ML102560303

From kanterella
Jump to navigation Jump to search

Summary of Teleconference to Clarify RAI Response Regarding Dynamic Analysis of Feedwater Valve Fast Closure
ML102560303
Person / Time
Site: Point Beach  NextEra Energy icon.png
Issue date: 09/03/2010
From: Hale S
Point Beach
To: Steve Jones
NRC/NRR/DSS/SNPB
kmz1
References
TAC ME1081, TAC ME1082
Download: ML102560303 (1)


Text

From: Hale, Steve [Steve.Hale@nexteraenergy.com]

Sent: Friday, September 03, 2010 1:13 PM To: Jones, Steve Cc: Beltz, Terry

Subject:

RE: Summary of Teleconference to Clarify RAI Response Regarding Dynamic Analysis of Feedwater Valve Fast Closure

Steve, You captured our discussion accurately. Thanks for your time.

Steve From: Jones, Steve [1]

Sent: Friday, September 03, 2010 12:18 PM To: Beltz, Terry Cc: Hale, Steve

Subject:

Summary of Teleconference to Clarify RAI Response Regarding Dynamic Analysis of Feedwater Valve Fast Closure The following people participated in a conference call at 9:00am on September 3, 2010, to clarify discussions of dynamic analyses of fast closure of main feedwater valves at Point Beach Nuclear Plant (PBNP):

Steve Jones - USNRC - Balance of Plant Branch.

Steve Hale - lead for the Point Beach EPU and associated amendments.

Jim Costedio - Point Beach Licensing Manager.

Harv Hanneman - Licensing Engineer.

Jim Connolly, Norm Hanley and Allan Traft - contract engineers from Shaw, Inc.

The responses to requests for additional information provided by letters dated June 24, 2010, and August 24, 2010, described the feedwater valve dynamic analysis and indicated that the closure of the main feedwater regulating valves (MFRVs) with the feedwater pumps operating was bounding because the MFRVs are faster acting. However, the EPU licensing report provided as an attachment to the license amendment request described that the MFRV operating time would be increased to 10 seconds and the new feedwater isolation valves would have a closure time of no more than 5 seconds. The licensee clarified that the licensing report described the maximum operating time for the valves, which is a consideration in the containment analysis for a the steam line break accident. However, the dynamic valve closure analysis considers the minimum operating time, which the licensee specified as 3 seconds for both valves. Because the MFRVs are control valves, the MFRVs would be only partially open for the initial condition of 100 percent uprated power at steady state, which was the initial condition of the dynamic analyses specified in the August 24, 2010, response. The MFIVs are isolation valves and would be fully open for all normal plant operating states. The licensee explained that the partially open state of the MFRVs was considered in determining the minimum valve closure times for the dynamic analysis.

Thus, the MFRVs would have the shortest closure time and provide a bounding input with respect to dynamic analysis of feedwater isolation.

Steve Jones Steven R. Jones Sr. Reactor Systems Engineer

NRR/DSS/SBPB 301-415-2712