ML17303A428

Special Rept 1-SR-87-019:on 870504,radiation Monitor Declared Inoperable Due to Spurious Detector Failure Alarms. Cause of Alarms Unknown.Monitor Returned to Operability After Completion of Surveillance Testing

ML17303A428
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
1-SR-87-019, 1-SR-87-19, 192-00227-JGH-T, 192-227-JGH-T, NUDOCS 8706160136
Download: ML17303A428 (6)

Text

t( r REGULA. Y INFORMATION DISTRIBUTI SYSTEM (RIDS)

ACCESSION NBR 870b160136 DOC. DATE: 87/Ob/08 NOTARIZED: NO DOCKET FACIL: STN-50-528 Palo Verde Nuclear Station> Unit 1> Arizona Publi 05000528 AUTH. NAME AUTHOR AFFILIATION HAYNES> J. G. Arizona Nuclear Power Pro Ject (formerly Arizona Public Serv REC IP. NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)

SUBJECT:

Special Rept 1-SR-87-019: on 870504> radiation monitor declared inoperable due to spurious detector failure alarms.

Cause of alarms unknown. Monitor returned to operability after comp 1etion of surveil lance testing.

DISTRIBUTION CODE: IERED COP IEB RECEIVED: LTR TITLE: 50. 73 Licensee Event Report (LER) >

g Incident ENCL Rpt>

g etc.SIZE:

NOTES: Standardized plant. M. Davis> NRR: 1Cg. 05000528 RECIP I ENT COP I ES REC IP IENT 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 1 INTERNAL: ACR 8 MI C HELSON 1 1 ACRS MOELLER 2 2 AEOD/DOA 1 1 AEOD/DSP/ROAB 2 2

• EOD/DSP/TPAB 1 1 DEDRO 1 1 NRR/DEST/ADE 1 0 NRR/DEST/ADS 1 0 NRR/DEST/CEB 1 1 NRR/DEST/ELB 1 1 NRR/DEST/ICSB NRR/DEST/MEB 1 NRR/DEBT/MTB 1 1 NRR/DEBT/PSB 1 1 NRR/DEST/RSB 1 1 NRR/DEBT/SGB 1 NRR/DLPG/HFB 1 1 NRR/DLPG/GAB 1 1 NRR/DOEA/EAB 1 1 NRR/DREP/RAB 1 1 NRR/DREP/RPB 2 2 1 1 NRR/PMAS/PTSB 1 REG L 02 1 RES DEP Y G I 1 RGNS FILE 01 1 EXTERNAL: EGbG GROH> M 5 5 H ST LOBBY l4ARD 1 1 LPDR 1 1 NRC PDR 1 1 NSIC HARRIS> J 1 NSIC MAYS> G 1 1 NOTES:

TOTAL NUMBER OF COPIES REQUIRED: LTTR 44 ENCL 42

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Arizona Nuclear Power Project P.o. BOX 52034 ~ PHOENIX, ARI2ONA 85072-2034 192-00227-JGH-TRB/TJB June 8, 1987 Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555

Subject:

Palo Verde Nuclear Generating Station (PVNGS)

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

Special Report 1-SR-87-019 File: 87-020-404

Dear Sirs:

Attached please find a Special Report 1-SR-87-019 prepared and submitted pursuant to Technical Specifications 3.3.3.1 and 6.9.2 This'eport discusses a Radiation Monitor 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 T. R. Bradish, Compliance Supervisor at (602) 932-5300, Ext. 6936.

Very truly yours, J. G. Ha nes Vice President Nuclear Production JGH/TRB/TJB/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 8706160136 870608 PDR ADOCK 05000828 PDR

PALO VERDE NUCLEAR GENERATING STATION Special Report No. 1-SR-87-019 RADIATION MONITORING UNIT NOT RESTORED WITHIN 72 HOURS Docket No. STN 50-528 License No. NPF-41 This Special Report is required by Palo Verde Unit 1 Technical Specification 3.3.3.1, Table 3.3-6, ACTION 27 for a Radiation Monitor which 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 />.

At approximately 0516 MST on May 4, 1987, Palo Verde Unit 1 was in Mode 1 (POWER OPERATION) operating at 100 percent power when a Containment Building Area Radiation Monitor (RU-149) was declared inoperable due to spurious detector failure alarms. The Preplanned Alternate Program to monitor the appropriate parameters was initiated as required when the monitor could not be restored to operability by 0516 on May 7, 1987.

Troubleshooting to determine the cause of the alarms was commenced under an approved work order. During the course of troubleshooting the monitor's signal and high voltage cables were removed and a simulated signal was introduced. The monitor was observed for any anomalies. Subsequent troubleshooting consisted of observing the monitor following the installation of a temporary ground, the subsequent restoration of the signal and high voltage cables, and the removal of the temporary ground. However, a cause for the spurious alarms could not be-.

determined. The radiation monitor was put back on line on May 14, 1987, but was maintained in an inoperable status to allow for additional troubleshooting and monitoring for approximately twenty three days. No failures or abnormalities were detected during this time period.

Because of the inability to recreate the spurious alarms and the inability to isolate a particular deficiency, no root cause could be identified. An Engineering Evaluation Request (EER) is currently being dispositioned to allow the monitor to be returned to service. Upon satisfactory disposition of the EER and the completion of the appropriate surveillance testing, RU-149 will be restored to an operable status. The monitor is expected to be declared operable by June 10, 1987. Should RU-149 exhibit similar problems, further troubleshooting will be conducted to try and determine a root cause.

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