ML16202A062

Deviation from BWR Vessel and Internals Project (BWRVIP) Guidelines - Surface Condition of Certain Welds for Replacement Steam Dryers

ML16202A062
Person / Time
Site:	Peach Bottom
Issue date:	07/20/2016
From:	Massaro M Exelon Generation Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML16202A062 (2)

Text

Exelon Generation 10CFR 50.4 July 20, 2016 U.S. Nuclear Regulatory Commission ATIN: Document Control Desk Washington, DC 20555-0001 Peach Bottom Atomic Power Station (PBAPS), Unit 2 and Unit 3 Renewed Facility Operating License No. DPR-44 and DPR-56 NRC Docket No. 50-277 and 50-278

Subject:

Deviation from BWR Vessel and Internals Project (BWRVIP) Guidelines - Surface Condition of Certain Welds for Unit 2 and 3 Replacement Steam Dryers

References:

1. BWRVIP-181-A, Steam Dryer Repair Design Criteria, Electric Power Research Institute (EPRI),

1020997, 2010.

2. BWRVIP-94NP, Revision 2: BWR Vessel and Internals Project, Program Implementation Guide, EPRI, 1024452, 2011

3. BWRVIP Letter (C. Terry) to NRC (B. Sherron), BWR Utility Commitments to the BWRVIP, dated 5/30/1997 Exelon Generation Company, LLC (EGC) is a member of the BWR Vessel and Internals Project (BWRVIP) and has committed in the Reference 3 letter to implementing BWRVIP products, including providing a notification to the NRC staff if a 'mandatory' or 'needed' aspect of a BWRVIP product will not be implemented.

Reference 1 requires all welds and heat affected zones on new steam dryers to be polished to minimize the possibility of Intergranular Stress Corrosion Cracking (IGSCC). However, some of the PBAPS Unit 2 and Unit 3 Replacement Steam Dryers (RSD) welds were not polished, which is considered a 'needed' requirement. During the fabrication of the RSDs, some welds were inaccessible for polishing due to either the fabrication sequence of the dryer or due to space constraints not permitting the usage of the polishing tool.

In accordance with Reference 2, the acceptability of not polishing all the RSD welds was documented in a deviation disposition. The fabrication processes and material selection of the PBAPS RSD's ensured that the instances of IGSCC and fatigue cracking would likely be prevented and if they were to occur, indications would be minimal and structural integrity would be assured. However, PBAPS has expanded its inspection plan to perform augmented inspections over the next several outages on accessible, selected welds that were not polished to identify any fatigue cracking or IGSCC.

This letter is being transmitted for your information in accordance with Section 3.5 of Reference 2.

1

Exelon Generation Company, LLC BWRVIP Guidelines - Replacement Steam Dryer There are no regulatory commitments contained in this letter. Should you have any questions, please contact William J. Reynolds at 717-456-4595.

~I~

Michael J. Massaro Site Vice President Peach Bottom Atomic Power Station cc: Senior Resident Inspector, USNRC, PBAPS R. R. Janati, Commonwealth of Pennsylvania Region 1 Administrator, USNRC CCN: 16-63 2