ML17306A390

Special Rept 1-SR-92-001:on 920102,determined That Leak Existed in Pressurizer Steam Space Instrument Nozzle Mfg from Inconnel 600.Caused by Nonvisible Intergranular Crack.Addl Investigation Underway

ML17306A390
Person / Time
Site:	Palo Verde
Issue date:	01/07/1992
From:	James M. Levine ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
1-SR-92-001, 1-SR-92-1, 192-00767-JML-T, 192-767-JML-T, NUDOCS 9201150191
Download: ML17306A390 (4)

Text

ACCELERATED DIjPIBUTION DEMONST>CTION SYSTEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:9201150191'OC.DATE: 92/01/07 NOTARIZED: NO DOCKET FACIL:STN-50-528 Palo Verde Nuclear Station, Unit 1, Arizona Publi 05000528 AUTH. NAME AUTHOR AFFILIATION LEVINE,J.M. Arizona Public Service Co. (formerly Arizona Nuclear Power RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk) R

SUBJECT:

Special Rept 1-SR-92-001:on 920102,determined that leak I existed in pressurizer steam space instrument nozzle mfg from Inconnel 600.Caused by nonvisible intergranular D crack.Addi investigation underway.

DISTRIBUTION CODE IE22D COPIES RECEIVED:LTR ENCL SIZE: S TITLE: 50.73/50.9 Licensee Event Report (LER), Incident Rpt, etc.

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NOTES:STANDARDIZED PLANT 05000528 RECIPIENT COPIES RECIPIENT 'COPIES D ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD5 LA 1 1 PD5 PD "1 1 D TRAMMELL,C 1 1 THOMPSONiM 1 1 INTERNAL: ACNW 2 2 ACRS 2 2 AEOD/DOA 1 1 AEOD/DS P/TPAB 1 1 AEOD/ROAB/DS P 2 2 NRR/DET/ECMB 9H 1 1 NRR/DET/EMEB 7E 1 1 NRR/DLPQ/LHFB10 1 1 NRR/DLPQ/LPEB1 0 1 1 NRR/DOEA/OEAB 1 1 NRR/DREP/PRPB11 2 2 NRR/DST/SELB 8D 1 1 NRR/DST/SICB8H3 1 1 NRR SPLB8D1 1 1 NRR/DST/SRXB 8E 1 1 G FILE 02 1 1 RES/DSIR/EIB 1 1 ILE 01 1 1 EXTERNAL: EGS(G BRYCE,J.H 3 3 L ST LOBBY WARD 1 1 NRC PDR 1 1 NSIC MURPHY,G.A 1 1 NSIC POORE,W. 1 1 NUDOCS FULL TXT 1 1 NOTES: 1 1 pd D pgg gg~l5~

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NOTE TO ALL "RIDS" RECIPIENTS PLEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOM PI-37 (EXT. 20079) TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!

TOTAL NUMBER OF COPIES REQUIRED: LTTR 35 ENCL 35

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Arizona Public Service Company PALO VERDE NUCLEAR GENERATING STATION P.O. BOX 52034 ~ PHOENIX. ARIZONA85072-2034 JAMES M. LEVINE 192-00767-JHL/TRB/WHD VICE PRESIOENT January 7, 1992 NUCLEAR PROOUCTION U. S. Nuclear Regulatory Commission Attention: Document Control Desk Hail Station Pl-37 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-92-001 e' 0-404 Attached please find Special Report 1-SR-92-001 prepared and submitted pursuant to Emergency Plan Implementing Procedure 03 (EPIP-03). This report discusses a condition requiring the declaration of a NOTIFICATION OF UNUSUAL EVENT due to a reactor coolant system leak.

I If you have any questions, please contact Thomas R. Bradish, Compliance Hanager, at (602) 393-2521. I Very truly yours, JML/TRB/WHD/nk Attachment cc: W. F. Conway (all with attachment)

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PALO VERDE NUCLEAR GENERATING STATION UNIT 1 Notification of Unusual Event Docket, No. 50-528 License No. NPF-41 Special Report 1-SR-92-001 This Special Report is being submitted pursuant to Emergency Plan Implementing Procedure 03 (EPIP-03), 'Notification of Unusual Event Implementing Actions',

to report a condition which required the declaration of an Unusual Event for Palo Verde Unit 1 at 1739 MST on January 2, 1992. The Unusual Event was terminated at 2336 MST on January 3, 1992.

On January 2, 1992, at approximately 1739 MST, Palo Verde Unit 1 was operating at 100 percent power in Mode 1 (Power Operation) when engineering, operations, and radiological control personnel determined that a leak existed in a pressurizer steam space instrument nozzle manufactured from Inconnel 600. The leak was not visually detectable but was detected with the use of a modified radiol'ogical protection (RP) device designed to investigate Xenon leakage.

The leakage was classified as PRESSURE BOUNDARY LEAKAGE. In accordance with, the PVNGS Technical Specifications (TS), the leakage exceeded the TS 3.4.5.2.(a) Limiting Condition for Operation (LCO) for reactor coolant system leakage of NO PRESSURE BOUNDARY LEAKAGE. Emergency Plan Implementing Procedures require the declaration of a Notification of Unusual Event (NUE) for exceeding TS reactor coolant system operational leakage. Technical Specification 3.4.5.2 Action (a) requires that with any PRESSURE BOUNDARY LEAKAGE, be in at least HOT STANDBY within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

PVNGS engineering and radiological control personnel attributed the leakage to a nonvisible intergranular crack in an Inconnel 600 pressurizer steam space instrument nozzle. At approximately 1739 MST, on January 2, 1992, an NUE was declared per Emergency Plan Implementing Procedures for"exceeding TS 3.4.5.2 Reactor Coolant System Leakage, and preparations for a power reduction were initiated.

By 1749 MST, January 2, 1992, the appropriate state and local agencies were notified of the condition requiring the declaration of an Unusual Event. At approximately 1756 MST on January 2, 1992, the Nuclear Regulatory Commission (NRC) Operations Center was notified. At approximately 2138 MST, on January 2, 1992, the reactor was manually tripped from 20 percent power in accordance with an approved operating procedure, The reactor trip 'was diagnosed as an uncomplicated reactor trip and the Unit was stabilized in Mode 3 (HOT STANDBY). Cooldown was initiated and Mode 5 (COLD SHUTDOWN) was achieved at approximately 2327 MST on January 3, 1992, and TS 3.4.5.2 exited. At approximately 2336 MST on January 3, 1992, the NUE was terminated as TS 3.4.5.2 Action (a) is only applicable in Modes 1 thru 4. Unit 1 had remained in the NUE for approximately 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

Further investigation into the pressure boundary leak is being.'performed in accordance with the PVNGS Incident Investigation Program, and the results will be reported in accordance with 10CFR50.73.