ML18009A885

Discusses 901116 Application to Delete Surveillance Requirements to Verify Operability of Auto Closure Interlock for RHR Sys Suction/Isolation Valves on RCS High Pressure

ML18009A885
Person / Time
Site:	Harris
Issue date:	05/02/1991
From:	Becker R Office of Nuclear Reactor Regulation
To:	Eury L CAROLINA POWER & LIGHT CO.
References
TAC-79187, NUDOCS 9105090208
Download: ML18009A885 (7)

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Docket No.

50-400 UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555 May 2, 1991 Mr. Lynn W. Eury Executive Vice President Power Supply Carolina Power 8 Light Company Post Office Box 1551

Raleigh, North Carolina 27062

SUBJECT:

COMMITMENT REVISION FOR RESIDUAL HEAT REMOVAL AUTO CLOSURE INTERLOCK DELETION -

SHEARON HARRIS NUCLEAR POWER PLANT, UNIT I (TAC NO.

79187)

By letter dated November 16,

1990, Power 8 Light Company submitted an requirements to verify operability residual heat removal (RHR) system system high pressure.

Elimination your plan to remove the RHR system Harris Nuclear Power Plant, Unit 1

and supplemented December 21, 1990, Carolina application to delete the surveillance of the auto closure interlock (ACI) for the suction/isolation valves on reactor coolant of the ACI surveillance was to support ACI during the March 1991 outage at Shearon (Harris).

Removal of the ACI was predicated on a generic review initiated by the Westinghouse Owners Group (WOG) with the submission, by letter dated April 22, 1988, of the topical report WCAP-11736, "Residual Heat Removal System Autoclosure Interlock Removal for the Westinghouse Owners Group."

A Safety Evaluation (SE) documenting the NRC review of WCAP-11736 was issued on August 8,

1989.

The generic SE concluded that a net safety benefit would result from removal of the RHR ACI provided the five plant improvements delineated in the generic SE

, were implemented.

These plant improvements would not be included in the Technical Specifications, but would be licensee commitments on a plant specific basis.

One of the plant improvements suggested in the generic SE and addressed in your request recommended sizing the RHR suction valve operator so that the valves cannot be opened against full system pressure.

In your submittal, you suggested an alternative to downsizing the operators, which is to reset the opening torque switch settings on these actuators to prevent valve opening under high differential pressures, yet still allow opening under design basis conditions.

A license amendment and supporting SER associated with your November 16,

1990, request were issued on March 4, 1991.

In the SER supporting the amendment, the staff accepted your commitment regarding resetting the opening torque switch improvement.

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5'105090208 910502 PDR 'PADOCK 05000400 P

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Mr. Lynn W. Eury By letter dated April 23, 1991, you informed the NRC that you found it impractical either to reset the opening torque switch settings to prevent valve opening under high differential pressures or to downsize the operators.

Your conclusion came from experience while performing motor-operated valve (MOV) diagnostic testing programs and MOV testing performed for Generic Letter 89-10, "Safety-Related Motor-Operated Valve Testing and Surveillance."

The MOV testing indicated that the valve's unseating thrust loads are dominated by forces attributable to "wedging loads,"

stem and friction loads, and other valve factors, and are not influenced significantly by the fluid differential pressure across the valve.

As an alternate, you propose relying on the existing redundant and diverse open permissive (pressure) interlocks, additional interlock while at power between the RHR isolation valves and the refueling water storage tank discharge line

valve, removal of motor operator

power, and strict procedural controls regarding valve alignment and operation.

The staff has reviewed your alternate proposal and finds it is consistent with a proposal accepted on the McGuire plant.

It should provide an equivalent level of safety and is, therefore, acceptable.

Sincerely, Original Signed By:

Richard A. Becker, Project Manager Project Directorate II-1 Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation NAME

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OAT5: 5/Q/91

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'~91 Document Name:

LTR EURY HARRIS

Mr. L. W. Eury Carolina Power 5 Light Company CC:

Mr. H.

Ray Starling Manager - Legal Department Carolina Power

& Light. Company P. 0.

Box 1551

Raleigh, North Carolina 27602 Resident Inspector/Harris NPS c/o U. S. Nuclear Regulatory Commission Route I, Box 315B New Hill, North Carolina 27562 Mr. R. B. Richey, Vice President Harris Nuclear Project Harris Nuclear Plant P. 0.

Box 165 New Hill, North Carolina 27562 Mr. H. A. Cole Special Deputy Attorney General State of North Carolina P. 0.

Box 629

Raleigh, North Carolina 27602 Shearon Harris Regional Administrator, Region II U.S. Nuclear Regulatory Commission 101 Marietta Street Suite 2900 Atlanta, Georgia 30323 Mr. C. S. Hinnant Plant General Manager Harris Nuclear Plant P. 0.

Box 165 New Hi 11, North Carolina 27562 Mr. Dayne H. Brown, Director Division of Radiation Protection N. C. Department of Environmental, Commerce 5 Natural Resources P. 0.

Box 27687

Raleigh, North Carolina 27611-7687

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D'ISTR IBUTION Docket:Fi-le NRC PDR Local PDR S.

Varga G. Lainas L. Reyes E.

Adensam P. Anderson R. Becker B. Jones OGC E. Jordan ACRS (10)

Harris Plant File 14-E-4 14-H-3 RII 14-B-20 14-B-20 14-B-20 15-B-18 NNBB-3302 P-315

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