ML19211C902

Submits Info in Response to NRC Requesting Commitment to Meeting Interim Position for Containment Purge & Vent Valve Operation. Interim Position Will Be Met Upon Completion of Bypass Line Wiring Mod

ML19211C902
Person / Time
Site:	Hatch
Issue date:	01/09/1980
From:	Kelly R GEORGIA POWER CO.
To:	Office of Nuclear Reactor Regulation
References
TAC-42603, TAC-42604, TAC-51984, TAC-51985, NUDOCS 8001150323
Download: ML19211C902 (2)

Text

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Georgia Power Cornpany 230 Peachtree Street Post Office Box 4545 Atlanta, Georgia 30302 Telephone 404 522-6C60 January 9, 1980 R. J. Kelly Georm Power Vice President and General Manager O

Power Generaten the scorrem e'ec:nc system U. S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Washington, D. C.

20555 NRC DOCKETS 50-321, 50-366 OPERATING LICENSES DPR-57, NPF-5 EDWIN I. HATCH NUCLEAR PLANT UNITS 1, 2 CONTAINMENT PURGING AND VENTING DURING NORMAL OPERATION Gentlemen:

The following information is provided in response to your October 22, 1979, letter which requested Georgia Power Company to commit to meeting the

" Interim Position for Containment Purge and Vent Valve Operation" at Plant Hatch.

Georgia Power Company does not operate either unit at Plant Hatch in a mode which requires continuous purging or venting. All purging and venting for both units is done intermittently as required to maintain the containment environment.

The operators for the 18-inch butterfly valves, which serve as containment isolation valves in the containment purge and inerting systems for Unit 1, have been blocked to less than 500 open. The Unit 2 modification is in progress with completion expected by January 31, 1980. However, Unit 2 does not operate with these valves open. Purging and venting during normal operation is performed via the normal operation bypass line. The 500 setting has been verified by the valve vendor as meeting the operability criteria required for these valves.

All other isolation valves in the system are less than 3-inch diameter.

The 2-inch normal operation bypass line's isolation logic is being modified to prevent bypass of the primary containment isolation signal (PCIS) to the bypass valves. This modification will be implemented on Unit 2 at the same time as the Category A implementation TMI items because a unit shutdown is required to implement the wiring modification. As discussed below, this bypass line cannot be used on Unit 1.

We, therefore, conclude that, following completion of the wiring modifica-tion, Plant Mtch Unit 2 will meet the interim position stated in your October 22, 1979, le 2r.

In the interim, until completion of the wiring modification, Georgia Power Company will not override, block or reset the PCIS for both units in order to operate the normal operation bypass line when the reactor is not in the cold shutdown or refuel modes. We also conclude that, with one exception, Plant Hatch Unit 1 can meet the interim position. As we stated in our August 29, 1979, letter, periodic purge or vent operations are not possible on Unit 1 through the normal operation 2-inch bypass line.

Insufficient flow is developed through the existing valves to adequately vent or purge. As a result, purge 1744 117 a

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Georgia Power d U. S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation January 9, 1980 Page Two operation is conducted via the 2-inch post-LOCA purge valves which bypass the 18-inch butterfly valves. The present design does not supply isolation logic to these post-LOCA bypass valves. As a result, an operator is stationed at the valve control panel whose sole duty during the vent or purge operation is to close the 2-inch isolation valves if isolation is required. We believe this procedure provides the necessary assurance that the valves would be closed.

Our letter of November 15, 1979, referred to preliminary evaluation of the 18-inch butterfly valves which proposed limiting valve travel to 300 The letter also committed to an expedited valve qualification program. The analysis required to qualify the 18-inch butterfly valves has been performed by the valve vendor and is being reviewed by Georgia Power Company. As a result of the analysis, it was determined that the valves could be opened up to 500 at Plant Hatch. As a practical matter, the angle of opening has been restricted to 300 for the present time, although the analysis allows 50. If this setting causes difficulty in operation, we may adjust the angle of opening to some value approaching 50. A summary of our valve qualification efforts will be provided when the review is complete.

Very truly yours, R. J. Kelly RDB/mb xc: Ruble A. Thomas George F. Trowbridge, Esquire R. F. Rogers, III 1744 118