ML15224A935

August 11, 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

ML15224A935
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-15-0403, TAC MF5346, TAC MF5347
Download: ML15224A935 (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 11, 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 11, 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 11, 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 11, 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: ML15224A935

• 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 11, 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 11, 2015 PARTICIPANTS AFFILIATION Jeff Mitchell U.S. Nuclear Regulatory Commission (NRC)

Matt Hardgrove NRC Seung Min NRC John Hufnagel Exelon Generation Co., LLC (Exelon)

Paul Weyhmuller Exelon Mike Guthrie Exelon Jim Jordan Exelon Cortney Scheidt Exelon

ENCLOSURE 2

SUMMARY

OF TELEPHONE CONFERENCE CALL LASALLE COUNTY STATION, UNITS 1 AND 2 LICENSE RENEWAL APPLICATION AUGUST 11, 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 11, 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 4.2.1-1

Background:

License Renewal Application (LRA) Section 4.2.1 describes the applicants time-limited aging analysis (TLAA) on reactor vessel fluence calculations. LRA Section 4.2.1 also indicates that the 54-effective full power year (EFPY) fluence projections for 60 years of operation were calculated using the Nuclear Regulatory Commission (NRC)-approved Radiation Analysis Modeling Application (RAMA) methodology. The LRA further states that the 54-EFPY fluence projections compile the cumulative fluence resulting from each past operating cycle and add the predicted fluence estimate for future operating cycles through the period of extended operation.

As discussed below, the NRC staff noted that these 54-EFPY fluence projections are independent of the fluence projections used in the current pressure-temperature (P-T) limits.

LRA Section 4.2.1 states that the neutron fluence projections used as inputs to the current 40-year neutron embrittlement analyses for LaSalle County Station (LSCS) Units 1 and 2 were developed in accordance with General Electric (GE) Licensing Topical Report NEDO-32983, General Electric Methodology for Reactor Pressure Vessel Fast Neutron Flux Evaluations (Agencywide Documents Access and Management System (ADAMS) under Accession No. ML072480121). LRA Section 4.2.1 also indicated that this GE methodology is in compliance with NRC Regulatory Guide 1.190, as approved by the NRC staff in the safety evaluation dated September 14, 2001.

Under LRA Section 4.2.1, the TLAA evaluation states that the 60-year RAMA neutron fluence projections compile the cumulative neutron fluence resulting from each past operating cycle and add the predicted neutron fluence estimated for future operating cycles through the period of extended operation. The RAMA neutron fluence projections are prepared using the Boiling Water Reactor Vessel and Internals Project Technical Report 126 (BWRVIP-126), RAMA Fluence Methodology Software, Version 1.0, methodology. These 60-year neutron fluence projections are independent of the neutron fluence projections used with the current P-T curve submittals.

In comparison, the following reference indicates that the current 40-year (32-EFPY) P-T limits for LSCS, Unit 1 use neutron fluence values that are calculated using the RAMA fluence methodology:

NRC Safety Evaluation, LaSalle County Station, Unit 1, Issuance of Amendment Revising Pressure and Temperature Limits (TAC No. MF3270), dated November 25, 2014 (ADAMS Accession No. ML14220A517).

Section 3.1, Neutron Fluence Calculation, of the above reference states that the safety evaluation shall not be constructed as endorsement, agreement with, or approval of, the position regarding the combined use of neutron fluence methods to determine a total neutron fluence.

Issue:

The LRA does not address the RAMA methodology that the NRC staff evaluated in the safety evaluation regarding the current P-T limits for LSCS Unit 1. Therefore, the NRC staff needs additional information as to the specific neutron fluence methodology that is used in the license renewal TLAAs. It is also unclear to the NRC staff how the applicant evaluates potential effects of updated neutron fluence calculations on existing neutron embrittlement analysis.

Request:

1.

Clarify whether the 54-EFPY neutron fluences described in the LRA are based on the GE methodology, the RAMA methodology, or the combination of the two methodologies.

2.

Clarify how the potential effects of updated neutron fluence calculations on neutron embrittlement analyses are evaluated.

Teleconference Summary:

The staff clarified Request 2, and agreed to revise the wording in the final RAI to request clarification regarding how the applicant will ensure that the actual fluence levels are bounded by the fluence level analyses in the license renewal application, Section 4.2.1.