05000267/LER-1982-040, Forwards LER 82-040/03L-0.Detailed Event Analysis Encl

Forwards LER 82-040/03L-0.Detailed Event Analysis Encl

ML20066B725
Person / Time
Site:	Fort Saint Vrain
Issue date:	11/01/1982
From:	Warembourg D PUBLIC SERVICE CO. OF COLORADO
To:	Jay Collins NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML20066B728	List: 05000267/LER-1982-040, Forwards LER 82-040/03L-0.Detailed Event Analysis Encl
References
P-82494, NUDOCS 8211090163
Download: ML20066B725 (5)

LER-1982-040, Forwards LER 82-040/03L-0.Detailed Event Analysis Encl

Event date:
Report date:
2671982040R00 - NRC Website

text

- A W

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public servlee company oe cellomde 16805 Road 19 1/2, Platteville, Colorado 80651-9298 November 1, 1982 Fort St. Vrain Unit No. 1 P-82494

,f.hhINIlI/i Mr. John T. Collins, Regional Administrator Region IV i

NOV 4 IE

. l Nuclear Regulatory Commission i

h ILO 611 Ryan Plaza Drive L

Suite 1000 Arlington, Texas 76011

Reference:

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

Dear Mr. Collins:

Enclosed please find a copy of Reportable Occurrence Report No. 50-267/82-040, Preliminary, submitted per the requirements of Technical Specification AC 7.5.2(b)1 and AC 7.5.2(b)2.

Also, please find enclosed one copy of the Licensee Event Report for Reportable Occurrence Report No. 50-267/82-040.

Very truly yours, hud Don Warembourg l

Manager, Nuclear Production DW/cls Enclosure p

h cc: Director, MIPC l

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'I 8211090163 821101 lSPDR ADOCK 05000267 i

PDR l

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..M REPORT DATE:

November 1, 1982 REPORTABLE OCCURRENCE 82-040 j

ISSUE O i

OCCURRENCE DATE:

October 2, 1982 Page 1 of 4 l

FORT ST. VRAIN NUCLEAR GENERATING STATION PUBLIC SERVICE COMPANY OF COLORADO 16805 WELD COUNTY ROAD 19 1/2 PLATTEVILLE, COLORADO 80651-9298 REPORT NO. 50-267/82-040/03-L-0 Preliminary IDENTIFICATION OF OCCURRENCE:

During performance-of scheduled surveillance tests, all six steam pipe rupture (under prestressed concrete reactor vessel) and seven of twelve steam pipe rupture (pipe cavity) ultrasonic detector channels were found inoperable. Since the reactor had been operated during the test interval, the channels must be considered to have been inoperable when the reactor was at power.

This is a degraded mode of LOO 4.4.1, Table 4.4-2, and is reportable per Fort St. Vrain Technical Specification AC 7.5.2(b)1 and 2.

EVENT

DESCRIPTION

On October 2 and October 8, 1982, while the reactor was shutdown for plant maintenance, SR 5.4.1.2.2j-R and SR 5.4.1.2.1j-R, respectively, were performed.

The fermer is a test and calibration of the steam pipe rupture detection system under the prestressed concrete reactor vessel.

The latter is a test and calibration of the steam pipe rupture detection system in the pipe cavity.

l SR 5.4.1.2.2j-R, under the prestressed concrete reactor vessel, i

requires that a calibrated noise source be applied to the individual j

microphones, and that the channel response be between 40% and 90% of full scale at the channel's trip module.

l SR 5.4.1.2.1J-R, pipe cavity, requires that a calibrated ultrasonic noise source be applied to the microphone to be tested, and the response of the channel indicate between 20% and 80% of full scale at the channel's trip module.

i Data taken during the tests are given in Table 1 and 2.

I As is shown in Table 1, there were no channels that could be considered operable as per LCO 4.4.1, Table 4.4-2, Note (s).

Note (s) states that both microphones for one channel must be operable in order for the channel to be considered operable.

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REPORTABLE OCCURRENCE 82-040 ISSUE O Page 2 of 4 However, during performance of scheduled monthly tests, just prior to SR 5.4.1.2.2j-R, all channels were shown to be responsive to a louder but uncalibrated noise source, and did in fact trip as required.

As Table 2 shows, each major channel (location) is composed of three microphones connected in a two of three trip circuit. Also, it can be seen that all four major channels were degraded.

In the case of Loop 2 north, one individual microphone channel was degraded, but in a conservative direction.

Even though these individual channels were found degraded using a calibrated noise source, they were found to trip when an uncalibrated noise source was used during scheduled monthly tests just prior to SR 5.4.1.2.1j-R.

CAUSE

DESCRIPTION:

The cause of these instrument channels being outside the limits required by LCO 4.4.1 is attributed to instrument calibration drift.

CORRELTIVE ACTION:

The individual microphone and/or transmitter gain was adjusted to an acceptable value for all microphones, and the surveillance tests were successfully completed.

Ultrasonic Detector Check, SR-RE-17-SA is being performed, as scheduled, on a semi-annual basis.

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

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REPORTABLE OCCURRENCE 82-040 ISSUE O Page 3 of 4 1

TABLE 1 Under PCRV - Range 40% to 90%

l l

l As Found l

As Left l

l Microphone No. I Transmitter No. I Meter Reading i Meter Reading l l

50%

l 50". O l

XE-93470A l

l 10".

I 45%

l-l XE-93480A I

XT-93470A i

l XE-93470B l

l 35% L1) l 45%

l l

XE-934808 l

XT-93470B l

4% (D l

45%

l l

45%

l 45% @-

l XE-93470C l

l 20%

l 45%

l l

XE-93480C 1

XT-93470C l

l 40%

l 40*. @

l XE-93471A l

l 0%

l 45%

l l

XE-93479A I

XT-93471A l

l 45%

l l

XE-93471B l

l 90*. @

10%

l 45%

l l

XE-93479B I

XT-934718 l

l 50%

l 50*. @

l XE-93471C l

l 10".

l 45%

l l

XE-93479C I

XT-93471C I

TABLE 2 Outside PCRV - Range 20% to 80%

l l

l As Found l

As Left l

l Location i Microphone No. I Meter Rending l Meter Reading l l

l XE-93457A l

10%

l 22%

l l

Loop 1, l XE-934578 l

3%

l 33%

l l

South I

XE-93457C l

3".

I 30%

l l

45".

l 45% @-

l l

XE-93455A l

15%

l 20".

l l

Loop 1, l XE-934558 l

I 40%

l l

l North I

XE-93455C 1

40". C1 0%

l 50*.

l i

l l

XE-93456A l

35". @

5%

l 30%

l l

Loop 2, l XE-934568 l

l 35%

l l

South I

XE-93456C i

l l

XE-93454A l

85% (,2) l 40%

l 2

l Loop 2, l XE-934548 l

30".

l 30%

l

[ North I

XE-93454C I

42%

I 42".

l l

@ Instruments found out of limits.

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

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REPORTABLE OCCURRENCE 82-040 ISSUE O Page 4 of 4 Prepared By:

as m 1

Duane L. Frye

/

Technical Services Technician 2N Reviewed By:

Charles Fuller Technical Services Engin r g Supervisor Reviewed By:

/

Edwin (k'lHill/v' Station Manager Approved By:

d 7E4.

Don Warembourg 47 Manager, Nuclear Production i

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