ML20040A567

LER 81-030/03L-0:on 811210,degraded Voltage Relay 27A1/B25 Found W/Voltage Setpoint Outside Allowable Band.Causes Being Considered Are Last Calibr Error & Unfamiliarity W/Time Delay Relay Characteristics

ML20040A567
Person / Time
Site:	Prairie Island
Issue date:	01/15/1982
From:	Musolf D NORTHERN STATES POWER CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML20040A562	List: ML20040A561 ML20040A567
References
LER-81-030-03L, LER-81-30-3L, NUDOCS 8201210249
Download: ML20040A567 (1)

Text

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NRC FOftM 3fs U.S. NUCLEAR REGULATORY COMMISSCN 47 77) e LICENSEE EVENT REPORT CONTROL BLOCK: l I

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61 DOCKET NUMBER 68 69 EVENT DATE 14 75 REPORT DATE 83 EVENT DESCRIPTION AND PROB ABLE CONSEQUENCES h

[ o l 2 I l During surveillance test, degraded voltage relay 27A1/B25 was found with l IoI3IL _v It.:.ge setpoint outside of the allowable band. A setpoint of 90 plus or l Io l4 l l minus 2 percent is specified. The as-found setpoint was 93 percent. The time l

[ o I s J l delay was within the specified 6 plus or minus 2 seconds. Technical Specification l 10 is I l Table TS.3.5-1 anolles. Sinflar occurrence reported ns IFR 81-026. No effect I l o l 7 l l since other relays in logic scheme would have prevented unnecessary transfer l l o is i l to alternr te source and initiated transfer when needed. l SYSTEM CAUSE CAUSE COYP.

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,,,,; ; testing. The following causes are being considered: (1) last calibration  ;

,i3l l error, (2) unfamiliarity with time delay relay characteristics. l l i l 41 1 I 7 8 9 80 STA S  % POWER OTHE R STATUS IS O R DISCOVERY DESCRIPTION s l1 l 5 ] l El@ l I l 0 l 0l@l NA l (_Bj@l Surveillance test l l A TtVITY CONTENT RE u AsED OF RELE ASF AVOUNT OF ACTIVITY LOC ATION OF RELEASE li' is "I [_Zj

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