ML17305A823

Special Rept 1-SR-90-004:on 900418,post-accident Sampling Sys Inoperable Greater than 7 Days.Event Caused as Result of Failure to Communicate Plant Status.Engineering Evaluation of Components Exposed to RCS Fluid & Pressure Begun

ML17305A823
Person / Time
Site:	Palo Verde
Issue date:	05/24/1990
From:	James M. Levine ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
1-SR-90-004, 1-SR-90-4, 192-000664-JML, 192-664-JML, NUDOCS 9005310132
Download: ML17305A823 (10)

Text

ACCELERATED DISTRIBUTION DEMONSTPWTION SYSTEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RI DS)

ACCESSION NBR:9005310132 DOC.DATE: 90/05/24 NOTARIZED: NO DOCKET 5 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)

SUBJECT:

Special Rept 1-SR-90-004:on 900418,post. accident sampling sys inoperable greater than 7 days.

DISTRIBUTION CODE: IE22D COPIES RECEIVED:LTR ENCL SIZE:

TITLE: 50.73i50.9 Licensee Event Report (LER), Incident Rpt, etc.

NOTES: 05000528 RECIPIENT COPIES RECIPIENT ID CODE/NAME LTTR ENCL 'ID CODE/NAME COPIES'TTR ENCL PD5 LA 1 1 PD5 PD 1 1 PETERSON,S. 1 1 CHAN,T 1 1 INTERNAL: ACNW 2 2 ACRS 2 2 AEOD/DOA AEOD/ROAB/DSP 1

2 1

2 AEOD/DS P/TPAB DEDRO 1,

1 1

1 NRR/DET/ECMB 9H NRR/DLPQ/LHFB11 NRR/DOEA/OEAB11 1,

1 1

1 1

1 NRR/DET/EMEB9H3 NRR/DLPQ/LPEB10 NRR/DREP/PRPB11 1

1 2

1 1

2 NRR/DST/SELB 8D 1 1 NRR/DST/SICB 7E 1 1 LB8Dl '1 1 NRR/DST/SRXB 8E 1" 1 E 02 1 1 RES/DSIR/EIB 1 1 RGN5 FILE 01 1 1 EXTERNAL EGGG STUART i V A 4 L ST LOBBY WARD 1 1 LPDR 1 1 NRC PDR 1 1 NSIC MAYS,G 1 1 NSIC MURPHY1G ~ A 1 1 NUDOCS FULL TXT 1 1 NOTES 1 1 NOTE TO ALL'RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE iVASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOM Pl-37 (EXT. 20079) TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!

TOTAL NUMBER OF COPIES REQUIRED: LTTR 38 ENCL 38

Arizona Public Service Company PALO VERDE NUCLEAR GENERATING STATION P.O, BOX 52034 ~ PHOENIX, ARIZONA 85072-2034 JAMES M. LEVINE 192-000664-JML/TRB/SBJ

>ICE PReSIDENT NUCI,EAR PRODUCTION

'Nay 24, 1990 U. S. Nuclear Regulatory Commission NRC Document Control Desk Washington, D.C. 20555

Dear Sirs:

Sub j ect: Palo Verde Nuclear Generating'Station Unit 1 (PVNGS)

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

Special Report 1-SR-90-004 File: 90-020-404 Attached please find Special Report 1-SR-90-004 prepared end submitted pursuant to Technical Specifications 3.3.3.1 ACTION 28 and 6.9.2, This report discusses the Post Accident Sampling System being inoperable for greater than 7 days.

If you have any questions, please contact T. R. Bradish, Compliance Manager, at (602) 393-2521.

Very truly yours, JML/TRB/SBJ/tlg Attachment CC: W. F. Conway (all w/attachment)

J. B. Martin T. L. Chan D. H. Coe A. C. Gehr A. L. Gutterman INPO Records Center

PALO VERDE NUCLEAR GENERATING STATION UNIT 1 Post Accident Sampling System Inoperable Greater Than 7 Days License No. NPF-41 Docket No. 50-528 Special Report 1-SR-90-004 Initial Conditions'n April 18, 1990 at approximately 1540 MST, Unit 1 entered MODE 3 (HOT STANDBY). Technical Specification 3.3.3.1 requires the Post Accident Sampling System (PASS) to be operable in MODES 1 (OPERATION), 2 (STARTUP), AND 3. On April 25, 1990 Palo Verde Unit 1 was in MODE 3 with the Reactor Coolant System (RCS) at approximately 2250 pounds per square inch absolute and 565 degrees Fahrenheit.

