ML19338F029

Forwards LER 80-048/03L-0

ML19338F029
Person / Time
Site:	Fort Saint Vrain
Issue date:	10/01/1980
From:	Warembourg D PUBLIC SERVICE CO. OF COLORADO
To:	Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML19338F030	List: ML19338F029 ML19338F032
References
P-80346, NUDOCS 8010070412
Download: ML19338F029 (5)

Text

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public Service Company & Cohemale

{ i 16805 ROAD 19%

L '- J PLATTEVILLE, COLOR ADO 80651 October 1, 1980 Fort St. Vrain Unit No. 1 P-80346 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/

80-48, Final, subnit'.ed 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. 50-267/80-48.

Very truly yours, MW Don Warembourg (/

Manager, Nuclear Production DW/cls Enclosure ec: Director, MIPC 1

DO s

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8010 07,of/f 3

REPORT DATE: October 1, 1980 REPORTABLE OCCURRENCE 80-48 ISSUE O OCCURRENCE DATE: September 1, 1980 Page 1 of 4 FORT ST. VRAIN NUCLEAR GENERATING STATION PUBLIC SERVICE COMPANY OF COLORADO 16805 WEID COUNTY ROAD 191/2 PLATTEVILLE, COLORADO 80651 REPORT NO. 50-267/80-48/03-L-0 Final IDENTIFICATION OF OCC'JRRENCE:

During performance of a scheduled surveillance test, all six " Steam Pipe Rupture Under PCRV" loop shutdown channels were identified as being inoper-able. Since the reactor had been operated during the surveillance interval, the channels must be considered to have been inoperable when the reactor was at power.

l This is interpreted as a degraded mode of LCO 4.4.1, Table 4.4-2, and is re-  !

portable per Fort St. Vrain Technical Specification AC 7.5.2(b)2. l EVENT DESCRIPTION:

On September 1,1980, while the reactor was in a shutdown condition, Surveil-lance Test SR 5.4.1.2.2j-R, Steam Pipe Rupture Under PCRV Calibration Test, was performed. The test requires that a calibrated ultrasonic noise source be fed to the microphone to be tested, and that the %ponse of the channel fall between 40 and 90% of full scale meter reading at the channel trip module. I 1

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

TABLE 1 Ac .ound As Left Microphone # Transmitter #_ Mete Readine Meter Reading XE-93470A 05 50" XT-93470A XE-93480A 0% 45%

1 XE-93470B ~

0% 50% '

XT-93470B XE-93480B 20% 45" XE-9V.70c 0" 50%

XT-93470C XE-93480C 60% 65%

i REPORTABLE OCCURRENCE 80-48 ISSUE O Page 2 of 4 EVENT ,

DESCRIPTION: (Cont'd) '

as Found Ae r, eft Microphone # Transmitter # Meter Reading Meter Reading XE-93471A 0% 50%

XT-93471A XE-93479A 100% 60%

XE-93471B 45% 60%

XT-934713 j XE-93479B 0% ) 60% l XE-93471C l 25% 50%

XT-93471C XE-93479C __

0% 70%

I The data shows that each channel had at least one microphone which did not  ;

give a measurable response to the noise source. Specification LCO 4.4.1, Notes for Tables 4.4-1 Through 4.4-1, Note (S), states that both microphones in a channel must be operable to make the channel operable. A single channel consists of two microphones, one transmitter, and one trip module. Theref ore, none of the channels are considered to have been operable prior to the ad- j j ustment mai a during the surveillance test.

However, it must be noted that Surveillance Test SR 5.4.1.2.2f-m/5.4.1.2.2g-m performed monthly, verifies that each channel will trip on a signal from an uncalibrated noise source. This test was performed successfully just prior to performance of SR 5.4.1.2.2j-R and indicated that a microphone showing no

. measurable response to the calibrated noise source is still responsive to a louder source and may be operable.

CAUSE DES CRIPTION:

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During the surveillance interval, numerous spurious " Steam Pipe Rupture Under PCRV" ultrasonic noise trips were received. In order to reduce the occur-rence of false trips, the gain of the microphones or transmitters causing the trip was reduced. The monthly performance of the functional test was believed to be sufficient indication of an opgrable channel.

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1 REPORTABLE OCCURRENCE 80-48 ISSUE O Page 3 of 4 CORRECTIVE ACTION:

The individual microphone and/or transmitter gain was adjusted to bring the trip module meter reading to an acceptable value for all microphones and the surveillance test successfully completed.

The microphone or transmitter gain will not be reduced to clear spurious trips.

No further corrective action is anticipated or required.

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' 1 REPORTABLE OCCURRENCE 80-48 ISSUE O Page 4 of 4 Prepared By: ,

Richard R. Frost Technical Services Technician l

Reviewed By: L. ///., /

' . ,W Cahm Technical Services Supervisor Reviewed By: J ,$1 [v, _

Frank M. Itachie /

Operation /:fanager /

Approved By: w [d, Don Warembourg /

Manager, Nuclear Production i

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