ML20028F233

Forwards LER 82-051/03L-0.Detailed Event Analysis Encl

ML20028F233
Person / Time
Site:	Fort Saint Vrain
Issue date:	01/19/1983
From:	Warembourg D PUBLIC SERVICE CO. OF COLORADO
To:	Jay Collins NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML20028F234	List: ML20028F233 ML20028F240
References
P-83024, NUDOCS 8301310289
Download: ML20028F233 (5)

Text

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• Public Servlee Company & Cdlendo

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

! January 19, 1983 Fort St. Vrain

, Unit No. 1

P-83024 Mr. John T. Collins, Regional Administrator Region IV '

Nuclear Regulatory Commission 611 Ryan Plaza Drive Suite 1000 Arlington, Texas 76011 i'

Reference:

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

Dear Mr. Collins:

Enclosed please find a copy of Reportable Occurrence Report No. 50-267/82-051, 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. 50-267/82-051.

Very truly yours, Don W < 5,u q yA nlf nyugA Don Warembourg Manager, Nuclear Production DW/cls Enclosure cc: Director, MIPC 0

40 8301310289 830119 PDR ADOCK 05000267 -

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. REPORT DATE: January 19. 1983 REPORTABLE OCCURRENCE 82-051 ISSUE O OCCURRENCE DATE: December 20. 1982 Page 1 of 4 FORT ST. VRAIN NUCLEAR GENERATING STATION PUBLIC SERVICE COMPANY OF COLORADO 16805 WELD COUNTY ROAD 19 1/2 PLATTEVILLE, COLORADO 80651-9298 REPORT NO. 50-267/82-051/03-L-0 Preliminary IDENTIFICATION OF OCCURRENCE:

During performance of a scheduled Surveillance Test, one of six steam pipe rupture (under prestressed concrete reactor vessel) and one of twelve steam pipe rupture (pipe cavity) ultrasonic detector channels were found inoperable. This is reportable as a degraded mode of LCO 4.4.1, Table 4.4-2 per Fort St. Vrain Technical Specification AC 7.5.2(b)2.

EVENT DESCRIPTION:

On December 20, 1982, with the reactor in a shutdown condition, Surveillance Test SR-RE-17-SA " Ultrasonic Detector Check" was  !

performed. The purpose of this temporary procedure is to check for I instrument drift in the ultrasonic detector channels. The test-requires that a calibrated ultrasonic noise source be applied to the individual microphones (elements) and that the response of the channel falls between 40% and 90% of full scale meter reading for the elements located under the prestressed concrete reactor vessel, and between 20% to 80% of full scale meter reading for the elements located outside of the prestressed concrete reactor vessel.

Data taken during the performance of the surveillance are given in Table 1.

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. REPCRTABLE CCCURRENCE 82-051 ISSUE O Page 2 of 4 TABLE 1 UNDER PCRV - RANGE 40% TO 90%

l l l l l TRANSMITTER OUTPUT l l l l l l  % (READ ON XSH l l l l l l METER) l l l l l l l .

lMICRCPHONElTRANSMITTERILOCATIONILOOP] AS F01LND l AS LEFT l lXE-93470A l l NE l2 l 15% Q) l 90% l lXE-93480A XT-93470A l SE I2 1 90% i 90% l lXE-93470B l NE l2 l 80*4 l 80*. l IXE-934808 i XT-934708 l SE l2 1 90% i 90% l lXE-93470C l l NE l2 l 90". l 90% l

[XE-93480C 1 XT-93470C I SE I2 1 90% i 90% l lXE-93471A l l NW I1 l 90*.' I 90% l

[XE-93479A I XT-93471A l SW I1 l 90% l 90% l IXE-934718 l l NW l1 l 90*4 l 90% l

!XE-934798 i XT-934718 i SW I1 l 80% 1 80% l lXE-93471C l l NW I1 l 90% l 90% l

[XE-93479C l XT-93471C l SW l1 l 90% l 90% l OUTSIDE PCRV - RANGE 20" TO 80%

l l l l TRANSMITTER OUTPUT l l l l l  % (READ ON XSH l l l l l METER) l l l l l l l MICROPHONE I LOCATION l LOOP l AS FOURD 1 AS LEFT l l XE-93454A l N. Will l 2 l 95*. Q) l 80% l l XE-93454B l N. Wall l 2 l 60% 60% l l XE-93454C l N. Wall l 2 l 100% @l l 70% l l XE-93455A l N. Wall l 1 l 100% l 80% l l XE-93455B l N. Wall l 1 l 0% l 20% l l XE-93455C 1 N. Wall 1 1 1 100% l 80% l l XE-93456A 1 S. Wall l 2 l 50*. l 50". l l XE-93456B l S. Wall l 2 l 100% l 80% l l XE-93456C 1 S. Wall 1 2 l 100% 2; I 80% l l XE-93457A l S. Wall l 1 1 35*. 3 5*. l l XE-934578 l S. Wall l 1 l 100% @ l l 80". l l XE-93457C I S. Wall l 1 1 50% l 50". l

@ Instruments found out of limits.

@ Instruments found out of limits, but in a conservative direction.

REPORTABLE OCCURRENCE 82-051

! ISSUE O Page 3 of 4 The data shows that one channel comprised of elements located under the prestressed concreta reactor vessel and one channel comprised of an element located outside of the prestressed concrete reactor vessel were found inoperable. Seven of the twelve elements located outside of the prestressed concrete reactor vessel were found with more conservative outputs than specified by Surveillance Test SR-RE-17-SA.

LCO 4.4.1, Table 4.4-2 indicates that all microphones and any associated transmitter or amplifier for a given channel must be .

operable in order for that channel to be considered operable.

CAUSE DESCRIPTION:

Component failure.

Microphone No. XE-93470A was found defective due to the failure of an electronic component in its internal circuitry (resistor, Hewlet- -

Packard part number 2100-1738, probe model 18020A).

The cause of the other instruments being out of tolerance is attributed to instrument drift.

CORRECTIVE ACTION:

A calibrated spare microphone was installed at the XE-93470A location under the prestressed concrete reactor vessel.

The other individual microphone / transmitters found out of tolerance were adjusted to acceptable values, and the Surveillance Test was successfully completed.

Surveillance Test SR-RE-17-SA, " Ultrasonic Detector Check" is being performed as schedueld on a semi-annual basis. The next surveillance is scheduled for July,1983.

Public Service Company's Nuclear Engineering Division is currently evaluating the ultrasonic steam pipe rupture detection system, the results of which will be included in a future supplemental report.

- REPORTABLE OCCURRENCE 82-051 ISSUE 0 Page 4 or 4 Prepared By: A/ w; >

Robert A. Dickerson Senior Technical Services Technician Reviewed By: / /I _

Charles Fuller Technical Services Engineering Supervisor Reviewed By: blb k M' Edwin 0. Hill G Station Manager Approved By: 1 13 . to , , , , A . . d, o+ils/ %7 l,-

Don Warembourg' /

Manager, Nuclear Production

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