ML15098A181
| ML15098A181 | |
| Person / Time | |
|---|---|
| Site: | Byron, Braidwood  |
| Issue date: | 04/23/2015 |
| From: | Daily J Division of License Renewal |
| To: | Office of Nuclear Reactor Regulation |
| Daily J | |
| Shared Package | |
| ML15106A733 | List: |
| References | |
| DLR-15-0191, TAC MF1879, TAC MF1880, TAC MF1881, TAC MF1882 | |
| Download: ML15098A181 (6) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 April 23, 2015 LICENSEE:
Exelon Generation Company, LLC FACILITY:
Byron Station, Units 1 and 2 Braidwood Station, Units 1 and 2
SUBJECT:
SUMMARY
OF TELEPHONE CONFERENCE CALL BETWEEN THE U.S.
NUCLEAR REGULATORY COMMISSION AND EXELON GENERATION COMPANY, LLC, CONCERNING REQUEST FOR ADDITIONAL INFORMATION, SET 48, PERTAINING TO THE BYRON STATION AND BRAIDWOOD STATION, LICENSE RENEWAL APPLICATION HELD ON MARCH 26, 2015 (TAC NOS. MF1879, MF1880, MF1881, MF1882)
The U.S. Nuclear Regulatory Commission (NRC or the staff) and representatives of Exelon Generation Company, LLC (Exelon or the applicant), held a telephone conference call on March 26, 2015, to discuss and clarify the staffs concerns in request for additional information (RAI) B.2.1.24-1c, related to the Byron Station, Units 1 and 2, and the Braidwood Station, Units 1 and 2, license renewal application. The telephone conference call was useful in clarifying the intent of the staffs concerns.
provides a listing of the participants, Enclosure 2 contains the RAI discussed with the applicant, including a brief description on the status of the items, and Enclosure 3 contains commentary documents provided by the applicant for the conference call; some sections were color-coded by the applicant for emphasis.
The applicant had an opportunity to comment on this summary.
/RA/
John Daily, Senior Project Manager Projects Branch 1 Division of License Renewal Office of Nuclear Reactor Regulation Docket Nos. 50-454, 50-455, 50-456, and 50-457
Enclosures:
- 1. List of Participants
- 2. List of Draft Request for Additional Information
- 3. Flux Thimble CallThursday, March 26, 2015 (Exelon Submittal) cc w/encls: Listserv
ML15106A733 (Package) ML15098A181 (Memo)
ML15106A736 (Enclosure 3)
- concurred via email OFFICE LA:DLR PM: RPB1:DLR BC:RPB1:DLR PM:RPB1:DLR NAME YEdmonds*
JDaily YDiazSanabria JDaily DATE 4/16/15 4/16/15 4/21/15 4/23/15
SUBJECT:
SUMMARY
OF TELEPHONE CONFERENCE CALL BETWEEN THE U.S. NUCLEAR REGULATORY COMMISSION AND EXELON GENERATION COMPANY, LLC, CONCERNING REQUEST FOR ADDITIONAL INFORMATION, SET 48, PERTAINING TO THE BYRON STATION AND BRAIDWOOD STATION, LICENSE RENEWAL APPLICATION HELD ON MARCH 26, 2015 (TAC NOS.
MF1879, MF1880, MF1881, MF1882)
DISTRIBUTION EMAIL:
PUBLIC RidsNrrDlr Resource RidsNrrDlrRpb1 Resource RidsNrrDlrRarb Resource RidsNrrDlrRasb Resource RidsOgcMailCenter RidsNrrPMByron Resource RidsNrrPMBraidwood Resource JDaily DMcIntyre, OPA EDuncan, RIII JBenjamin, RIII AGarmoe, RIII JMcGhee, RIII JRobbins, RIII VMitlyng, RIII PChandrathil, RIII
ENCLOSURE 1 TELEPHONE CONFERENCE CALL BYRON STATION, UNITS 1 AND 2, AND BRAIDWOOD STATION, UNITS 1 AND 2 LICENSE RENEWAL APPLICATION LIST OF PARTICIPANTS March 26, 2015 Participants Affiliation John Daily U.S. Nuclear Regulatory Commission (NRC)
Dennis Morey NRC Roger Kalikian NRC Bart Fu NRC John Hufnagel Exelon Generation Company, LLC (Exelon)
Michael Gallagher Exelon Al Fulvio Exelon Don Warfel Exelon Albert Piha Exelon Casey Muggleston Exelon Don Brindle Exelon Ralph Wolen Exelon John Mathews Exelon Gary Becknell Exelon
ENCLOSURE 2 TELEPHONE CONFERENCE CALL
SUMMARY
BYRON STATION, UNITS 1 AND 2, AND BRAIDWOOD STATION, UNITS 1 AND 2 LICENSE RENEWAL APPLICATION March 26, 2015 The U.S. Nuclear Regulatory Commission (NRC or the staff) and representatives of Exelon Generation Company, LLC (Exelon or the applicant), held a telephone conference call on March 26, 2015, to discuss and clarify the staffs concerns in request for additional information (RAI) B.2.1.24-1c, related to the Byron Station, Units 1 and 2, and the Braidwood Station, Units 1 and 2, license renewal application. The telephone conference call was useful in clarifying the intent of the staffs concerns.
