ML17304B006

Special Rept 3-SR-89-001:on 890105,plant Vent Sys Radioactive Gaseous Effluent Monitors Inoperable for More than 72 H.Caused by Monitors Needing Corrective Maint & Design Enhancements.Monitors Restored to Svc on 890108

ML17304B006
Person / Time
Site:	Palo Verde
Issue date:	01/31/1989
From:	Haynes J ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
192-00446-JGH-T, 192-446-JGH-T, 3-SR-89-001, 3-SR-89-1, NUDOCS 8902070363
Download: ML17304B006 (5)

Text

REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)'ACCESSION NBR:8902070363

, DOC.DATE: 89/01/31 NOTARIZED:

NO DOCKET FACIL:STN-50-530 Palo Verde Nuclear Station, Unit 3, Arizona Publi 05000530 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 3-SR-89-001:on 890105,inoperability of RU-143&RU-144 discovered.

DISTRIBUTION CODE: IE22D COPIES RECEIVED:LTR ENCL SIZE: TITLE: 50.73 Licensee Event Report (LER), Inci ent Rpt, etc.NOTES:Standardized plant.05000530~RECIPIENT ID CODE/NAME PD5 LA DAVIS,M.J.

INTERNAL: ACRS MICHELSON ACRS WYLIE AEOD/DS P/TPAB ARM/DCTS/DAB NRR/DEST/ADE 8H 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 FILE 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 1 1 2 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 AEOD/ROAB/DSP DEDRO 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 RR/DRY/~B 9A EG FILE~02 DSR/PRAB FORD BLDG HOY,A LPDR NSIC HARRIS,J COPIES LTTR ENCL 1 1 1 1 2 2 1 1 2 2 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 S h NOXK K)ALL"RZDS" RECIPZENIS:

PIZASE HELP US IO REDUCE%ASZE!CGNZACT'IHE IXXXMEN1'ONGEAL DESK, ROOM Pl-37 (EXT.20079)KO ELIMINATE YOUR NAME HKH DIPHGBUTIGN LISTS FOR DOCuMENI'S YOU DOlN'T NEEDf TOTAL NUMBER OF COPIES REQUIRED: LTTR 47 ENCL 46

Arizona Nuclear Power Project P.O.BOX 52034~PHOENIX, ARIZONA 85072-2034 192-00446-JGH/TDS/JJN January 31, 1989 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-89-001 File: 89-020-404 Attached please find Special Report 3-SR-89-001 prepared and submitted pursuant to Technical Specifications 3.3.3.8 and 6.9.2.This report discusses the inoperability of RU-143 and RU-144.If you have any questions, please contact T.D.Shriver, Compliance Manager, at (602)393-2521.Very tru y yours, JGH/TDS/JJN/kj Attachment J.G.Haynes Vice President Nuclear Production cc: D.B.Karner E.E.Van Brunt, Jr.J.,B.Martin T.J.Polich M.J.Davis A.C.Gehr INPO Records Center (all w/attachments)

PALO VERDE NUCLEAR GENERATING

~IATION Radiation Monitoring Unit Inoperable for Greater Than 72 Hours License No.NPF-74 Docket No.STN 50-530 Special Report No..3-SR-89-001 This Special Report is being submitted pursuant to Technical Specification 3.3.3.8 ACTION 42b and Technical Specification 6.9.2 to report an event in which.a Radioactive Gaseous Effluent Monitor (Plant Vent High Range Gaseous Activity Monitor RU-144)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 returning to operability was exceeded at approximately 0950 HST on January 8, 1989.'-At approximately 0950 HST on January 5, 1989, Palo Verde Unit 3 was in Mode 1 (POWER OPERATION) at approximately 100 percent power when the Plant Vent System R'adioactive Gaseous Effluent Monitors.(RU-143 and RU-144)were declared inoperable for corrective maintenance and design enhancements.

Pursuant to Technical Specification 3.3.3.8 ACTION 42a the Preplanned Alternate Sampling Program was initiated to monitor the Plant Vent System.Monitors RU-143 and RU-144 work as a pair with RU-143 being the low range monitor and RU-144 being the high range monitor.Normal configuration consists of RU-143 operating and RU-144 in standby.When RU-143 reaches a predetermined setpoint, RU-144 automatically starts and RU-143 goes to standby.RU-144'is provided for tracking of postulated accident releases.RU-144 must be declared inoperable when RU-143 is inoperable.

Design enhancements were performed under an approved work document to replace integrated circuits (E-Proms)on RU-143.These new E-Proms contained improved software for converting count rate to radiation level, eliminating unnecessary alarms, and correcting the interface between the internal clock and the data-processing.

Corrective maintenance was performed on RU-144's display to replace the Light Emitting Diodes (LEDs).Finally, corrective maintenance was'erformed on the RU-143 Channel 2 high voltage power supply.The diodes on the power supply limited output voltage to 1250 volts.This condition did not affect operability (

Reference:

Special Report 3-SR-88-003 submitted August 10, 1988).During the performance of the corrective maintenance to replace the diodes the I&C technician identified that the part number on the engineering document in the work order did not match, the part installed in the detector.Further evaluation determined that the correct part number was installed but that the engineering document was in error.The part number specified was for the Channel 1 power supply which is comparable to the Channel 2 power supply except for the number of output ports.This error occurred while transcribing the part number.A"one" was substituted for a"two" in the last digit.However, this disposition of the engineering document was equally valid for both part numbers.New diodes were installed in accordance with the revised engineering document to restore the monitor to the original design configuration.

On January 8, 1989, at approximately 1022 MST, the monitors were restored to service.The monitors were inoperable for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> and 32 minutes.

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