ML15160A168
| ML15160A168 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 06/16/2015 |
| From: | Nicholas Difrancesco Japan Lessons-Learned Division |
| To: | Bryan Hanson Exelon Generation Co, Exelon Nuclear |
| Wyman S, NRR/JLD, 415-3041 | |
| References | |
| TAC MF5247, TAC MF5248 | |
| Download: ML15160A168 (3) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 June 16, 2015 Mr. Bryan C. Hanson Senior Vice President Exelon Generation Company, LLC President and Chief Nuclear Office Exelon Nuclear 4300 Winfield Road Warrenville, IL 60555
SUBJECT:
LASALLE COUNTY STATION, UNITS 1 AND 2 - STAFF REVIEW OF INTERIM EVALUATION ASSOCIATED WITH REEVALUATED SEISMIC HAZARD IMPLEMENTING NEAR-TERM TASK FORCE RECOMMENDATION 2.1 (TAC NOS. MF5247 AND MF5248)
Dear Mr. Hanson:
By letter dated March 12, 2012 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML12053A340), the U.S. Nuclear Regulatory Commission (NRC) issued a request for information pursuant to Title 10 of the Code of Federal Regulations Part 50, Section 50.54(f) (hereafter referred to as the 50.54(f) letter). The request was issued as part of implementing lessons-learned from the accident at the Fukushima Dai-ichi nuclear power plant.
Enclosure 1 to the 50.54(f) letter requested that licensees reevaluate seismic hazards at their sites using present-day methodologies and guidance. Enclosure 1, Item 6, of the 50.54(f) letter requested that licensees identify "interim evaluation and actions taken or planned to address the higher seismic hazard relative to the design basis as appropriate, prior to completion of the
[seismic] risk evaluation." In addition to the interim evaluation provided in the March 2014 Seismic Screening and Hazard report, the licensees for the Central and Eastern United States committed to providing the Expedited Seismic Evaluation Process (ESEP) report, an interim evaluation, by December 31, 2014.
By letter dated December 19, 20141, Exelon Generation Company, LLC (Exelon, the licensee),
provided its ESEP report in response to Enclosure 1, Item (6) of the 50.54(f) letter, for the LaSalle County Station, Units 1 and 2 (LaSalle). The NRC staff assessed Exelon's implementation of the ESEP guidance through the completion of a reviewer checklist2. Based on the NRC staff review of the ESEP report and responses to the staff's questions, the NRC staff concludes that the licensee's implementation of the interim evaluation meets the intent of the guidance.
The NRC staff concludes that, through the implementation of the ESEP guidance, the licensee identified and evaluated the seismic capacity of certain key installed mitigating strategies 1
The December 16, 2014, letter can be found under ADAMS Accession No. ML14353A085.
2 The LaSalle ESEP NRC review checklist can be found under ADAMS Accession No. ML15161A502.
B. Hanson equipment that is used for core cooling and containment functions to cope with scenarios that involve a loss of all alternating current power and loss of access to the ultimate heat sink to withstand a seismic event up to 1.83 times the safe shutdown earthquake. The licensee's ESEP assessment provides additional assurance which supports continued plant safety while the longer-term seismic evaluation is completed to support regulatory decision making. The NRC staff concludes that the licensee responded appropriately to Enclosure 1, Item (6) of the 50.54(f) letter. Application of this review is limited to the interim evaluation as part of the Recommendation 2.1 Seismic review.
If you have any questions, please contact me at (301) 415-1115 or via e-mail at Nicholas.DiFrancesco@nrc.gov.
Sincerely, Nicholas J. DiFrancesco, Senior Project Manager Hazards Management Branch Japan Lessons-Learned Division Office of Nuclear Reactor Regulation Docket Nos. 50-373 and 50-37 4 cc: Distribution via Listserv
B. Hanson equipment that is used for core cooling and containment functions to cope with scenarios that involve a loss of all alternating current power and loss of access to the ultimate heat sink to withstand a seismic event up to 1.83 times the safe shutdown earthquake. The licensee's ESEP assessment provides additional assurance which supports continued plant safety while the longer-term seismic evaluation is completed to support regulatory decision making. The NRC staff concludes that the licensee responded appropriately to Enclosure 1, Item (6) of the 50.54(f) letter. Application of this review is limited to the interim evaluation as part of the Recommendation 2.1 Seismic review.
If you have any questions, please contact me at (301) 415-1115 or via e-mail at Nicholas.DiFrancesco@nrc.gov.
Sincerely, IRA/
Nicholas J. DiFrancesco, Senior Project Manager Hazards Management Branch Japan Lessons-Learned Division Office of Nuclear Reactor Regulation Docket Nos. 50-373 and 50-374 cc: Distribution via Listserv DISTRIBUTION:
PUBLIC RidsNrrDorllpl3-1 DJackson, NRO JLD R/F RidsNrrLASLent MShams, NRR RidsOeMaiiCenter RidsRgn3MaiiCenter NDiFrancesco, NRR RidsNrrPMLaSalle RidsNrrOd ADAMS Accession Number: ML15160A168
- concurrence via e-mail OFFICE NRR/JLD/JHMB/PM NRR/JLD/LA NRO/DSEA/RGS2*
NAME SWyman Slent DJackson DATE 06/09/15 06/09/15 06/08/15 OFFICE NRR/JLD/JHMB/BC NRR/JLD/JHMB/PM NAME MS hams NDiFrancesco DATE 06/13/15 06/16/15 OFFICIAL RECORD COPY