ML20028G265

Forwards LER 82-054/03L-0.Detailed Event Analysis Encl

ML20028G265
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
ML20028G266	List: ML20028G265 ML20028G271
References
P-83036, NUDOCS 8302070574
Download: ML20028G265 (4)

Text

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public Service Company H'CODomde

.* . 16805 Road 19 1/2, Platteville, Colorado 80651-9298 January 28, 1983 Fort St. Vrain Unit No. 1 r

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, FEB - 119EB Mr. John T. Collins, Regional Administrator i Region IV i Nuclear Regulatory Commission 611 Ryan Plaza Drive Suite 1000 Arlington, Texas 76011

Reference:

Facility Operating License No. DPR-34 Docket No. 50-267

Dear Mr. Collins:

j Enclosed please find a copy of Reportable Occurrence Report No. 50-267/82-054, Final, submitted per the requirements of Technical

] Specification AC 7.5.2(b)2.

Also, please find enclosed one copy of the Licensee Event Report for

! Reportable Occurrence Report No. 50-267/82-054. -

Very truly yours, O 16I [c/

i ili Do Warembourg Manager, Nuclear Production ,

DW/cis Enclosure cc: Director, MIPC i-o

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9 REPORT DATE: Janua y 28, 1993 REPORTAGLE OCCURRENCE S2-054 ISSUE n OCCURRENCE DATE: December 29. 1982 Page 1 of 3 FORT ST. VRAIN NUCLEAR GENERATING STATION .

PUBLIC SERVICE COMPANY OF COLORADO 16305 WELD COUNTY ROAD 19 1/2 PLATTEVILLE, COLCRADO E0651-9298 REPORT NO. 50-267/82-054/03-L-0 Final IDENTIFICATION OF OCCURRENCE:

On December 31, 1982, with the reactor at less than 1% thermal power, the outlet temperatures of both loops of the prestressed concrete reactor vessel (PCRV) cooling water system (System 46) exceeded 120 F.

This is reportable as a degraded mode of LCO 4.2.15(b) per Fort St.

Vrain Technical Specification AC 7.5.2(b)2.

EVENT DESCRIPTION:

Prior to this event, the plant had been in a shutdown or low power condition for a period of approximately three months. Because of this condition, the heat load on the PCRV cooling water system (System 46) was unusually low, and the service water flow to the System 46 heat exchangers had been isolated in an attempt to maintain

System 46 temperatures above the minimum allowed in LCO 4.2.15(b).

The PCRV cooling water was still in this altered condition when the reactor was taken critical at approximately 1933 hours0.0224 days <br />0.537 hours <br />0.0032 weeks <br />7.355065e-4 months <br /> on December 30, 1982.

At approximately 0530 hours0.00613 days <br />0.147 hours <br />8.763227e-4 weeks <br />2.01665e-4 months <br /> on December 31, 1982, Operations personnel determined that both loops of the PCRV cooling water system had exceeded 120 F. The service water supply to the Syrtem 46 heat exchangers was immediately returned to its norm:1 operating configuration.

The maximum System 46 outlet temperature reached was 123 F.

The 120 F limit specified in LCO 4.2.15(b) was exceeded for a period of approximately one hour and twenty minutes.

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REPORTABLE OCCURRENCE S2-054 ISSUE 0 Page 2 of 3 l CAUSE DESCRIPTIONi Personnel error.

The failure to return the service water (System 42) flow to a normal operating configuration through the PCRV cooling water heat exchangers, following the increase in reactor power (i.e., the increase in heat load on System 46), prevented the PCRV cooling water temperature controls from performing their design function of

, maintaining temperatures as required by LCO 4.2.15(b).

CORRECTIVE ACTION:

The normal service water fkow was established through the PCRV cooling water heat exchangers. This caused the Loop I and Loop 2 outlet temperatures to return within required limits.

Correct operation of the PCRV cooling water system during all conditions will be reviewed with all licensed operators by the Training Department.

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! Since this appears to be a recurring problem, a design modification

, is in progress to provide early warning of conditions approaching LCO 4.2.15 temperature limits.

No further corrective action is anticipated or required.

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REPORTABLE OCCURRErlCE 82-054 ISSU2 0 Page 3 of 3 Prepared By: __ /

Robert A. Dickerson Senior Technical Services Technician Reviewed By: e Charles Fuller Technical Services Engineering Supervisor Reviewed By: kbDk@

Edwin D. Hill 6 Station Manager i Approved By: _' $[ b/

0on'Warembourg Manager, Nuclear Production F

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