05000267/LER-1979-055, Forwards LER 79-055/03L-0

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Forwards LER 79-055/03L-0
ML19210E339
Person / Time
Site: Fort Saint Vrain Xcel Energy icon.png
Issue date: 11/26/1979
From: Warembourg D
PUBLIC SERVICE CO. OF COLORADO
To: Seyfrit K
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML19210E340 List:
References
P-79280, NUDOCS 7912040362
Download: ML19210E339 (5)


LER-1979-055, Forwards LER 79-055/03L-0
Event date:
Report date:
2671979055R00 - NRC Website

text

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Public service company e conomde 16805 Weld County Road 19 1/2, Platteville, Colorado 80651

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Novembe r 26, 1979 Fort St. Vrain Unit No. 1 P-79280 1

Mr. Y.ari V. Seyfrit, Director Nuclear P.egulatory Commission Region IV Office of Inspection and Enforcement 611 Ryan Pla:a Drive Suite 1000 Arlington, Texas 76012 REF: Facility Operating License No. DPR-34 Docket No. 50-267

Dear Mr. Seyfrit:

Enclosed please find a copy of Reportable Occurrence Report No. 50-267/79-55, Preliminary, 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. 50-267/79-55.

Very truly yours,

~~ W%w Don Wareebourg Manager, Nuclear Production W/alk cc: Director, MIPC 1473 192

/)ook S

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7912040 M ^-

REPORT DATE:

November 26, 1979 REP 0FTABLE OCCURRENCE 79-55 ISSUE O OCCURRENCE DATE:

Oc tob er 26, 1979 Page 1 of 4 FORT ST. VRAIN NUCLEAR GENERATING STATION PUBLIC SERVICE COMPANY OF COLORADO 16805 WELD COUNTY ROAD 191/2 PLAITEVILLE, COLORADO 80651 REPORT NO. 50-267/ 79-55/03-L-0 Prelimicary IDENTIFICATION OF OCCURRENCE :

On October 26, 1979, during performance of a scheduled surveillance test, it was found that a stuck open check valve (V-22370) would have prevented opera-tion of helium circulators on boosted emergency condensate or fire water for motive force via the emergency condensate line.

The reactor had been operated at power during the surveillance interval. LCO 4.2.19 requires that at least one fire water booster pump be operable during power operation. Contrary to this requirement the stuck open check valve rendered both fire water boosted pumps inoperable for helium circulator drive via the emergency condensate line during a period when the reactor must be assumed to have been at power.

This is r portable per Fort St. Vrain Technical Sepcification AC 7.5.2(b)2.

EVENT

DESCRIPTION

On October 26, 1979, a surveillance test required by the Fort St. Vrain Tech-nical Specifications (SR 5.2.7a-A) was being performed. As part of this test the helium circulators are operated with reduced pressure condensate supplied to the suction of the firewater booster pumps to simulate operation on fire-water.

Figure 1 is a simplified schematic of the piping arrangement of the emergency condensate header and the fire water booster pumps P-2109 and P-2110. With reference to Figure 1 the test portion being performed requires that the pressure of the condensate at the suction of P-2109/P-2110 is reduced to approximately 114 psig. The pump to be tested is then started and the speed of the circulator driven by the boosted water be verified as sufficient to give the required helium flow. When this was done on October 26,19 79, the circulator speed was less than the required value and pressure gauges installed at the pump suction and discharge indicated the same pressure.

Investigation by an operator revealed no problem with the pump. When V-22370 was rapped sharply the valve was heard to close and circulator speed immediately increased to above the required value.

Sinca the reactor had been operated at power since the last previous demon-stration of fire water booster pump operability it must be assumed that the reactor was operated at power without at least one operable firewater booster p u=p.

TA73 193

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REPORTABLE OCCURRENCE 79-55 ISSUE O Page 2 of 4

CAUSE

DESCRIPTION:

The cause of this eient was the failure of V-22370 to close when required to do so.

Failure of the valve to close in turn rendered both fire water booster pumps inoperable for circulator drive using the emergency conde ate supply line. Refer to Figure 1.

By installation of the spoo piece, l', closing could have been})used to supp the NO valve, (

, and opening NC valves (3) and 4j 3 the ooster pu=ps the circulator water tu ine drains via the emergency feedwater header, CORRECTIVE ACTION :

The immediate corrective action was to free the disc by rapping the valve body sharply.

The valve will be opened and inspected as soon as plant conditions permit.

The results of this inspection will be reported in a supplement to this report as soon as they are known.

\\ 47 T 194

REPORTABLE OCCURRENCE 79-55 ISSUE Q age 3 of 4 Eme rgency Condensate Supply V

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Loop 1 Loop 2 Loop 2 Steam Loop 1 S team S team Gen-S team Gen-Gene rato r Generator erator Re-erator Re-Economizer Economizer heaters heaters b V-22370 Loop 1 t"

Circula-tor Water Turbines Loop 2 2 [NO Circulator Water Tur-bines NO f

N N

- M 3

P-2109 No N

[NO Emergency Feed-water Header V

X NO NO 3

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A From Fire M N

N ()

NC NC y

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Water System NC NC NO Spool V

Steam

- 2 10 ce To Circulator Generator NO Water Turbine Drives Tell-Tale Drain FIGURE 1 EMERGENCY CONDENSATE HEADER AND FIREWATER BOOSTER PUMPS

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Normally Open - NO Normally Closed - NC

REPORTABLE OCCURRENCE 79-55 ISSUE O Page 4 of 4 Prepared by:

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,d Richa @ R. Frost Q

Technical Services Technician Reviewed by:

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echapcal Services Supervisor

.a Reviewed by:

Frank M. Mathie Operations Manager Approved by:

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Don Warembourg

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Manager, Nuclear Production 3

196