ML17306A958

Suppls 870910 Requests for Relief from Inservice Testing Program Covering SI Tank Discharge Check Valves & SI Tank/ RCS Loop Check Valves.Improvements Can Be Realized by full- Stroke Exercising of Valves.W/Two Oversize Drawings

ML17306A958
Person / Time
Site:	Palo Verde
Issue date:	09/08/1992
From:	Conway W ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML17306A959	List: ML17306A958 ML17306A963
References
102-02269-WFC-J, 102-2269-WFC-J, NUDOCS 9209170159
Download: ML17306A958 (24)

Text

ACCELERATED DI RIBVTION DEMONS ATION SYSTEM QEGULATO INFORMATION DISTRIBUTION TEM (RIDS)

ACCESSION 'NBR 9209170159 DOC.DATE: 92/09/08 NOTARIZED: NO DOCKET FACIL:STN-50-528 Palo Verde Nuclear Station, Unit 1, Arizona Publi 05000528 STN-50-529 Palo Verde Nuclear Station, Unit 2, Arizona Publi 05000529 STN-50-530 Palo Verde Nuclear Station, Unit 3, Arizona Publi 05000530 AUTH. NAME AUTHOR AFFILIATION CONWAY,W.F. Arizona Public Service Co. (formerly Arizona Nuclear Power RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)

SUBJECT:

Forwards revised relief requests for PVGS Inservice Testing Program.

DISTRIBUTION CODE: A047D COPIES RECEIVED:LTR ENCL SIZE:

TITLE: OR Submittal: Inservice Inspection/Testa.ng/Relic from ASME Code S

NOTES:STANDARDIZED PLANT 05000528 Standardized plant. 05000529/

Standardized plant. 05000530 A

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD5 LA 1 0 PDS PD 1 1 TRAMMELL,C 2 2 INTERNAL: ACRS 6 6 NRR/DET/ECMB 9H 1 1 NRR/DET/EMEB 7E 1 1 NUDOCS-ABSTRACT 1 1 OC LF 1 0 OGC/HDS1 1 0 E LE 01 1 1 RES MILLMAN,G 1 1 ES" DSTR EIB 1 1 EXTERNAL EGSG BROWN g B 1 1 EG&G RANSOME,C 1 1 NRC PDR 1 1 NSIC 1 1 D

NOTE TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENT CONTROL DESK.

ROOM PI-37 (EXT. 504-2065) TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!

TOTAL NUMBER OF COPIES REQUIRED: LTTR 22 ENCL 19

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r 10 CFR 50.55a Arizona Public Service Company P.O. BOX 53999 ~ PHOENIX, ARIZONA85072-3999 WILLIAMF. CONWAY EXECUTIVEVICEPRESIDENT 102-02269-WFC/JRB NUCLEAR September 08, 1992 U. S. Nuclear Regulatory Commission ATIN: Document Control Desk Mail Station P1-37 Washington, DC 20555

Reference:

Letter 161-00496-JGH/BJA, dated September 10, 1987, from J. G. Haynes, APS, to NRC, "PVNGS Inservice Testing Program"

Subject:

Palo Verde Nuclear Generating Station (PVNGS)

Units 1,2, and 3 Docket Nos. STN 50-528/529/530 Revised Relief Requests for PVNGS Inservice Testing Program File: 92-056-026 In the referenced letter, Arizona Public Service Company (APS) submitted Valve Relief Request Numbers 33 and 34 in accordance with 10 CFR 50.55a(g)(5)(iii). These relief requests requested relief from ASME Section XI, paragraph IWV-3520 for Safety Injection Tank discharge check valves and Safety Injection Tank/Reactor Coolant System loop check valves. APS has identified several improvements which can be realized by full-stroke exercising these valves to the position required to fulfill their safety function during each refueling outage. Pursuant to 10 CFR 50.55a(g)(5)(iii), revised Valve Relief Request Numbers 33 and 34 which incorporate this improved testing methodology are being submitted as Enclosure 1. Additional information regarding these revised relief requests is provided in Enclosure 2. Currently approved Valve Relief Request Numbers 33 and 34 are provided as Enclosure 3. The check valves to which Valve Relief Request Numbers 33 and 34 apply are depicted on the Piping and Instrumentation Diagram provided as Enclosure 4.

