ML26048A410
| ML26048A410 | |
| Person / Time | |
|---|---|
| Site: | 99902130 |
| Issue date: | 02/18/2026 |
| From: | Denise Mcgovern NRC/NRR/DANU/UAL2 |
| To: | Alissa Neuhausen Office of Nuclear Reactor Regulation |
| References | |
| EPID L?2024?LRM?0111 | |
| Download: ML26048A410 (0) | |
Text
MEMORANDUM TO:
Alissa Neuhausen, Branch Chief Advanced Reactor Licensing Branch 2 Division of Advanced Reactors and Non-power Production and Utilization Facilities Office of Nuclear Reactor Regulation FROM:
Denise McGovern, Sr Project Manager Advanced Reactor Licensing Branch 2 Division of Advanced Reactors and Non-power Production and Utilization Facilities Office of Nuclear Reactor Regulation
SUBJECT:
SUMMARY
OF JANUARY 29, 2026 PUBLIC MEETING WITH ENERGY NORTHWEST NEW NUCLEAR, LLC, ACCEPTABILITY OF HISTORICAL INFORMATION-GEOTECHNICAL WHITE PAPER DISCUSSION (EPID NO. L2024LRM0111)
Meeting Information:
Applicant: Energy Northwest New Nuclear, LLC (ENNN)
Docket/Project No.: 99902130 Public Meeting Notice Agencywide Documents Access and Management System (ADAMS)
Accession No.: ML26022A366 ENNN Presentation Slides, ADAMS Accession No.: ML26019A054 ENNN-Acceptability of Historical Information-Geotechnical white paper, ADAMS Accession No.: ML26013A121 Meeting Attendees: See the enclosure for a list of meeting attendees.
CONTACT:
Michelle Vega Rodriguez, NRR/DANU 301415-1170 February 18, 2026 Signed by McGovern, De on 02/18/26
A. Neuhausen Meeting Summary On January 29, 2026, the U.S. Nuclear Regulatory Commission (NRC) staff conducted a public meeting with Energy Northwest New Nuclear, LLC.(ENNN) in accordance with NRC Management Directive 3.5, Attendance at NRC Staff-Sponsored Meetings (ML21180A271).
The discussion covered the ENNN Presentation Slides (ML26019A054), which was an overview of the ENNN white paper submittal, Acceptability of Historical Information - Geotechnical, (ML26013A121).
ENNN shared their plans to use historical geotechnical and seismic data from the Columbia Generating Stations licensing basis for the Cascade Advanced Energy Facility (Cascade)
Construction Permit Application (CPA).
Cascade Project Overview Cascade plans to build up to 12 Xe100 small modular reactors on Washington Nuclear Project (WNP)-1/4 site adjacent to Columbia Generating Station (CGS) (WNP2). ENNN will leverage historical geotechnical and seismic data from Columbia and WNP1/4 for Cascades CPA.
ENNN shared outcomes of their internal assessment to determine applicability of the historical information to facilitate the analysis of the white paper content.
ENNN Findings Site Uniformity: Cascade, Columbia, and WNP1/4 share consistent lithology (Pasco Gravel, Ringold Formation, Saddle Mountain Basalt), supporting applicability of historical data.
Historical Analyses:
o Seismic: Post-Fukushima re-evaluations (2014 Hanford Sitewide Senior Seismic Hazard Analysis Committee Level 3 Probabilistic Seismic Hazard Analysis (PSHA), 2015 Ground Motion Response Spectrum (GMRS), 2019 Wood GMRS) accepted by NRC.
o Geotechnical: Original site investigations (used in licensing proceedings of these facilities 1970s-1980s) documented soil properties, foundation stability, and slope stability.
Historical data deemed applicable with justification for regulatory/methodology changes; confirmatory work required for CPA and Operating License Application (OLA).
Differences in regulations (General Design Criteria versus Principal Design Criteria) and guidance updates do not invalidate historical analyses. ENNN will plan updates to ensure compliance with guidance.
A. Neuhausen ENNN Plans During CPA Stage:
o Develop GMRS under Appendix B QA program, incorporating minimum epistemic uncertainty (RIL 202115), updated literature (e.g., Cascadia Subduction Zone), corrected control point per RG 1.208.
o Conduct non-invasive surveys (MAM/MASW) for versus profiles.
o Perform sensitivity studies to assess the impact of the new shear-wave velocity data in site response and the resulting GMRS.
o Document justification for historical data use in preliminary safety analysis report.
During OLA Stage:
o Perform invasive borings for foundation design of safety-related structures.
o Update geotechnical parameters and confirm historical assumptions.
o Incorporate findings into final safety analysis report and design.
