ML17289A916

Special Rept:On 920905,channel 1 on Main Steam Line D Nozzle in Drywell Did Not Pass Surveillance & Inoperable for More than 30 Days.Caused by Faulty Equipment in Drywell. Maint Work Request Initiated to Repair Failed Channel

ML17289A916
Person / Time
Site:	Columbia
Issue date:	10/07/1992
From:	John Baker WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:	Martin J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
References
GO2-92-234, NUDOCS 9210160019
Download: ML17289A916 (10)

Text

FORD 1 REGULATO INFORMATION DISTRIBUTION bYSTEM (RIDS)

ACCESSION NBR:9210160019 DOC.DATE: 92/10/07 NOTARIZED: NO DOCKET FACIL:50-397 WPPSS Nuclear Project, Unit 2, Washington Public Powe 05000397 AUTH. NAME AUTHOR AFFILIATION BAKERPJ.W. Washington Public Power Supply System RECIP.NAME RECIPIENT AFFILIATION MARTIN,J.B. Region 5 (Post 820201)

SUBJECT:

Special rept:on 920905,channel 1 on main steam line D nozzle in drywell did not pass surveillance a inoperable for more than 30 days. Caused by faulty equipment in drywell.

Maint work request initiated to repair failed channel.

DISTRIBUTION CODE: IEOID COPIES RECEIVED:LTR ENCL C) SIZE! 2-TITLE: General (50 Dkt)-Insp Rept/Notice of Vio ation Response S NOTES:

/

F RECIPIENT COPIES RECIPIENT COPIES 0 ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD5 PD DEANPW.

INTERNAL: ACRS AEOD AEOD/DEIB AEOD/DSP/TPAB AEOD/TTC DEDRO NRR MORISSEAUPD NRR/DLPQ/LHFBPT NRR/DLPQ/LPEB10 NRR/DOEA/OEAB NRR/DREP/PEPB9H NRR/PMAS/ILRB12 NUDOCS-ABSTRACT OGC/HDS1

~JR REG FILE 02 RGN5 FILE 01 EXTERNAL: EGGG/BRYCEiJ.H. 1 NRC PDR NSIC 1 1 U

SeCOnd JiSfrIhW4-iOP1'4><

s c N

T NOTE TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENT CONTROL DESK.

ROOM P 1-37 (EXT. 504-2065) TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!

TOTAL NUMBER OF COPIES REQUIRED: LTTR 24 ENCL

l WASHINGTON PUBLIC POWER SUPPLY SYSTEMNRC P.O. Bax968 ~ 3000Geoge Wasbfngron Way ~ Richland, Washington 99352 ~ Q'09)372-5000 October 7, 1992 602-92-234 Docket No. 50-397 Mr. 0. B. Martin Regional Administrator US NRC, Region V 1450 Maria Lane, Suite 210 Walnut Creek, Ca. 94596

Subject:

WNP-2, OPERATING LICENSE NPF-21 SPECIAL REPORT:

LOOSE-PART DETECTION INSTRUMENTATION TECHNICAL SPECIFICATION 3.3.7.10 This request report is submitted pursuant to the requirements of WNP-2 Technical Specification 3.3.7. 10 "Loose-Part Detection Instrumentation" which requires the instruments to be operable at all times. The action statement for this specification requires that "with one or more loose-part detection system channels inoperable for more than 30 days, in lieu of any other report required by Specification 6.9. 1, prepare and submit a Special Report to the Commission pursuant to Specification 6.9.2 within the next 10 days outlining the cause of the malfunction and the plans for restoring the channel(s) to OPERABLE status."

The loose-part detection system has been designed and installed to detect the presence of internal loose parts in the reactor vessel. The loose parts monitoring system is a system dedicated to monitoring the reactor vessel via the use of 10 permanently mounted sensors in various locations around the reactor vessel. A signal of twice the general background noise from any one sensor will generate an alarm. The alarm would alert the Shift Technical Advisor to listen to the signals with head phones and try to determine the cause of the alarm. The signals causing the alarm are automatically recorded and are available for vendor analysis, if necessary.

