05000338/LER-1981-008-03, /03L-0:on 810117,steam Generator a Protection Channel 2 Narrow Range Level Transmitter LT-1475 Found Out of Calibr.Caused by Voltage Drift in Level Transmitter Serving Instrument Loop.Recalibr & Returned to Svc

/03L-0:on 810117,steam Generator a Protection Channel 2 Narrow Range Level Transmitter LT-1475 Found Out of Calibr.Caused by Voltage Drift in Level Transmitter Serving Instrument Loop.Recalibr & Returned to Svc

ML19343C084
Person / Time
Site:	North Anna
Issue date:	02/11/1981
From:	Cartwright W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML19343C057	List: 05000338/LER-1981-008, Forwards LER 81-008/03L-0 05000338/LER-1981-008-03, /03L-0:on 810117,steam Generator a Protection Channel 2 Narrow Range Level Transmitter LT-1475 Found Out of Calibr.Caused by Voltage Drift in Level Transmitter Serving Instrument Loop.Recalibr & Returned to Svc
References
LER-81-008-03L-01, LER-81-8-3L-1, NUDOCS 8102180569
Download: ML19343C084 (2)

LER-1981-008, /03L-0:on 810117,steam Generator a Protection Channel 2 Narrow Range Level Transmitter LT-1475 Found Out of Calibr.Caused by Voltage Drift in Level Transmitter Serving Instrument Loop.Recalibr & Returned to Svc

Event date:
Report date:
3381981008R03 - NRC Website

text

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U.S. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT l

CONTROL BLOCK / / / / / / / (1) (PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION)

/0/1/

/V/A/N/A/S/1/ (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 [L/(6)

/0/5/0/0/0/3/3/8/

(7)

/0/1/1/7/8/1/ (8) /o/2/1/1/8/1/_ (9)

DOCKET NUMBER EVENT DATE REPORT DATE EVENT DESCRIPTION AND PROBABLE CONSEQUENCES (10) 1

/0/2/

/ On January 17, 1981 while in refueling mode, "A" steam generator protection chan-/

I

/0/3/

/ nel II narrow range level transmitter LT-1475 was found to be out of calibration /

/0/4/

/ low. Worst case would have caused indicator to read 2.7% lower than actual resul-/

/0/5/

/ ting in delayed turbine trip and feedwater isolation signals on Hi-Hi level for /

/0/6/

/ that channel.

Because redundant narrow range level instrumentation was either

/

j

/0/7/

/ operational or in the tripped condition, the health and safety of the general

/

/0/8/

/ public were not affected. This event is reportable pursuant to T.S. 6.9.1.9.a

/

1 SYSTEM

CAUSE

CAUSE COMP.

VALVE CODE CODE SUBCODE COMPONENT CODE SUBCODE SUBCODE i

/0/9/

/I/B/ (11) /E/ (12) [EL (13) /I/N/S/T/R/U/ (14) [T/ (15)

[Z/ (16)

SEQUENTIAL OCCURRENCE REPORT REVISION 3

LER/R0 EVENT YEAR REPORT NO.

CODE TYPE NO.

(17) REPORT NUMBER

/8/1/

[-L /0/0/8/

/\\/

/0/3/

[Lf,

/-/

[0]

ACTION FUTURE EFFECT SHUTDOWN '

ATTACHMENT NPRD-4 PRIME COMP. COMPONENT-TAKEN ACTION ON PLANT METHOD HOURS SUBMITTED FORM SUB. SUPPLIER MANUFACTLTER [E[ (18) [2[ (19) [Z[ (20) /Z/ (21) /0/0/0/0/ (22) LY/ (23) [N[ (24) /N/ (25) /R/3/6/9/ (26) i l

CAUSE DESCRIPTION AND CORRECTIVE ACTIONS (27)

/1/0/

/ The cause of the error in indication was a voltage drift in the level transmitter /

/1/1/

/ serving the instrument loop. The channel was satisfactorily recalibrated and

/

/1/2/

/ returned to service.

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/1/3/

/

/

/1/4/

/

/

FACILITY METHOD OF j

STATUS

% POWER OTHER STATUS DISCOVERY DISCOVERY DESCRIPTION (32)

/1/5/

/H/ (28)

/0/0/0/ (29) /

NA

/ (30) /B/ (31) / Periodic Surveillance /

t ACTIVITY CONTENT RELEASED OF RELEASE AMOUNT OF ACTIVITY (35)

LOCATION OF RELEASE _(36)

{

/1/6/

/Z/ (33)

/Z/ (34) /

NA

/

/

NA

/

PERSONNEL EXPOSURES 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

/

LOSS OF OR DAMAGE TO FACILITY I' )

TYPE

DESCRIPTION

/1/9/

-[Z] (42) /

NA

/

PUBLICITY t

' ISSUED DESCRIPTION (45)

NRC USE ONLY

/2/0/

[NL (44) /

NA

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NAME OF PREPARER W. R. CARTWRIGHT PHONE

-(703) 894-5151 810278056,7

Virginia Electric and Power Company North Anna Power Station, Unit 1 Attachment: Page 1 of 1 Docket No. 50-338 Report No. LER 81-008/03L-0

Description of Event

On January 17, 1981, with the unit in Mode 6, "A" steam generator protection II narrow range level transmitter LT-1475 was found to be out of tolerance low by as much as 108 mvde during periodic surveillance of the channel. This event is contrary to T.S. 3.3.2.1 and reportable pursuant to T.S. 6.9.1.9. a.

Probable Consequences of Occurrence The out of calibration condition would have resulted in a high-high steam generator level turbine trip and feedwater isolation signal at a level 2.7% higher than normal setpoint. The low and low-low level reactor trip functions were not adversely affected because they would have occurred earlier and thus be more conservative. High-high level turbine trip and feedwater isolation emanates from 2 of 3 steam generator narrow range level channels. Because redundant narrow range level protection channel III remained operable and channel I was either operable or in the tripped condition (See LERs 80-97 and 80-100/03L-0), the public health and safety were not affected.

Cause of Event

The cause of the channel being out of calibration was voltage drift in level transmitter LT-1475

Immediate Corrective Action

The level channel was recalibrated, satisfactorily checked, and returned to service.

Scheduled Corrective Action No scheduled corrective action is required.

Actions Taken to Prevent Reccurrence No further actions are required.

Generic Implications There are no generic implications associated with this event.