ML19351F582

LER 80-096/03L-0:on 801208,power Supply to PQ-2475 in Steam Generator 1A Steam Pressure Channel III Reading Low.Caused by Instrument Drift.Power Supply Recalibr

ML19351F582
Person / Time
Site:	North Anna
Issue date:	01/06/1981
From:	Cartwright W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML19351F577	List: ML19351F576 ML19351F582
References
LER-80-096-03L, LER-80-96-3L, NUDOCS 8101130539
Download: ML19351F582 (2)

Text

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• U.S. NUCLEAR REGULATORY CorffISSION LICENSEE EVENT REPORT C0hTROL BLOCK / / / / / / / (1) (PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION)

/0/1/ /V/A/N/A/S/2/ (2) /0/0/-/0/0/0/0/0/-/0/0/ (3) /4/1/1/1,1 (4) / / / (5)

LICENSEE CODE LICENSE NUMBER LICENSE TYPE CAT

/0/1/ /L/ (6) /0/5/0/0/0/3/3/9/ (7) /1/2/0/8/8/0/ (8) /o/1/o/6/8/1/ (9)

DOCKET NUMBER EVENT DATE REPORT DATE EVENT DESCRIPTION AND PROBABLE CONSEQUENCES (10)

/0/2/ / On December 8, 1980 while in Mode 3 operation, the power supply to PQ-2475 in /

/0/3/ / the Steam 'ienerator 1A Steam Pressure Channel III was reading 112 mvde low. /

/0/4/ / Since the remaining channels functioned properly and the unit was in Mode 3 /

/0/5/ / operation, the health and safety of the public were not affected. This event /

/0/6/ / is reportable pursuatt to T.S. 6.9.1.9.a. /

/0/7/ / /

/0/8/ / /

SYSTEM CAUSE CAUSE COMP. VALVE CODE CODE SUBCODE COMPONENT CODE SUBCODE SUBCODE

/0/9/ /I/B/ (11) /E/ (12) /G/ (13) /I/N/S/T/R/U/ (14) g/ (15) g/ (16)

SEQUENTIAL OCCURRENCE REPORT REVISION LER/R0 EVENT YEAR REPORT NO. CODE TYPE NO.

(17) REPORT NUMBER /8/0/ /-/ /0/9/6/ /\/ /0/3/ /L/ /-/ $/

ACTION FUTURE EFFECT SHUTDOWN ATTACHMENT NPRD-4 PRIME COMP. COMPONENT TAKEN ACTION ON PLANT METHOD HOURS SUBMITTED FORM SUB. SUPPLIER MANUFACTURER

[E/ (18) /Z/ (19) /Z/ (20) /Z/ (21) /0/0/0/0/ (22) g/ (23) /N/ (24) /N/ (25) /W/1/2/0/(26)

CAUSE DESCRIPTION AND CORRECTIVE ACTIONS (27)

/1/0/ / This event was caused by instrument drift. The power supply was recalibrated, /

/1/1/ / tested and returned to service. -

/

/1/2/ / /

/1/3/ / /

/1/4/ /_ /

FACILITY METHOD OF STATUS  % POWER OTHER STATUS DISCOVERY DISCOVERY DESCRIPTION (32)

/1/5/ [B/ (28) /0/0/0/ (29) / NA / (30) /B/ (31) / Operator Observation /

ACTIVITY CONTENT RELEASED OF RELEASE AMCUNT OF ACTIVITY (35) LOCATION OF RELEASE (36)

/1/6/ [ZL (33) [Z[ (34) / NA / / NA /

PERSONNEL EXPOSURES l NUMBER TYPE DESCRIPTION (39)

/1/7/ /0/0/0/ (37) /Z/ (38) / '

NA /

PERSONNEL INJURIES NUMBER DESCRIPTION (41)

/1/8/ /0/0/0/ (40) / NA /

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LOSS TYPE OF OR DAMAGE TO FACILITY (43)

DESCRIPTION

/1/9/ /Z/ (42) / NA /

PUBLICITY ISSUED DESCRIPTION (45) NRC USE ONLY

/2/0/ g[ (44) / NA /////////////

NAME OF PREPARER W. R. CARTWRIGHT PHONE (703) 894-3151 8 3 0 ~

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Vir:; inia Electric and Power Company North Anna Power Station, Unit 2

Attachment:

Page 1 of I Docker No. 50-339 Report No. LER 80-096/03L-0 Description of Event On December 8, 1980, it was discovered that the PQ-2475 non-isolated power supply was reading 112 avde low. In addition, the isolated power supply was found to be 104 mvde low. A loop calibration was performed which indicated that the NLP card was reading low creating the low voltages throughout the circuit.

Probable Consequences of Occurrence The low voltage from the non-isolated power supply (112 mvde) would have caused the P1 signal to read 15.68 psig higher than desired. The low voltage from the isolated power supply (104 mvde) would have caused the indicator and the computer to indicate 14.65 psig lower than actual pressure. Since the remaining pressure channels were functioning properly, the consequences of this event are negligible.

Cause of Event This event was caused by instrument drift in the NLP card.

Immediate Corrective Action The circuit was recalibrated, tested and returned to service. In addition the periodic test was performed to verify the corrective action (2-PT-32.6.2).

Scheduled Corrective Action No further action required.

Actions Taken to Prevent Reccurrence No further action required.

l Generic Implications l

There are na generic implications associated with this event.

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