ML15135A437

Approval of Steam Dryer Methodology and Resumption of EPU Power Ascension

ML15135A437
Person / Time
Site:	Peach Bottom
Issue date:	05/15/2015
From:	Richard Ennis Plant Licensing Branch 1
To:	Borton K Exelon Generation Co
Ennis R, NRR/DORL/LPLI-2, 415-1420
References
TAC MF4792
Download: ML15135A437 (1)

Text

From: Ennis, Rick Sent: Friday, May 15, 2015 2:39 PM To: Kevin Borton (kevin.borton@exeloncorp.com)

Cc: Ken Ainger; Rommel, John C.:(GenCo-Nuc); David Neff; Uhle, Jennifer; Lubinski, John; Ross-Lee, MaryJane; Pettis, Robert; Manoly, Kamal; Basavaraju, Chakrapani; Lund, Louise; Wilson, George; Broaddus, Doug; Bower, Fred; Barber, Scott; Hansell, Samuel; Smith, Brian; Breach, Michael; Vik Shah; Stephen Hambric; Samir Ziada

Subject:

Peach Bottom Unit 2 - Approval of Steam Dryer Methodology and Resumption of EPU Power Ascension Importance: High

Kevin, The NRC staff and its contractors have reviewed the proposed change to the methodology for establishing the replacement steam dryer (RSD) strain limits for Peach Bottom Atomic Power Station (PBAPS), Unit 2, as described in the licensees letters dated February 3, March 24, April 5, and May 15, 2015. Based on this review, the NRC staff finds that:

1) The proposed methodology conservatively accounts for non-main steam line acoustic loads in the low frequency range (i.e., 0 - 50 Hz).

2) The method of combining the non-main steam line acoustic and main steam line acoustic stresses is acceptable.

Based on the above findings, the NRC staff concludes that the proposed methodology is acceptable for establishing the RSD strain limits for PBAPS, Unit 2. As such, the staff approves the proposed methodology, for use at PBAPS, Unit 2, consistent with the requirements in license condition 2.C(15)(d)3.

The licensees analysis, using the proposed methodology, predicts that the RSD minimum alternating stress ratio (MASR) will remain greater than 1.0 at full EPU operating conditions (i.e., stresses are below the ASME Code endurance limit of 13,600 psi). Based on use of an approved methodology and a predicted MASR greater than 1.0, the NRC concludes that there is reasonable assurance that the PBAPS, Unit 2, RSD will maintain its structural integrity at full extended power uprate (EPU) operating conditions. Therefore, the NRC staff has no current concerns or objections toward resumption of power ascension at PBAPS, Unit 2, to the full approved EPU power level (i.e., 112.4% of 3514 MWt).

The NRC will formally document the above conclusions in a forthcoming letter.

Thanks, Rick