ML20028G275

Forwards LER 82-053/03L-0.Detailed Event Analysis Encl

ML20028G275
Person / Time
Site:	Fort Saint Vrain
Issue date:	01/28/1983
From:	Warembourg D PUBLIC SERVICE CO. OF COLORADO
To:	Jay Collins NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML20028G276	List: ML20028G275 ML20028G283
References
P-83035, NUDOCS 8302070584
Download: ML20028G275 (4)

Text

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r publie S'rViee (Ompany 00' (dOMd@

.- 16805 Road 19 1/2, Platteville, Colorado 80651-9298 f

l January 28, 1983 Fort St. Vrain Unit tio. 1 i

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Mr. John T. Collins, Regional Administrator -

Region IV i* fluclear Regulatory Commission i

611 Ryan Plaza Drive Suite 1000 l Arlington, Texas 76011

Reference:

Facility Operating License 7 flo. DPR-34 Docket flo. 50-267 l

Dear Mr. Collins:

i Enclosed please find a copy of Reportable Occurrence Report

flo. 50-267/82-053, Final, submitted per the requirements of Technical

Speci fication AC 7.5.2(b)2.

i Also, please find enclosed one copy of the Licensee Event Report for Reportable Occurrence Report flo. 50-267/82-053.

Very truly yours, f). , w . k sy l yv 7 2f m a.r a Don Warembourg N ,ager, fluclear Production DW/cis i Enclosure l cc: Director, MIPC D

0 8302070504 030120  ;

PDR ADOCK OSOOO S

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, REPORT CATC; January 28,19c3 REPORTABLE OCCURRENCE 82-053 ISSUE O OCCURRENCE DATE: December 29, 1982 Page 1 of 3 d

FORT ST. VRAIN NUCLEAR GENERATING STATION .

PUBLIC SERVICE COMPANY OF COLORADO 16805 WELD COUNTY ROAD 19 1/2 PLATTEVILLE, COLORADO 80651-9298 REPORT NO. 50-267/82-053/03-L-0 Final i

1 IDENTIFICATION OF OCCURRENCE:

On December 29, 1982, at 2200 hours0.0255 days <br />0.611 hours <br />0.00364 weeks <br />8.371e-4 months <br />, the pressure in the fuel storage wells slightly exceeded atmospheric pressure and remained above atmospheric pressure until about 0800 hours0.00926 days <br />0.222 hours <br />0.00132 weeks <br />3.044e-4 months <br /> on December 30, 1982.

Since eleven irradiated fuel elements were in one of these wells at i the time, this constitutes a degraded mode of LCO 4.7.3(c) and is I

reportable per Fort St. Vrain Technical Specification AC 7.5.2(b)2.

i j EVENT DESCRIPTION:

To prevent oxidation of irradiated fuel, the fuel storage wells are maintained under a dry helium atmosphere at oc near atmospheric pressure. Any pressure buildup in the wells is vented, by way of a pressure control valve, to the gas waste system vacuum tank (T-6301).

T-6301 is maintained subatmospheric by two gas waste compressors. At the time of this occurrence, however, one compressor was out of service for maintenance, and the second compressor, although operable, was pumping at less than rated capacity.

At approximately 2200 hours0.0255 days <br />0.611 hours <br />0.00364 weeks <br />8.371e-4 months <br /> on December 29, 1982, with the reactor shutdown, the pressure in the fuel storage facility (H-1401) had increased from a slight vacuum to about 1.8 psig due to an apparent surge in the gas waste system inputs. The pressure continued increasing to a maximum of 3.5 psig at approximately 0700 hours0.0081 days <br />0.194 hours <br />0.00116 weeks <br />2.6635e-4 months <br /> on December 30, 1982, and returned to atmospheric pressure one hour later.

. CAUSE DESCRIPTION:

Component failure.

With one gas waste compressor out af service for maintenance, the 4 'imited capacity of the second compressor was insufficient to maintain the gas waste vacuum tank at subatmospheric pressure. Since the fuel storage facility vents to this tank, the increased backpressure caused the fuel storage facility pressure to increase to about 3.5 psig.

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4 REPORTABLE OCCURRENCE 82-053 ISSUE O Page 2 of 3 ,

CORRECTIVE ACTION:

Repairs were completed on the inoperable compressor. The second compressor was later removed from service and repaired to bring it back to normal pumping capacity.

No further corrective action is anticipated or required.

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• 2 REPORTABLE OCCURREi4CE 82-053 TSSUE O Page 3 of 3 i

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Prepared By:

Duade L. Frye

. N/aer 4. 4orsA Senior T2chnical Services Technician l

1 Reviewed By: [

Charles Fuller t

l Technical Services Engineering Supervisor I

i l Reviewed By. b M k S-l Edwin D. Hill G i Station Manager I

5 Approved By: O~ v..._6.,. 4 w W m,o a j Don Warencourg # / /

Manager, Nuclear Production l

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