RS-16-166, Supplemental Information Related to Inservice Inspection Interval Relief Request I5R-08

Supplemental Information Related to Inservice Inspection Interval Relief Request I5R-08

ML16236A251
Person / Time
Site:	Dresden
Issue date:	08/22/2016
From:	Simpson P R Exelon Generation Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
CAC MF8090, CAC MF8091, RR-I5R-08, RS-16-166
Download: ML16236A251 (3)

Text

Exelon Generation RS-16-166 10 CFR 50.55a(z)(1)

August22,2016 U.S. Nuclear Regulatory Commission ATIN: Document Control Desk Washington, D.C. 20555-0001

Subject:

Dresden Nuclear Power Station, Units 2 and 3 Renewed Facility Operating License Nos. DPR-19 and DPR-25 NRC Docket Nos. 50-237 and 50-249 Supplemental Information Related to Dresden Nuclear Power Station lnservice Inspection Interval Relief Request 15R-08

References:

(1) Letter from P. R. Simpson (Exelon Generation Company, LLC (EGC)) to NRC, "Dresden Nuclear Power Station lnservice Inspection Interval Relief Request 15R-08," dated June 30, 2016 (2) Letter from R. S. Haskell (NRC) to B. C. Hanson (EGC), "Dresden Nuclear Power Station, Unit Nos. 2 and 3 -Supplemental Information Needed for Acceptance of Requested Licensing Action Re: lnservice Inspection Interval Proposed Alternative (15R-08) (CAC Nos. MF8090 and MF8091 )," dated August 18, 2016 In Reference 1, EGC requested relief from weld inspection frequency requirements in accordance with ASME Code Case N-702, "Alternative Requirements for Boiling Water Reactor (BWR) Nozzle Inner Radius and Nozzle-to-Shell Welds,Section XI, Division 1," and Boiling Water Reactor Vessel Inspection Program (BWRVIP)-241, "Probabilistic Fracture Mechanics Evaluation for the Boiling Water Reactor Nozzle-to-Vessel Shell Welds and Nozzle Blend Radii." During its review of the Reference 1 request, the NRC determined that supplemental information is required for the NRC to conduct a detailed technical review of the request as documented in Reference

2. EGC's response to the NRC's Reference 2 request is contained in the attachment to this letter.

August22,2016 U.S. Nuclear Regulatory Commission Page2 There are no regulatory commitments contained within this letter. Should you have any questions concerning this letter, please contact Mr. Mitchel A. Mathews at (630) 657-2819.

Patrick R. Simpson Manager -Licensing Exelon Generation Company, LLC

Attachment:

Supplemental Information Related to Dresden Nuclear Power Station lnservice Inspection Interval Relief Request 15R-08 Supplemental Information Related to Dresden Nuclear Power Station lnservlce Inspection Interval Relief Request ISR-08 Following is the NRC's request for supplemental information in bold italicized font followed by Exelon Generation Company LLC's (EGC's) response:

Section 5 (pg. 2 of 8) of the submittal (RS-16-2016), dated June 30, 2016, states, in part: " .. .including at least one nozzle from each system and nominal pipe size, during each inspection interval [emphasis added] in accordance with ASME code Case N-702 ... ": 1.) Please clarify what is meant by "inspection interval," as annotated in the submittal.

Will the Code Case N-702 examination requirements at DNPS for the current fifth 10-year /SI interval (ending on January 20, 2023) and the subsequent sixth 10-year IS/ interval (covering the period until the renewed operating licenses expire) continue to be met? EGC Response:

Each inspection interval described in Attachment 1, Section 5 of the June 30, 2016, submittal refers to the Dresden Nuclear Power Station (DNPS), Units 2 and 3 current fifth and upcoming sixth 120-month lnservice Inspection (ISi) Program intervals.

The Code Case N-702 examination requirements will be met during this entire timeframe.

Specifically, a minimum of 25% of nozzle inner radii and nozzle-to-shell welds, including at least one nozzle from each system and nominal pipe size, as identified in Relief Request ISR-08 will be examined during each 120-month ISi inspection interval in accordance with the conditions for the implementation of Code Case N-702. These conditions are defined in NRC Regulatory Guide 1.147, Rev. 17, "lnservice Inspection Code Case Acceptability, ASME Section XI, Division 1." EGC will adhere to these requirements during both of the remaining DNPS, Units 2 and 3 120-month ISi Program intervals which span the balance of the DNPS, Units 2 and 3 period of extended operation.

2.) Please describe the impact, if any, on the inspection frequency for the subject welds and inner radii. EGC Response:

EGC does not plan to deviate from the previously evaluated Code Case N-702 examination frequency for the welds described in the June 30, 2016, request. Page 1of1