Questions and Comments NRC staff emphasized:
o Need for clarity on survey locations and methods for both existing and new (i.e.,
Microtremor Array Measurement (MAM) / Multi-Channel Analysis of Surface Waves (MASW)) shear-wave velocity data.
o Consideration of variations in stratigraphy (e.g., Cold Creek unit, Hanford Formation thickness).
o Plans for addressing potential discrepancies between existing and new data.
o Consideration on the use of conservative bounding parameters for geotechnical properties and methodologies for preliminary stability evaluations.
ENNN confirmed that for the CPA stage:
o Any divergent findings will be investigated.
o The impact of new information post-dating the 2014 Hanford sitewide PSHA (i.e.,
updated recurrence, interface, and ground motion models for the Cascadia Subduction Zone) will be assessed.
o Estimation of geotechnical parameters and historical boring logs will be available.
A. Neuhausen o Parameters, methods, and results to demonstrate site suitability will be documented.
Next Steps NRC staff will review ENNNs white paper and provide written feedback.
Conclusion ENNN proposed how they will use historical geotechnical and seismic data to provide a strong foundation for Cascade licensing. ENNN will perform confirmatory evaluations to address gaps and ensure compliance with NRC guidance.
No regulatory decisions were made as a result of this meeting.
Docket/Project No.(s): 99902130
Enclosure:
List of Meeting Attendees cc: Cascade Advanced Energy Facility GovDelivery
A. Neuhausen
SUBJECT:
SUMMARY
OF JANUARY 29, 2026, PUBLIC MEETING WITH ENERGY NORTHWEST NEW NUCLEAR, LLC, ACCEPTABILITY OF HISTORICAL INFORMATION-GEOTECHNICAL WHITE PAPER DISCUSSION (EPID NO. L2024LRM0111). DATED: FEBRUARY 18, 2026 DISTRIBUTION:
PUBLIC RidsNrrDanuUal1 Resource RidsNrrDanuUal2 Resource RidsNrrDanu Resource ANeuhausen MVegaRodriguez DMcGovern TTate CCook LVechioliFeliciano KMcElwee AGhosh LCandelario-Quintana JThompson STabatabai ADAMS Accession Number: ML26048A410 NRR106 OFFICE NRR/DANU/UAL2/PM NRR/DANU/UAL2/PM NRR/DANU/UAL2/BC NAME Michelle Vega Rodriguez Denise McGovern Alissa Neuhausen DATE 02/17/2026 02/18/2026 02/18/2026 OFFICE NRR/DANU/UAL2/PM NAME Denise McGovern DATE 02/18/2026 OFFICIAL RECORD COPY
Enclosure List of Meeting Attendees January 29, 2026, Public Meeting with Energy Northwest New Nuclear, LLC, Acceptability of Historical Information-Geotechnical White Paper Discussion Name Organization Denise McGovern U.S. Nuclear Regulatory Commission (NRC)
Michelle Vega Rodriguez NRC Lucieann Vechioli Feliciano NRC Christopher Cook NRC Luissette Candelario-Quintana NRC Sarah Tabatabai NRC Travis Tate NRC Kristin McElwee NRC Alissa Neuhausen NRC Jenise Thompson NRC Madelyn Nagel NRC Amit Ghosh NRC Jason White NRC Nathan D. Clark Energy Northwest New Nuclear, LLC. (ENNN)
Donald W. Gregoire ENNN Lisa L. Williams ENNN Theresa Howell ENNN Miranda G. Vesely ENNN Crystal D. Slavens ENNN Ashlynn Tate ENNN Stephan C. Moen ENNN Jeanette Ardiente ENNN Denise M. Brandon (Bent)
ENNN Jim Grice Colorado Department of Public Health and Environment Shiya Wang Colorado Department of Public Health and Environment Paul Schlavin Eden Radioisotopes, LLC. (EdenRad)
Rick Weis Eden Rad Deric Tilson Breakthrough Institute Lisa Matis Tetra Tech Whitney LaMarche Tetra Tech Clarence H. Tolliver Pillsbury Winthrop Shaw Pittman, LLP Anne Leidich Pillsbury Winthrop Shaw Pittman, LLP Maury A. Pressburger Sargent & Lundy David E. Nielson Sargent & Lundy Greg Boswell Sargent & Lundy Brian Lipinski William Sale Partnership Global Inc. (WSP)
Valentina Montaldo Falero WSP Chris Musselman WSP Milton Gorden X-Energy (X-energy)
Michael I. Dudek X-energy Megan Wright X-energy Jared W member of the public Bob Y member of the public Shanna Bobbins member of the public