05000339/LER-1981-003-03, /03L-0:on 810104,casing Cool Tank Level Indication LI-RS-203B Failed High.Caused by Frozen Transmitter Due to Heat Tracing Failure.Transmitter Was Thawed Out & Redundant Heat Tracing Turned on

/03L-0:on 810104,casing Cool Tank Level Indication LI-RS-203B Failed High.Caused by Frozen Transmitter Due to Heat Tracing Failure.Transmitter Was Thawed Out & Redundant Heat Tracing Turned on

ML20009C343
Person / Time
Site:	North Anna
Issue date:	01/21/1981
From:	Cartwright W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML20009C337	List: 05000339/LER-1981-003, Forwards LER 81-003/03L-0 05000339/LER-1981-003-03, /03L-0:on 810104,casing Cool Tank Level Indication LI-RS-203B Failed High.Caused by Frozen Transmitter Due to Heat Tracing Failure.Transmitter Was Thawed Out & Redundant Heat Tracing Turned on
References
LER-81-003-03L, LER-81-3-3L, NUDOCS 8107200477
Download: ML20009C343 (2)

LER-1981-003, /03L-0:on 810104,casing Cool Tank Level Indication LI-RS-203B Failed High.Caused by Frozen Transmitter Due to Heat Tracing Failure.Transmitter Was Thawed Out & Redundant Heat Tracing Turned on

Event date:
Report date:
3391981003R03 - NRC Website

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r-d' U.S. NUCLEAR REGULAT0dY COMMISSION LICENSEE EVENT REPORT CONTROL BLOCK / / / / / / / (1)

(PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION)

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/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 TYPF CAT

/0/1/

LL/ (6)

/0/5/0/0/0/3f3/9/

(7)

/0/1/0/4/8/1/

(8) / 0/1/ 2/1/ 8/1/ (9)

UR DOCKET NUMBER EVENT DATE REPORT DATE r

EVENT DESCRIPTION AND PROBABLE CONSEQUENCES (10)

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On January 4, 1981 LI-RS-203B (Casing Cool tank level Indication) failed high. /

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With level failed high MOV-RS-200B (Casing Cooling pump discharge valve and

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and containment isolation valve) would not have closed on a low casing cooling /

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tank level. However, because MOV-RS-201B (in series with the RS-200B value)

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would close on casing cooling pump low recirc flow with a CDA signal present,

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containment isolation, i f necessary could have been maintained, and tM health /

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and safety of the public would not be affected.

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SYSTEM

CAUSE

CAUSE COMP.

VALVE CODE CODE SUBCODE COMPON.NT CODE SUBC0DE SUBCODE

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/S/B / (11) /C/ (12) /Z/ (13) /I/N/Srl'/R/U/ (14) /T/ (15)

/Z/ (16)

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

CODE TYPE NO.

(17) REPORT NUMBER

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ACTION FUTURE EFFECT SHUT.)0W ATTACHMENT NPRD-4 PRIME COMP.

COMPONENT TAKEN ACTION ON PLANT METHCD HOURS SUBMITTED FORM SUB. SUPPLIER MANUFACTURER [B/ (18) g/ (19) g/ (20) /Z/ (21) /0/0/0/0/ (22) g/ (23) /N/ (24) /A/ (25) /F/1/8/0/ (26)

CAUSE DESCRIPTION AND CORRECTIVE ACTIONS (27)

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Level indication LI-RS-203B failed high as a result of the associated trans-

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mitter freezing due to a heat tracing failure for that transmitter. The trans-/

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mitter was thawed out, redundant heat tracing turned on and the transmitter

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checked for proper operation.

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FACILITY METHOD OF STATUS

% POWER OTHER STATUS / (30pISCOVERY DISCOVERY DESCRIPTION (32)

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/E/ (28)

/1/0/0/ (29) /

NA

/A/ (31)

/ OPERATOR OBSERVATION /

ACTIVITY CONTENT RELEASED OF RELEASE AMOUNT OF ACTIVITY (35)

LOCATION OF RELEASE (36)

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/Z/ (33)

/Z/ (34)

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NA

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PERSONNEL EXPOSURES NUMBER TYPE DESCRIPTION (39)

/1/7/ /0/0/0/ (37) LZ/ (38) /

NA

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PERSONNEL INJURIES NUMBER DESCRIPTION (41)

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NA

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LOSS OF OR DAMAGE TO FACILITY (43)

TYPE

DESCRIPTION

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NA

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PUBLICITY ISSUED DESCRIPTION (45)

NRC USE ONLY

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/N/ (44)

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NA

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8107200477 810121

'.R W. R. CARTWRIGHT PHONE (703) 894-5151 PDR ADOCK 05000339 S

repW_____ _ _ __ _ _ ____ _ _._ _. _

o 9

Virginia Electric and Power Company North Anna Power Station, Unit #2

Attachment:

Page 1 of 1 Docket No. 50-339 Rcport Ne LER 81-03/03L-0

Description of Event

On January 4, 1981 LI-RS-203B (Casing Cooling Tank level indicator) failed high thereby preventing MOV-RS-200B (Castog Cooling pump discharge valve and containment isolation valve) from closing, This event is contrary to the requirements of T.S. 3.6.2.2 and 3.6.3.1, and reportable pursuant to T.S. 6.9.1.9.b.

Probable Consequences of Occurrence With LI-RS-203B out of service MOV-RS-200B (Containment isolation valve) was inoperable. However, if level would have dropped below setpoint, MOV-RS-201B (in series with MOV-RS-200B) would have closed on Casing Cooling Pump low recire flow with a CDA signal locked in.

Therefore, containment isolation if needed, would have been maintained.

In addition, LI-RS-203A provides an additional level indication for the Casing Cooling tank.

Consequently, the health and safety of the public would not be affected.

Cause of Event

LI-RS-203B failed high (therefore rendering MOV-RS-200B inoperable) as a result of the primary heat tracing circuit failing causing the associated transmitter (LT-RS-203B) to freeze due to cold outside tempera-tures.

Immediate Corrective Action

The immediate corrective action was to verify Casing Cooling tank level normal, shif t to redundant heat tracing and to thaw out LT-RS-203B.

Scheduled Corrective Action The scheduled corrective action is to repair the primary circuit of heat tracing.

A formal winterization program will be developed to insure that freeze protection equipment remains operable. The program will be implemented during the fall of 1981.

Actions Taken to Prevent Recurrence No further action required.

Generic Implications There are no generic implications to this event.