ML061920110

Draft RAI on Relief Requests REL-002 and REL-021

ML061920110
Person / Time
Site:	Cook
Issue date:	07/07/2006
From:	Tam P NRC/NRR/ADRO/DORL/LPLIII-1
To:	Scarpello M, Vasey B American Electric Power Co
References
REL-002, REL-021, TAC MC2498, TAC MC2499, TAC MD0939, TAC MD0940
Download: ML061920110 (2)

Text

From:

Peter Tam To:

Scarpello, Michael; Vasey, Bob Date:

07/07/2006 3:50:39 PM

Subject:

Cook: Draft RAI on Relief Requests REL-002 and REL021 (TAC MD2498, 99, MD0939, 40)

Bob, Mike:

We are reviewing REL-002 in your 12/28/05 and REL-021 in your 3/31/06 submittals. Ou reviewer Jack McHale has written the following draft RAI questions. Please call me to schedule a conference call to discuss how we can disposition these questions:

1.

What is/are the specific failure scenario(s) leading to classification of the subject valves as Category A? Describe the rationale for re-categorizing the valves as Category A, including specific postulated failures of the check valve and gate valve pairs.

2.

The proposed alternative is to test the subject valves in the direction opposite the direction in which the leakage function applies using the head of RWST water. What is the expected differential pressure for this test and how does it compare with the accident condition where leakage is a concern? Describe how this test provides assurance that the disc face needed for isolation of accident leakage will fulfill its safety function.

3.

In discussing the burden caused by compliance with the Code, you stated that a system modification would be required to allow isolation of the RWST (REL-021). Describe what modifications were considered and the extent of burden that would be caused by their implementation.

4.

If system configuration allows for accident direction testing of check valves (SI-101 and SI-185) in series with the motor-operated gate valves (IMO-261, IMO-910, IMO-911) that meets Code requirements for Category A leak testing, has consideration been given to using this test path to test MOV (IMO-261, IMO-910, IMO-911) with the associated check valve internals removed? Are these check valves disassembled and inspected on a regular frequency that would allow a window of opportunity to establish accident direction test conditions for the valves for which relief is requested?

5.

You stated that at line pressures below 100 psi, the pressure force alone is not sufficient to create a seal and the mechanical force resulting from the disc being wedged between the seat rings provides the additional force necessary to provide a seal. Describe how normal valve operation in the closed direction gives assurance that a leak tight seal is achieved, while still preserving the ability to re-open the valve.

The sole purpose of this e-mail is to prepare you and others for the requested conference call. This e-mail does not convey an NRC staff position, nor does it formaly request for information.

Peter S. Tam, Senior Project Manager Plant Licensing Branch III-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation e-mail: pst@nrc.gov Tel.: 301-415-1451 CC:

McHale, John Mail Envelope Properties

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Subject:

Cook: Draft RAI on Relief Requests REL-002 and REL021 (TAC MD2498, 99, MD0939, 40)

Creation Date 07/07/2006 3:50:39 PM From:

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PST@nrc.gov Recipients Action Date & Time aep.com Transferred 07/07/2006 3:51:17 PM mkscarpello (Michael Scarpello) rgvasey (Bob Vasey) nrc.gov TWGWPO01.HQGWDO01 Delivered 07/07/2006 3:50:48 PM JJM1 CC (John McHale)

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