ML17300B234

Special Rept 2-SR-89-008:on 891124,gaseous Effluent Monitors RU-142 & RU-144 Taken Out of Svc & Declared Inoperable for More than 72 H to Implement Site Mod.Caused by Use of Rectifier in Power Supply Circuit.Site Mod Completed

ML17300B234
Person / Time
Site:	Palo Verde
Issue date:	12/23/1989
From:	James M. Levine ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
192-00609-JML-T, 192-609-JML-T, S-SR-89-008, S-SR-89-8, NUDOCS 9001050319
Download: ML17300B234 (6)

Text

BUTI ON DE MON SWA,TION SYSTEM

%EGUL RY INFORMATION DISTRIBUTI SYSTEM (RIDS)

ACCESSION NBR:9001050319 DOC.DATE: 89/12/23 NOTARIZED: NO -

DOCKET I

,FACIL:STN-50-529 Palo Verde Nuclear Station, Unit 2, Arizona Publi 05000529 AUTH. NAME AUTHOR AFFILIATION LEVINE,J.M. Arizona Public Service .Co. (formerly Arizona Nuclear Power RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)

SUBJECT:

Special Rept 2-SR-89-008:on 891124,radiatio'n monitoring unit inoperable for greater than 72 h.

DISTRIBUTION CODE: ZE22D COPIES RECEIVED:LTR ENCL SIZE:

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

NOTES:Standardized plant. 05000529 S

RECIPIENT COPIES RECIPIENT C.OP IES ZD CODE/NAME LTTR ENCL ,

ZD CODE/NAME LTTR ENCL PD5 LA .1 PD5 PD 1 1 CHAN,T 1 1 DAVIS,M. 1 INTERNAL: ACRS MICHELSON 1 1 ACRS MOELLER 2 2 ACRS WYLIE 1 1 AEOD/DOA 1 1' AEOD/DSP/TPAB 1 1 AEOD/ROAB/DSP 2 DEDRO 1 1 NRR/DET/ECMB 9H -

1 1 NRR/DET/EMEB9H3 1 1 NRR/DET/ESGB 8D 1 1 NRR/DLPQ/LHFB11 1 1 NRR/DLPQ/LPEB10 1 1 NRR/DOEA/OEAB11 1 1 NRR/DREP/PRPB11 2 2 NRR/DST/SELB 8D 1 1 NRR/DST/SICB 7E 1 1 NRR/DST/SPLB8D1 1 1 NRR DSZ/ XB 8E 1 1 NUDOCS-ABSTRACT 1 1 FG F~ 02 1 1 RES/DSIR/EIB 1 1 RGNS FILE 01 1 1 EXTERNAL: EGSG WILLIAMS,S 4 4 L ST LOBBY WARD 1 1 LPDR 1 1 NRC PDR 1 1 NSIC MAYS,G 1 1 NSIC MURPHY,G.A 1 1 NUDOCS "ULL TXT 1 1 I R NOTES: 1 1 I D

S NCTE K) ALL "RIDS" RECIPIENIS'LEASE HELP US IO REDUCE HASTE CGNIACT IHE DXUMEÃ7 COÃZRDL DESK I ROCK Pl-37 (EXT. 20079) K) ELIMINATE YOUR MOP. FBQH DIS'HGBVZXCN .

LISTS FOR DOCQKMIS YOU DOHFT NEED)

TOTAL NUMBER OF COPiES REQUIRED: LTTR 40 ENCL 40

Arizona Public Service Company PALO VERDE NUCLEAR GENERATING STATION P 0 BOX 52034 ~ PHOENIX. ARIZONA85072-2034 JAMES M, LEVINE 192-00609-JML/TDS/RKR VICE PASSIOEkT kVCLEAR PRO00CTIOk December 23, 1989 U. S. Nuclear Regulatory Commission Document Control Desk Vashington, DC 20555

Dear Sirs:

Subj ect: Palo Verde Nuclear Generating Station (PVNGS)

Unit 2 Docket No. STN 50-529 (License No. NPF-51)

Special Report 2-SR-89-008 File: 89-020-404 Attached please find Special Report 2-SR-89'-008 prepared and submitted pursuant to Technical Specifications 3.3.3.8 ACTION 42.b and 6.9.2. This report discusses radiation monitors inoperable for greater than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

If you have any'uestions, please contact T. D. Shriver, Compliance Manager, at (602)-393-2521.

Very truly your J HL/TDS/RKR/k j Attachment cc' V, F Conway (all w/attachment)

J. B. Hartin E. E. Van Brunt T. J. Polich H. J. Davis A. C. Gehr 900f050319 891223 PDR ADOCK 05000529 8 PNU

PALO VERDE NUCLEAR GENERATING STATION UNIT 2 Radiation Monitoring Unit Inoperable Greater Than 72 Hours License No. NPF-51 Docket No. STN 50-529 Special Report No. 2-SR-89-008 This Special Report is submitted in accordance with Technical Specifications 3.3.3.8 ACTION 42.b and 6.9.2 to report an event in which the Condenser Evacuation System High Range Radioactive Gaseous Effluent Monitor (RU-142) and Plant Ventilation System High Range Radioactive Gaseous Effluent Monitor (RU-144) were 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 was exceeded at approximately 0819 MST on November 27, 1989.

At approximately 0819 MST on November 24, 1989 Palo Verde Unit 2 was in Mode 4 (HOT SHUTDOWN) when Gaseous Effluent Monitors RU-142 and RU-144 were taken out of service and declared inoperable for implementation of a site modification.

The site modification is being implemented to correct a previous event on August 12, 1989 described in Supplement 1 to Special Report 3-SR-89-006. The site modification bypasses a rectifier in the power supply circuit for the monitor flow transmitter. Radiation Monitors RU-142, RU-144, and RU-146 are=

designed to be powered by an AC or DC power source. APS uses a 24 VDC power supply for these monitors. There is a rectifier in the power supply circuit to convert AC supplied power to the 24 VDC used, by the monitor.

Troubleshooting of the monitor found that with a 24 VDC power supply input to the rectifier, the rectifier reduces the actual supply voltage to the monitors flow transmitter. This provides marginal operating voltage for this design and affects calibration of the flow transmitter.

Radiation Monitors RU-142 and RU-144 were returned to service at approximately 1320 MST on November 27, 1989 when the site modification and appropriate surveillance testing were completed.

The site modification w'as developed for monitors RU-142, RU-144, and RU-146.

The site modification has been completed in Units 2 and 3. Unit 1 will complete the site modification prior to startup from their current outage.

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