ML19347E319

LER 81-018/03L-0:on 810329,power Operated Relief Valves Lifted to Limit Overpressure Condition Due to Safety Injection.Caused by Inadvertent Blocking of Low Pressurizer Pressure Safety Injection Signal During Train B Testing

ML19347E319
Person / Time
Site:	North Anna
Issue date:	04/20/1981
From:	Cartwright W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML19347E317	List: ML19347E316 ML19347E319
References
LER-81-018-03L-02, LER-81-18-3L-2, NUDOCS 8104240567
Download: ML19347E319 (2)

Text

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,q U.S. NUCLEAR REGULATORY COMMISSION Q LICENSEE EVENT REPORT g CONTROL BLOCK / / / / / / / (1) (PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION)

([1f, /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

/0/1/ /L/ (6) /0/5/0/0/0/3/3/8/ (7) /0/3/2/9/8/1/ (8) /o/4/2/o/8/1/ (9)

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

/0/2/ / On March 29, 1981, with Unit I in Mode 5, both power operated relief valves /

/0/3/ / (PORV) lifted in order to mitigate a reactor coolant system pressure transient /

/0/4/ / caused by an inadvertant safety injection while operating in solid plant condi- /

/0/5/ / tions. Since the operation of the relief valves, the resetting of safety injec- /

/0/6/ / tion and the subsequent lowering of RCS pressure below setpoint prevented an over/

/0/7/ / pressure condition from continuing, the public health and safety were not affect-/

/0/8/ / ed. This item is reportable per T.S. 6.9.2 as required by T.S. 3.4.9.3. /

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

/0/9/ /C/J/ (11) /A/ (12) /A/ (13) /V/A/L/V/E/X/ (14) /F/ (15) /B/ (16)

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

(17) REPORT NUMBER /8/1/ /-/ /0/1/8/ /\/ /0/3/ /L/ /-/ /0/

' ACTION FUTURE EFFECT SHUTDOWN ATTACHMENT NPRD-4 PRIME COMP. COMPONENT TAKEN ACTION ON PLANT METHOD HOURS SUBMITTED FORM SUB. SUPPLIER MANUFACTURER M / (18) /G/ (19) /Z/ (20) /Z/ (21) /0/0/0/0/ (22) /Y/ (23) /N/ (24) /N/ (25) /W/1/2/0/ (26) b CAUSE DESCRIPTION AND CORRECTIVE ACTIONS (27)

-~ '

/1/0/ / This event was caused by an inadvertant unblocking of the low pressurizer /

/1/1/ / pressure safety injection signal during Train B solid state protection testing. /

/1/2/ / The Boron Injection Tank discharge was stopped, the safety injection signal /

/1/3/ / was reset, and RCS pressure was reduced below PORV setpoint. /

/1/4/ / /

FACILITY METHOD OF STATUS  % POWER OTHER STATUS DICC0VERY DISCOVERY DESCRIPTION (32)

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

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) /ZL (38) / NA /

PERSONNEL INJURIES NUMBER DESCRIPTION (41)

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

LOSS TYPE OF OR DAMAGE TO FACILITY (43)

DESCRIPTION

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

PUBLICITY ISSUED DESCRIPTION (45) NRC USE ONLY i~ p!0/

t [NL(44) / NA /////////////

NAME OF PREPARER W. R. CARTWRIGHT PHONE (703) 894-5151 8184240562

O virsinie E1ectric end eewer CemPenv North Anna Power Station, Unit 1

Attachment:

Page 1 of 1 Docket No. 50-338 Report No. LER 81-018/03L-C Description of Event On March 29, 1981, with Unit I in mode 5, the Reactor Coolant System power operated relief valves lifted in order to limit an over-pressure condition caused by a safety injection while operating in solid plant conditions.

Probable Consequences of Occurrence Since the power operated relief valves acted promptly and without failure to mitigate the RCS pressure transient, the public health and safety was not affected.

Cause of Event -

This event was caused by an inadvertant unblocking of the low pressurizer pressure safety injection signal during Train "B" Solid State Protection testing. Prior to restoring Train B from " Test" to

" Normal", the operator was instructed to go to go to " Block" on both Train A and B block switches. In response to this instruction, the i operator noticing that he did not have his block status light went to b ~

" reset" first and then " Block". Going to reset on Train A resulted in removing the block on Train A resulting in a safety injection on Train A only.

j Immediate Corrective Action The initial action taken was to stop safety injection through the Boron Injection tank, to reset the safety injection signal, and to take

.unual control of pressure in order that RCS pressure would be reduced to below the pressure required for lifting of the relief' valves.

Scheduled Corrective Action No scheduled corrective action is required.

l Actions Taken to Prevent Reccurrence l

Periodic surveillance test (PT-36.1) will be revised to caution the operator that with the output cabinet in either Train in the " Test" position, the safety injection block status light will not be lit.

Generic Implications There are no generic implications to this event.

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