ML17303A726

Special Rept 3-SR-87-009:on 871211,plant Vent High Range Gaseous Activity Monitor RU-144 Inoperable for Greater than 72 H.Caused by Isolation Board Malfunction.Board Replaced & Retested & Surveillance Tests for Monitors Completed

ML17303A726
Person / Time
Site:	Palo Verde
Issue date:	01/07/1988
From:	Haynes J ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
192-00331-JGH-J, 192-331-JGH-J, 3-SR-87-009, 3-SR-87-9, NUDOCS 8801130351
Download: ML17303A726 (8)

Text

AC CELERLTED e

MSI'RIBUTION e

DEMONSTRATION SYSTEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:8801130351 DOC.DATE: 88/01/07 NOTARIZED- NO DOCKET FACIL:STN-50-530 Palo Verde Nuclear Station, Unit 3, Arizona Publi 05000530 AUTH. NAME AUTHOR AFFILIATION HAYNES,J.G. Arizona Nuclear Power Project (formerly Arizona Public Serv RECIP 'NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)

SUBJECT:

Special Rept 3-SR-87-009:on 871211,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. I plant. 05000530'OTES:Standardized RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME PD5 LA LICITRA,E LTTR ENCL 1

1 1

1 ID PD5 PD CODE/NAME DAVIS,M LTTR ENCL 1

1 1

1 j

A INTERNAL: ACRS MICHELSON 1 1 ACRS MOELLER 2 2 AEOD/DOA 1 1 AEOD/DS P/NAS 1 1 AEOD/DSP/ROAB 2 2 AEOD/DS P/TPAB 1 1 ARM/DCTS/DAB 1 1 DEDRO 1 1 NRR/DEST/ADS 1 0 NRR/DEST/CEB 1 1 NRR/DEST/ELB 1 1 NRR/DEST/ICSB 1 1 NRR/DEST/MEB 1 1 NRR/DEST/MTB 1 1 NRR/DEST/PSB 1 1 NRR/DEST/RSB 1 1 NRR/DEST/SGB 1 1 NRR/DLPQ/HFB 1 1 NRR/DLPQ/QAB 1 1 NRR/DOEA/EAB 1 1 NRR/DREP/RAB 1 1 NRR/DREP/RPB 2 2 RIS/SIB 1 1 NRR/PMAS/ILRB 1 1 IL 02 1 1 RES DEPY GI 1 1 EXP D,J 1 1 RES/DE/EIB 1 1 RGN5 FILE 01 1 1 EXTERNAL: EGGG GROH,M 5 5 FORD BLDG HOY,A 1 1 H ST LOBBY WARD 1 1 LPDR 1 1 NRC PDR 1 1 NSIC HARRIS,J 1 1 NSIC MAYS,G 1 1 NOTES:

S 9

D TOTAL NUMBER OF COPIES REQUIRED: LTTR 48 ENCL 47

'l 14 4

I I

I Ii

Arizona Nuclear Power Project P.O. BOX 52034 ~ PHOENIX, ARIZONA85072-2034 192-00331-JGH/JEM January 7, 1988 U.S. Nuclear Regulatory Commission NRC Document Control Desk Washington, D .C. 20555

Subject:

Palo Verde Nuclear Generating Station (PVNGS)

Unit 3 Docket No. STN 50-530 (License No. NPF-74)

Special Report 3-SR-87-009 File: 88-020-404 Attached please find Special Report 3-SR-87-009 prepared and submitted pursuant to Technical Specification 3.3.3.8 Action 42b 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 J. E. flalik, (Acting) Compliance Lead at (602) 393-3527.

Very tru y yours, J. G. Haynes Vice President Nuclear Production JGH/JEM/kj Attachment cc: 0. M. DeMichele (all w/a)

E. E. Van Brunt, Jr.

J. B. Martin J. R. Ball E. A. Licitra A. C. Gehr INPO Records Center 880ii3035i 05000530 PDR ADOCK 880107 ~gZ Z.

8 DCD I/i

PALO VERDE NUCLEAR GENERATING STATION Radiation Monitoring Unit Inoperable for Greater Than 72 Hours License No. NPF-74 Docket No. STN 50-530 Special Report No. 3-SR-87-009 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 flonitor (Plant Vent High Range Gaseous Activity Monitor RU-144) 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 returning to operability was exceeded at approximately 2130 MST on December 11, 1987. Pursuant to Technical Specification 3.3.3.8 ACTION 42a the Preplanned Alternate Sampling Program was initiated to monitor the Plant Vent System.

At 2130 MST on December 8, 1987, Palo Verde Unit 3 was in Mode 1 (POWER OPERATION) when the Plant Vent System Radioactive Gaseous Effluent Monitors, low range RU-143 and high range RU-144, were declared inoperable due to RU-144 spuriously becoming active and inactive. Monitors RU-143 and RU-144 work as a pair with RU-143 being the low range monitor and RU-144 being the high range monitor. Normal configuration consists of RU-143 operating and RU-144 in standby. When RU-143 reaches a predetermined point, RU-144 starts and RU-143 goes to standby. RU-144 is provided for tracking of postulated accident releases.

An authorized work document was issued to troubleshoot the monitors. A recorder was connected to RU-143 to monitor the communication between the monitors. Miscommunication between the monitors could result in spurious actuation of RU-144. The recorder results were reviewed after approximately 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> with no indications of spurious signals being generated.

"On line" testing was conducted on RU-143 to verify that the monitor would, under prescribed conditions, activate and deactivate RU-144. These tests were completed with satisfactory results. Additional testing was also conducted on RU-144. During the test of RU-144 the "Equipment Failure" light illuminated and the "Pump On" indication was not received. In the configuration used during the test, RU-143 secured and RU-144 activated, the circulation pump is required to be in operation. The pump circulates sample air from the plant vent through the monitor and returns the sample to the vent. The pump and RU-144 were verified to be operating properly. It was also verified that the indications received were erroneous. Additionally the auxiliary contacts on the pump breaker, which generates the "Pump On" signal, were verified to be operating properly. Further troubleshooting identified an isolation board in RU-144 which was not functioning properly.

0 4 Special Report 3-SR-87-009 Page 2 The board was replaced and the indications were verified to be properly operating. The spurious activation of RU-144 has not recurred and is believed to have been caused by the isolation board. An Engineering Evaluation Request has been submitted to perform an analysis on RU-144.

A retest of RU-144 was satisfactorily completed. After the completion of appropriate surveillance tests RU-143 and RU-144 were declared operable at 0420 HST on December 12, 1987. The monitors were out of service for approximately 78 hours9.027778e-4 days <br />0.0217 hours <br />1.289683e-4 weeks <br />2.9679e-5 months <br /> and 50 minutes.

o,9V 4I