RS-18-043, Supplement to Request for Extension of Due Date for Seismic Probabilistic Risk Assessment Submittal

Supplement to Request for Extension of Due Date for Seismic Probabilistic Risk Assessment Submittal

ML18088A020
Person / Time
Site:	Peach Bottom
Issue date:	03/28/2018
From:	David Helker Exelon Generation Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
RS-18-043
Download: ML18088A020 (2)

Text

Exelon Generation-.

RS-18-043 March 28, 2018 ATIN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555 Peach Bottom Atomic Power Station, Units 2 and 3 Renewed Facility Operating License Nos. DPR-44 and DPR-56 NRC Docket Nos. 50-277 and 50-278 1 O CFR 50.54(f)

Subject:

Supplement to Request for Extension of Due Date for Seismic Probabilistic Risk Assessment Submittal

References:

1. Exelon Generation Company, LLC Letter to NRC, Peach Bottom Atomic Power Station, Units 2 and 3 - Request for Extension of Due Date for Seismic Probabilistic Risk Assessment Submittal, dated March 15, 2018 (ML18074A303)

2. Exelon Generation Company, LLC Letter to NRC, Peach Bottom Atomic Power Station, Units 2 and 3 - Expedited Seismic Evaluation Process Report (CEUS Sites), Response to NRC Request for Information Pursuant to 1 O CFR 50.54(f) Regarding Recommendation 2.1 of the Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accident, dated December 19, 2014 (ML14353A333)

In Reference 1, Exelon Generation Company, LLC (EGC) requested an extension of the March 31, 2018 due date for submittal of a Seismic Probabilistic Risk Assessment (SPRA) for the Peach Bottom Atomic Power Station, Units 2 and 3 to September 28, 2018.

The purpose of this letter is to provide a correction to the statement in Reference 1 indicating that all the actions needed to meet the Expedited Seismic Evaluation Process (ESEP) beyond-design basis seismic criterion for the credited plant equipment have been completed. The Peach Bottom Atomic Power Station, Units 2 and 3 ESEP, provided in Reference 2, determined that Unit 3 Relay 3-13A-K033 and Unit 2 Relay 2-13A-K033 required further evaluation and modification, if required, to increase seismic margin. In accordance with the commitments provided in Reference 2, the Unit 3 relay evaluation and modification was completed in the Fall 2017 Refuel Outage; and the Unit 2 relay evaluation and modification is scheduled to be completed in the Fall 2018 Refuel Outage. Therefore, the Unit 2 relay evaluation and modification has not yet been completed as originally stated in Reference 1.

Peach Bottom Atomic Power Station, Units 2 and 3 Supplement to Request for Extension of Seismic PRA Submittal Date Page 2 This correction does not impact the basis for the conclusion supporting the requested extension to the Peach Bottom Atomic Power Station, Units 2 and 3 SPRA submittal date provided in Reference 1. The previous EGG and industry actions taken in response to the Near-Term Task Force requirements continue to provide assurance of safety with respect to beyond-design basis seismic hazards during the extension period.

EGG considers that continued plant operation during the extension period is justified based on considerations that include: consistency with the NRG overall schedule tor submittal of all Near-Term Task Force related plant SPRAs, the defense-in-depth provided by compliance with all NRG Orders regarding beyond-design-basis events, completion of the NRG endorsed Expedited Seismic Evaluation Process and the actions identified by that process with the exception of the Unit 2 relay evaluation and modification described above, the inherent nuclear power plant design margins as described in an NRG recognized Electric Power Research Institute report, the comparable ratio of reevaluated hazard to design hazard tor Peach Bottom Atomic Power Station, Units 2 and 3 and other SPRA plants, and the completion of the evaluation demonstrating the beyond-design-basis seismic robustness of the Peach Bottom Atomic Power Station, Units 2 and 3 Spent Fuel Pools.

This letter contains no new regulatory commitments or revisions to existing regulatory commitments.

If you have any questions regarding this report, please contact David J. Distel at 610-765-5517.

I declare under penalty of perjury that the foregoing is true and correct. Executed on the 281h day of March 2018.

Respectfully submitted, David P. Helker Manager - Licensing & Regulatory Affairs Exelon Generation Company, LLC cc:

Regional Administrator - NRG Region I NRG Senior Resident Inspector-Peach Bottom Atomic Power Station NRG Project Manager, NRR - Peach Bottom Atomic Power Station Mr. Eric E. Bowman, NRR/JLD/JHMB, NRG Mr. Brett A. Titus, NRR/JLD/JCBB, NRG Mr. Stephen M. Wyman, NRR/JLD/JHMB, NRG Director, Bureau of Radiation Protection - Pennsylvania Department of Environmental Resources S. T. Gray, State of Maryland R. R. Janati, Chief, Division of Nuclear Safety, Pennsylvania Department of Environmental Protection, Bureau of Radiation Protection