ML19309F850

Forwards LER 80-018/03L-0

ML19309F850
Person / Time
Site:	Fort Saint Vrain
Issue date:	04/25/1980
From:	Warembourg D PUBLIC SERVICE CO. OF COLORADO
To:	Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML19309F851	List: ML19309F850 ML19309F858
References
P-80088, NUDOCS 8005010439
Download: ML19309F850 (4)

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public service company oe conende 16805 Weld County Road 191/2, Platteville, Colorado 80651 l

April 25,1980 Fort St. Vrain Unit No. 1 P-80088 Mr. Karl V. Seyfrit, Director Nuclear Regulatory Commission Region IV Office of Inspection and Enforcement 611 Ryan Plaza Drive Suite 1000 Arlington, Texas 76012

Reference:

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/

80-18, Final, submitted per the requirements of Technical Specificction AC 7.5.2(b)2.

Also, please find enclosed one copy of the Licensee Event Report for l Reportable Occurrence Report No. 50-267/80-18.

I Very truly yours, WOA4 Don Warembourg Manager, Nuclear Production DW/cls Enclosure cc: Director, MIPC 7

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.IPORT DATE:

April 25,1980 REPORTABLE OCCURRENCE 80-18 ISSUE O OCCURRENCE DATE: March 27,1980 Page 1 of 3 FORT ST. VRAIN NUCLEAR GENERATING STATION PUBLIC SERVICE COMPANY OF COLORADO 16805 WELD COUNTY ROAD 191/2 PLATTEVILLE, COLORADO 80651 REPORT NO. 50-267/80-18/03-L-0 Final IDENTIFICATION OF OCCURRENCE:

One of the three Loop 2 hot reheat header activity monitors was inoperable due to a failed operational amplifier.

This resulted in operation in a degraded mode of LCO 4.4.1, Table 4.4-2 and is reportable per Fort St. Vrain Technical Specification AC 7.5.2(b)2.

EVENT DESCRIPTION: -

At approximately 2200 hours0.0255 days <br />0.611 hours <br />0.00364 weeks <br />8.371e-4 months <br /> on March 27, 1980, with the plant operating at approximately 51% thermal power and 158 HRe, Operations personnel noted that the "no fail" indication for RIS-93252-11 had been extinguished and would not reset. This instrument is one of three plant protective system hot reheat header activity monitors designed to provide a Loop 2 shutdown input. A trip of these monitors is indicative of a reheat tube leak which would allow primary coolant to leak into the reheat piping. Immediately af ter it was observed that the "no fail" light on this monitor was off, the module was replaced with a spare, which also lost "no fail" indication within five minutes. The "no fail" indication is normally illuminated, which indicates there is a signal from the detector to the electronic conditioning components in the RIS module. Loss of the "no fail" light indicates a loss of detector input signal; thus, this monitor would be incapable of providing a trip input to the plant protective system on reheat header activity.

Per LCO 4.4.1, Table 4.4-2, two monitors per loop are required to be oper-able, and any inoperable channel must be tripped unless the trip would cause the protective action to occur. Failure to place this switch in the tripped condition upon loss of "no fail" indication resulted in oper-ation in a degraded mode of LCO 4.4.1.

The switch module was repaired and returned to service on March 28, 1980.

During this time period, the two other Loop 2 monitors were available and operable.

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l REPORTABLE OCCURRENCE 80-18 l ISSUE O j Page 2 of 3  !

CAUSE DESCRIPTION:

The operational aglifier on the detector pre-amplifier to RIS-93252-ll failed due to normal service.

i CORRECTIVE ACTION:

The failed operational aglifier chip was replaced and the monitor returned to ServiCS.

No further corrective action is anticipated or required.

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REPORTABLE OCCURRENCE 80-18 ISSUE O Page 3 of 3 Prepared By: '.r/ur $ :-c!d Cathy O'. Hirsch Technical Services Technician Reviewed By: L. / _ 7/ wf/

. W. Galtfli Technical Services Supervisor Revteued By: f/a. $/r $. , , 1[]W Frank M. Mathie ' (;f Operations Manager .

Approved By: ,

b ut.t w b Don Warembourg ,y Manager, Nuclear Production

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