ML24122A992

Summary of the January 17, 2024 Public Meeting with X Energy, Llc. Approach for Graphite Qualification for the XE-100 High Temperature Gas Reactor

ML24122A992
Person / Time
Site:	99902071
Issue date:	05/23/2024
From:	Hernandez J NRC/NRR/DANU/UAL2
To:	Michael Wentzel NRC/NRR/DANU/UAL2
Jorge Hernandez, NRR/DANU
References
EPID L-2018-LRM-0076
Download: ML24122A992 (1)

Text

MEMORANDUM TO:

Michael Wentzel, Chief Advanced Reactor Licensing Branch 2 Division of Advanced Reactors and Non-power Production and Utilization Facilities Office of Nuclear Reactor Regulation FROM:

Jorge Hernandez, Project Manager Advanced Reactor Licensing Branch 2 Division of Advanced Reactors and Non-power Production and Utilization Facilities Office of Nuclear Reactor Regulation

SUMMARY

OF THE JANUARY 17, 2024, PUBLIC MEETING WITH X ENERGY, LLC. (X-ENERGY), APPROACH FOR GRAPHITE QUALIFICATION FOR THE XE-100 HIGH TEMPERATURE GAS REACTOR (EPID NO. L-2018-LRM-0076)

Meeting Information:

Applicant: X ENERGY, LLC. (X-energy)

Docket/Project No.(s): 99902071 Public Meeting Notice Agencywide Documents Access and Management System (ADAMS)

Accession No.: ML24017A127 Applicant Presentation Slides ADAMS Accession No.: ML24002B166 Meeting Attendees: See the enclosure for a list of meeting attendees.

CONTACT:

Jorge Hernandez, NRR/DANU (301) 287-9096 May 23, 2024 Signed by Hernandez Munoz, Jorge on 05/23/24

M. Wentzel

Background:

By letter dated July 31, 2023 (ML23212B211), X-energy transmitted a regulatory engagement plan focused on material qualification of graphite and other graphite-related matters, along with the proposed schedule for the meetings.

Prior to this meeting, the following meetings have been held, in accordance with the aforementioned regulatory engagement plan:

August 24, 2023 (ML23271A128): partially closed meeting to discuss scope of graphite qualification and methodologies that will be included in the Preliminary Safety Analysis Report (construction permit) for the Xe-100 reactor at the Dow Chemical Company facility in Long Mott, TX and referenced technical reports and the information that is planned to be provided in the Final Safety Analysis Report at the operating license application stage.

October 5, 2023 (ML23319A239): partially closed meeting to discuss X-energys modelling approach for the stress analysis of irradiated graphite components.

October 12, 2023 (ML23319A359): partially closed meeting to discuss development of X-energys proprietary computer model, named Irradiated Graphite Numerical Iterative Solver (IGNIS).

November 9, 2023 (ML23355A076): partially closed meeting to discuss the design loadings and service level definitions for the graphite core assembly.

The meeting summaries are collected in ADAMS Package No. ML23271A128, Meeting Summary - X-energy Graphite Qualification Engagement Meetings Series (2023/2024).

Meeting Summary:

The U.S. Nuclear Regulatory Commission (NRC) staff conducted the meeting in accordance with NRC Management Directive 3.5, Attendance at NRC Staff-Sponsored Meetings (ML21180A271).

This meeting was the fifth meeting included in X-energys regulatory engagement plan for graphite components.

The X-energys staff presentation discussed the following topics:

The methodologies that X-energy intends to use for the consideration of transient and seismic events that will impact the graphite core assembly.

An introduction to the Price model, the fatigue analysis method that will be used, and homologous stress as used in the model.

A description of the effects of temperature, volume, and irradiation on graphite fatigue life.

The seismic qualification framework and reasoning behind the use of the intended approach.

A description of how X-energy will validate and verify the seismic model through software commercial grade dedication and testing.

M. Wentzel The NRC staff made the following questions/observations (including X-energys responses):

The NRC staff asked X-energy what quality assurance programs they will be committing to for data quality and software. X-energy indicated that this will be addressed in future technical report submittals.

