05000339/LER-1982-017, Updated LER 82-017/03X-1:on 820413,number of Containment Isolation Valves Had Unacceptable Leak Rate.Caused by Misaligned Limit Switches on Svc Water Valves & Seating Surface Degradation or Fouling on Other Valves

Updated LER 82-017/03X-1:on 820413,number of Containment Isolation Valves Had Unacceptable Leak Rate.Caused by Misaligned Limit Switches on Svc Water Valves & Seating Surface Degradation or Fouling on Other Valves

ML20054E412
Person / Time
Site:	North Anna
Issue date:	06/02/1982
From:	Cartwright W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML20054E400	List: 05000339/LER-1982-017, Updated LER 82-017/03X-1:on 820413,number of Containment Isolation Valves Had Unacceptable Leak Rate.Caused by Misaligned Limit Switches on Svc Water Valves & Seating Surface Degradation or Fouling on Other Valves
References
LER-82-017-03X-01, LER-82-17-3X-1, NUDOCS 8206110187
Download: ML20054E412 (3)

LER-2082-017, Updated LER 82-017/03X-1:on 820413,number of Containment Isolation Valves Had Unacceptable Leak Rate.Caused by Misaligned Limit Switches on Svc Water Valves & Seating Surface Degradation or Fouling on Other Valves

Event date:
Report date:
3392082017R00 - NRC Website

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UPDATE REPORT: PREVIOUS REPORT DATE 05-10-82 U.S. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT CONTROL 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) f4/1/1/1/1/(4) / /- / (5)

LICENSEE CODE LICENSE NUMBER LICENSE TYPE CAT-0 RC / (6) /0/5/0/0/0/3/3/9/ (7) /0/4/1/3/8/2/ (8) /0 /6 /0 /2 /8 /2 / . (9)

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

/0/2/ / During Unit No. 2 Refueling Outage, Type C tests revealed that a number of con- /

/0/3/ / tainment isolation valves had an unacceptable 3eak rate. The as found leakage of/

/0/4/ / all these valves exceeded the total allowable Type C leakage of 0.60 La. Integ- /

/0/5/ / rity was maintained in all cases by the redundant valve, the steam generator, re-/

/0/6/ / circ. spray or other heat exchanger shells; therefore the health and safety of /

/0/7/ / the general public were not affected. This is contrary to T.S. 3.6.1.2 and re- /

/0/8/ / portable pursuant to T.S. 6.9.1.9.d. /

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

/0/9/ /s/A/ (11) /E/ (12) /D/ (13) /V/A/L/V/E/X (14) /X/ (15) /D/ (16)

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

) (17) REPORT

, NUMBER /8/2/ /-/ /0/1/7/ /\/ /0/3/ /X/ /-/ /1/ l ACTION FUTURE EFFECT SHUTDOWN ATTACHMENT NPRD-4 PRIME COMP. COMPONENT l TAKEN ACTION ON PLANT METHOD HOURS SUBMITTED FORM SUB. SUPPLIER MANUFACTURER

/A/ (18) /Z/ (19) /Z/ (20) /Z/ (21) /0/0/0/0/ (22) /Y/ (23) /N/ (24) /A/ (25) /X/9/9/9/ (26)

CAUSE DESCRIPTION AND CORRECTIVE ACTIONS (27)

'/1/0/ / All of the valves (except the service water butterfly valves) failed due to /

/1/1/ / degradation of the seating surfaces. The limit switches on the service water /

/1/2/ / valves were misaligned. .The valve seats were lapped, parts replaced or cleaned /

)

/1/3/ / and the limit switches adjusted to restore the leak rate to an acceptable level./

! /1/4/ / /

! FACILITY METHOD OF i

STATUS  % POWER DISCOVERY DISCOVERY DESCRIPTION (32)

./1/5/ /H/ (28) /0/0/0/ (29) OTHER NA STATUS/ (

/. /B/ (31) / TYPE C TESTING /

ACTIVITY CONTENT RELEASED OF RELEASE AMOUNT OF ACTIVITY (35) LOCATION OF RELEASE (36) i /1/6/ /Z/ (33) /Z/ (34) / NA / / NA /

' PERSONNEL EXPOSURES i 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 @3)

TYPE DESCRIPTION l

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

PUBLICITY ISSUED DESCRIPTION (45) NRC USE ONLY

'/2/0/ /N/ (44) / NA /////////////

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

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B206110187 B26502 PDR ADOCK 05000339

{ S PDR

UPDATE REPORT: Previous Report Date 05-10-82 Virginia Electric and Power Company North Anna Power Station, Unit No. 2

Attachment:

Page 1 of 2 Docket No. 50-339 Report No. LER 82-017/03X-1 Description of Event During the Unit No. 2 Refueling Outage it was determined that 24 containment isolation valves had leak rates in excess of 35 SCFH each, and one valve had a leak rate of 6 SCFH. The valves were being tested as part of the refueling type C leakage determination. The maximum type B and type C leakage allowed by T.S. 3.6.1.2 is 0.60 La which corre-sponds to a leak rate of 154 SCFH.

Probable Consequences of Occurrence Redundant isolation valves or heat exchangers provided containment integrity for all of the leaky valves. The blowdown isolation valves rely on the integrity of the steam generator shell. The component cooling valves have redundant isolation provided by the containment air coolers, the RHR heat exchangers and the excess letdown heat exchanger.

The service water valves have redundant isolation provided by the recirculation spray heat exchanger shell. The charging line check valve and the letdown trip valve provide redundant isolation for the charging stop valve and letdown orifice valves respectively.

The containment purge and exhaust isolation valves were Type C tested satisfactorily prior to the present outage. The failed test occurred after the valves had been opened and flowed for 2 months. The seats were cleaned and all of these valves were tested satisfactorily.

All valves had redundant isolation during operation; therefore, the health and safety of the general public were not affected.

Cause of Event The cause of valve leakage was due to seating surface degradation or fouling for all valves except the service water valves. The service water valves had excessive leakage due to misaligned limit switches.

Immediate Corrective Action The valve seats were lapped, parts replaced or cleaned and the limit switches were adjusted to restore the leak rate to an acceptable level.

Scheduled Corrective Action No further corrective action is scheduled.

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Attachment:

Page 2'of 2~

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- Actions Taken to Prevent Recurrence

!. No-further action is required.

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Ceneric Implications-

. There are no generic implications associated with this event. >

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