ML19210D093

LER 79-049/03L-0;on 791014,while Operating at 63% Power, Upset in Circulator Buffer Helium Sys Caused Release of Radioactivity to Reactor Bldg & Ventilation Exhaust Stack. Caused by Leaking Velan Valve HV-21352.Valve Repaired

ML19210D093
Person / Time
Site:	Fort Saint Vrain
Issue date:	11/13/1979
From:	Gahm J PUBLIC SERVICE CO. OF COLORADO
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML19210D088	List: ML19210D087 ML19210D093
References
LER-79-049-03L, LER-79-49-3L, NUDOCS 7911200523
Download: ML19210D093 (2)

Text

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LICENSEE EVENT REPORT CONTROL BLOCK: l 1

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(PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION) 7 0 1 8 9 Cl0lFlSlV 1l@l0 0 l- l 0 l0 0 l 0 l 0 l- l0 l 0 l@l 4 l1LICENSE LICENSEE CODE 14 15 LICENSE NUMBER 25 26 l1 l2TYPE l0 40l@l57 CAT l 58 l@

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3{0R[ ,c l L l@l61 015 l 0DOCKET 60 l 0 lNUMBER 0 l 2 l 6 1768 @l63 1 l 0EVENT l1 i4 l 7 l 9 74l@l175 11 REPORT D ATE EVENT DESCRIPTION AND PROBABLE CONSEQUENCES o 2 On Octobe r 14. 1979, while operating at 63% reactor cover and 200 MW eb ctrical power i o a l an upset in the circulators buffer helium system resulted in a release of activity to l o 4 i the reactor building and the ventilation exhaust stack. No personnel received signi- l o s I ficant exposure and there was no effect on public health or safety. This is report- l o e t able pe r Fo rt S t . Vrain Technical Specification AC 7.5.2(b)4, at the request of the  ;

o T l Inspection and Enforcement Resident Inspector. l o 8 l I 80 7 8 9 DE CODE SLBC E COMPONENT CODE SLBC DE SU E 7

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41 lN [g Ajg V l0 l8 l5 lg 47 42 43 44 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS 1 o l Cause of buffer helium system problec) was a leaking valve, HV-21352, which caused I y I cross-tower leakage drver in the tower. Valve has been repaired and the system i

, 7 i modified to alleviate this problem. The valve was a Velan valve with teflon seats i 3 lwhich had failed. I i 4 l l 7 8 9 80 STA S  % POWER OTHER STATUS IS O RY DISCOVERY DESCRIPTION 1 5 E l@ l0 l 6 l 3 l@l N/A l l A l@l Operator Observation l ACTIVITY CD TENT RELEASED OF RELEASE AMOUNT OF ACTIVITY LOCATION OF RELEASE 6 l l Reactor Building Vent to Atmosphere l 7

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@ l 10M l@l110.197uCi or I-131 44 45 80 PERSONNEL EXPOSURES N U M C 't TYPE DESCRIPTION i 7 l 0 l 0 l 0 l@l Z l@l' N/A l PERSONNE L INJU' ES I b O Td _'

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R :"tEDIATE RELEASE October M,1979 CD:iTACT: Robert A. Burns (303) 759-9740 (Home)

Gary D. Reeves (303) 424-4958 (Home) fiarily McAdams (303) 777-7953 (Home)

CIRCULATOR PROBLEM SHUTS DOWN FORT ST. VPAIfi DELIVER -- Public Service Co. of Colorado announc '; Sunday that at approximately 7 a.m. Sunday the Fort St. Vrain tiuclear Generating Station near Platteville was shut down due to an operating problem in the helium circulator system.

There was a minute release of radioactivity in the reactor building. but the safety of the employees was not jeopardized and there was no meas' le release into the atmosphere. At no time was there any hazard to thi _ ..c.

Officials said present plans call for Fort St. Vrain to return to its authorized power level when the cause of the problem has been determined and recti fied. The plant is scheduled to be shut down for planned maintenance on Oct. ,20.

At the time the problem occurred, the reactor was operating at 68 percent reactor power and was producing 200 megawatts of electricity.

The fluclear Regulatory Comission in Washington, D.C. , and the Colorado Department of Health were notified of the incident.

--PSCo-- l3/j m1