ML19321A718

LER 80-016/03L-0:on 800621,during Startup & Shutdown,Valve 1-203-2C Failed to Close While Testing.Caused by Improper Adjustment of Exhaust Restrictor on Pilot Valve.Pilot Valve Dismantled & Adjusted

ML19321A718
Person / Time
Site:	Quad Cities
Issue date:	07/21/1980
From:	COMMONWEALTH EDISON CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML19321A714	List: ML19321A713 ML19321A718
References
LER-80-016-03L-03, LER-80-16-3L-3, NUDOCS 8007240109
Download: ML19321A718 (2)

Text

NRC FoR?.13GG U.S. MuCLEAR REGULATORY CCM.%iS33oN (7 77) .

1.lCENSEE EVENT REPORT

~_ CONTROL'sLOCx: l l l l 1 l l@ (PLEASE PRINT OR TYPE ALL REQl' IRED INFORMAT1oN)

@ l8l9l L lLICENSEE 7 Q l ACOOEl D l 1 l@15l0 l0 LICENSE 14 l0 l- NUf.itlER l0 l0 l0-l- l0 25l0. l0l@l4l1l1l1l1l@l 26 LICENSE TYPE J0 l

57 CAT SJ l@

CON'T -

IoI*I 3 [j"J l L ]@l 0 l 5 l0 l0 10 l2 l 5 l4 l@l0 16 l 2 l 1 l 8 l 0 }@l75017REPORT

~4 l 2 lDATE 1 l 8 l080l@

> 8 60 61 DOCKET NUMSER 68 69 EVENT DATE EVENT DESCRIPTION AND PROBABLE CONSEQUFNCES h Al On June 21, 1980, with Unit I in startup and on July 3,1980, with Unit 1 in shut- I 4

down, valve 1-203-2C failed to close while testing. Consequences were minimal l io i3i g o i4 i l because valve l-203-IC would have supplied the required isolation had the need ]

IOIsl l risen. ]

10161l I 10171 I I IO ta i l 60 l

7 8 9 E OE SUSC i COMPONENT CODE SUSC dE SU E 10191 l C l o l@ [A_j@ lC l@ l V l A l L lV l0 lP l@ l Dl@ 20W @

7 8 9 to 11 12 13 18 19 sEOUENTIAL OCCUR R ENCE REPORT REVislON LE R!HO EVENT YEAR REPCRT NO. COOE TYPE N O. ,

@ PE [8 l0 l l_l 23 l 0l1l 6l 24 26 l ,,,, -l 27 l0 l3 l 28 23 lLl 30 l-l 31 l0l 32 J

_ 21 22 fd'es '#CIYs #!ET ""FEIT SOURS ^VE"TVls' s ,#"W8. '"el'PSTP "'

uff#fCTJn'ER

{j@lG l@

3J 34 lZ 3a l@ l36Z l@ l0l0l 31 040@llY di 0l@l l42N l@ l43Nl@ lA 4

l6 l1 l347l@

CAUSE DESCRIPTION AND CORRECTIVE ACTIONS h lilc l l The cause of both occurrences was an improper adjustment of the exhaust restrictor l ii iii ; on the pilot valve resulting in a pneumatic lock which prevented the main valve i

,, ,,,; from closing. The pilot valve was dis.1antled and properly adjusted. Procedures l are being revised to detect this type of failure. , g

,,,3, iitei l l

'sT'2N7s* asPowER . OTHER status b 6' '*isEOEv' OisCOveRy DE:CRiPTiON l i i r, j l F l@ l 03 0l0l@l NA l lAl@l Shutdown to Hot Standbv l ACrivnv CO3rENr PELEA:Eo OFRELEAsE LOCATION OF RELEASE @

l_1,[ G j [_Z_j @ [Z_j g l 8 9 10 AuOUnT NA Or ACTiviTv 44 l

45

@l NA 80 l

7 11 ,

PcHSONNEL EXPOSURES j

. NU?.*a f A -

TYPE DESCRIPTION t

l i l i l l0 l0 l0l@lZl@l l Pin 50!'NEL #Njg IES

'.u'J P E D DESOftlPTIO*4 l1 ! .. l l 0 l 010 lgl NA l 1 - , 11 17 L75 Mi G' Oil DA'JAGE TO FACILI Tv ~

, UEscnteTION HA l l t l 9 l l .Z lgl _ l 7 e <. io s3

'I u $h.nariON O 8Oggg / , """ {S [ ,,g

' r. e ,' . sn . es ca n.;

i.'v--,-. ;G4-6c.4-0241. 'cxt . 178

l.- LER NUMBER: 80-16/03L

11. LICENSEE NAME: Commonwealth Edison Company 4.ad-Cities Nuclear Power Station 111. FACILITY NAME: Unit One IV. DOCKET NUMBER; 050-254 V. EVENT DESCRIPTION:

On June 21, 1980, Unit One was in startup and in the process of maintaining a hot standby condition. While attempting to close valve 1-203-2C the valve gave a dual indication. Upon further investigation it was found that the valve had not closed. Work Request Q06091 was written to correct the problem.

On July 3,1980, Unit One was shutdown for a minor maintenance outage.

While attempting to close the outboard main steam isolation valves as part of a Out-Of-Service procedure it was found valve 1-203-2C did not

'close. Work Request Q06354 was written to correct the problem. In both cases, the valve closed when the air supply to the valve was shut.

VI. PROBABLE CONSEQUENCES OF THE OCCURRENCE:

The consequences of this occurrence are minimal because valve 1-203-lC which is an in-line isolation valve, would have supplied the required isolation had the need risen.

Vll. .CAUSE: ,

The cause of both occurrences was an improper adjustment of the exhaust restrictor on the pilot valve. This blocked the exhaust flow resulting in a pneumatic lock on the pilot valve which prevented the main valve from closing. The valves have closing time requirement of three to five seconds and are adjusted externally to meet this requirement. It seens an operator closed dnwn on this exhaust restrictor when he was sent to reset the valve c'osure timing. The valve would work as required until it was exercised using the test switch. This locked up the operator pilot and prevented closure. After the June 21 incident maintenance was done replacing the 4-way control valve. The valve .:as then tested and proven operable. Later after using the test switch the second occurrence of July 3 took place.

Vill. CORRECTIVE ACTION:

Following the July 3 incident the p~oper maintenance was performed. The pilot valve was dismantled from the valve and the exhaust restrictor was adjusted to the prope'r setting. A similar incident of the type occurred February 24,_1980, on valve 1-203-1B. Procedures are being revised to detect this type of failure. The valve will be operated using the control switch following opecation by the test swi tch. l I

I E ,

e

,k' E l