ML17304B141

Special Rept 1-SR-89-003:on 890330,condenser Evacuation Sys High Range Effluent Monitor RU-142 Declared Inoperable for More than 72 H Due to Engineering Concerns Re Moisture in Gas Channel.Long Term Design Mods Implemented

ML17304B141
Person / Time
Site:	Palo Verde
Issue date:	04/25/1989
From:	Haynes J ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
1-SR-89-003, 1-SR-89-3, 192-00472-JGH-T, 192-472-JGH-T, NUDOCS 8905080297
Download: ML17304B141 (6)

Text

REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:8905080297 DOC DATE- 89/04/25 NOTARIZED: NO DOCKET 1~T FACIL:STN-50-528 Palo Verde Nuclear Station, Unit 1, Arizona Publi 05000528 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 1-SR-89-003:on 890330,radiation monitor inoperable for greater than 72 h.

DISTRIBUTION CODE IE22D COPIES RECEIVED:LTR ENCL SIZE:

TITLE: 50.73/50.9 Licensee Event Report (LER), Incident Rpt, etc.

NOTES:Standardized plant. 05000528S RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD5 LA 1 1 PD5 PD 1 1 CHAN,T 1 1 DAVIS,M 1 1 INTERNAL: ACRS MICHELSON 1 1 ACRS MOELLER 2 2 ACRS WYLIE 1 1 AEOD/DOA 1 1 AEOD/DSP/TPAB 1 1 AEOD/ROAB/DSP 2 2 DEDRO 1 1 IRM/DCTS/DAB 1 1 NRR/DEST/ADE 8H 1 1 NRR/DEST/ADS 7E 1 0 NRR/DEST/CEB 8H 1 1 NRR/DEST/ESB 8D 1 1 NRR/DEST/ICSB 7 1 1 NRR/DEST/MEB 9H 1 1 NRR/DEST/MTB 9H 1 1 NRR/DEST/PSB 8D 1 1 NRR/DEST/RSB 8E 1 1 NRR/DEST/SGB 8D 1 1 NRR/DLPQ/HFB 10 1 1 NRR/DLPQ/QAB 10 1 1 NRR/DOEA/EAB 11 1 1 NRR/DREP/RPB 10 2 2 NRR/'>> -% SIB 9A 1 1 NUDOCS-ABSTRACT 1 1 G 02 1 1 RES/DSIR/EIB 1 1 RES/DSR/PRAB 1 1 RGN5 FILE 01 1 1 EXTERNAL EG&G WILLIAMSi S 4 4 FORD BLDG HOY,A 1 1 R L ST LOBBY WARD 1 1 LPDR 1 1 NRC PDR 1 1 NSIC MAYS,G 1 1 I

NSIC MURPHY,G.A 1 1 NOTES: 1 1 D

NOTE 'ZO ALL "RIES" S

RECIPIENIS'IZAS HELP US K) REDUCE WASTE.'XNI'AC1'lHE DOCUMENT CONSOL DESK, ROOM Pl-37 (EXI'. 20079) XO ELDGNATE KN3R NAME PKH DlSTRIK7ZIGN LISTS FOR DOCUMEÃI'S YOU DON'T NEED!

TOTAL NUMBER OF COPIES REQUIRED: LTTR- 46 ENCL 45

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Arizona Nuclear Power Project P,O BOX 5203' PHOENIX, ARIZONA 85072.2034 192-00472-JGH/TDS/DAJ April 25, 1989 U. S. Nuclear Regulatory Commission NRC Document Control Desk Washington, D.C. 20555

Subject:

Palo Verde Nuclear Generating Station (PVNGS)

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

Special Report 1-SR-89-003 File: 89-020-404 Attached please find Special Report 1-SR-89-003 prepared and submitted pursuant to Technical Specifications 3.3.3.8 ACTION 42(b) and 6.9..2. This report discusses an inoperable radiation monitor.

If you have any questions, please contact T. D. Shriver, Compliance Hanager; at (602) 393-2521.

Very trul yours, J. G. Ha es Vice President Nuclear Production JGH/TDS/DAJ/kj Attachment cc: D. B. Karner (all w/attachments)

E. E. Van Brunt, Jr.

J. B. Hartin T. J. Polich H. J. Davis A. C. Gehr INPO Records Center 890~0c;0

'O<<V OSOO0~2 FDC

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PALO VERDE NUCLEAR GENERATING STATION UNIT 1 Radiation Monitoring Unit Inoperable for Greater Than 72 Hours License No. NPF-41 Docket No. 50-528 Special Report No. 1-SR-89-003 This Special Report is submitted in accordance with Technical Specification 3.3.3.8 ACTION 42(b) and 6.9.2 for an event in which the Unit 1 Condenser Evacuation System high range effluent 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 inoperability was exceeded at approximately 1135 HST on April 2, 1989. Pursuant to Technical Specification 3.3.3.8 ACTIONS 37 and 40, the Preplanned Alternate Sampling Program (PASP) was initiated at approximately 1135 HST on March 30, 1989.

At approximately 1135 HST on March 30, 1989, RU-142 was declared inoperable as a result of the Condenser Evacuation System low range effluent monitor.

(RU- 141) being declared inoperable. RU-141 was declared inoperable due to engineering concerns regarding the effects of moisture in the gas channel.

Radioactive effluent monitor RU-141 continuously monitors the condenser vacuum pump/gland seal exhaust for gaseous activity resulting from primary to secondary leakage. Monitors RU-141 and RU-142 work as a pair with RU-141 as the low range monitor and RU-142 as the high range monitor. Normal configur'ation consists of RU-141 operating with RU-142 in standby. Based upon gas channel readings, low range monitor RU-141 automatically starts RU-142 and initiates filtration of the condenser vacuum pump/gland seal exhaust whenever a HIGH-HIGH alarm condition is registered. RU-142 is provided for tracking radioactive effluents during postulated accident scenarios. RU-142 must be declared inoperable when RU-141 is inoperable.

PVNGS has experienced several instances wherein moisture buildup has resulted in Condenser Evacuation System radioactive effluent monitor improper operation. In order to correct this problem, PVNGS engineering personnel, with the assistance of an independent consulting firm, are reviewing the design of the monitor. During this review, information was obtaine'd from the independent consulting firm on Harch 27, 1989, which brought into question the sensitivity, and thus the accuracy, of the gas chamber. .This information was reviewed by PVNGS engineering and management personnel. As a prudent measure, RU-141 was declared inoperable until engineering resolution of the moisture problem could be effected.

As an interim measure to expedite returning the monitors to service, an engineering evaluation is in progress to determine if additional heat tracing would be effective. This engineering evaluation is expected to be completed by Hay 15, 1989. If additional heat tracing is determined to be effective, the heat tracing will be installed on RU-141 and -142 and returned to service during the current Unit 1 refueling outage.

Based upon the results of the evaluation provided by the independent consultant firm, long term design modifications will be implemented to permanently resolve the moisture problem. The parts required to implement the design modification are expected to be available by August 1, 1989. Based upon parts availability, the design modification is expected to be implemented by August 15, 1989.

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