ML15222A006

August 5, 2015, Summary of Telecon Held Between the NRC and Exelon Generation Co., LLC, Concerning Request for Additional Information Set 9 Pertaining to the LaSalle County Station License Renewal Application

ML15222A006
Person / Time
Site:	LaSalle
Issue date:	08/28/2015
From:	Jeffrey Mitchell Division of License Renewal
To:
Mitchell J, NRR/DLR,415-3019
References
DLR-15-0397, TAC MF5346, TAC MF5347
Download: ML15222A006 (6)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 August 28, 2015 LICENSEE:

Exelon Generation Co., LLC FACILITY:

LaSalle County Station, Units 1 and 2

SUMMARY

OF TELECON HELD ON AUGUST 5, 2015, BETWEEN THE NRC AND EXELON GENERATION CO., LLC, CONCERNING REQUEST FOR ADDITIONAL INFORMATION SET 9 PERTAINING TO THE LASALLE COUNTY STATION LICENSE RENEWAL APPLICATION (TAC NOS. MF5347 AND MF5346)

The U.S. Nuclear Regulatory Commission (NRC or the staff) and representatives of Exelon Generation Co., LLC (Exelon or the applicant) held a telephone conference call on August 5, 2015, to discuss and clarify the staffs draft requests for additional information (DRAIs) provided in Enclosure 2 concerning the LaSalle County 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 DRAIs discussed with the applicant, including a brief description on the status of the items.

The applicant had an opportunity to comment on this summary.

Sincerely,

/RA/

Jeffrey S. Mitchell, Project Manager Projects Branch 1 Division of License Renewal Office of Nuclear Reactor Regulation Docket Nos. 50-373 and 50-374

Enclosures:

1. List of Participants

2. Summary of Telephone Conference Call cc: Listserv

August 28, 2015 LICENSEE:

Exelon Generation Co., LLC FACILITY:

LaSalle County Station, Units 1 and 2

SUMMARY

OF TELECON HELD ON AUGUST 5, 2015, BETWEEN THE NRC AND EXELON GENERATION CO., LLC, CONCERNING REQUEST FOR ADDITIONAL INFORMATION SET 9 PERTAINING TO THE LASALLE COUNTY STATION LICENSE RENEWAL APPLICATION (TAC NOS. MF5347 AND MF5346)

The U.S. Nuclear Regulatory Commission (NRC or the staff) and representatives of Exelon Generation Co., LLC (Exelon or the applicant) held a telephone conference call on August 5, 2015, to discuss and clarify the staffs draft requests for additional information (DRAIs) provided in Enclosure 2 concerning the LaSalle County 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 DRAIs discussed with the applicant, including a brief description on the status of the items.

The applicant had an opportunity to comment on this summary.

Sincerely,

/RA/

Jeffrey S. Mitchell, Project Manager Projects Branch 1 Division of License Renewal Office of Nuclear Reactor Regulation Docket Nos. 50-373 and 50-374

Enclosures:

1. List of Participants

2. Summary of Telephone Conference Call cc: Listserv DISTRIBUTION:

See next page ADAMS Accession Number: ML15222A006

• Concurred via e-mail OFFICE LA:DLR PM:RPB1:DLR PM:RPB1:DLR BC:RPB1:DLR PM:RPB1:DLR NAME YEdmonds JMitchell RPlasse YDiaz-Sanabria JMitchell DATE 8/ 19 /15 8/ 25 /15 8/ 26 /15 8/ 28 /15 8/ 28 /15 OFFICIAL RECORD COPY

Memo to Exelon Generation Co. from J. Mitchell dated August 28, 2015

SUMMARY

OF TELECON HELD ON AUGUST 5, 2015, BETWEEN THE NRC AND EXELON GENERATION CO., LLC, CONCERNING REQUEST FOR ADDITIONAL INFORMATION SET 9 PERTAINING TO THE LASALLE COUNTY STATION LICENSE RENEWAL APPLICATION (TAC NOS. MF5347 AND MF5346)

DISTRIBUTION:

E-MAIL:

PUBLIC RidsNrrDlr Resource RidsNrrDlrRpb1 Resource RidsNrrDlrRpb2 Resource RidsNrrDlrRerb Resource RidsNrrDlrRarb Resource RidsNrrDlrRasb Resource RidsNrrDlrRsrg Resource RidsNrrPMLaSalle Resource J. Mitchell R. Plasse D. Drucker B. Wittick J. Wachutka, OGC D. McIntyre, OPA M. Kunowski, RIII V. Mitlyng, RIII P. Chandrathil, RIII H. Logaras, RIII C. Lipa, RIII S. Sheldon, RIII R. Ruiz, RIII J. Robbins, RIII

