ML17291A413

Special Rept:On 940825,loose Part Detection Sys Channel Number Eight Actuated Associated MCR Alarm & on 940908 Subj Channel Began Alarming Due to Electronic Noise Originating in Drywell.Electronic Module of Channel Removed

ML17291A413
Person / Time
Site:	Columbia
Issue date:	09/26/1994
From:	Parrish J WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
GO2-94-223, NUDOCS 9410030211
Download: ML17291A413 (5)

Text

1 H.lC3R.I P'Y'(ACCELERATED RIDS PROCESSIX REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)ACCESSION NBR:9410030211 DOC.DATE: 94/09/26 NOTARIZED:

NO DOCKET I FACIL:50-397 WPPSS Nuclear Project, Urfit 2, Washington Public Powe 05000397 AUTH.NAME AUTHOR AFFILIATION PARRISH,J.V.

Washington Public Power Supply System RECIP.NAME RECIPIENT AFFILIATION Document Control.Branch (Document Control Desk)

SUBJECT:

Special rept:on 940825,loose part detection sys channel number eight actuated associated MCR alarm&on 940908 subj channel began alrming again, due to electronic noise originating in drywell.Electronic module of channel removed.DISTRIBUTION CODE: IE22D COPIES.RECEIVED LTR ENCL 5 SIZE: TITLE: 50.73/50.9 Licensee Event Report (LER), ncident Rpt, etc.NOTES: RECIPIENT ID CODE/NAME PD4-2 PD INTERNAL: ACRS AEOD/SPD/RRAB NRR/DE/EELB NRR/DORS/OEAB NRR/DRCH/HICB NRR/DRSS/PRPB NRR/DSSA/SRXB RES/DSIR/EIB EXTERNAL: EG&G BRYCE,J.H NOAC MURPHY,G.A NRC PDR COPIES LTTR ENCL 2.1 1 RECIPIENT ID CODE/NAME CLIFFORD,J AEOD/ROAB/DS P FILE'CENTER 02 RR/DE/EMEB NRR/DRCH/HHFB NRR/DRCH/HOLB NRR/DSSA/SPLB NRR/PMAS/IRCB-E RGN4 FILE 01 L ST LOBBY WARD NOAC POORE I W NUDOCS FULL TXT COPIES LTTR ENCL NOTE TO ALL"RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE iVASTE!CONTACI'THE DOCI:MENT CONTROL DESK, ROOIiI PI-37 (EXT.S04-2083)TO ELI iIINATE YOUR NA!iI E FRO.'il DISTRIBUTION LISTS I'OR DOCl'MENTS YOU DON"I'L'ED!

TOTAL NUMBER OF COPIES REQUIRED: LTTR 27 ENCL

/Q WASHINGTON PUBLIC POWER SUPPLY SYSTEM P.O.Box 968~3000 George Washington Way~Riel>land, Washington 99352-0968

~(509)372-5000 September 26, 1994 G02-94-223 Docket No.50-397 U.S.Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C.20555 Gentlemen:

Subject:

WNP-2, OPERATING LICENSE NPF-21 SPECIAL REPORT: LOOSE-PART DETECTION SYSTEM This special report is submitted pursuant to the requirements of WNP-2 Technical Specification 3.3.7.10,"Loose-Part Detection System", which requires the associated instruments to be operable during plant Startup and Power Operation.

The associated ACTION statement 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 ten days outlining the cause of the malfunction and the plans for restoring the channel(s) to OPERABLE status." The Loose-Part Detection System (LPDS)detects the presence of internal loose parts in the Reactor Pressure Vessel (RPV).This system uses ten permanently-mounted sensors in various locations around the RPV.A signal of twice the general background noise for each sensor actuates an alarm in the main control room.The alarm would alert personnel to listen to the signal via headphones to determine the cause.Associated LPDS equipment would automatically record the signal and make the recording available for analysis.On August 25, 1994, LPDS channel number eight actuated an associated main control room alarm.Investigation did not reveal a noise indicative of a loose part.Operations personnel subsequently bypassed the channel, declared it inoperable, and entered the applicable LPDS ACTION statement.

The system engineer was called to help investigate, but the channel stopped alarming before he could begin.The system engineer requested that the channel be placed back 9420030222 940926 PDR ADOCK 05000397 S PDR

%QQ Page 2 SPECIAL REPORT: LOOSE-PART DETECTION SYSTEM in its OPERATE mode (while still in the ACTION statement) so he could monitor the channel and obtain data for analysis.The applicable surveillances were performed for this channel during the time that it was in OPERATE.On September 8, 1994, this channel began alarming again, and from recorded data, the system engineer determined that the channel's signal was electronic noise originating in the Drywell.Technicians have removed the electronic module for LPDS channel number eight to prevent further spurious alarms until the channel can be repaired.Channel number eight detector is one of four loose-part detectors located in close proximity to one another at the bottom of the RPV.Thus, a single inoperable LPDS channel in this area has minimal impact on the ability for the LPDS to detect a loose part.Channel number eight will remain inoperable until the Drywell is available to make the necessary repairs.The remainder of the LPDS is operable.Should you have any questions or desire additional information regarding this matter, please call me or Mr.D.A.Swank at (509)377-4563.Sincerely,.V.Parrish (Mail Drop 1023)Assistant Managing Director, Operations KBL/ml cc: LJ Callan-NRC RIV KE Perkins, Jr.-NRC RIV, Walnut Creek Field Office NS Reynolds-Winston 0 Strawn JW Clifford-NRC DL Williams-BPA/399 NRC Sr.Resident Inspector-927N