05000267/LER-1981-054, Forwards LER 81-054/03L-0.Detailed Event Analysis Encl

Forwards LER 81-054/03L-0.Detailed Event Analysis Encl

ML20032A728
Person / Time
Site:	Fort Saint Vrain
Issue date:	09/18/1981
From:	Warembourg D PUBLIC SERVICE CO. OF COLORADO
To:	Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML20032A729	List: 05000267/LER-1981-054, Forwards LER 81-054/03L-0.Detailed Event Analysis Encl 05000267/LER-1981-054-03, /03L-0:on 810820,emergency Feedwater to Loop 1 Helium Circulator Water Turbine Drive Was Isolated.Caused by Repair Necessary to Stop Leakage Between Seat Ring & Valve Body of Pressure Control Valve.Gasket Resurfaced
References
P-81234, NUDOCS 8111020261
Download: ML20032A728 (4)

LER-1981-054, Forwards LER 81-054/03L-0.Detailed Event Analysis Encl

Event date:
Report date:
2671981054R00 - NRC Website

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..c public Senlee Company Cf Od eds September 18, 1981 Fort St. Vrain Unit No. 1 P-81234 g

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OCT3 01981 k Mr. Karl V. Seyfrit. Director M v.5. tag"g fy/'

Nuclear Regulatory Commission i

j Region IV Office of Inspection and Enforcement Q

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611 Ryan Plaza Drive

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Suite 1000 M

N Arlington, Texas 76012 A

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Reference:

Facility Operating License No. DPR-34 i

Docket No. 50-267

Dear Mr. Seyfrit:

1 Enclosed please find a copy of Reportable Occurrence Report No. 50-267/81-054, Final, submitted per ;the requirements of Technical-3 Specification AC 7.5.2(b)2.

Also, please find erclosed one copy of the Licensee Event Report for Reportable Occurreace Report No. 50-267/81-054.

I Very truly yours, 2'YT m A-Don Warembourg Manager, Nuclear Production i

i DW/cis Enclosure cc: Director, MIPC q

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8111020/6/

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REPORT DATE:

September 18, 1981 REPORTABLE OCCURRENCE 81-054 ISSUE 0 OCCURRENCE DATE:

August 20, 1981 Page 1 of 4 FORT ST. VRAIN NUCLEAR GENERATING STATION PUBLIC SERVICE COMPANY OF COLORADO.

16835 WELD COUNTY ROAD 19 1/2 PLATTEVILLE, COLORADO 80651 REPORT NO. 50-267/81-054/03-L-0 Final IDENTIFICATION OF OCCURRENCE:

During steady state power operation, the emergency feedwater header supply to Loop 1 helium circulator water turbine drives was isolated.

This is a degraded mode of LC0 4.2.2 and is reportable per Fort St.

Vrain Technical Specification AC 7.5.2(b)2.

EVENT

DESCRIPTION

On August 20, 1981, with the r,lant operating at 70% thermal power and 235 MWe, excessive leakage tnrough PV-21243 necessitated isolation of emergency feedwater to Loop 1 helium cir:ulator water turbine drives to effect repairs.

Refer to Figure 1 for simplified diagram of this system.

A pressure control system is provided to control emergency feedwater flow lo each of the circulator pelton wheel supply headers A and (B) und r flow and no-flow conditions.

Under flow A

conditions, PV-21243 U1 controls _ supply header pressure.

Under no-flow conditions, PV-21243-1 U3 is provided to relieve excess header pressure to the turbine water drain tank in the event PV-21243 leaks through.

In this instance, leakage through PV-21243 war in excess of the capab'lities of PV-21243-1, and increased Loop 1 supply header pressure.

This would not, in itself, render the emergency feedwater to Loop 1 circulators inoperable. A Plant Trouble Report was initi ted, and the emergency feedwater was isolated ahead of PV-21243 5 at 0700 hours0.0081 days <br />0.194 hours <br />0.00116 weeks <br />2.6635e-4 months <br /> on August 20, 1981.

Repairs were made to PV-21243, and emergency feedwater was restored ta service at 0600 hours0.00694 days <br />0.167 hours <br />9.920635e-4 weeks <br />2.283e-4 months <br /> on August 21, 1981, within the 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> allowed by LCO 4.2.2(a).

Had it been necessary during this time, the affected helium circulators could have been operated at reduced speed utilizing a water supply from the emergency condensate or firewater systems.

CAUSE

DESCRIPTION:

Excessive leakage through PV-21243 required isolation of emergency feedwater to Loop 1 helium cir ulators to effect repairs.

The leakage was due to wear on the gasket-surface between the seat ring and the valve body.

k REPORTABLE OCCURRENCE 81-054 l

ISSUE O Page 2 of 4 CORRECTIVE ACTION:

J The gasket surface in the valve body of PV-21243 was built up by applying devcon compound to eliminate leakage.

The valve was re-assembled, and the system returned to service.

No further corrective action is anticipated or required.

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Emcrgency Feedwater To Backup leader Bearing Water O

To Imop 1 llelium Circulator V 211615 1

PV-2124 3 Water Turbine Drives bN/

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REPORTABLE OCCiiRRENCE 81-054 ISSUE O Pege 4 of 4 Prepared By:

Paul $ (re

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Techn16dl Services Manager Reviewed By:

W M 777J J Milt McBride Technical Services Manager Reviewed By:

Edwin (K111 F V Station Manager d7PmmL Approved By:

Don Warembourg g

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Manager, Nuclear Productitrn