During performance of the daily channel check, on September 5, 1992, with the plant in Mode 1 {RUN), it was noted that channel 81 did not pass the surveil-lance. On the next working day, the system engineer determined there was a system problem and initiated an HWR. Maintenance ordered a part to be used for troubleshooting on September 10, 1992. On September 15, 1992, it was determined that the problem with channel 81 was with the equipment in the drywell. All of the equipment in the drywell for this channel was repl.aced at the end of the, R7 1992 refueling outage, therefore the exact cause of the failure is not known.

Page Two LOOSE-PART DETECTION INSTRUHENTATION Channel ¹I is located on the Hain Steam Line D nozzle in the drywell. Analysis of the signal relationship from the 10 channels is used to determine the location of the suspected loose part. There are two sensors located on steam lines to monitor the top of the vessel. Therefore 4etermining the location of suspected loose parts at the top of the vessel will be impacted with the loss of channel

¹1. The alarm logic is determined by the relationship of the background noise level (long time constant RHS average) of a channel vs the signal noise level (short time constant RHS average) of the same channel and is independent of the number of channels in service. The system output is an annunciator, on Board S in the control room and a magnetic tape recording of all ten signals at the time of the alarm. There are no automatic actuations produced by this instrument.

While the Technical Specification requires the system to be declared inoperable, the loose parts monitor system design allows the system to be partially operational when less than the full ten channels are operational. The failed equipment is located in the drywell and is not accessible during reactor operation. An HWR has been initiated to repair the failed channel the next time the drywe11 is accessible. WNP-2 wil1 continue to monitor the functionality of the remaining channels.

Very truly yours, J.W. Baker (H/D 927H)

WNP-2 Plant Hanager DLD/bk cc: NRC Document Control Desk Hr. J. W. Clifford - NRC Hr;- W. Ang, NRC Resident Inspector - (H/D 901A)

Hr. D. L. Williams, BPA (H/0 399)

NRC Resident Inspector Walkover Copy

0 I

A.CCEI ERATED REGULARDISTRIBUTION DEMOTRATION Y INFORMATION DISTRIBUTI YSTEM (RIDS)

SYSTEM ACCESSION NBR:9'210160019 DOC.DATE: 92/10/07 NOTARIZED: NO DOCKET FACIL:50-~97 WPPSS Nuclear Project, Unit 2, Washington Public Powe 05000397 AUTH. NAME AUTHOR AFFILIATION BAKER,J.W. Washington Public Power Supply System RECIP.NAME RECIPIENT AFFILIATION MARTIN,J.B. Region 5 (Post 820201)

SUBJECT:

Special rept:on 920905,channel 1 on main steam line D nozzle in drywell did not pass surveillance & inoperable for more than 30 days. Caused by faulty equipment in drywell.

Maint work request initiated to repair failed channel.

DISTRIBUTION CODE: IE22D COPIES RECEIVED:LTR ENCL SIZE:

TITLE: 50.73/50.9 Licensee Event Report (LER), Incident Rpt, etc.

NOTES:

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL A

PD5 LA PDS PD DEANgW.

0 INTERNAL: ACNW ACRS 2 AEOD/DOA AEOD/DSP/TPAB 1 AEOD/ROAB/DSP NRR/DET/EMEB 7E 1 NRR/DLPQ/LHFB10 NRR/DLPQ/LPEB10 1 NRR/DOEA/OEAB NRR/DREP/PRPB11 2 NRR/DST/SELB 8D NRR/DST/SICB8H3 1 NRR J3 SPLB8Dl NRR/DST/SRXB 8E 1

~ZL 02 RES/DSIR/EIB 1 RGN5 FILE 01 EXTERNAL: EG&G BRYCEiJ.H L ST LOBBY WARD 1 NRC PDR NSIC MURPHYiG.A 1 NSIC POORE,W. NUDOCS FULL TXT 1 1 NOTE TO ALL RIDS RECIPIENTS:

PJ EASE HELP US TO REDUCE iVASTE! CONTACT THE DOCUMENT CONTROL DESK.

