ML20086B453

AO 50-267/74-11:on 740625,gas Waste Release 50 Took Excessive Length of Time & Flow Continued from Receiver Outlet Valve B Leak When Receiver a Empty.Caused by Defective Isolation Valve B.Second Valve Will Be Installed

ML20086B453
Person / Time
Site:	Fort Saint Vrain
Issue date:	07/05/1974
From:	Brey H, Rodgers W PUBLIC SERVICE CO. OF COLORADO
To:
Shared Package
ML20086B449	List: ML20086B446 ML20086B452 ML20086B453 ML20086B459
References
AO-50-267-74-11, NUDOCS 8311170237
Download: ML20086B453 (2)

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, 'DATE :' .101v i 1974 ABNOPJIAL OCCURRENCE FORT ST. VRA1:I UUCLEAR GE:!CRKrI::G STAT 10:1 PUl!1.1C SERVICE CO:!PA:;Y OF COLORid)0 P. O. E0X 361 PLATTEVILLE, COLORADO 80651 REPORT MO. 50-267/74/11 Preliminary 3DENTIFJ CATIO:10F OCCURRENCE:

The foJ1oving in considered nn Abnorcal Occurrence under definition of 2.1 e of the Technical Specifications.

On 6/25/74 under gan vante release nunber 50 it was not.cd that the release took an excessive length of tine and when the A receiver was empty flow continued from a leak through the E receiver outlet valve.

CONDIT]O:iS PRIOR TO OCClJRRE:CE: Stea'y State Power Routine Shutdown Hot Shutdown Routine Lcad Change Cold Chutdown' X Other (specify)

Refueling Shutdown Prior to low power Routine Startup physics tests A-9 The major plant parameters at the time of the event were as follous:

Power PTR, N/A 107th ELECT, n/A In?c Secondary Coolant Pressure N/A pois ,

Temperature  ;@ *F Flou  ;@ #/hr.

Primary Coolant Pressurc 0 psig Temperature 135 *F Core Inlet l

! 135 F Core Outlet l 8311170237 PDR ADOCK 74102205000267 PDR g Flov 0 #/hr.

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l' age 2 *

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, , 1 1)ESCRIPTIO!! OP OCCURRENCE: el On 6/25/74 gas vacte release number 50 from the A receiver was clarted  ?

.at 0100 and this receiver uan not capty until 0045 on 6/28/74. The t 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> period in too long for a release of the tank volume at the controlled rato of 15 actu. Uith the A receiver enpty and isolated a ,

flow of 4 acfm van indicated on FT-6351 flow transuitter. Th!n indicated ,

a leakage from the B receiver. Plant trouble repart 6-395 was written on the ,

' valve Icakage. Tank analynis showed no radioactive naterial was releaced. +

APPARENT CAUSP.

OF OCCURRENCl:- Design Unucual Service Cond. -

Including Environ.

Manufacturc X Component Failure c Installation / __ Other (specify)

~

Const. , p Operator Procedure  ;

t On 7/3/74 the B gas waste receiver outlet isolation valve van dismantled .

and it was found to be defective, cauning the J eahage. E t.

AMAINSIS OF ocCU!un:nCI:- '

Analysia of the system shovs that the valve 1cahage could not be determined, using the Syntca Operating Procedure .as written, until the "A" receiver vcs cupty. No radioactive material was present in the B receiver.

CORRECTIVI: ACTIO:I:

A second isolation valve will be added to each gas waste receiver outlet i_

wit h a vent valve from the innerspace which venta to the vacuum tank. I Thiu will assure that no 1;as can Icak from a tank to the vent system. .

A change in SOP-63 will assure that FT-6351 shows no flow prior to the  !

start of the discharge. <

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,P/AILURE DATA /STMILAR REPORTED OCCURRENCES (

None l t

I j PROCRAM:1ATIC IMPACT I

, f No programmatic impact expected. l CODE IMPACT . }

y None .

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W. Duanc Rodgers, operations Supv.

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o Operations H.LarryBrey{ Supt.

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