ML14323A625
| ML14323A625 | |
| Person / Time | |
|---|---|
| Site: | Byron, Braidwood  |
| Issue date: | 12/04/2014 |
| From: | Robinson L License Renewal Projects Branch 1 |
| To: | |
| Robinson L, NRR/DLR/RPB1, 301-415-4115 | |
| References | |
| TAC MF1879, TAC MF1880, TAC MF1881, TAC MF1882 | |
| Download: ML14323A625 (7) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 December 4, 2014 LICENSEE:
Exelon Generation Company, LLC FACILITY:
Byron Station, Units 1 and 2 Braidwood Station, Units 1 and 2
SUBJECT:
SUMMARY
OF TELEPHONE CONFERENCE CALL HELD ON OCTOBER 7, 2014, BETWEEN THE U.S. NUCLEAR REGULATORY COMMISSION AND EXELON GENERATION COMPANY, LLC CONCERNING DRAFT REQUEST FOR ADDITIONAL INFORMATION, SET 42, PERTAINING TO THE BYRON STATION AND BRAIDWOOD STATION, LICENSE RENEWAL APPLICATION (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 October 7, 2014, to discuss and clarify the staffs draft request for additional information (DRAI),
Set 42, concerning 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 DRAIs.
provides a listing of the participants, and Enclosure 2 contains the DRAI discussed with the applicant, including a brief description on the status of the items.
The applicant had an opportunity to comment on this summary.
/RA/
Lindsay Robinson, 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 cc w/encls: Listserv
- concurred via e-mail OFFICE LA:RPB1:DLR* PM: RPB1:DLR BC:RPB1:DLR PM:RPB1:DLR NAME YEdmonds LRobinson YDiaz-Sanabria LRobinson DATE 12/2/14 12/3/14 12/4/14 12/4/14
SUBJECT:
SUMMARY
OF TELEPHONE CONFERENCE CALL HELD ON OCTOBER 7, 2014, BETWEEN THE U.S. NUCLEAR REGULATORY COMMISSION AND EXELON GENERATION COMPANY, LLC CONCERNING DRAFT REQUEST FOR ADDITIONAL INFORMATION, SET 42, PERTAINING TO THE BYRON STATION AND BRAIDWOOD STATION, LICENSE RENEWAL APPLICATION (TAC NOS. MF1879, MF1880, MF1881, MF1882)
DISTRIBUTION EMAIL:
PUBLIC RidsNrrDlr Resource RidsNrrDlrRpb1 Resource RidsNrrDlrRarb Resource RidsNrrDlrRasb Resource RidsOgcMailCenter RidsNrrPMByron Resource RidsNrrPMBraidwood Resource LRobinson 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 October 7, 2014 PARTICIPANTS AFFILIATIONS Lindsay Robinson U.S. Nuclear Regulatory Commission (NRC)
Bart Fu NRC Roger Kalikian NRC John Hufnagel Exelon Generating Company, LLC (Exelon)
Al Fulvio Exelon Don Warfel Exelon Jim Annett Exelon Albert Piha Exelon Don Brindle Exelon Ralph Wolen Exelon Gary Becknell Exelon
ENCLOSURE 2 DRAFT REQUEST FOR ADDITIONAL INFORMATION BYRON STATION, UNITS 1 AND 2, AND BRAIDWOOD STATION, UNITS 1 AND 2, LICENSE RENEWAL APPLICATION October 7, 2014 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 October 7, 2014, to discuss and clarify the following draft request for additional information (DRAI), Set 42, concerning the Byron Station, Units 1 and 2, and Braidwood Station, Units 1 and 2, license renewal application (LRA).
DRAI B.2.1.24-1a Applicability:
Byron Station and Braidwood Station (BBS), all units
Background:
By letter dated May 19, 2014, the staff issued request for additional information (RAI) B.2.1.24-1 requesting additional information regarding higher-than expected wear rates in flux thimble tubes at Braidwood Units 1 and 2, and also an explanation that examinations were not performed on a few tubes.
In a letter dated June 9, 2014, the applicant provided a response to the staffs RAI.
Issue:
In the RAI response, the applicant discussed issues based on outage inspections from 2007 to 2012 for both Braidwood Unit 1 and Unit 2. The staff recently discovered from the NRC 71002 inspection that, during the applicants most recent outage inspections in May of 2014 for Unit 2 and in September of 2013 for Unit 1, the applicant was not able to complete eddy current examinations on most of the flux thimble tubes. These issues were not disclosed to the staff during the onsite audit in December 2013, nor in the RAI response dated June 9, 2014.
Request:
- 1) Describe results of the latest flux thimble tube inspections at both Braidwood Units 1 and
- 2. Provide specific information where tube wear data were not obtained.
- 2) Justify the adequacy of the program when tube examinations are not performed as planned.
- 3) Provide technical basis to assure that tube wear acceptance criteria are met and that the inspection program is adequate.
- 4) Clarify if there have been similar issues at Byron Units 1 and 2, such as not being able to complete eddy current examinations or failure to obtain data on any of the tubes.
Describe cases in which higher-than expected wear or under-predicting of wear has occurred on any of the tubes.
Discussion: The applicant requested clarification on the staffs request regarding the wording not disclosed. The applicant understood the request but claimed to be confused by the staffs background and issue regarding the request. The applicant suggested a different wording such as, not provided, for the staffs consideration. The staff revised the background, issue, and request (see below) to better clarify the staffs concern. This DRAI was formally sent as an RAI to the applicant on October 10, 2014, titled: RAI B.2.1.24-1a.
Background:
By letter dated May 19, 2014, the staff issued request for additional information (RAI)
B.2.1.24-1, requesting additional information regarding higher-than expected wear rates in flux thimble tubes at Braidwood Units 1 and 2. In addition, the staff also questioned the adequacy of the program because it was not able to perform examinations on all the tubes.
By letter dated June 9, 2014, the applicant provided a response to the staffs RAI. In the response, the applicant discussed high wear-rate issues, and its failure to obtain data on a few tubes based on outage inspections from 2007 to 2012 for both Braidwood Unit 1 and Unit 2. The applicant also stated that several corrective actions are being implemented to address the issues related to completing eddy current examinations.
One corrective action was to increase the inspection frequency to perform examinations every outage. The staff closed the issue based on the applicants response.
During the NRC 71002 inspection at Braidwood in October of 2014, the staff discovered that the applicant was not able to complete eddy current examinations on any of the 58 tubes at Braidwood Unit 1 during the September 2013 outage, and completed only seven of the 58 flux thimble tubes at Braidwood Unit 2 during the May 2014 inspection.
The information regarding the Braidwood Unit 1 inspection was not provided to the staff during the onsite audit in December of 2013. In addition, the information regarding the Braidwood Unit 2 inspection along with the Braidwood Unit 1 problems was not discussed in the RAI response dated June 9, 2014.
Issue:
The staff is concerned that the Flux Thimble Tube Inspection aging management program may not be adequate if tube wear examinations are not performed.
Request:
- 1) Describe results of the latest flux thimble tube inspections at Braidwood Units 1 and 2. Provide specific information where tube wear data were not obtained.
- 2) Justify the adequacy of the program when tube examinations are not performed as planned.
- 3) Provide technical basis to assure that tube wear acceptance criteria are met and that the inspection program is adequate.
- 4) Clarify if there have been similar issues at Byron Units 1 and 2, such as not being able to complete eddy current examinations or failure to obtain data on any of the tubes. Describe cases in which higher-than expected wear or under-predicting of wear has occurred on any of the tubes.
- 5) Clarify if there have been any leakage events at BBS due to flux thimble tube wear.