ML17305B355

Special Rept 1-SR-91-001:on 910111,fuel Bldg Ventilation Sys high-range Radioactive Gaseous Effluent Monitor Inoperable for More than 72 H.Caused by Need to Replace Power Supply. Monitors Returned to Operable Status on 910113

ML17305B355
Person / Time
Site:	Palo Verde
Issue date:	02/04/1991
From:	James M. Levine ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
1-SR-91-001, 1-SR-91-1, 192-00712-JML-T, 192-712-JML-T, NUDOCS 9102110240
Download: ML17305B355 (8)

Text

ACCELERATED P+TRIBUTION DEMONSATION SYSTEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:9102110240 DOC.DATE: 91/02/04 NOTARIZED: NO DOCKET 7 FACIL:STN-50-528 Palo Verde Nuclear Station, Unit 1, Arizona Publi 05000528 AUTH. NAME AUTHOR AFFILIATION LEVINE,J.M.. 'rizona Public Service Co. (formerly Arizona Nucleax Power RECIP.NAME , RECIPIENT AFFILIATION Document Control Branch (Document 'Control Desk) R

SUBJECT:

Special Rept 1-SR-91-001:on 910111,fuel bldg ventilation sys high-range radioactive gaseous effluent monitor inoperable for more than 72 h.Caused by need to replace power supply. D Monitors returned to operable status on 910113.

DISTRIBUTION CODE: IE22D COPIES RECEIVED:LTR TITLE: 50.73/50.9 Licensee Event Report A ENCL 4 SIZE:

(LER),incident Rpt, etc. /

NOTES:STANDARDIZED PLANT 05000528 A

RECIPIENT COPIES RECIPIENT 'OPIES D ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD5 LA 1 1 PD5 PD 1 ' D TRAMMELL,C '

1 TRAMMELL,C. 1 1 INTERNAL: ACNW 2 2 ACRS 2 2 AEOD/DOA '1 1 AEOD/DSP/TPAB 1 1 AEOD/ROAB/DSP 2 2 NRR/DET/ECMB 9H 1 1 NRR/DET/EMEB 7E 1 1 NRR/DLPQ/LHFB11 1 1 NRR/DLPQ/LPEB10 1 1 NRR/DOEA/OEAB 1 f.

NRR/DREP/PRPB11 2 2 NRR/DST/SELB 8D 1 1 NRR/DST/SICB 7E 1 1 BRED LBBDl 1 1 NRR/DST/SRXB 8E 1 1 G 02 1 1 RES/DSIR/EIB 1 1 RGN5 FILE 01 1 1 EXTERNAL: EGGG BRYCE,J.H 3 3 L ST LOBBY WARD 1 1 NRC PDR 1 1 NSIC MAYS,'G 1 1 NSIC MURPHY7G ~ A 1 1 NUDOCS FULL TXT 1 1 NOTES 1 '

D A

D NOTE TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE iVASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOliI Pl-37 (EXT. 20079) TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISTS FOR DOCUb IENTS YOU DON'T NEED!

TOTAL NUMBER OF COPIES REQUIRED: LTTR 35 ENCL 35

Arizona Public Service Company PALO VERDE NUCLEAR GENERATING STATION P.O BOX 52034 ~ PHOENIX. ARIZONA85072-2034 192-00712-JML/TRB/KR JAMES M. LEVINE V(CE PRESIDENT February 4, 1991 NUClEAR, PRODUCTION U. S. Nuclear Regulatory Commission Attention: Document Control Desk Mail Station Pl-37 Washington, D.C. 20555

Dear Sirs:

Subj ect Palo Verde Nuclear Generating Station (PVNGS)

Unit 1 Docket No. STN 50-528 (License No. NPF-41)

Special Report 1-SR-91-001 File: 91-020-404 Attached please find Special Report 1-SR-91-001 prepared and submitted pursuant to Technical Specifications 3.3.3.8 ACTION 42(b) and 6 '.2. This report discusses a radiation monitor being inoperable for a period 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 questions, please contact T. R.,Bradish, Compliance Manager at (602) 393-2521.

Very truly yours, JML/TRB/KR/dmn Attachment cc: W. F ~ Conway (all with attachment) >ipse.

J. B. Martin D. H. Coe A. C. Gehr A. H. Gutterman

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ill PALO VERDE NUCLEAR GENERATING STATION UNIT 1 Radiation Monitoring Unit Inoperable Greater Than 72 Hours License No. NPF-41 Docket No. 50-528 Special Report 1-SR-91-001 Initial Conditions r

On January 11, 1991 Palo Verde Unit 1 was in Mode 1 (POWER OPERATION) at approximately 100 percent power.

Descri tion of Event'his Special Report is being submitted pursuant to Technical Specification (TS) 3.3.3.8 ACTION 42b and TS 6 '.2 which the Fuel Building Ventilation System High Range Radioactive to report an event in Gaseous Effluent Monitor (RU-146) was inoperable for a period greater than 72 hours. The 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> period for returning the monitor to service was exceeded at approximately 1355 MST on January 11, 1991.

On, January 8, 1991 at approximately 1355 MST, Radiation Monitors RU-145 (Fuel Building Ventilation System Low Range Radioactive Effluent Monitor) and RU-146 were removed from service in accordance with an approved work document for scheduled 18 month calibration and surveillance tests (ST). Radiation Monitors RU-145 and RU-146 monitor the Fuel Building Ventilation Exhaust for release of radioactivity due to a fuel handling accident. Radiation Monitors RU-145 and RU-146 work as a pair with RU-145 being the low range monitor for normal radioactive gaseous effluents and RU-146 being the high range monitor for post-accident radioactive gaseous effluents. Normal configuration consists of RU-145 operating and RU-146 in standby. When RU-145 reaches a predetermined setpoint, RU-146 starts and RU-145 goes to standby. RU-145 initiates a Fuel Building Essential Ventilation Actuation Signal (FBEVAS) when the activity exceeds a predetermined limit. Since RU-145 empowerRU-146 work in tandem, RU-146 must be declared inoperable

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and is out of service. Pursuant to TS 3.3.3.8 ACTION 42.a, the Preplanned if RU-145 Alternate Sampling Program was initiated to monitor the Fuel Building Ventilation System.

During the performance of the calibration and surveillance, the RU-145 detector would not. pass the surveillance testing acceptance criteria due to a faulty low voltage power supply. While waiting for a replacement supply, testing began on RU-146. Additional corrective maintenance was also performed to replace the'exadecimal display board for RU-145. Corrective maintenance and the 18 month STs were completed and the monitors were returned to service at approximately 1250 MST on January 13, 1991.

1 Special Report 1-SR-91-001 Page 2 Cause of Event The length of time to complete the 18 month STs and perform the corrective maintenance (i.e., replace the power supply and the hexadecimal display board) exceeded the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> period allowed by TS.

Correcti~e Actions'adiation monitors RU-145 and RU-146 were returned to an OPERABLE status at approximately 1250 MST on January 13, 1991 following, satisfactory completion of the STs. The power supply failure .has been addressed in

'previous root cause of failure (RCF) evaluations. Based on the RCF, when the power supply malfunction is detected, an upgraded replacement power supply is being'nstalled in the monitors.

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