ML17300A941

Special Rept 2-SR-87-018:on 870523,high & Low Range Noble Gas Activity Monitors Inoperable for Greater than 72 H. Caused by Defective Amplifier Displacement Card Which Caused Low Readings.Card Replaced

ML17300A941
Person / Time
Site:	Palo Verde
Issue date:	06/22/1987
From:	Haynes J ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
192-00232-JGH-T, 192-232-JGH-T, 2-SR-87-018, 2-SR-87-18, NUDOCS 8706300379
Download: ML17300A941 (3)

Text

REGULA .Y INFORMATION DISTRIBUTIQ YSTEM (RIDS)

ACCESSION NBR: 8706300379 DOC. DATE: 87/06/22 NOTARIZED: NO DOCKET FACIL: STN-50-529 Palo Vev de Nucleav Station> Unit 2i Av izona Publi 05000529 AUTH. NAME AUTHOR AFFILIATION HAYNES'. Q. Av i zona Nucleav Power Prospect < fov mev lg Av i zona, Public Serv RECIP. NAME RECIPIENT AFFILIATION Document Contvol Bvanch <Document Contvol Desk)

SUBJECT:

Special v ept 2-sv-87-018: on 870523> high 5 lorn v ange noble gas activity monitors inoperable for greater than 72 h.

Caused bg defective amplifiev displacement card which cause lou v eadings. Cav d replaced.

DISTRIBUTION CODE: IE22D COPIES RECEIVED: LTR J ENCL i SIZE:

TITLE: 50. 73 Licensee Event Repov t <LER? Incident Rpti etc.

NOTES:,Standardized plant. M. Davisi NRR: 1Cg.

0500052)'EC IP IENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD5 L* 1 PD5 PD LICITRAiE 1 DAVIS' 1 INTERNAL: ACRS MICHFLSON 1 ACRS MQELLER 2 2 AEQD/DOA 1 AEOD/DSP/ROAB AEOD/DSP/TPAB 1 1 DEDRO NRR/DEST/ADE 1 0 NRR/DEST/ADS 0 NRR/DEST/CEB NRR/DEBT/ELB NRR/DEST/ICSB NRR/DEST/MEB NRR/DEST/MTB NRR/DEST/PSB 1 NRR/DEBT/RSB NRR/DEST/SQB NRR/DLPG/HFB NRR/DLPG/GAB NRR/DQEA/EAB NRR/DREP/RAB NRR/DREP/RPB 2 2 N AS/ILRB 1 NRR/PMAS/PTSB 1 REQ FIi 02 RES DEPY QI N LE 01 EXTERNAL: EQM GROHi M 5 5 H ST LOBBY WARD 1 LPDR 1 NRC PDR 1 NSIC HARRIS J NSIC MAYST Q NOTES:

TOTAL NUMBER OF COPIES REGUl RED: LTTP. 44 ENCL 42

Arizona Nudeai Power Project P.o. BOX 52034 ~ PHOENIX, ARIZONA85072-2034 192-00232-JGH-TRB/ESP June 22, 1987 Document Control Desk U. S. Nuclear Regulatory Commission Washington, D. C. 20555

Subject:

Palo Verde Nuclear Generating Station (PVNGS)

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

Special Report 2-SR-87-018 File: 87-020-404

Dear Sirs:

Attached please find a Special Report 2-SR-87-018 prepared and submitted pursuant to Technical Specifications 3.3.3.8 and 6.9.2. This report discusses Radiation Monitoring Units 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 any questions, please contact T. R. Bradish, Compliance Supervisor at (602) 932-5300, Ext. 6936.

Very truly yours, J. G. Haynes Vice President Nuclear Production JGH/TRB/ESP/ibb Attachemnt 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 8706300379 870622 PDR ADOCK 05000529 S PDR

PALO VERDE NUCLEAR GENERATING STATION Radiation Monitors Inoperable for Greater Than 72 Hours License No. NPF-51 Docket No. STN 50-529 Special Report No. 2-SR-87-018 This Special Report is being submitted pursuant to Technical Specification (T.S.) 3.3.3.8 ACTION 42 b and T.S. 6.9.2 to report an event in which the hi and low range noble gas activity monitors,(RU-145 and RU-146) 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 for operability was exceeded at approximately 1308 MST on May 23, 1987. Pursuant to T.S. 3.3.3.8 ACTION 42 a the Preplanned Alternate Sampling Program was initiated to monitor the fuel building ventilation system.

At approximately 1308 MST on May 20, 1987, Palo Verde Unit 2 was in Mode 1 (POWER OPERATION) when RU-145 and RU-146 were taken out of service to allow the performance of the 18 month calibration test.

During testing it was discovered that RU-146 Channel 2 was reading lower than expected during calibration. A work authorizing document was issued to troubleshoot and repair the detector. Troubleshooting revealed that a defective amplifier displacement card was causing the low readings.

In the event that Channel 2 had been reading low during the period between calibration, increased radiation levels would have been detected by the low range monitor (RU-145).

As an immediate corrective action, the card was replaced. A root cause of failure request has been initiated and will address the potential of similar cases in other monitors encompassing all three units.

Upon completion of the work order and appropriate surveillance test, RU-145 and 146 will be restored to an operable status. The monitors are expected to be returned to service before July 1, 1987.