ENCLOSURE 1 TELEPHONE CONFERENCE CALL LASALLE COUNTY STATION, UNITS 1 AND 2 LICENSE RENEWAL APPLICATION LIST OF PARTICIPANTS AUGUST 5, 2015 PARTICIPANTS AFFILIATION Jeff Mitchell U.S. Nuclear Regulatory Commission (NRC)

Chris Hovanec NRC Seung Min NRC Paul Cervenka Exelon Generation Co., LLC (Exelon)

Don Warfel Exelon Jim Jordan Exelon

ENCLOSURE 2

SUMMARY

OF TELEPHONE CONFERENCE CALL LASALLE COUNTY STATION, UNITS 1 AND 2 LICENSE RENEWAL APPLICATION AUGUST 5, 2015 The U.S. Nuclear Regulatory Commission (NRC or the staff) and representatives of Exelon Generation Co., LLC (Exelon or the applicant) held a telephone conference call on August 5, 2015, to discuss and clarify the following draft requests for additional information (DRAIs) concerning the LaSalle County Station, Units 1 and 2 license renewal application (LRA).

DRAI 4.2.8-1

Background:

LRA Section 4.2.8 describes the TLAA for the loss of preload of the reactor pressure vessel (RPV) core plate rim hold-down bolts resulting from irradiation effects. The LRA states that a fluence evaluation based on 54 EFPY has identified the bolts with the highest fluence values after 60 years of operation for Unit 1 (3.60x1019 n/cm2) and Unit 2 (3.85x1019 n/cm2). The LRA also states that an average fluence value of 3.85x1019 n/cm2 was evaluated for 40 years of operation which resulted in a maximum relaxation of 19 percent in preload for the RPV core plate rim hold-down bolts. The TLAA is dispositioned in accordance with 10 CFR 54.21(c)(1)(i) to remain valid through the period of extended operation.

The loss of preload analysis was performed as part of BWRVIP-25, BWR Core Plate Inspection and Flaw Evaluation Guidelines. Section 2.1.3 of BWRVIP-25 states that it has been determined that a 5 percent to 19 percent reduction in preload is expected over a 40-year operating experience and that the bolts will maintain some amount of preload throughout the life of the plant. Section B.4 of Appendix B states that the loss of preload was recalculated based on 60 years of plant operation and that the reduction in preload remains 5 percent to 19 percent.

Issue:

The staff is unable to determine if the amount of relaxation experienced after 60 years of operation is bounded by the 40-year analyses because the fluence values used to determine the range in percent reduction of preload are not provided in BWRVIP-25 or the appendices of the report.

Request:

Provide the analysis used to determine that an average fluence value of 3.85 x1019 n/cm2 produces a maximum relaxation of 19 percent in preload for the RPV core plate rim hold-down bolts. Justify that the analysis adequately considers plant-specific configurations of reactor vessel internals and is bounded by the relaxation evaluations in BWRVIP-25.

Teleconference Summary:

The staff clarified that the Background and Request sections contained an error in the average fluence value number, and will correct that number in the final RAI.

DRAI 4.2.10-1

Background:

Section 4.7.3.1.3 of the Standard Review Plan for License Renewal (SRP-LR) (NUREG-1800, Rev. 2) provides the NRCs review procedures for plant-specific TLAAs which will be managed in accordance with 10 CFR 54.21(c)(1)(iii). SRP-LR Section 4.7.3.1.3 states that the staff is to review the aging management program proposed by the applicant to verify the program is adequate to manage the aging effects associated with the TLAA.

LRA Section 4.2.10 describes the TLAA evaluation for the loss of preload of the jet pump slip joint repair clamp. LRA Section 4.2.10 dispositions the TLAA in accordance with 10 CFR 54.21(c)(1)(iii), to be managed by Commitment No. 47 in LRA Section A.5. This commitment states:

Prior to exceeding the limiting fluence value of 1.17E+20 n/cm2 at the Unit 1 jet pump slip joint clamp location, estimated to be at 50.7 EFPY, revise the analysis for the slip joint clamps for a higher acceptable fluence value or take other corrective action such as repair or replacement of the clamps to ensure acceptable clamp preload.

The implementation schedule for Commitment No. 47 is Prior to the period of extended operation.

Issue:

The LRA does not clearly identify how the applicant will ensure that the limiting fluence value is not exceeded. The staff is unable to determine if the applicants program or activities are adequate to ensure that the limiting fluence value is not exceeded.

Request:

Identify the program or a set of activities that will be used for the jet pump slip joint repair clamp to ensure that the limiting fluence value is not exceeded. Justify that the program or activities are adequate for managing the aging effect of loss of preload of the jet pump slip joint repair clamp.

Teleconference Summary:

The staff clarified the level of detail that is being requested for the description of the program or set of activities in the Request section.