ML17303A427

Special Rept 2-SR-87-016:on 870509,radioactive Gaseous Effluent Monitor Exceeded 72 H Limit for Operability.Caused by Maint of Low Flow Alarm.Surveillance Test Performed & Monitor Declared Operable on 870512

ML17303A427
Person / Time
Site:	Palo Verde
Issue date:	06/08/1987
From:	Haynes J ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
2-SR-87-016, 2-SR-87-16, NUDOCS 8706160033
Download: ML17303A427 (3)

Text

REGULA d INFORMATION DISTRIBUTIOI YSTEM (RIDS)

ACCESSION NBR: 8706160033 DOC. DATE: 87/06/08 NOTARIZED: NO DOCKET 0 FACIL: STN-50-529 Palo Verde Nuclear Station> Unit 2> Arizona Publi 05000529 AUTH. NAME 'AUTHOR AFFILIATION HAYNES> J. G. Arizona Nuclear Poeer Prospect (formerly Arizona Public Serv RECIP. NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)

SUBJECT:

Special Rept 2-SR-87-016: on 870509> radioactive gaseous effluent monitor exceeded 72 h limit for test operability. Caused bg maint- of lou floe alarm. Surveillance performed 8.

monitor declared oper'able on 870512.

DISTRIBUTION CODE: IE22D COPIES RECEIVED: LTR ENCL SIZE:

TITLE: 50. 73 Licensee Event Report (LER)> Incident Rpt> etc.

NOTES: Standardized plant. M. Davis> NRR: 1Cg. 05000529 RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD5 LA 1 1 PD5 PD 1 1 LICITRA> E =

1 1 DAVIS> M 1 INTERNAL: ACRS MICHELSON 1 ACRS MOELLER 2 2 AEOD/DOA 1 AEOD/DSP/ROAB 2 2 AEOD/DSP/TPAB 1 1 DEDRO 1 1 NRR/DEST/ADE 1 0 NRR/DEBT/ADS 1 0 NRR/DEBT/CEB 1 1 NRR/DEST/ELB 1 NRR /DEST/ ICSB 1 1 NRR/DEBT/MEB 1 1 NRR/DEST/MTB 1 1 NRR/DEST/PSB 1 NRR/DEST/RSB 1 NRR/DEST/SGB 1 1 NRR/DLPG/HFB 1 NRR/DLPG/GAB 1 1 NRR/DOEA/EAB 1 1 NRR/DREP/RAB 1 1 NRR/DREP/RPB 2 2 ~$ 4'-RN* ILR8 1 1 NRR/PMAS/PTSB 1 REG FILE 02 1 1 RES DEPY GI 1 R FILE 01 1 EXTERNAL: EGhG GROH M 5 5 H ST LOBBY NARD 1 1 LPDR 1 1 NRC PDR 1 1 NSIC HARRIS> J 1 1 NSIC MAYS> G 1 1 NOTES: 1 1 TOTAL NUMBER OF COPIES REQUIRED: LTTR 44 ENCL 42

PALO E NUCLEAR GENERATING STATION Radiation Monitoring Unit Inoperable for Greater Than 72 Hours License No. NPF-51 Docket No. STN 50-529 Special Report 2-SR-87-016 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, (Condenser Evacuation High Range Noble Gas Activity 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 operability was exceeded at approximately 0230 MST on May 9, 1987.

Pursuant to Technical Specification 3.3.3.8 ACTION 42a the Preplanned Alternate Sampling Program was initiated to monitor the condenser Evacuation System.

At approximately 0230 MST on May 6, 1987, Palo Verde Unit 2 was in Mode 1 (POWER OPERATION) when the Condenser Evacuation System Radioactive Gaseous Effluent Monitors, low range RU-141 and high range RU-142, were declared inoperable due to the low flow alarm not working during a weekly surveillance test.

Monitors RU-141 and RU-142 work as a pair with RU-141 being the low range monitor and RU-142 being the high range monitor. Normal configuration consists of RU-141 operating and RU-142 in standby. When RU-141 reaches it's maximum range, RU-142 starts and RU-141 goes to standby. Since RU-141 and RU-142 work in tandem, both monitors must be declared inoperable if the other malfunctions.

Troubleshooting, rework, and replacement of components was performed in accordance with an approved work control document. The cause of the low flow alarm not working was air leakage past an 0-ring. The 0-ring creates a seal between the filter and the filter housing. During the surveillance test the inlet valve for the monitor is closed. The low flow alarm should then alarm. Due to the leakage past the 0-ring there was flow at all times therefore the low flow alarm would not come in. The filter and 0-ring were replaced and the low flow alarm worked as designed.

Prior to the work document closure, low flow alarms began continuously cycling on and off. Troubleshooting found the bellows assembly for a flow control valve to be broken. The bellows assembly is a brass coupling between the valve stem and actuator. The bellows assembly rotates clockwise or counterclockwise, depending whether the valve is to be opened or closed. The bellows had a broken solder

)oint which was caused by overextending the bellows. This was due to the lower limit switch arm being loose and not stopping valve travel when closing the valve.

The valve disc was then 5ammed in the valve seat. When the valve was opened, the bellows was overextended and the solder )oint broke. The bellows was replaced and the limit switch was readjusted to prevent the valve from jamming into the seat.

The Surveillance Test was performed satisfactorily and RU-141 and RU-142 were declared operable at 1620 MST on May 12, 1987. The monitors were inoperable for 6 days 13 hours1.50463e-4 days <br />0.00361 hours <br />2.149471e-5 weeks <br />4.9465e-6 months <br /> and 50 minutes.

8706160033 870608 PDR ADOCK 05000529 8 PDR

Arizona Nuclear Power Project P.o. BOX 52034 ~ PHOENIX, ARIZONA85072-2034 192-00219-JGH/TRB/JEM June 8, 1987 NRC Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555

Subject:

Palo Verde Nuclear Generating Station Unit 2 Docket No. STN 50-529 (License NPF-51)

Special Report 2-SR-87-016 File: 87-020-404

Dear Sirs:

Attached please find a Special Report 2-SR-87-016 prepared and submitted pursuant to Technical Specifications 3.3.3.8 and 6.9.2. This report discusses a Radiation Monitoring Unit 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 questions, please contact Tom Bradish, Compliance Supervisor at (602) 932-5300, Ext. 6936.

Very trul yours, CP J. G. Haynes Vice President Nuclear Production JGH/TRB/JEM/cld Attachment cc: 0. M. DeMichele (all w/a)

E. E. Van Brunt, Jr.

J. B. Martin R. P. Zimmerman R. C. Sorenson E. A. Licitra A. C. Gehr INPO Records Center