If you should have any questions, please contact Thomas R. Bradish at (602) 393-5421.

Sincerely, WFC/JRB/pmm Enclosures cc: J. B. Martin (all w/enclosures)

J. A. Sloan 15004'209170159 05000528 920908'DR ADQCK PDR

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ENCLOSURE 1 REVISED VALVE RELIEF REQUEST NOS. 33 AND 34

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VALVE RELIEF REQUEST NO. 33 SYSTEM: Safety Injection and Shutdown Cooling (Sl)

COMPONENTS: SIE-V215, SIE-V225, SIE-V235, SIE-V245 P&ID COORDINATES: 13-M-SIP-002 @A15, A12, A7, and A5 CATEGORY: AC CLASS FUNCTION: OPEN to provide a flow path from the Safety Injection Tanks to the Reactor Coolant System.

CLOSE to prevent backflow of primary coolant into the Safety Injection Tanks.

TEST REQUIREMENT: Full-stroke exercise every three months, or part-stroke exercise every three months and full-stroke test during cold shutdown.

BASIS FOR RELIEF: Full-stroke exercising these valves is not practical in any plant mode except refueling shutdown when the reactor vessel head is removed. Part stroke testing every 3 months is not practical since a plant mode reduction would be required to perform the test.

ALTERNATE TESTING: Full-stroke exercise during each refueling outage when the reactor vessel head is removed.

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VALVE RELIEF REQUEST NO. 34 SYSTEM: Safety Injection and Shutdown Cooling (Sl)

COMPONENTS'IE-V217, SIE-V227, SIE-V237, SIE-V247 P8 ID COORDINATES: 13-M-SIP-002 A13, A10, A6, and A3 CATEGORY: AC CLASS:

FUNCTION'PEN to provide a flow path from Safety Injection and Shutdown Cooling to the Reactor Coolant System (RCS).

CLOSE to prevent pressurization of Sl piping from RCS loop pressure.

TEST REQUIREMENT: Full-stroke open every three months, or part-stroke open every three months and full-stroke open at cold shutdown.

BASIS FOR RELIEF: These valves can only be stroked open by initiating flow through the valves into the RCS. Safety Injection pump head is not sufficient to overcome RCS pressure and stroke the valves during plant operation. Full-stroke exercising is not practical during any plant mode except refueling shutdown when the reactor vessel head is removed. Part stroke testing every three months is not practical since a plant mode reduction would be required to perform the test.

ALTERNATE TESTING: Full-stroke exercise during each refueling outage when the reactor vessel head is removed.

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ENCLOSURE 2 ADDITIONALINFORMATION REGARDING REVISED VALVE RELIEF REQUEST NOS. 33 AND 34

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ADDITIONALINFORMATION REGARDING REVISED VALVE RELIEF REQUEST NOS. 33 AND 34 ASME Section XI Re uirement ASME Section XI, paragraph'IWV-3520, requires check valves to be exercised at least once every three months to the position required to fulfill their function unless such operation is not practical during plant operation. If only limited operation is practical during plant operation, the check valve shall be part-stroke exercised during plant operation and full-stroke exercised during cold shutdowns.

Basis For Relief The Safety Injection Tank (SIT) discharge check valves (SIE-V215, SIE-V225, SIE-V235, SIE-V245) and the Safety Injection Tank/Reactor Coolant System (SIT/RCS) loop check

. valves (SIE-V21 7, SIE-V227, SIE-V237, SIE-V247) can only be full-stroke exercised during refueling shutdowns when the vessel head is removed.

Current Alternate Testin Method One SIT discharge check valve and one SIT/RCS loop check valve are disassembled and inspected to verify freedom of disc movement each refueling outage. If a disassembled valve's full-stroke capability is questionable, the other three SIT discharge check valves or SIT/RCS loop check valves, as applicable, are disassembled, inspected, and full-stroke exercised during the same outage. In addition, the SIT discharge check valves are part-stroke exercised in Mode 3 after each refueling outage when the SIT pressure is above 600 psig.

Pro osed Alternate Testin Method Each SIT discharge check valve and SIT/RCS loop check valve will be full-stroke exercised to the position required to fulfillits safety function during each refueling outage.

