05000267/LER-1979-049-03, /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

/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: 05000267/LER-1979-049, Forwards LER 79-049/03L-0 05000267/LER-1979-049-03, /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
References
LER-79-049-03L, LER-79-49-3L, NUDOCS 7911200523
Download: ML19210D093 (2)

LER-1979-049, /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

Event date:
Report date:
2671979049R03 - NRC Website

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LICENSEE EVENT REPORT CONTROL BLOCK: l l

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60 61 DOCKET NUMBER 68 63 EVENT D ATE 74 75 REPORT DATE 80 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 l an upset in the circulators buffer helium system resulted in a release of activity to l o

a i the reactor building and the ventilation exhaust stack. No personnel received signi-l o

4 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 l Inspection and Enforcement Resident Inspector.

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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 lwhich had failed.

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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.

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--PSCo--