ML17304A508

Special Rept 3-SR-88-005:on 880818,high Range Noble Gas Monitor RU-142 Inoperable for Greater than 72 H,Per Tech Spec 3.3.3.8,Action 42(b).Approved Work Document Initiated to Troubleshoot Cause of Monitor Malfunction & Rework

ML17304A508
Person / Time
Site:	Palo Verde
Issue date:	09/08/1988
From:	Haynes J ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
192-00408-JGH-T, 192-408-JGH-T, 3-SR-88-005, 3-SR-88-5, NUDOCS 8809140245
Download: ML17304A508 (5)

Text

~cczmm~,,~PR@tK,k~

pe,,@mx~,~ACCESSION NBR:8809140245 DOC.DATE: 88/09/08 NOTARIZED:

NO DOCKET 5 FACIL:STN-50-530 Palo Verde Nuclear Station, Unit 3, Arizona Publi 05000530.AUTH'AME AUTHOR AFFILIATION HAYNESiJ.G.

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

SUBJECT:

Special Rept 3-SR-88-005:on 880818,radiation monitoring unit inoperable for greater than 72 h.DISTRIBUTION CODE: IE22D COPIES RECEIVED:LTR ENCL/SIZE: TITLE: 50.73 Licensee Event Report (LER), Incident Rpt, etc.NOTES:Standardized plant.RECIPIENT ID CODE/NAME PDS LA LICITRAiE INTERNAL: ACRS MICHELSON ACRS WYLIE AEOD/DSP/NAS 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 TELFORDgJ RES/DSIR/EIB EXTERNAL'GS(G WILLIAMS g S H ST LOBBY WARD NRC PDR NSIC MAYSiG 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 1 1 2 2 1 1 1 1 1 1 h 4 4 1 1 1 1 1 1 1, 1 RECIPIENT ID CODE/NAME PD5 PD DAVISiM ACRS MOELLER AEOD/DOA AEOD/DSP/ROAB 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 SIB 9A REG FIL 02 RES DSIR DEPY RGN5 FIL'E 01~~FORD BLDG HOY,A LPDR NSIC HARRISgJ COPIES LTTR.ENCL 1 1 1 1 2 2 1 1 2 2 1 1 1'1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 05000530 S h h TOTAL NUMBER OF COPIES REQUIRED: LTTR 48 ENCL 47

Arizona Nuclear Power Project P.O.8OX 52034~PHOENIX, ARIZONA 85072-2034 192-00408-JGH/TDS/DAJ September 8, 1988 U.S.Nuclear Regulatory Commission NRC Document Control Desk Washington, D.C.20555

Subject:

Palo Verde Nuclear Generating Station (PVNGS)Unit 3 Docket No.STN 50-530 (License No.NPF-74)Special Report 3-SR-88-005 File: 88-020-404 Attached please find Special Report 3-SR-88-005 prepared and submitted pursuant to Technical Specifications 3.3.3.8 and 6.9.2.This report discusses an inoperable radioactive effluent monitor If you have any questions, please contact T.D.Shriver, Compliance Hanager at (602)393-2521.Very truly yours, l4 J~~J.G.Haynes Vice President Nuclear Production JGH/TDS/DAJ/kj Attachment cc: D.B.Karner (all w/a)E.E.Van Brunt, Jr.J.B.Hartin T.J.Polich M.J.Davis A.C.Gehr INPO Records Center 8809i40245 880908 PDR ADQCK 05000530 8 PNU PALO VERDE NUCLEAR GENERATING STATION Radiation Monitoring Unit Inoperable for Greater than 72 Hours License No.'PF-74 Docket No.STN 50-530 Special Report No.3-SR-88-005 This Special Report is submitted in accordance with Technical Specification 3.3.3.8 ACTION 42(b)and 6.9.2, for an event in which a high range noble gas monitor (RU-142)was inoperable for greater than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.The 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> limit for inoperability was exceeded at approximately 0815 MST on August 18, 1988.At approximately 0815 MST on August 15, 1988, with Palo Verde Unit 3 in Mode 3 (HOT STANDBY), the Condenser Vacuum Pump/Gland Seal Exhaust High Range Monitor (RU-142)was declared inoperable since the monitor would not stay on line.Radioactive effluent monitors RU-141 and RU-142 continuously monitor the condenser vacuum pump/gland seal exhaust for gaseous activity resulting from primary to secondary leakage.Monitors RU-141 and RU-142 work as a pair, with RU-141 as the low range monitor and RU-142 as the high range monitor.Normal configuration consists of RU-141 operating with RU-142 in standby.Low Range Monitor RU-141 automatically starts RU-142 and initiates filtration of the condenser vacuum pump/gland seal exhaust whenever the monitor registers a HIGH-HIGH alarm condition.

RU-142 is provided for tracking radioactive effluents during postulated accident scenarios.

An approved work document was initiated to troubleshoot the cause of the monitor malfunction and rework as necessary.

During the troubleshooting, it was discovered that a system board was not operating properly.The system board is utilized by the monitor's microcomputer as an interface between the central processing unit and the peripheral monitor functions.

The system board was replaced and the monitor appeared to be functioning properly.A root cause of failure engineering evaluation has been initiated for the malfunctioning monitor.Following the performance of the troubleshooting and rework activities, the monitor was not returned to'n OPERABLE status in order to support the performance of the scheduled 18-month surveillance testing.Following the satisfactory performance of 18-month surveillance testing, RU-142 will be returned to service.The monitor is expected to be returned to service by September 9, 1988.

ty v t