ROOM Pl-37 (EXT. 504-2065) TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!

TOTAL NUMBER OF COPIES REQUIRED: LTTR 31 ENCL

WASHINGTON PUBLIC POWER SUPPLY SYSTEM P.O. Bocc96'8 ~ 3000 Geog'asbtngson Way ~ RIcbland, Washington 99352C968 ~ (509) 372-5000 October 7, 1992 G02-92-234 Docket No. 50-397 Hr. J. B. Martin Regional Administrator US NRC, Region V 1450 Maria Lane, Suite 210 Walnut Creek, Ca. 94596

Dear Hr. Hartin:

Subject; WNP-2, OPERATING LICENSE NPF-21 SPECIAL REPORT:

LOOSE-PART DETECTION INSTRUMENTATION TECHNICAL SPECIFICATION 3.'3.7. 10 This request report is submitted pursuant to the requirements of WNP-2 Technical Specification 3.3.7. 10 "Loose-Part Detection Instrumentation" which requires the instruments to be operable at all times. The action statement for this specification requires that "with one or more loose-part detection system channels inoperable for more than 30 days, in lieu of any other report required by Specification 6.9. 1, prepare and submit a Special Report to the Commission pursuant to Specification 6.9.2 within the next 10 days outlining the cause of the malfunction and the. plans for restoring the channel(s) to OPERABLE status."

e The loose-part detection system has been designed and installed to detect the presence of internal loose parts in the reactor vessel. The loose parts monitoring system is a system dedicated to monitoring the reactor vessel via the use of 10 permanently mounted sensors in various locations around the reactor vessel. A signal of twice the general background noise from any one sensor will generate an alarm. The alarm would alert the Shift Technical Advisor to listen to the signals with head phones and try to determine the cause of the alarm. The signals causing the alarm are automatically recorded and are available for vendor analysis, if necessary.

During performance of the daily channel check, on September 5, 1992, with the plant in Mode 1 (RUN),,= it was noted that channel ¹1 did not pass the surveil-lance. On the next working day, the system engineer determined there was a system problem and initiated an HWR. Maintenance ordered a part to be used for troubleshooting on September 10, 1992. On September 15, 1992, it was determined that the problem with channel ¹1 was with the equipment in the drywell. All of the. equipment in the drywell for this channel was replaced at the end of the R7 1992 refueling outage, therefore the exact cause of the failure is not known.

a 0 I'P;.

9210160019 921007 PDR ADOCK 05000397 u' S PDR

Page Two LOOSE-PART DETECTION INSTRUHENTATION Channel ¹I is located on the Hain Steam Line 0 nozzle in the drywell. Analy'sis of the signal relationship from the 10 channels is used to determine the location of the suspected loose part. There are two sensors located on steam lines to monitor the top of the vessel. Therefore determining the location of suspected loose parts at the top of the vessel will be impacted with the loss of channel

¹1. The alarm logic is determined by the relationship of the background noise level (long time constant RHS average) of a channel vs the signal noise level (sho'rt time constant RHS average) of the same channel and is independent of the number o'f channels in service. The system output is an'annunciator on Board S in the control room and a magnetic tape recording of all ten signals at the time of the alarm. There are no automatic actuations produced by this instrument.

While the Technical Specification, requires the system to be declared inoperable, the loose parts monitor system design allows the system to be partially operational when less than the full ten channels are operational. The failed equipment is located in the drywell and is not accessible during reactor operation. An MWR has been initiated to repair the failed channel the next time the drywell is accessible. WNP-2 will continue to monitor the functionality of the remaining channels.

Very truly yours, WNP-2 Plant Hanager DLO/bk CC: NRC Document, Control Desk Hr. J. W. Clifford - NRC Hr. W. Ang, NRC Resident Inspector - (H/D 901A)

Hr. D. L. Williams, BPA (H/0 399)

NRC Resident Inspector Walkover Copy

i ~

I