ML15173A385

Staff Review of Interim Evaluation Associated with Reevaluated Seismic Hazard Implementation Near-Term Task Force Recommendation 2.1

ML15173A385
Person / Time
Site:	Peach Bottom
Issue date:	06/30/2015
From:	Frankie Vega Japan Lessons-Learned Division
To:	Bryan Hanson Exelon Nuclear
Wyman S, NRR/JLD, 415-3041
References
TAC MF5259, TAC MF5260
Download: ML15173A385 (3)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 June 30, 2015 Mr. Bryan C. Hanson President and Chief Nuclear Officer Exelon Nuclear 4300 Winfield Road Warrenville, IL 60555

SUBJECT:

PEACH BOTTOM ATOMIC POWER STATION, UNITS 2 AND 3 - STAFF REVIEW OF INTERIM EVALUATION ASSOCIATED WITH REEVALUATED SEISMIC HAZARD IMPLEMENTATING NEAR-TERM TASK FORCE RECOMMENDATION 2.1 (TAC NOS. MF5259 AND MF5260)

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 Hazard and Screening 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 a response to Enclosure 1, Item (6) of the 50. 54(f) letter, for the Peach Bottom Atomic Power Station, Units 2 and 3 (Peach Bottom). The NRC staff assessed Exelon's implementation of the ESEP guidance through the completion of a reviewer checklist2.

In support of NRC staff questions, Exelon provided a response dated April 14, 2015 3 ,

documenting submittal information. 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 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 19, 2014, letter can be found under ADAMS Accession No. ML14353A333.

2 The Peach Bottom ESEP NRC review checklist can be found under ADAMS Accession No. ML15173A360.

3 The Exelon response to NRC staff questions can be found ADAMS Accession No. ML15139A012.

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 two 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 Recommendation 2.1 Seismic review.

The NRC staff notes that Enclosure 2 of the December 19, 2014, letter contains Regulatory Commitments to complete the identified evaluations and any necessary modifications by outage P2R22 in fall 2018 for Unit 2 and outage P3R21 in fall 2017 for Unit 3.

If you have any questions, please contact me at (301) 415-1617 or via e-mail at Frankie.Vega@nrc.gov.

Sincerely, 1~v Frankie G. Vega, Project Manager Hazards Management Branch Japan Lessons-Learned Division Office of Nuclear Reactor Regulation Docket Nos. 50-277 and 50-278 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 two 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 Recommendation 2.1 Seismic review.

The NRC staff notes that Enclosure 2 of the December 19, 2014, letter contains Regulatory Commitments to complete the identified evaluations and any necessary modifications by outage P2R22 in fall 2018 for Unit 2 and outage P3R21 in fall 2017 for Unit 3.

If you have any questions, please contact me at (301) 415-1617 or via e-mail at Frankie.Vega@nrc.gov.

Sincerely, IRA/

Frankie G. Vega, Project Manager Hazards Management Branch Japan Lessons-Learned Division Office of Nuclear Reactor Regulation Docket Nos. 50-277 and 50-278 cc: Distribution via Listserv DISTRIBUTION:

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