSION 1'

m

4 i

i 1450 MARIA LANE SUITE 210 k r" WALNUT CREEK CA 94596

(" -

f

'/

s b

j y

,x hr u 4a.30-312 N ' '~ f y

'- ~

Lit'U4SE N0s OPR-54 REPORTABLE OCCURRENCE 81-57 in accordance wi th Rancho Seco Nuclear Ge% rating Station Technical Specifications Section 6.9.4.2a and Regulatory Guide 1.16 Section C.2.b. (1), the Sacramento Municipal Ut ili ty Dist rict i s subrei t t i ng the fo' lowing 30-day report of Reportable Occ.2rrence 81-57 On December 8, 1981, Reactor Protection Channel C was found to be indicating approximately 15 psi higher than Channels A, B, and D.

This was recognized as a possible zero shift on the transmitter so the channel was bypassed and Instrument Test 1-116, RPS Pressure Drift Test, was performed on December 9, 1981.

Baseline data on Channel C had been obtained on December 7, 1981.

Comparison of tha data confi rmed the dri f t on Channel C.

At that point it was considered possible that the Channel C t ransmi t ter had failed.

Channel C was therefore administratively declared inoperable and lef t in bypass.

Engineering investigation will continue on ttis problem, however, containment entry is requi red to make a final determination of transmitter status.

Cntry will be deferred until the next scheduled outage, at which time final resolution of this t ransmi tter p roblem wiil be made.

The transmitter is a Westinghouse Pressure Transmitter Mode 1 59PH.

Technical Speci ficat ions Sect ion 3.5.1.2 provides for cont inued oper-ation with one channel bypassed, which results in a two-out-of-three logic.

~1 No transients resulted from this event, nor was plant or public safdty 4e ed.

R I

8201110715 811223 t'

f I

)

hDRADOCK 05000312 9

I

')%

43p'@

, Fj' PDR o

,o John J. M.t imoe 5

6 Assistant' eneral Manager 73 l!

and Chief Engineer cc:

ISE Washington (30), MIPC (3), INP0 J E E / ! N,7 YO'>

THAN 50t.000 IN THt HEART OF CAtIFORNiA AN CLECTPIC SY3Tl