ML17300B068

Special Rept 2-SR-87-024:on 870915,fuel Bldg B Vent Exhaust Low & High Range Monitors Declared Inoperable & Placed in Bypass Due to Problems W/Recurrent Voltage Spiking & False Background Readings.Engineering Evaluation Underway

ML17300B068
Person / Time
Site:	Palo Verde
Issue date:	10/14/1987
From:	Haynes J ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
192-00289-JGH-T, 192-289-JGH-T, 2-SR-87-024, 2-SR-87-24, NUDOCS 8710210103
Download: ML17300B068 (4)

Text

REGULAT Y INFORMATION DISTRIBUTIO YSTEM (RIDS)

ACCESSION NBR: 8710210103 DOC. DATE: 87/10/14 NOTARIZED: NO DOCKET FAC IL: STN-50-525'alo Verde Nuclear Station> Unit 2 Ari z ona Pub 1 i 05000529 AUTH. N*NE AUTHOR AFFILIATION HAYNES> J. G. Arizona Nuclear Power ProJect <formerly Arizona Public Serv RECIP. NAME, RECIPIENT AFFILIATION Document Control Branch (Do'cument Control Desk)

SUBJECT:

Special Rept 2-SR-87-024: on 870915> fuel bldg B vent exhaust low i. high range monitors declaT ed inoperable a placed in bypass due to problems w/recurrent voltage spiking Zc false background readings. Engineering evaluation underway.

DISTRIBUTION CODE: IE22D COPIES RECEIVED: LTR ENCL SIZE:

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

> etc.

NOTES: Standardized plant. 05000529 REC IP IENT COPIEB RECIPIENT COP IEB ID CODE/NAME LTTR ENCL ID CODE/NANE LTTR ENCL PD5 L* 1 1 PD5 PD 1 1 LIC ITRA. E 1 1 DAVIS> M 1 INTERNAL: ACRB NICHELSON 1 1 ACRB NOELLER AEOD/DOA 1 1 *EOD/DSP/NAB 1 AEOD/DBP/ROAB 2 2 AEOD/DBP/TP*B 1 1 ARM/DCTS/DAB 1 1 DEDRO 1 NRR/DEBT/ADS 1 0 NRR/DEST/CEB 1 1 NRR/DEBT/ELB 1 NRR/DEST/ ICSB 1 1

NRR/DEBT/NEB 1 1 NRR/DEST/NTB 1 1 NRR/DEST/PSB 1 1 NRR/DEST/RSB 1 NRR/DLPG/HFB .1 1' NRR/DEBT/SGB 1 1 NRR/DLPG/Q*B 1 1 NRR/DOEA/EAB 1 NRR/DREP/RAB 1 1 NRR/DREP/RPB 2 2

/SIB 1 1 NRR/PM*8/ ILRB 1 REG FILE 02 1 1 RES DEPY GI 1 1 ORD> J 1 1 RES/DE/EIB 1 1 RGN5 F I LE 01 1 1 EXTERNAL: EG8cG GROH> N> 5 5 H ST LOBBY WARD 1 1 LPDR 1 1 NRC PDR 1 1 NBIC HARRIS> J 1 1 NBIC MAYS> G 1 1 NOTES: 1 1 TOTAL NUMBER OF COP IEB REQUIRED: LTTR 47 ENCL 46

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-87-024, 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-146) 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 0927 MST on September 18, 1987.

At approximately 0927 MST on September 15, 1987 Palo Verde Unit 2 was in Mode 1 (POWER OPERATION) at 100 percent power when the Fuel Building "B" Vent Exhaust Low and High Range Monitors (RU-145/146) were declared inoperable and placed in bypass due to problems with recurrent voltage spiking and false background radiation readings on RU-145.

Monitors RU-145 and RU-146 monitor the fuel building ventilation exhaust for release of activity due to a fuel handling accident. Monitor RU-145 performs the safety function of isolating the normal ventilation system by initiating a Fuel Building Essential Ventilation Actuation Signal (FBEVAS) on a HIGH-HIGH activity alarm. Monitors RU-145 and RU-146 work as a pair, with RU-145 being the low range monitor and RU-146 being the high range monitor. Normal configuration consists of RU-145 operating and RU-146 in standby. When RU-145 reaches its maximum range, RU-146 starts and RU-145 goes to standby. RU-145 and RU-146 are required to be operable in Modes 1, 2, 3 and 4 or when irradiated fuel is in the fuel storage pool. Since RU-145 and RU-146 work in tandem, RU-146 must be declared inop'erable if RU-145 malfunctions.

Flowrate estimates were initiated at least once every four hours, grab samples at least once every twelve hours, and particulate and iodine sampling on a continuous basis, in accordance with T.S. 3.3.3.8 ACTIONS 36, 37 and 40.

Provisions were also made to ensure compliance with T.S. 3.3.3.8 ACTION 41 and 3.9.12 ACTION (b). 'I At approximately 1950 MST on September 17, 1987, the particulate and iodine samplers, flowrate monitor and sample flowrate measuring device of the subject monitors were determined to be unaffected by the voltage spiking problem. These functions were returned to service at approximately 2035 MST on September 18, 1987, at which time T.S. 3.3.3.8 ACTIONS 36 and 40 were exited. The noble gas monitor function for both monitors remained inoperable under the provisions of T.S. 3.3.3.8 ACTION 37, 41, 42 and 3.9.12 ACTION (b), as noted above.

At approximately 0915 MST on September 24, 1987, all functions for RU-145/146 were declared inoperable to permit troubleshooting and engineering evaluation under an approved work document, at which time the compensatory measures specified by T.S. 3.3.3.8, ACTIONS 36 and 40 were reinstated. These actions are currently in effect pending completion of the engineering evaluation and implementation of appropriate corrective action.'

supplement to this special report will be issued upon completion of the activities noted above.

~l Arizona Nuclear Power Project P.O. SOX 52034 ~ PHOENIX. ARIZONA85072-2034 192-00289-JGH-TRB/KCP October 14, 1987 U.S. Nuclear Regulatory Commission NRC Document Control Desk d5 Washington, D.C. 20555

Subject:

w Palo Verde Nuclear Generating Station (PVNGS) n Unit 2 C3 Docket No. STN 50-529 (License NPF-51)

Special Report 2-SR-87-024 File: 87-020-404 Pl

~ Attached please find a Special Report 2-SR-87-024 prepared and submitted pursuant to Technical Specifications 3.3.3.8 and 6.9.2. This report discusses a radiation monitor that 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 />.

If you have any questions, please contact T. R. Bradish, Compliance Supervisor at (602) 393-3531.

Very truly yours, c) . I4~

J. G. Haynes Vice President Nuclear Production JGH/TRB/KCP/cld 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 INFO Records Center 8710210103 871054 PDR ADDCK 05000529 S PDR zp>