ML102560006

E-mail on Hope Creek Main Steam Flow Element CASS Material, Dated September 9, 2010

ML102560006
Person / Time
Site:	Hope Creek
Issue date:	09/09/2010
From:	Hufnagel J Exelon Corp
To:	Bennett Brady License Renewal Projects Branch 1
References
Download: ML102560006 (1)

Text

Brady, Bennett From: john.hufnagel@exeloncorp.com Sent: Thursday, September 09, 2010 11:53 AM To: Brady, Bennett Cc: donald.warfel@exeloncorp.com; Peter.Tamburro@exeloncorp.com; Paul.Cervenka@exeloncorp.com

Subject:

Follow-up from yesterday's chat with Albert Wong and Ginesh

Bennett, We have done a review and confirmed that there have been no repairs to the Main Steam Flow Element CASS material over the course of Hope Creek plant operation. Therefore, as discussed yesterday, and per BWRVIP-75A, stress corrosion cracking should not be a concern.

With regard to the secondary question on ferrite content, it appears that some of the MS flow elements contain CASS material with ferrite at the higher end of the range, but the CASS section (upstream half of the flow element) is welded to the downstream carbon steel section (half) which is then welded to the carbon steel pressure boundary piping. The upstream end of the CASS section is free to move, thus minimizing any stresses on the component. This configuration explains the statement in the RAI 3.4.2.4-01 response that there is no tensile stress in the CASS portion of the nozzle to promote stress corrosion cracking, in that only one end of the component is attached (to the downstream carbon steel section). The upstream end is free to move, thus preventing tensile stresses.

Hopefully this provides the information needed to confirm the adequacy of this item. Please let me know. Thanks, Bennett.

- John.

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