Applicability:
Braidwood, Units 1 and 2 Discussion The staff and the applicant discussed the draft of RAI B.2.1.24-1c, followup RAI for the applicants Flux Thimble Tube Inspection Aging Management Program (AMP), LRA Section B.2.1.24 (as applicable to Braidwood Units 1 and 2). This RAI is composed of three portions, each of which has a background, issue and request:
(a) In Issue 1, the staff noted from the applicants earlier responses that its program failed to obtain useful data from most of its flux thimble tubes during some recent outage inspections since 2012, due to restrictions inside the flux thimble tubes. The staff is concerned that the applicant has yet to identify the root cause and, as a result, is not able to implement effective corrective actions to resolve the problem. The staff is also concerned that an increasing trend in the numbers of uninspectable flux thimble tubes, unique to Braidwood, may be due to an age-related deformation of the tubes (e.g.,
reduction in inside diameter).
(b) In Issue 2, the staff noted that several program elements in the applicants program are not consistent with those of the GALL Report program. The staff observed that the applicant could ultimately be replacing several flux thimble tubes at some programmatic frequency instead of performing monitoring and trending inspections.
(c) In Issue 3, the staff noted that the applicants response dated February 23, 2015 (Table 2, Page 13), indicated that three tubes had to be replaced after only one cycle of service due to indications of wear; the staff noted that this appears to contradict the applicants statement that No flux thimble tube has been replaced due to age-related degradation in less than four (4) cycles (since the staff considers wear to be aging-related). The applicants RAI response (RS-15-071 dated February 23, 2015) had concluded that the high initial wear was considered to be associated with startup rather than aging, and the applicant further explained its position as declared in that RAI response. The staff stated it understood the applicants response but disagreed with its conclusion, in that wear is wear and is aging-related. The staff also explained that the 3 Cycle 1 flux thimble tube wear-related failures were not the only focus of its concerns, however: other flux thimble tubes in subsequent operating cycles also showed problematic wear patterns (e.g., Braidwood Unit 1, Cycle 3; Braidwood Unit 1, 2010 (this one was a replacement thimble tube); Braidwood Unit 2; and others). The staff was also
concerned that, in view of the applicants supplied wear data and the results of some similar industry experiences, high wear rates can continue into (or originate in) subsequent cycles; therefore the applicants proposal to replace flux thimble tubes at a three-cycle frequency may not appropriately account for worst-case wear rates and may not be adequately conservative.
The applicant offered two written commentaries to summarize its previously-submitted materials and to propose a forum for the discussion. Those commentary documents are included into this summary as Enclosure 3 (ADAMS Accession No. ML15106A736). Based on the discussions held, the applicant indicated it understood the staffs current issues and requests.
The applicant presented and discussed two primary response options, particularly two resolution paths that it was proposing. The applicants stated that these both arose based upon an assumption that the ability (or inability) to present a comprehensive set of eddy current data during its [upcoming] Braidwood outage is a key to its ultimate RAI response. One path was based upon the possibility that it might not be able to obtain a comprehensive set of eddy current data. The second path was based upon the (more likely) outcome where it was indeed able to obtain that data. The applicants understanding of follow-up RAI B.2.1.24-1c was that this ability/inability was a central concept that would drive its response in one way or the other.
The staff stated that Exelons willingness to supply a full set of eddy current data could play a definite role in responding to the RAI, but the staff indicated that the RAI is directed primarily at the programmatic aspects of the AMP itself and the components of the AMP, and the requests and issues identified in the RAI would need to be responded to regardless of the data that might or might not come from the [upcoming] Braidwood outage. Therefore, if the applicant decided to include this data, it could be useful information; however, the staff did not believe this set of eddy current data in and of itself would completely address its concerns.
The staff and the applicant also discussed the general considerations related to and the differences between an AMP that is considered to be: (1) consistent with the GALL Report; (2) consistent with enhancements; (3) consistent with exceptions; (4) consistent with enhancements and exceptions; and (5) a plant-specific AMP. The applicant chooses which form of AMP it will implement and the staff reviews it under the applicable guidance of both the GALL Report and the SRP-LR.
The staff and the applicant agreed that the call and exchange of ideas on the RAI were helpful, and the applicant indicated it would consider the staff concerns as it prepares its responses.
The conference call was then concluded.