To conduct the test, an initial SIT level and pressure will be selected to maximize rate and duration of flow without discharging nitrogen into the RCS or exceeding the capacity of the SIT structural supports. Flow will be initiated by opening the SIT discharge motor-operated valve located just upstream of the SIT discharge check valve. The rate of change in SIT pressure and level will be recorded and analyzed to determine the system hydraulic resistance or, 'k'actor. Hydraulic resistance, or 'k'actor, is a function of piping configuration and check valve disc position, but is independent of flow rate.

Therefore, the 'k'actor determined during this test will be representative of system performance during accident conditions. The determined 'k'actor will be compared to the calculated maximum 'k'actor provided in the UFSAR. A 'k'actor less than or equal

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to,the maximum 'k'actor provided in the UFSAR will demonstrate the ability of the check valve to fulfill its safety function.

Two full-scale tests have been performed using this test method. The first test was performed on Unit 2 in the fall of 1991 and the second test was performed on Unit 1 in the spring of 1992. Acoustic data from both tests provided additional assurance that the check valves actually stroked fully open during the tests.

Justification For Pro osed Alternate Testin Method The proposed alternate testing method offers the following improvements over the current alternate testing method:

Full-stroke exercising the SIT discharge check valves and SIT/RCS loop check valves with flow to the position required to fulfill their safety function provides greater assurance that the valves function properly.

Each SIT discharge check valve and SIT/RCS loop check valve will be tested every refueling outage.

Full-stroke exercising the SIT discharge check valves to the position required to fulfill their safety function eliminates the need to part-stroke exercise the valves after each refueling outage.

The possibility of reassembly errors and bonnet sealing problems encountered during the current testing method of disassembly and inspection will be eliminated.

The proposed alternate testing method will result in reduced personnel radiation exposures.

ENCLOSURE 3 CURRENTLY APPROVED VALVE RELIEF REQUEST NOS. 33 AND 34 (TYPICAL OF UNITS 1, 2, AND 3)

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ENCLOSURE i IIFORMATlloà 0,.

NUCLEAR ADMINISTRATIVEAND TECHNICAL MANUAL Revisioa PVNGS ASME SECTION XI PUMP AND 73PR-1XI01 0 VALVE INSERVICE TESTING PROGhi, UNIT 1 Appendix C Page 38 of 50 VALVE RELIEF RE UEST NO. 33 SYSTEM: Safety Injection and Shutdown Cooling (SI)

COMPONENTS: SIE-V215, SIE-V225, SIE-V235. SIE-V245 P&ID COORDINATES:. 13-M-SIP-002 9 A15, A12, A7 and A5 CATEGORY: AC CLASS:

FUNCTION: To prevent backflow of Primary Coolant into the Safety Injection Tanks while providing a flow path for Safety Injection Tank water into the RCS loops.

TEST RE UIREMENT: Full stroke exercise every three months or part stroke exercise every three months and full stroke test during cold shutdown.

BASIS FOR -RELIEF: Full stroke testing to stroke these valves is noq practical during any plant mode other than when t>e reactor vessel head 's removed, fuel 's off-loaded, and the core barrel is removed. Part stroke testing is feasible during hot shutdown. Plant design conditions allows part stroke testing with a maximum of 35gpm through the valve. Full stroke testing would require a full blowdown of SIT. This is not feasible and would create a significant crud burst, and airborne contamination.

ALTERNATE TESTING: 1. Part stroke exercise in Mode 3 after each refuelirig outage when the Safety Injection Tank pressure is above 600 psig.

2. Disassemble valves and verify freedom of movement of disc motion on a re'fueling basis, such that one valve is inspected every refueling outage.

3. If it is found that th.. d3.sassembled valve's full-stroke capability is in question, the other valves shall also be disassembled, inspected and manually Eu'll-stroked the same outage.

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A'~" e disassembled, inspected and manually full-stroked the same .outage.

NOTE: Valves SIE-V540, V541. V542 and V543 are now covered under CSJ-31.

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ENCLOSURE 4 PIPING AND INSTRUMENTATION DIAGRAM DEPICTING SAFETY INJECTION TANK DISCHARGE CHECK VALVES AND SAFETY INJECTION TANK/REACTOR COOLANT SYSTEM LOOP CHECK VALVES