RC-97-0052, Submits Response to GL 96-05, Periodic Verification of Design-Basis Capability of Safety-Related Movs

Submits Response to GL 96-05, Periodic Verification of Design-Basis Capability of Safety-Related Movs

ML20136H074
Person / Time
Site:	Summer
Issue date:	03/13/1997
From:	Gabe Taylor SOUTH CAROLINA ELECTRIC & GAS CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
GL-96-05, GL-96-5, RC-97-0052, RC-97-52, NUDOCS 9703190045
Download: ML20136H074 (4)

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South Cir: lina Electric & Gas Company G ryJ. Taylor i

4" P.o. Box 88 Vics Pr:sident Jenkinsville, SC 29065 Nuclear Operations (803) 345-4344 SCE&G j

Asanwicamey j

March 13, 1997 RC-97-0052

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Document Control Desk i

U. S. Nuclear Regulatory Commission l

Washington, DC 20555

Subject:

VIRGIL C. SUMMER NUCLEAR STATION DOCKET NO. 50/395 OPERATING LICENSE NO. NPF-12 RESPONSE TO GENERIC LETTER 96-05

" PERIODIC VERIFICATION OF DESIGN BASIS CAPABILITY OF i

SAFETY-RELATED MOTOR-OPERATED VALVES" Gentlemen:

Pursuant to the subject generic letter, South Carolina Electric & Gas Company l

(SCE&G) is submitting the following response under oath of affirmation.

j SCE&G established a periodic verification program to ensure that safety-related motor-l operated valves (MOVs) continue to be capable of performing their safety functions within the current licensing bases of the facility in response to GL 89-10.

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SCE&G has performed the requested review of its established program and has made the necessary changes where appropriate, in light of the information contained in GL 96-05.

1 A written summary description of SCE&G's MOV periodic verification program is attached.

Should you have any questions, please call Mr. J. W. Pease, at (803) 345-4124.

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Very truly yours, f) 9703190045 970313

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PDR ADOCK 05000395

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PDR aryJ. ayloP JWP / GJT/nkk ggggggg Enclosure c:

J.L.Skolds NRC Resident inspector W.F.Conway J.B.Knotts Jr.

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R.R.Mahan (w/o Enclosure)

NSRC h

R.J. White File (815.14) jF L. A. Reyes RTS (LTR960005)

A.R.Johnsor:

DMS (RC-97-0052) 190078 NUCLEAR EXCELLENCE - A SUMMER TRADITIONI

i Document Control Desk LTR 960005 i

RC-97-0052 Page 2 of 2 l

STATE OF SOUTH CAROLINA TO WIT :

COUNTY OF FAIRFIELD a Notary Pubtfc of the State of South baro #7ue/

I hereby certif that on the 6 d

of 19 97. before me, the subscriber, lina personally appeared Kenneth W. Nettles, i

1 being duly sworn, and states that he has signature authority for the Vice President, Nuclear Operations of the South Carolina Electric & Gas Company, a corporation of the

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State of South Carolina, that he provides the foregoing response for the purposes therein set forth, that the statements made are true and correct to the best of his knowledge, information, and belief, and that he was authorized to provide the response on behalf of i

said Corporation.

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' WITNESS my Hand and Notarial Seal A

gg Notary Public My Commission Expires J./y 24, 2oo f

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Date

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Enclosuro 1 to Document Control Dssk Lctter i

LTR 96 05 i

RC-97,-0052 l

Pege 1 of 2 3

VIRGIL C. SUMMER NUCLEAR STATION DOCKET NO. 50-395/ LICENSE NO. NPF-12 GENERIC LETTER 96-05180 DAY SUBMITTAL j

(MOV Periodic Verification Program Summary Description) i l

In response to the requested actions contained in GL 96-05 " Periodic Verification Of Design Basis Capability of Safety-Related Motor-Operated Valves",

V.C. Summer

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Nuclear Station has reviewed its MOV GL 89-10 " Safety-Related Motor-Operated Valve Testing and Surveillance" periodic verification program to determine whether any changes were appropriate in light of the information contained in GL 96-05. The following is a summary description of the station's MOV periodic verification program established in accordance with the Requested Actions in GL 96-05:

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Scope -

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The scope of the station's GL 96-05 MOV periodic verification (PV) program is the j

same as the antion's GL 89-10 program.

