ML17310A758

Special Rept 1-SR-93-004:on 931008,high Range RM RU-146 Made Inoperable for Period of Greater than 72 H as Result of Scheduled Electrical Bus Outage.Maint on Associated Bus Completed on 931015 & RU-146 Returned to Service

ML17310A758
Person / Time
Site:	Palo Verde
Issue date:	10/30/1993
From:	James M. Levine ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
1-SR-93-004, 1-SR-93-4, 192-00866-JML-B, 192-866-JML-B, NUDOCS 9311090161
Download: ML17310A758 (5)

Text

ACCEI.ERA'FED DOCUMENT DISTRIBUTION SYSTEM REGUL'ORY INPORMATION DISTRIBU'.QN SYSTEM (RIDE)

SUBJECT:

Special Rept 1-SR-93-004:on 931008,high range RM RU-146 made inoperable for period of greater than 72 h as result of scheduled electrical bus outage.Maint on associated bus completed on 931015 6 RU-146 returned to service.DISTRIBUTION CODE: ZE22D COPIES RECEIVED:LTR J ENCL 1 SIZE: TITLE: 50.73/50.9 Licensee Event Report (LER), Incident Rpt, etc.NOTES:STANDARDIZED PLANT 05000528 ACCESSION NBR:9311090161 DOC.DATE: 93/10/30 NOTARIZED:

NO'OCKET FACIL:STN-50-528 Palo Verde Nuclear Station, Unit 1, Arizona Publi 05000528 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)D-RECIPIENT ID CODE/NAME PDV LA HOLIAN,B INTERNAL: ACRS AEOD/DSP/TPAB NRR/DE/EELB NRR/DORS/OEAB NRR/DRCH/HICB NRR/DRIL/RPEB NRR S SPLB 02.RGN5 FILE 01 EXTERNAL: EG&G BRYCEEJ.H NRC PDR NSIC POORE,W.COPIES LTTR ENCL 1 1 1 1 2 2 1'1 1'1 1 1 1 1 1 1 1 1 1 1 2 2 1 1 1 1 RECIPIENT ID CODE/NAME PDV PD TRAN,L AEOD/DOA AEOD/ROAB/DSP NRR/DE/EMEB NRR/DRCH/HHFB NRR/DRCH/HOLB'RR/DRSS/PRPB NRR/DSSA/SRXB RES/DSIR/EIB L ST LOBBY WARD NSIC MURPHY,G.A NUDOCS FULL TXT COPIES LTTR ENCL 1 1 1 1 1 1 2 2 1 1 1 1 1 1 2 2 1 1 1 1 1 1 1 1 1 1 D D NOTE TO ALL"RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTEI CONTACT THE DOCUMENT CONTROL DESK, ROOM Pl-37 (EXT.504-2065)TO ELIMINATE YOUR NAME FROM DISTRIBUTION LISIS FOR DOCUMENTS YOU DON'T NEED!D TOTAL NUMBER OF=COPIES REQUIRED: LTTR 31 ENCL 31 JAMES M.LEVINE VICE PRESIDENT NUCEEAR PRODUCTION Arizona Public Service Company PALO VERDE NUCLEAR GENERATING STATION P.O.8OX 52034~PHOENIX.ARIZONA 85072-2034 192-00866-JML/BAG/R JR October 30, 1993'.S.Nuclear Regulatory Commission Attention:

Document Control Desk Mail Station P1-37 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-93-004 File: 93-020-404 Enclosed please find.Special Report 1-SR-93-004 prepared and submitted pursuant to the PVNGS Offsite Dose Calculation Manual requirements and Technical Specification 6.9.2.This report discusses the Fuel Building Ventilation System High Range 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 Burton A.Grabo, Supervisor, Nuclear Regulatory Affairs, at (602)393-6492.Sincerely, JML/BAG/R JR/rv Enclosure cc: W.F.Conway (all with attachment)

B.A.Faulkenberry J.A.Sloan INPO Records Center%K 9311090161.

931030 PDR ADOCK 05000528 PDR

[

PALO VERDE NUCLEAR GENERATING STATION UNIT 1 Fuel Building Ventilation System-.Hlgh Range Radiation Monitor (RU-146)Inoperable License No.NPF-41 Docket No.50-528 Special Report 1-SR-93-004 Initial Conditions On October 8, 1993, Palo Verde Unit 1 was in a refueling outage with the core off loaded to the Fuel Building (FB)fuel storage pool.Descrl tlon of Event This special report is being submitted pursuant to the PVNGS Offsite Dose Calculation Manual (ODCM)and Technical Specification (TS)6.9.2 to report an event in which the FB Ventilation System High Range Radiation Monitor (RU-146)was 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 />.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 minimum number of High Range Radiation Monitor channels to an OPERABLE condition was exceeded at approximately 1343 MST on October 11, 1993.ODCM Section 2.1 requires that a high range radiation monitor with a minimum of one noble gas, iodine, and particulate sample channel, and one sample flow rate measuring device be OPERABLE during MODES 1, 2, 3, and 4, or when irradiated fuel is in the fuel storage pool.The RU-146 consists of a set of three particulate and iodine samplers and a dual channel noble gas monitor along with the associated pumping and flow control system.This forms the high range portion of the Fuel Building exhaust discharge post accident monitoring required by NUREG-0737 and Regulatory Guide 1.97, Rev 2.The purpose of these monitors is to assess releases through FB Essential Ventilation Exhaust under post accident conditions.

Cause of Event At approximately 1343 MST on October 8, 1993, the 480 volt Class IE load center that powers RU-146 was de-energized for preventive maintenance during the current Unit 1 refueling outage.As a result of this scheduled electrical bus outage, RU-146 was made inoperable.

NRC Document Control Desk Page 2 of 2 Special Report 1-SR-93-004 Corrective Action The electrical bus outage was expected to take 168 hours0.00194 days <br />0.0467 hours <br />2.777778e-4 weeks <br />6.3924e-5 months <br />.This would make RU-146 inoperable beyond the 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> allowed by the ODCM.Because of this, ODCM ACTIONS 41 and 42,"operate the Fuel Building Essential Ventilation System while moving irradiated fuel" and"initiate the preplanned alternate sampling program," were entered at approximately 1323 MST on October 8, 1993, prior to de-energizing the 480 volt load center.Maintenance on the associated electrical bus was completed at approximately 1346 MST on October 15, 1993, and RU-146 was returned to service.