ML17304A776

Special Rept 1-SR-88-008:on 881113,Tech Specs Violated. Caused by Loose Part Detection Channel Being Inoperable for More than 30 Days Due to Problems W/False Alarms.Sys Will Be Monitored Once Per 24 H & Investigation Initiated

ML17304A776
Person / Time
Site:	Palo Verde
Issue date:	11/22/1988
From:	Haynes J ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
1-SR-88-008, 1-SR-88-8, 192-00433-JGH-T, 192-433-JGH-T, NUDOCS 8811290358
Download: ML17304A776 (6)

Text

.'C CI:LERATED DISIGBUTION DEMONST1LON SYSTEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)ACCESSION NBR:8811290358 DOC DATE: 88/11/22 NOTARIZED-NO DOCKET.FACIL:STN-50-528.

Palo Verde Nuclear Station, Unit 1, Arizona Publi 05000528~AUTH.NAME AUTHOR AFFILIATION HAYNES,J.G.

Arizona Nuclear Power Project (formerly Arizona Public Serv RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)

SUBJECT:

.Special Rept 1-SR-88-008:on 881113,loose part detection channel inoperable for more than 30 days.DISTRIBUTION CODE IE22D COPIES RECEIVED:LTR ENCL SIZE: TITLE: 50.73 Licensee Event Report (LER), Inci ent Rp , etc.NOTES:Standardized plant.RECIPIENT ID CODE/NAME PD5 LA CHAN,T INTERNAL: ACRS MICHELSON ACRS WYLIE AEOD/DSP/TPAB DEDRO NRR/DEST/CEB 8H.NRR/DEST/ICSB 7 NRR/DEST/MTB 9H NRR/DEST/RSB 8E'NRR/DLPQ/HFB 10 NRR/DOEA/EAB 11 NRR/DREP/RPB 10 NUDOCS-ABSTRACT RES/DSIR/EIB RGN5'ILE 01 EXTERNAL: EG&G WILLIAMS,S H ST LOBBY WARD NRC PDR NSIC MAYS,G NOTES COPIES LTTR ENCL 1 1 1 1~1 1 1 1 1 1 1 1 1 1 1 1, 1.1 1 1.1 1 1 1'2 1 1 1 1 1~1 4 4 1 1.1 1 1 1 1 1 RECIPIENT ID CODE/NAME PD5 PD DAVIS,M ACRS MOELLER AEOD/DOA ARM/DCTS/DAB NRR/DEST/ADS 7E NRR/DEST/ESB 8D NRR/DEST/MEB 9H NRR/DEST/PSB 8D~NRR/DEST/SGB 8D NRR/DLPQ/QAB 10 NRR/DREP/RAB 10 NRR/DRIS/SIB 9A 02 RES/DSR/PRAB FORD BLDG HOY,A LPDR NSIC HARRIS,J COPIES LTTR ENCL 1 1 1 1 2 2 1 1 1 1 1 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1'05000528~S'NCTE K ALLRZDS" RECIPIENTS:

PXEASE HELP US TO REDUCE%ASTE!QMIRCT XHE DOCUNEÃZ COEQUAL DESK, HXM Pl-37 (EXT.20079)TO XXaTMZNATFi HX3R NAME HKH DISTRIBUTION ZiZSKS KR DOCEKMXS YOU D0IN'T NEEDf D 1 D 8', TOTAL NUMBER OF COPIES REQUIRED:, LTTR 44 ENCL 43

Arizona Nuclear Power Project P.O.BOX 52034~PHOENIX, ARIZONA 85072-2034 192-00433-JGH/TDS/DAJ November 22, 1988 U.S.Nuclear Regulatory Commission NRC Document Control Desk Washington, D.C..20555

Subject:

Palo Verde Nuclear Generating Station (PVNGS)Unit 1 Docket No.STN 50-528 (License No.NPF-41)Special Report 1-SR-88-008 File: 88-020-404 Attached please find Special Report 1-SR-88-008 prepared and submitted pursuant to Technical Specifications 3.3 3.7, ACTION".a" and 6.9.2.This report discusses an inoperable Loose Parts Detection System Channel.If you have any questions, please contact T.D.Shriver, Compliance Manager at (602)393-2521.'ery trul yours, J.G.Hay es Vice President Nuclear Production JGH/TDS/DAJ/kj Attachment cc: D.B.Karner (all w/a)E.E.Van Brunt, Jr.J.B.Martin T.J.Polich M.J.Davis A.C.Gehr INPO Records Center PDR i~8 SP$$2"7 K 0~00 POC Qpg,Z i l I

'o Verde Nuclear Generating St n Unit I Loose Part Detection Instrumentation License No.NPF-41 Docket No.50-528 Special Report No.I-SR-88-008 This Special Report is being submitted pursuant to Technical Specification 3.3.3.7, ACTION"a" and Technical Specification 6.9.2 addressing a Loose Part Detection channel being inoperable for more than thirty (30)days.The 30 day period for returning the channel to an operable status was exceeded at approximately 2145 MST on November 13, 1988 The Loose Part Detection System consists of eight (8)channels.Each channe1 consists of a piezoelectric crystal motion sensor and associated amplification, indication, and recording circuitry.

The sensors are positioned in the following locations:

two (2)mounted on the Reactor Vessel upper head, two (2)mounted on the Reactor Vessel lower incore nozzle, and one (I)on each of the two (2)Steam Generators'nlet and outlet nozzles.The piezoelectric sens'ors'etect the loose parts using acoustic signals which are generated when loose parts impact a Reactor Coolant System component or structure.

Signals in excess of the alarm setpoint will result in an alarm'ondition.

The alarms are the"latch-on" type, i.e., the alarm will remain on when the system returns to normal and will not clear until the alarm is manually reset.There is one alarm indicator in the Control Room for the eight channels such that a"latch on" alarm effectively renders the Control.Room alarm indication inoperable for the remaining channels upon receipt of an alarm condition.

In addition'to the alarm in the Control Room, a tape recorder will start.There.are two tape recorders; four system channels input into one tape recorder.On October 14, 1988 Palo Verde Unit I was in Mode I (POWER OPERATION) at approximately 100 percent power when Loose Part Detection System Channel 5 (Steam Generator 1A inlet)was declared inoperable due to repeated spurious alarms.An approved work document was initiated to troubleshoot the cause of the spurious alarms.As a result of the troubleshooting, it was determined that no component malfunctions existed and that the alarm setpoint being near background noise levels resulted in the spurious alarms.In order to enable the reflash capability for the visual alarm indication in the Control Room and the automatic recording feature for the other channels sharing the recorder utilized by Channel 5, the Channel 5 setpoint has been raised to prevent false alarms.This renders Channel 5 inoperable; however, it remains functional.

During the period of Channel 5 inoperability, Operations Department personnel will audibly monitor the, Loose Part Detection System at least once per twenty-four hours.Additionally, ANPP Vibration Group and Engineering personnel will monitor the inoperable channel once per week during the period of.inoperability.

An engineering evaluation has been initiated to investigate the problem with the Loose Part Detection System Channel 5 and develop a solution.Based upon the engineering evaluatin, appropriate actions will be taken to return the system to an operable status.A supplement to this report will be submitted to describe the corrective actions and schedule for restoring the system to service.

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