ML17300B156

Special Rept 2-SR-87-029:on 871126,high Range Noble Gas Monitor (RU-142) Found Inoperable for More than 72 H.Caused by Water in RU-141 Sample Line.Moisture Traps Will Be Installed in Sample Lines During Next Refueling Outage

ML17300B156
Person / Time
Site:	Palo Verde
Issue date:	12/24/1987
From:	Haynes J ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
192-00327-JGH-T, 192-327-JGH-T, 2-SR-87-029, 2-SR-87-29, NUDOCS 8712300128
Download: ML17300B156 (3)

Text

1 t AC CELERATZD Ds BUTION DEMONS'HilATJON SYSTEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)ACCESSION NBR:8712300128 DOC.DATE: 87/12/24 NOTARIZED:

NO DOCKET FACIL:STN-50-529 Palo Verde Nuclear Station, Unit 2, Arizona Publi 05000529 AUTH.NAME AUTHOR AFFILIATION HAYNES,J.G.

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

SUBJECT:

Special Rept 2-SR-87-029:on 871123,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.R I NOTES:Standardized plant.RECIPIENT ID CODE/NAME PD5 LA LICITRA,E INTERNAL ACRS MICHELSON AEOD/DOA AEOD/DSP/ROAB ARM/DCTS/DAB NRR/DEST/ADS NRR/DEST/ELB NRR/DEST/MEB NRR/DEST/PS B NRR/DEST/SGB NRR/DLPQ/QAB NRR/DREP/RAB NRR/SIB G FX.LE 02 EFORD, J RGN5 FILE 01 EXTERNAL: EG&G GROH,M H ST LOBBY WARD NRC PDR NSIC MAYS,G NOTES: COPIES LTTR ENCL 1 1 1 1 1 1 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 5 5 1 1 1 1 1 1 1 1 RECIPIENT ID CODE/NAME PD5 PD DAVISM ACRS MOELLER AEOD/DSP/NAS AEOD/DSP/TPAB DEDRO NRR/DEST/CEB NRR/DEST/ICSB NRR/DEST/MTB NRR/DEST/RSB NRR/DLPQ/HFB NRR/DOEA/EAB NRR/DREP/RPB NRR/PMAS/ILRB RES DEPY GI RES/DE/EIB FORD BLDG HOY,A LPDR NSIC HARRIS,J COPIES LTTR ENCL 1 1 1 1 2 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 i 2 1 1 1 1 1 1 1 1 1 1"l 1 0500'0529 D.8 1';TOTAL NUMBER QF COPIES REQUIRED: LTTR 48 ENCL 47 Arizona Nuclear power project P.O.BOX 52034~PHOENIX.ARIZONA 85072-2034 192-00327-JGH/TRB/DAJ December 24, 1987 U.S.Nuclear Regulatory Commission NRC Document Control Desk Washington, D.C.20555

Subject:

Palo Verde Nuclear Generating Station (PVNGS)Unit 2 Docket iVo.STN 50-529 (License No.NPF-51)Special Report 2-SR-87-029 File: 87-020-404 Attached please find Special Report 2-SR-87-029 prepared and submitted pursuant to Technical Specification 3.3.3.8 Action 42b and 6.9.2.This report discusses a High Range Noble Gas Monitor that was inoperable for over 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 J.E.tlalik, (Acting)Compliance Lead at (602)393-3527.Very truly yours, JGH/JEH/KCP/kj Attachment cc: 0.f1.DeMichele (all w/a)E.E.Van Brunt, Jr.J.B.Hartin J.R.Ball E.A.Licitra A.C.Gehr INPO Records Center J.G.Haynes Vice President Nuclear Production

'8712300i28 87i224 PDR ADOCK 05000529~8 DCD g&

PALO VERDE NUCLEAR GENERATING STATION RADIATION MONITORING UNIT INOPERABLE FOR GREATER THAN 72 HOURS License No.NPF-51 Docket No.STN 50-529 Special Report No.2-SR-87-029 This Special Report is being submitted in accordance with Technical Specification (T.S.)3.3.3.8 ACTION 42(b)and 6.9.2 to report 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 1308 HST on November 26, 1987.At approximately 1308 HST on November 23, 1987 Palo Verde Unit 2 was in Node 3 (HOT STANDBY)at 0 percent power when the Condenser Vacuum Pump/Gland Seal Exhaust Low and High Range Monitors (RU-141/142) were declared inoperable and placed in bypass due to water in the RU-141 sample line.t1onitors RU-141 and RU-142 monitor the condenser vacuum pump/gland seal exhaust for release of activity resulting from primary to secondary leakage.RU-141 provides automatic initiation of filtration of the condenser vacuum pump/gland exhaust whenever the monitor channel is in a HIGH-HIGH alarm condition.

t1onitors 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 and RU-142 in standby.When RU-141 reaches a predetermined setpoint, RU-142 starts and RU-141 goes to standby.RU-141 and RU-142 are required to be operable in Nodes 1 through 4.Since RU-141 and RU-142 work in tandem, RU-142 must be declared inoperable if RU-141 is placed in an inoperable status.As immediate corrective action the appropriate compensatory measures were initiated to obtain flow rate estimates, grab samples, and continuous particulate and iodine samples in accordance with T.S.3.3.3.8 ACTIONS 36, 37, and 40.Troubleshooting revealed that approximately one quart of water had accumulated in the detector cavity of the monitor.It was determined that the water accumulated in the cavity from the installed sample lines due to the high moisture content of the monitored exhaust.The accumulated water was drained from the sample line and detector cavity, and the detector cavity dried out and restored to an operable condition.

This work was completed at approximately 1530 on November 27, 1987, and surveillance testing initiated in accordance with 36ST-9Sg07,"Radiation Monitoring Calibration Test for New Scope Process Monitors," and 75ST-9ZZ07,"Effluent Monitoring System Daily Surveillance Testing".In addition, RU-141 and RU-142 were placed under observation for several days to verify proper operation of the monitors.In order to preclude recurrence of this event in Unit 2, moisture traps are planned to be installed in the sample lines dur ing the next refueling outage.A similar installation is in process for Unit 1, and has been completed for Unit 3.At 1455 HST on November 30, 1987, RU-141 and RU-142 were declared operable following satisfactory completion of the surveillance testing noted above.The duration of this event was approximately 7 days.