1 Risk Ranking -

Risk insights were used in conjunction with deterministic considerations to prioritize i

MOV test activities. Each MOV in the station's PV program has been placed into a Probabilistic Risk Assessment (PRA) Group. This grouping has been reviewed by an expert panel. The groups in descending order of Risk Significance, are 1 (High Risk),2 l

(Medium Risk), and 3 (Low Risk).

l PV Program Testing -

l The importance of the MOV and the MOV's Safety Function Margin are considered when determining the appropriate type and frequency of diagnostic testing. The GL 96-l 05 PV program MOVs are all periodically exercised per the station's ASME Section XI i

inservice Testing Program. Static testing will be periodically performed on all the MOVs in the GL 96-05 PV program. The periodicity of the static testing is based on the risk l

significance and safety function thrust capability margin of the specific MOV. All MOVs i

in PRA group 1 (High Risk), as well as those MOVs in PRA group 2 (Medium Risk),

with less than 100% safety function thrust capability margin, will be statically tested l

once per five years or three refueling outages, whichever is longer. Those MOVs in PRA group 2 (Medium Risk) with safety function thrust capability margin equal to or i

greater than 100%, as well as all PRA group 3 (Lower Risk) MOVs, will be subject to static testing once per ten years or six refueling outages, whichever is longer. Butterfly 1

l MOVs which are not in PRA group 1 (High Risk) will be subject to periodic static diagnostic testing once per ten years or six refueling outages, whichever is longer. Two l

. additional dynamic tests will be performed on a minimum of six valves by July 27, 2005.

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The six valves that are presently assigned for additional dynamic (DP) testing were 1

l rEnclosuro 1 to Documant Control Dask Lettsr l

LTR 96 05 RC 97-0052

'Page 2 of 2 chosen based on being the most risk significant dynamically testable MOVs that would i

provide meaningful data to ensure the station's PV program is adequate (data that can be applied to the stations other MOVs). The valves presently assigned for additional dynamic testing are butterfly valve XVB03116A-SW ( SW Pump "A" Discharge) and j

gate valves XVG03107A-SW ("A" Train RB Cooling Unit Outlet Return to SW Pond),

l XVG03109B-SW (RB Cooling Unit 2A Outlet Isolation),

XVG08706A-RH (Charging /HHSI Pump Suction from RHR/LHSI "A"), XVG08801 A-SI (High Head i

Injection to RCS Cold Legs) and XVG08801B-SI (High Head injection to RCS Cold Legs). The erivironmental conditions for the MOVs selected for dynamic testing is well representative of the overall environmental conditions of the station's MOVs (one is l

located in the Reactor Building, one is located in the Service Water Building, two are l

located in the Auxiliary Building and two are located in the Fuel Handling Building).

i VCSNS is also participating in the Joint Owners Group MOV PV program.

i PV Program Evaluations and Monitoring -

The static and dynamic test data will be evaluated consistent with the existing MOV j

program requirements and the results will be used to verify switch settings and to detect potential MOV failure, deficiencies, or degradation. The MOV performance data including the diagnostic test data, MOV failure, deficiency, maintenance, and industry data (including the JOG PV program results) will be evaluated, trended, and periodically (at least every two years) incorporated back into the station's PV program to determine if adjustments are required. PV program adjustments will include, but are not limited to, possible - changes to test frequency, design basis calculations, maintenance activities, procedures, and other program documentation.

MOV Test Program -

The station's MOV PV test program provides reasonable assurance that the program's MOVs will remain operable until the next scheduled test, by maintaining all of the MOVs in the PV program in the same manner and including additional allowances for degradation, load sensitive behavior, spring pack relaxation, and aging effects in the calculations for minimum required stam thrust. Periodic diagnostic testing and PV program feedback when combined with the allowances for degradation / aging will ensure that sufficient thrust margin exists to support MOV operability until the next scheduled test.

Conclusion -

VCSNS's PV program provides reasonable assurance of the long-term capability of the program's MOVs to perform their design-basis safety functions.