RS-18-040, Correction to License Amendment Request to Adopt 1O CFR 50.69, Risk-informed Categorization and Treatment of Structures, Systems, and Components for Nuclear Power Reactors
| ML18094A955 | |
| Person / Time | |
|---|---|
| Site: | Byron, Braidwood  |
| Issue date: | 04/04/2018 |
| From: | Gullott D Exelon Generation Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| RS-18-040 | |
| Download: ML18094A955 (2) | |
Text
Exelon Generation 4300 Winfield Road Warrenville, IL 60555 630 65 7 2000 Office RS-18-040 April 04, 2018 U. S. Nuclear Regulatory Commission Washington, DC 20555-0001 ATTN: Document Control Desk Braidwood Station, Units 1 and 2 Renewed Facility Operating License Nos. NPF-72 and NPF-77 N RC Docket Nos. 50-456 and 50-457 Byron Station, Units 1 and 2 Renewed Facility Operating License Nos. NPF-37 and NPF-66 NRC Docket Nos. 50-454 and 50-455 10 CFR 50.90 10 CFR 50.69
Subject:
Correction to License Amendment Request to Adopt 1 O CFR 50.69, 11Risk-informed categorization and treatment of structures, systems, and components for nuclear power reactors"
Reference:
Letter from D.M. Gullatt (Exelon Generation Company, LLC) to U.S. Nuclear Regulatory Commission, "Application to Adopt 1 O CFR 50.69, 'Risk-informed categorization and treatment of structures, systems, and components for nuclear power reactors,"' dated September 1, 2017 In the referenced letter, Exelon Generation Company, LLC (EGC) requested an amendment to Renewed Facility Operating License Nos. NPF-72 and NPF-77 for Braidwood Station, Units 1 and 2, and Renewed Facility Operating License Nos. NPF-37 and NPF-66 for Byron Station, Units 1 and 2. The amendment would modify the licensing basis by the addition of a license condition to allow for the implementation of the provisions of Title 1 O of the Code of Federal Regulations (10 CFR), Part 50.69, "Risk-informed categorization and treatment of structures, systems and components for nuclear power reactors."
The Enclosure to the referenced letter provided the basis for the proposed change to both Braidwood Station and Byron Station Units 1 and 2 Renewed Facility Operating Licenses. Also discussed in the referenced letter, EGC intends to submit a separate license amendment request to revise both Braidwood Station and Byron Station Units 1 and 2 Technical Specifications to adopt TSTF-505, Revision 1, "Provide Risk Informed Extended Completion Times - RITSTF Initiative 4b, 11 using the same PRA model described in the Enclosure to the referenced letter. During preparation of the separate license amendment request to adopt TSTF-505, an error was identified within the "Disposition of Key Assumptions/Sources of Uncertainty" table in Attachment 6 of the Reference 1 Enclosure. The disposition column includes a qualitative assessment related to a prior Fire PRA model and is no longer applicable.
There is no impact on the main body of the Reference 1 Enclosure, Sections 1 through 6.
April 04, 2018 U.S. Nuclear Regulatory Commission Page 2 The revised text, page 63 of Reference 1, for the "Disposition" column of "Fire-Induced Risk Model" should read (revised text italicized):
FPI E and fire PRA peer reviews (including the F&O resolution process) and internal assessments are useful in exercising the model and identifying weaknesses with respect to this assumption. Though it is possible that not every scenario will ultimately result in a reactor trip, this is determined to have a minimal impact on the analysis.
Typically, these scenarios result in low risk contributors, either due to ignition frequency and/or the resultant CCDP.
There is no change to the text in the 11Description 11 or "Sources of Uncertainty" columns.
EGC has reviewed the information supporting a finding of no significant hazards consideration that was previously provided to the NRC in the Reference 1 Enclosure. The revised text in this letter does not affect the bases for concluding that the proposed license amendments do not involve a significant hazards consideration.
In accordance with 10 CFR 50.91, "Notice for public comment; State consultation," paragraph (b), a copy of this letter is being provided to the designated State of Illinois official.
EGC has entered this issue into the Corrective Action Program, regarding the Enclosure to the referenced letter, Attachment 6.
There are no regulatory commitments contained within this letter. Should you have any questions concerning this letter, please contact Ryan Sprengel at (630) 657-2814.
I declare under penalty of perjury that the foregoing is true and correct. Executed on this 4th day of April, 2018.
Respectfully, David M. Gullott Manager - Licensing Exelon Generation Company, LLC cc:
NRC Regional Administrator, Region Ill, USNRC NRC Senior Resident Inspector - Braidwood Station NRC Senior Resident Inspector-Byron Station Illinois Emergency Management Agency - Division of Nuclear Safety