05000220/LER-1981-004, Forwards LER 81-004/01T-0

Forwards LER 81-004/01T-0

ML17053C372
Person / Time
Site:	Nine Mile Point
Issue date:	02/20/1981
From:	Lempges T NIAGARA MOHAWK POWER CORP.
To:	Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML17053C373	List: 05000220/LER-1981-004, Forwards LER 81-004/01T-0 05000220/LER-1981-004-01, /01T-0:on 810209,main Steam Radiation Monitor 111 Signal Fluctuated,Causing Multiple Half Scrams.Caused by Loose detector-to-cable Connector.Connector Tightened
References
NMP-2890, NUDOCS 8103030753
Download: ML17053C372 (4)

LER-1981-004, Forwards LER 81-004/01T-0

Event date:
Report date:
2201981004R00 - NRC Website

text

e NWP-2890 NIAGARAMOHAWKPOWER CORPORATION/300 ERIE BOULEVARDWEST, SYRACUSE, N.Y. 13202/TELEPHONE (315) 474-1511 Feb/uuvry 20, 1981 N.. Boyce H. GJIi.et',

Mn,e&o/L Unbred S~es Nu&ea/L Regulator/

Commission.

Region I 631 Put% Avenue.

G'.ng of P~akx, Pennsylvania 19406 RE:

17ock& No. 50-220 LER 8.L-04

@~~ EjPgp gears hh,.

G/Ii.e/L:

In accordance eu".h N~ne NLe Pokunt Nuclea/L S~n U~ <1 Technical Speci,)~~ow, we he/Leby submit Che (ollowing Liceruee Eveet RepoM:

LER 81-04 wMch m be ng sub~ed in acco/cdance ~h

'Se~on

6. 9. 2a,(2), op~on o$ Che ueLt o/I.

a((ec4.'ed agCene when any paruunMe/L o/I, op~on 6ubj'e& Co a Liming concKtionke luh conee/Lva-Wve Chan Che l~C conte/Ivative aepeM o( Che Lining con~on (o/L operation m&bLQ hed in Che Cechru'.cal apen.P~ru TRQ rcepoM wm complied in Che Jotunn deeigna4.'ed in NUREG-01 6 1, dated July 1977.

Ve/U/ ~y yo~,

Thomas E.

Lempge6 Vice Pau~deef:

Nucl~ Gen~on PAH:jl Attachme~

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Nrce&o/L, 0)g.ce o$ ISE (30 copiu)

Vme&o/L, 0)gce o) MIPC (3 copi.u)

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LER 81-04 DOCKET NO. 50-220 0

ATTACHMENT ADDITIONAL INFORMATION This occurrence was initially discovered during the same day by manage-ment review of a jumper/block log sheet which indicated that a block had been installed in the RPS actuation relay for the purpose of check-ing out the detector cable while the associated Trip System was left in the untripped condition.

The NRC Region I office was immediately noti-fied by telephone that the Technical Specification governing the Main Steam Radiation Monitoring Instrument Channel/Trip System operability requirements had been violated.

The following day a telecopy report was submitted as required, which provided details of the occurrence.

Further management review of the occurrence has revealed that the SSS expected at the time that the troubleshooting effort would lead to an Instrument Channel calibration, which would allow the monitor to be made inoperable.

The SSS then granted permission to install the relay block, based on operator judgment that a faulty instrument and/or cable was causing the spurious half scrams, and that further half scrams and RPS relay actuations caused by the trouble shooting and calibration effort could result in unnecessary wear and damage to the relay mechanisms.

A manual half scram should have been inserted in Trip System 11 prior to placing the relay block in order to satisfy Technical Specifications operability requirements.

Previously mentioned steps are being taken to make all Operations and Instrument 6 Control personnel aware of this requirement.

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