Descri tion of Event:

This Special Report is being submitted pursuant to Technical Specification 3.3.3.1 ACTION 28 and Technical Specification 6.9.2 to report an event, in which the Post Accident Sampling System (PASS) was inoperable for greater than 7 days. The 7 day period for returning PASS to service was exceededI at approximately 1540 MST on April 25, 1990.

PASS surveillance testing was initiated on April 18, 1990, in accordance with the surveillance testing schedule. During the performance of the PASS surveillance test, a valve was not correctly positioned, resulting in reactor coolant entering and overpressurizing the PASS air sample lines. The engineering evaluations and corrective maintenance required because of the overpressurization could not be completed prior to exceeding the 7 day period for returning PASS to service.

The PASS surveillance test requires a reactor coolant sample to be obtained. The sample is obtained from the RCS hot leg, processed through PASS, and discharged to either the Equipment Drain Tank (EDT) or Reactor Drain Tank (RDT). On April 21, 1990, at approximately 2125 MST, a chemistry technician notified a control room operator that the RCS sample line would be lined up to PASS. The chemistry technician and control room operator discussed the required test position (open) of the Equipment Drain Tank (EDT) return valve (SSV-209). The valve was verifed to open. However, the required test position (open) of the Reactor Drain Tank (RDT) return valve (CHV-715) and the current position (closed) of the RDT return valve were not clearly established between the control room operator and the chemistry technician. At approximately 2155 MST, RCS sample flow to PASS was established with the return flow to the EDT.

On April 22, 1990 at approximately 0055 MST, a chemistry technician informed a control room operator that the surveillance test with PASS

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Special Report 1-SR-90-004 Page 2 aligned to the EDT was complete and PASS flow was being realigned to RDT. The chemistry technician repositioned the appropriate PASS valves, in accordance with the surveillance test procedure, from the PASS control module in order to redirect flow from the EDT to the RDT. This did not effect the position of the RDT and EDT return valves. At approximately 0415 MST, on April 22, 1990, a chemistry technician entered the Chemistry Nuclear Sampling Room to make preparations for sampling the reactor coolant and discovered reactor coolant leaking from the PASS containment air sample injection port. The chemistry technician then proceeded to the PASS control module and closed the hot leg sample valve. The Shift Supervisor was then notified.

With PASS isolated from the RCS, the PASS remained pressurized since there was no discharge path for the reactor coolant with the RDT return valve closed. The chemistry technician therefore reestablished the PASS flow path to the EDT and depressurized PASS. An engineering evaluation was initiated to determine the effects of the overpressurization event.

An'pproved work authorization was initiated to rework components as necessary.

On April 25, 1990, at approximately 1540 MST, the 7 day period for establishing PASS operable was 'exceeded. The Preplanned Alternate Sampling Program (PASP) was initiated in accordance with ACTION 28 of Technical Specification 3.3.3.1.

On May 4, 1990, at approximately 0334 MST, Unit 1 entered Mode 4 (HOT SHUTDOWN) and exited ACTION 28 of Technical Specification 3.3.3.1.

Cause of Event:

The 7 day period to establish PASS operability was exceeded because a chemistry technician and control room operator'id not clearly communicate the plant status and required valve alignments for PASS surveillance testing. This resulted in the RDT return valve not being opened during surveillance testing. When PASS was aligned to the RDT from the PASS control module, the closed RDT return valve (controlled from main control room) did not allow a discharge path. Subsequently, PASS was subjected to RCS pressure and was over pressurized. The inspection and repairs necessary to return PASS to service could not be completed prior to the 7 day period being exceeded.

Corrective Actions:

An engineering evaluation of the PASS components exposed to the RCS fluid and pressure has been initiated. The air portion of PASS exposed to reactor coolant was dried and inspected. Pressure tests, flow tests, and valve stroking have not identified any equipment damage. PASS surveillance tests will be performed as required when Unit 1 reenters Mode 3 in order to establish PASS operability.

I Special Report 1-SR-90-004 Page 3 The chemistry technician and control room operator were counseled on the need to ensure that the status of plant equipment is established and clearly communicated.

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