ML17300A712

Ro:On 861104,MSIV SGE-UV-1709 Opened,Causing Cooldown of Rcs.Valve Closed & Plant Stabilized.Occurrence Could Not Be Duplicated.No Problems W/Valve Identified.Removal of Fast Open Circuitry After Installation of Valves Verified

ML17300A712
Person / Time
Site:	Palo Verde
Issue date:	03/20/1987
From:	Van Brunt E ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
161-00092-EEVB, 161-92-EEVB, NUDOCS 8703300462
Download: ML17300A712 (8)

Text

REGULATORNFORNATION DISTRIBUTION:- TEll. (RIDSl ACC< ION NBR: 8703300462 DOC. DATE: 87/03/20 NOTAR ZED: NO DOCKET FCC IL: STN-50-530 Palo Verde Nuclear Station> Uni t 3I Arizona Pub 1 i 05000530 AUTH. N'AME AUTHOR AFF1LIATIGN Prospect VAN BRUNTI E. E. Arizona Nuclear Pouer f

( ormer lg Ari zona Pub 1 ic Serv RECIP. NAME RECIPIENT AFFILIATION Document Control Branch <Document Control Desk)

SUBJECT:

RO: on 861104I MSIV SQE-UV-1709 openedi causing cooldown of RCS. Valve closed 5 plant stabilized. Occurrence could no~. be duplicated. No problems w/valve identified. Removal of fast open circuitrg after installation of valves verified.

DISTRIBUTION CODE: B021D COPIES RECEiVED: LTR J ENCL 0 SIZF:

TITLE: QR/Licensing Submittal: Combined Qeneral Distribution NOTES: Standardized plant. M. Davisi NHR: 1Cg. 05000530 RECIPIENT COPIES REC IP l ENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL-PWR-B ADTS Pla'R-B EB PIJR-B PE ICSB 2 PWR-B FOB PIJR-B PD7 LA 1 PliR-B PD7 PD LICITRA> E PliR-B PEICSB PWR-B RSB 1 INTERNAL: ACRS 8 ADM/LFMB NRR BMR ADTS 1 NRR PNR-A *DTS NRR PMR-B ADTS 1 NRR/DSRO DIR QQC/HDS1 EQ ILE 01 1 RMI/DDAMI/MIB EXTERNAL: LPDR NRC PDR NSIC PNL QRUELIR NOTES:

0 TOTAL NUMBER OF COPIES REQUIRED: LT1R 32 ENCL

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Arizona Nuclear Power Project 8703300462 870320 ). BOX 52034 ~ PHOENIX. ARIZONA85072-2034 PDR ~A'OCK 05000530 March 20, 1987.

161-00092-. EEVB/BJA U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555

Subject:

Palo Verde Nuclear Generating Station (PVNGS)

Units 1, 2 and 3 Docket Nos. STN 50-'528-(License No. NPF-41)

STN 50-529 (License No. NPF-51)

STN 50-530 Corrective Actions for Inadvertent MSIV'pening and Unit 2 Inverter Problems File: 87-A-056-026

Dear Sir:

At 19:35 on November 4, 1986, during Precore Hot Functional Testing on PVNGS Unit 3, Main Steam Isolation Valve (MSIV) SGE-UV-170 opened, which caused a cool-down of the reactor coolant system. The,.valve was subsequently closed by the secondary operator and the plant was stabilized and returned to normal pressure and temperature. No adverse effects were experienced as a result of the cooldown.

While all indications were those indicative of an MSIV opening in the "fast open" mode, the occurrence could not be duplicated, nor did subsequent troubleshooting reveal any problems with the valve, its power supply or normal operating environ-ment.

The following items were performed during troubleshooting:

1. The fast open circuitry was verified to have been removed following instal-lation of the valves.

2. All wiring for SGE-UV-170 was verified to be "per design".

3. Proper operation of SGE-UV-170 and associated solenoid valves was verified twice by stroking the MSIV using the "slow mode".

4. Proper DC voltages were verified using a strip chart recorder in the auxil'-

iary relay cabinet.

DC valves, powered from the same bus, were stroked to ensure that no pertur-bations in MSIV logic power were caused by the valve operators.

0 4 ~ '

U.S. Nuclear Regulatory Commission Attention: Document Control Desk

Subject:

Corrective Actions for Inadvertent MSIV Opening and Unit 2 Inverter Problems 161- 00092 Page 2

6. The "A" train battery charger was de-energized and re-energized to ensure that no, perturbations in MSIV l'ogic power were caused by the chargers.

7. Operations and Security radios were operated inside the MSIV logic circui-try cabinet at distances of one foot and five feet from the cabinet with no adverse'ffect on MSIV circuitry.

8. Mechanical vibrations of the cabinet were "simulated" with no adverse effect on the MSIV circuitry.

PVNGS Operations Engineering has reviewed the results of the troubleshooting effort and other related testing and concludes that the event of November 4, 1986 was an isolated incident which could not be duplicated and has no impact on the ability of the valve to perform its design function.

As requested by Region V, the previous testing in items 3, 4, 5 and 6 will be performed again during the Post-Core Hot Functional Testing. Any exceptions will be documented and justified. The justifications will .be reviewed by the Plant Review Board. In addition, these valves will be periodically tested to comply with the ASME Section XI program which insures, that all MSIVs meet their Technical Specification stroke time requirements. Therefore, it of PVNGS that this event does not present a constraint to the progress towards is the position fuel loading and power ascension.

Unit 2 Inverter Problem; A "fix" for the inverters has been identified and tested in Unit 2. This fix will be implemented in Unit 3 prior to fuel load. Other enhancements to the inverters are currently being evaluated.

Very truly yours, E. E. Van Brunt, Jr.

Executive Vice President Project Director

-EEVB/BJA/rw

Qi U.S. Nuclear Regulatory Commission Attention: Document Control Desk

Subject:

Corrective Actions for inadvertent MSXV Opening and Unit 2 Xnverter Problems 161-00092 ccrc page 3 0.. M. De Michele J.. B. Martin G. W. Knighton R. P. Zimmerman A. C. Gehr

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