The NRC staff asked about the use of test data to model fatigue of graphite components.

X-energy responded that it does not expect fatigue to be a significant degradation mechanism; however, it acknowledged the question to address in future licensing submittals.

The NRC staff discussed the topic of low-frequency and high-consequence seismic event sequences to be analyzed as part of the probabilistic risk assessment as the design matures when implementing the Licensing Modernization Project process in RG 1.233, Guidance for Technology-Inclusive, Risk-Informed, and Performance-Based Approach to Inform the Licensing Basis and Content of Applications for Licenses, Certifications, and Approvals for Non-Light-Water Reactors (ML20091L698). X-energy stated that it understands the issue, which is an industrys generic challenge, and will work with the NRC staff in the future as necessary.

The NRC staff questioned if Miner's Rule can be applied to graphite. X-energy responded in the affirmative.

No regulatory decisions were made as a result of this meeting.

Project No. 99902071

Enclosure:

List of Meeting Attendees cc: X-energy Xe-100 via GovDelivery

ML24122A992 NRR-106 OFFICE NRR/DANU/UAL2/PM NRR/DANU/UTB1/BC NRR/DANU/UAL2/BC NAME JHernandez GOberson MWentzel DATE 05/01/2024 05/23/2024 05/23/2024 OFFICE NRR/DANU/UAL2/PM NAME JHernandez DATE 05/23/2024

Enclosure List of Meeting Attendees For the January 17, 2024 Public Meeting With X Energy, LLC. (X-Energy), Approach for Graphite Qualification for the Xe-100 High Temperature Gas Reactor Open Meeting Name Organization Christopher Welch U.S. Nuclear Regulatory Commission (NRC)

Dan Beacon NRC Greg Oberson NRC Ian Jung NRC James Gaslevic NRC Jorge Hernandez Munoz NRC Jose Pires NRC Joseph Bass NRC Madhumita Sircar NRC Matthew Gordon NRC Vince Voltaggio NRC Doug Kalinousky X-energy Emna Sghaier X-energy FJ van Zanten X-energy Jaime A Cano X-energy James Roll X-energy Jasmine Wang X-energy Jim Fogarty X-energy Jon Facemire X-energy Maggie Staiger X-energy Sam Baylis X-energy Steve Vaughn X-energy Tim Lucas X-energy Alex Dean X-energy (contractor)

Gwennael Beirnaert X-energy (contractor)

Michael Saitta X-energy (contractor)

Mark Feltner Dow William E. Windes Idaho National Laboratory Addison Hall Dominion Energy Chuck Marks Dominion Energy David Gross Dominion Energy James A. Brownell Energy Northwest Lisa L. Williams Energy Northwest Steven Pope Information Systems Laboratory Nicole Schlichting Kairos Power Ali Member of Public Chong Chen Member of Public Douglas J. Roll Member of Public Raja sekhar Tripuraneni Member of Public Tom Roberts Member of Public Nassia Tzelepi National Nuclear Laboratory Benjamin D. Kosbab SGH Jordan M. Seawright SGH

2 Name Organization Michael Scott DeFilippis Tennessee Valley Authority Keith W. Means Westinghouse Zefeng Yu Westinghouse Closed Meeting Name Organization Alexander Chereskin NRC Christopher Welch NRC Dan Beacon NRC Greg Oberson NRC Ian Jung NRC James Gaslevic NRC Jorge Hernandez Munoz NRC Joseph Bass NRC Jose Pires NRC Madhumita Sircar NRC Yamir Diaz-Castillo NRC Doug Kalinousky X-energy Emna Sghaier X-energy FJ van Zanten X-energy Jaime A Cano X-energy James Roll X-energy Jasmine Wang X-energy Jim Fogarty X-energy Jon Facemire X-energy Maggie Staiger X-energy Sam Baylis X-energy Steve Vaughn X-energy Tim Lucas X-energy Alex Dean X-energy (contractor)

Benjamin D. Kosbab X-energy (contractor)

Gwennael Beirnaert X-energy (contractor)

Jordan M. Seawright X-energy (contractor)

Michael Saitta X-energy (contractor)