ML17305A659

Suppl 1 to Special Rept 2-SR-89-010:updates 891105 Incident When post-accident Sampling Sys Declared Inoperable & Not Returned to Svc within 7-day Required Period.Caused by Leakage in Check Valve.Leaking Check Valve Replaced

ML17305A659
Person / Time
Site:	Palo Verde
Issue date:	04/02/1990
From:	James M. Levine ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
192-00643-JML-T, 192-643-JML-T, 2-SR-89-010, 2-SR-89-10, NUDOCS 9004180104
Download: ML17305A659 (10)

Text

REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:9004180104 DOC ~ DATE: 90/04/02 NOTARIZED: NO DOCKET r.

FACIL:STN-50-529 Palo Verde Nuclear Station, Unit 2, Arizona Publi 05000529 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)

SUBJECT:

Special Rept 2-SR-89-010:on 891105 post accident sampling sys declared inoperable.

DISTRIBUTION CODE: IE22D COPIES RECEIVED:LTR TITLE: 50.73/50.9 Licensee Event Report (LER),

0incident ENCL Q SIZE:

Rpt, etc. S NOTES:Standardized plant. 05000529 RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD5 LA 1 1 PD5 PD 1 1 D PETERSON,S. 1 1 CHAN,T 1 1.

INTERNAL: ACNW 2 2 ACRS 2 2 AEOD/DOA 1 1 AEOD/DS P/TPAB 1 1 AEOD/ROAB/DSP 2 2 DEDRO 1 1 NRR/DET/ECMB 9H 1 1 NRR/DET/EMEB9H3 1 1 NRR/DET/ESGB 8D 1 1 NRR/DLPQ/LHFB11 1 1.

NRR/DLPQ/LPEB10 1 1 NRR/DOEA/OEAB11 1 1 NRR/DREP/PRPB11 2 2 NRR/DST/SELB 8D 1 1 NRR/DST/SICB 7E 1 1 S SPLB8Dl 1 1 NRR/DST/SRXB 8E 1 1 REG F 02 1 1 RES/DSIR/EIB 1 1 G FILE 01 1 1 EXTERNAL: EG&G STUART,V.A 4 4 L ST LOBBY WARD 1 1 LPDR 1 1 NRC PDR 1 1 NSIC MAYS,G 1 1 NSIC MURPHY,G.A 1 1 NUDOCS FULL TXT 1 1 R NOTES 1 1 D

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NOTE TO ALL "RIDS" RECIPIENTS:

PLEA% HELP US TO REDUCE WASTETH CONTACI'HE,DOCUMENT CONTROL DESK, ROOM Pl-37 (EXT. 20079) TO ELMINATEYOUR NAME FROM DISIRIBUTION LISIS FOR DOCUMENTS YOU DON'T NEED)

TOTAL NUMBER OF COPIES REQUIRED'TTR 39 ENCL 39 Mp

I Arizona Public Service Company PALO VERDE NUCLEAR GENERATING STATION P.O. BOX 52Q34 ~ PHOENIX, ARIZONA85Q?2-2Q34 JAMES M. LEVINE '192-00643-JML/TRB/RKR VICE PRESIDENT NUCLEAR PRODUCTIDII April 2, 1990 U. S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555

Subject:

Palo Verde Nuclear Generating Station (PVNGS)

Unit 2 Docket No. STN 50-529 (License No. NPF-51)

Special Report 2-SR-89-010 File 90-020-404 Attached please find Supplement Number 1 to Special Report 2-SR-89-010 prepared and submitted pursuant to Technical Specifications 3.3.3.1 ACTION 28 and 6.9.2. This report discusses the Post Accident Sampling System inoperable for greater than seven days. This report is submitted to provide updated information from the original report.

If you have any questions, please contact T. R. Bradish, (Acting)

Compliance Manager at (602) 393-2521.

Very truly yours, JML/TRB/RKR/tlg Attachment CC:

W. F. Conway (all with attachment)

J. B. Martin D. H. Coe T. L. Chan A. C. Gehr A. H. Gutterman 004180104 900402 ggS PDR ADOCK 05000529

PALO VERDE NUCLEAR GENERATING STATION Post Accident Sampling System Inoperable for Greater Than 7 Days License No. NPF-51 Supplement 1 to Special Report 2-SR-89-010 I. DESCRIPTION OF WHAT OCCURRED:

A. Initial Conditions:

On December 1, 1989 at approximately 0508 MST, Palo Verde Unit 2 was in Mode 2 with the reactor coolant system (RCS)(AB) at approximately 2241 psia and 565 degrees Fahrenheit.

