ML15244B353

RAI for the Review of the LaSalle County Station, Units 1 and 2 License Renewal Application - Set 11

ML15244B353
Person / Time
Site:	LaSalle
Issue date:	09/14/2015
From:	Jeffrey Mitchell License Renewal Projects Branch 1
To:	Gallagher M Exelon Generation Co
Mitchell J, NRR/DLR,415-3019
References
DLR-15-0427, TAC MF5346, TAC MF5347
Download: ML15244B353 (4)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 September 14, 2015 Mr. Michael P. Gallagher Vice President, License Renewal Projects Exelon Generation Company, LLC 200 Exelon Way Kennett Square, PA 19348

SUBJECT:

REQUESTS FOR ADDITIONAL INFORMATION FOR THE REVIEW OF THE LASALLE COUNTY STATION, UNITS 1 AND 2 LICENSE RENEWAL APPLICATION - SET 11 (TAC NOS. MF5347 AND MF5346)

Dear Mr. Gallagher:

By letter dated December 9, 2014, Exelon Generation Company, LLC (Exelon) submitted an application pursuant to Title 10 of the Code of Federal Regulations Part 54, to renew the operating licenses NPF-11 and NPF-18 for LaSalle County Station (LSCS), Units 1 and 2, respectively. The staff of the U.S. Nuclear Regulatory Commission (NRC or the staff) is reviewing the information contained in the license renewal application and has identified, in the enclosure, areas where additional information is needed to complete the review.

These requests for additional information were discussed with Mr. John Hufnagel, and a mutually agreeable date for the response is within 30 days from the date of this letter. If you have any questions, please contact me at 301-415-3019 or by e-mail at Jeffrey.Mitchell2@nrc.gov.

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

Enclosure:

As stated cc: Listserv

September 14, 2015 Mr. Michael P. Gallagher Vice President, License Renewal Projects Exelon Generation Company, LLC 200 Exelon Way Kennett Square, PA 19348

SUBJECT:

REQUESTS FOR ADDITIONAL INFORMATION FOR THE REVIEW OF THE LASALLE COUNTY STATION, UNITS 1 AND 2 LICENSE RENEWAL APPLICATION - SET 11 (TAC NOS. MF5347 AND MF5346)

Dear Mr. Gallagher:

By letter dated December 9, 2014, Exelon Generation Company, LLC (Exelon) submitted an application pursuant to Title 10 of the Code of Federal Regulations Part 54, to renew the operating licenses NPF-11 and NPF-18 for LaSalle County Station (LSCS), Units 1 and 2, respectively. The staff of the U.S. Nuclear Regulatory Commission (NRC or the staff) is reviewing the information contained in the license renewal application and has identified, in the enclosure, areas where additional information is needed to complete the review.

These requests for additional information were discussed with Mr. John Hufnagel, and a mutually agreeable date for the response is within 30 days from the date of this letter. If you have any questions, please contact me at 301-415-3019 or by e-mail at Jeffrey.Mitchell2@nrc.gov.

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

Enclosure:

As stated cc: Listserv DISTRIBUTION:

See next page ADAMS Accession Number: ML15244B353

• Concurred via e-mail OFFICE LA:DLR*

PM:RPB1:DLR PM:RPB1:DLR BC:RPB1:DLR PM:RPB1:DLR NAME YEdmonds PClark RPlasse (Sayoc for) YDiaz-Sanabria JMitchell DATE 09/ 08 /15 09/10/15 09/11/15 09/ 14 /15 09/ 14 /15 OFFICIAL RECORD COPY

Letter to Michael Gallagher from Jeffrey S. Mitchell dated September 14, 2015

SUBJECT:

REQUESTS FOR ADDITIONAL INFORMATION FOR THE REVIEW OF THE LASALLE COUNTY STATION, UNITS 1 AND 2 LICENSE RENEWAL APPLICATION - SET 11 (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 J. Danna 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 LASALLE COUNTY STATION, UNITS 1 AND 2 LICENSE RENEWAL APPLICATION REQUESTS FOR ADDITIONAL INFORMATION - SET 11 (TAC NOS. MF5347 AND MF5346)

RAI 4.2.7-1a

Background:

By letter dated August 6, 2015, the applicant responded to RAI 4.2.7-1 that requested sufficient information on the parameters used in the reactor vessel reflood thermal shock analysis (LRA Section 4.2.7). In its response, the applicant indicated that the maximum initial flaw depth postulated in the analysis is 5.2 percent of the reactor vessel wall thickness per ASME Code Section XI, Table IWB-3510-1.

Issue:

License Renewal Application (LRA) Table 4.2.7-2 and associated discussion in LRA Section 4.2.7 describe applied stress intensity factor values (KI-applied) at 52 percent of the reactor vessel wall thickness during the recirculation line break transient. The LRA also compares these KI-applied values with the adjusted fracture toughness values (KIc/1.414) of the LSCS limiting reactor vessel material during the transient. It is not clear to the staff why LRA Table 4.2.7-2 and associated discussion in Section 4.2.7 refer to the location at 52 percent of the reactor wall thickness for the fracture toughness comparison rather than 5.2 percent of the wall thickness that corresponds to the postulated initial flaw depth.

In addition, the staff noted that LRA Section 4.2.7 does not provide the KI-applied value and the allowable fracture toughness value (KIc/1.414) that were evaluated in the applicants analysis for N6 low pressure coolant injection nozzles.

Request:

1.

Clarify why LRA Table 4.2.7-2 and associated discussion in Section 4.2.7 assume a flaw depth of 52 percent of the wall thickness which is different from the postulated initial flaw depth per ASME Code Section XI, Table IWB-3510-1.

2.

Provide the KI-applied value and the allowable fracture toughness value (KIc/1.414) that were evaluated in the applicants analysis for N6 low pressure coolant injection nozzles.