ML19333B896

50.54(f) SPRA Submittal - Completeness Review Done and Path Forward

ML19333B896
Person / Time
Site:	Dresden
Issue date:	11/29/2019
From:	Milton Valentin-Olmeda Office of Nuclear Reactor Regulation
To:	Distel D Exelon Generation Co
Valentin-Olmeda M
References
Download: ML19333B896 (3)

Text

From:

Valentin-Olmeda, Milton To:

Distel, David J:(GenCo-Nuc)

Cc:

Mathews, Mitchel A:(Exelon Nuclear); Philpott, Stephen

Subject:

Dresden 50.54(f) SPRA Submittal - Completeness review done and path forward Date:

Friday, November 29, 2019 11:23:00 AM

David, The purpose of this email is to inform you that: 1) the NRC staff has finalized its completeness (similar to an acceptance) review of the Dresden 50.54(f) seismic probabilistic risk assessment (SPRA) submittal (ADAMS Accession No. ML19304B567), 2) that the submittal to have sufficient information to proceed to stage 2 of the detailed audit review, 3) to share our proposed review timeline, and 4) to request that information be provided on the Dresden SPRA ePortal audit folder (Scientech (OneCWCloud)) to support the staffs detailed review of the submittal.

Completeness (Acceptance) Review The staff has completed its acceptance review (Stage 1) and has determined that sufficient information has been provided to proceed to Stage 2.

The tentative review schedule for the staffs review can be found below.

Proposed Review Timeline (subject to change)

Stage (1): Completeness Review - DONE Stage (2): Verify that SPRA is Suitable for Decision-Making and Develop Recommendation Prepare first draft of the Technical Review Checklist (ADAMS Accession No. ML17041A327) - February 2019 Have clarification call with licensee (if needed) - March 2019 Updated Technical Review checklist using responses to clarification questions and have tentative recommendation - May 2020 Technical Review Board Briefing - June 2020 Senior Management Review Panel (SMRP) Briefing - July 2020 Issue Staff Response Letter - August 2020, unless SMRP concludes that further evaluation (Stage 3) is needed Request for ePortal Information To support the staffs review, please make the following documents (or portions supporting the submittal) and information available in Scientech (OneCWCloud):

1. Dresden Generating Station Seismic Probabilistic Risk Assessment: Reactor Building

- Turbine Building Structural Response Analysis, Revision 2, October 17, 2018; (EXDR025-REPT-002; Reference [14])

2. Dresden Generating Station Seismic Probabilistic Risk Assessment: Station Blackout Building Structural Response Analysis, Revision 1, July 26, 2019; (EXDR025-REPT-003; Reference [15])

3. Dresden Generating Station Seismic Probabilistic Risk Assessment: Crib House, Revision 1, July 26, 2019 (EXDR025-REPT-004; Reference [16])

4. Addenda to EXDR025-REPT-002 Analysis Case-Specific ISRS and 3x GMRS Updated Vertical, Revision 0, April 19, 2019; (EXDR025-REPT-010, Reference [58])

5. Dresden PRA Fragility Modeling Notebook, Revision 1; (DR-PRA-020.005, Vol. 1, Reference [50])

6. Fragility Analysis Report [Reference #21]; specifically the following appendices and information:

a. Appendix C24 addressing resolution of F&O 19-14

b. Appendix C29 addressing resolution of F&O 21-7 (item #3)

c. Documentation that shows resolution of F&O 22-2

d. Appendix A25.4 addressing resolution of F&O 22-5

e. Appendix D23 addressing resolution of F&O 24-3

f. Appendix C28 addressing resolution of F&O 24-4

g. Appendix B21.3 addressing resolution of F&O 24-8

h. Appendix A32 addressing resolution of F&O 24-6

i. Use of the CDFM/H Methodology for Fragility Analysis and Selection of Dominant Risk Contributors that Require Fragility Analysis Using the Separation of Variables Methodology for the following structures: Control Panel Group C20-4 (S-INCP04-), RPV Internals (Scram) (SCRAM), Instrument Rack Group 18-9-1-1 (2202-7) (S-INIR18-9-), SBODG2 Battery 6A and SBODG3 Battery 7A (S-DCBY3), Crib House (CRIB), Structural failure mode Dresden Lock and Dam (DAM), Relay Chatter ID 361A (EDG2, EDG3-Recov.) (S-CH361A), and Structural fragility for Reactor-Turbine Building (CDFM)

7. SPRA Peer Review Reports (Full-Scope, Focused-Scope, and Close-Out, as applicable) (References [23] or any others)

8. SPRA Human Reliability Analysis Notebook (References [49] and any others)

9. SPRA Plant Response Notebook (References [46, 47, 48] and any others)

10. SPRA Quantification Notebook (Reference [52])

11. SPRA Modeling Notebooks (References [46, 47, 48] or any others

12. Seismic-Induced Fire and Flood Assessment (References [31] or any others)

13. Uncertainty and Sensitivity (References [52] or any others)

14. Internal Events PRA Peer Review Report (Full-Scope, Focused-Scope, and Close-Out, as applicable) (References [17] or any others)

15. Confirmation that the licensees SPRA model incorporates the latest resolutions to all IEPRA peer review finding level F&Os (open as well as closed). Provide justification that the exclusion of those resolutions from the SPRA as well as dispositions of open findings does not significantly change the corresponding results. The rationale for requesting items 14 and 15 is to determine the acceptability of the base IEPRA model.

Please feel free to give me a call if you have any questions regarding this email of if you would like to discuss this request.

We may have additional information needs in the near future and we will communicate those as the review progresses.

It will be very helpful to know when these are uploaded to the Dresden SPRA audit folder.

Thanks in advance.

Respectfully, Milton Valentín, PM US NRC Division of Licensing Projects Beyond Design Basis Management (Fukushima)

Office of Nuclear Reactor Regulation Milton.Valentin@nrc.gov 301-415-2864