Reportable Event Description (Including Dates and Approximate Times of Major Occurrences):

Event Classification: Submitted in accordance with ACTION 28 of Technical Specification 3.3.3.1 At. approximately 1400 MST on November 5, 1989 the Post Accident Sampling System (PASS).(IP) was declared inoperable in order to perform scheduled preventive maintenance and surveillance tests.

At this time Unit 2 was in Mode 4 (HOT SHUTDOWN). On November 24, 1989 at approximately 0508 MST, Unit 2 entered Mode 3 (HOT STANDBY). Technical Specification (TS) 3.3.3.1 requires PASS to be operable when in Modes 1, 2, or 3. TS 3.3.3.1 ACTION 28 requires PASS to be restored to an operable status within 7 days or initiate the Preplanned Alternate Sampling Program (PASP) and prepare and submit a special report. Technical Specifications permitted entry into Mode 3 from Mode 4 with PASS inoperable.

PASP was initiated on November 24, 1989 at approximately 0740 MST.

On December 1, 1989 at approximately 0508 MST, the 7 day limit of TS 3.3.3. 1 ACTION 28 was exceeded.

After completion of the scheduled preventive maintenance activities it was determined that the PASS booster pump seals were leaking. Troubleshooting determined that the PASS booster pump discharge check valve was allowing leakage that pressurized the pump to a pressure above the 150 psig seal rating. The leaking check valve was replaced and a new PASS booster pump has been installed.

At approximately 1730 MST on February 7, 1990 while performing post maintenance testing to return PASS to service, the sample bomb could not be depressurized prior to taking a Reactor Coolant System gas sample. An approved work document was initiated to troubleshoot and correct the problem.

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Special Report. 2-SR-89-010-01 Page 2 Status of structures, systems, or components that were inoperable at the start of the event that contributed to the event:

Not applicable - no structures, systems, or components were inoperable which contributed to this event.

Cause of each component or system failure, if known:

The cause of the booster pump seal leakage was excessive pressure because of the discharge check valve leakage. The cause of the check valve leakage is under investigation and will be provided in a supplemental report.

Failure mode, mechanism, and effect of each failed component, if known:

The failure of the booster pump check valve is not known at this time. An investigation is being performed to determine the failure mode.

For failures of components with multiple functions, list of systems or secondary functions that were also affected:

Not applicable - no failures of components with multiple functions were involved.

For failures that rendered a train of a safety system inoperable, estimated time elapsed from the discovery of the failure until the trains were returned to service:

Not applicable - the component failures did not render a train of a safety system inoperable.

Method of discovery of each component or system failure or procedural error:

The leaking check valve was discovered during testing to determine the cause of the booster pump seal leakage.

I. Cause of Event:

The PASS was made inoperable to perform scheduled maintenance and calibrations on the system. The leaking check valve caused the duration of the system outage to be extended.

Safety System Response:

Not applicable - no safety system 'responses were involved.

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Special Report 2-SR-89-010-01 Page 3 K. Failed Component Information:

Check Valve 2PSSNV874 - VALVE!; stainless steel 6C-1/3NUPRO.

II. ASSESSMENT OF THE SAFETY CONSEQUENCES AND IMPLICATIONS OF THIS EVENT:

The PASS system is provided to obtain reactor coolant and containment atmosphere samples during post accident operation'. The inoperability of PASS did not effect the ability to obtain and analyze reactor coolant samples during normal plant operation. The PASP ensures that necessary RCS and containment atmosphere samples can be obtained in the event of an accident when PASS is inoperable. Therefore, this event did not effect the health and safety of the public.

III. CORRECTIVE ACTIONS:

Immediate The scheduled preventive maintenance was completed. The leaking check valve was replaced. A replacement booster pump has been installed. Troubleshooting and action to correct the inability to depressurize the sample bomb is being performed during the current Unit 2 refueling outage. The testing required to return PASS to service will then be performed when Unit 2 is in Mode 3 (Hot Standby) at normal operating temperature and pressure.

B. Action to Prevent Recurrence:

Investigations to determine the cause of the leaking check valve and inability to depressurize the sample bomb are being performed.

These investigations are expected to be completed approximately 45 days after the troubleshooting, corrective action, and testing is completed to return PASS to service. A supplemental report will be provided approximately 30 days after completion of these investigations.

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