ML25118A101
| ML25118A101 | |
| Person / Time | |
|---|---|
| Site: | 99902076 |
| Issue date: | 05/20/2025 |
| From: | Chauhan M, Kevin Roche Office of Nuclear Reactor Regulation |
| To: | Carleton D Terrestrial Energy USA |
| References | |
| EPID L-2025-TOP-0000 | |
| Download: ML25118A101 (1) | |
Text
TERRESTRIAL ENERGY USA, INC.
AUDIT PLAN FOR TOPICAL REPORT POSTULATED INITIATING EVENTS FOR THE IMSR400, REVISION A EPID: L-2025-TOP-0000 Applicant:
Terrestrial Energy USA, Inc.
Applicant Address:
537 Steamboat Road, Suite 200, Greenwich, CT, 06830 Plant Name:
IMSR400 Project No.:
99902076
Background:
By letter dated December 27, 2024, Terrestrial Energy USA (TEUSA), submitted the topical report Postulated Initiating Events for the IMSR400, Revision A, (Agencywide Documents Access and Management System (ADAMS) Package Accession No. ML25006A141), to the U.S. Nuclear Regulatory Commission (NRC) for review and approval.
Following initial review, the NRC staff has determined that conducting a regulatory audit, as set forth in this plan, will facilitate the timely completion of the evaluation process.
Purpose:
The purpose of the audit is for the NRC staff to enhance their understanding of the methodology used to develop a set of postulated initiating events (PIEs) for the Integral Molten Salt Reactor (IMSR) design and identify information that will require docketing to support the NRC staffs regulatory findings. Performing a regulatory audit is necessary to assist the NRC staff in efficiently conducting its review and gaining insights to the applicants proposed methodology.
Regulatory Audit Basis:
A regulatory audit is a planned regulation-related activity that includes the examination and evaluation of primarily non docketed information. The audit is conducted with the intent to gain understanding, verify information, and identify information that will require docketing to support the basis of a regulatory decision. Performing a regulatory audit is expected to assist the NRC staff in efficiently conducting its review and gaining insights to the applicants methodology and procedures. Information that the NRC staff relies upon to make the safety determination must be submitted on the docket.
Regulatory Audit Scope and Methodology:
The NRC staff will perform the audit in accordance with the Office of Nuclear Reactor Regulation (NRR) Office Instruction LIC-111, Regulatory Audits, Revision 1 (ML19226A274). The NRC staff will examine supporting information provided by TEUSA through an online reference
portal and meet with applicants and subject matter experts regarding the acceptability of the proposed methodology. The scope of this audit includes, but is not limited to the proposed PIE methodology, identification of IMSR PIEs, categorization of PIEs, classification of individual PIEs, and quality control.
Information and Other Material Necessary for the Regulatory Audit:
The NRC staff will share with TEUSA the questions and additional material needed during the audit in a timely manner. Any information necessary to support the NRC staffs findings and conclusions related to the review of the PIE methodology will be requested to be submitted on the docket. The following documents should be made available for NRC staff review:
- 1. IMSR400-30823-ASD-001, Rev. 1, Preliminary Hazard Assessment for Basic Engineering
- 2. IMSR400-30821-CALC-001, Rev. 0, PIE Frequency Assessment
- 3. IMSR400-30800-PLA-001, Rev. 0, Safety Analysis Postulated Initiating Events Update Plan.
Team Assignments:
The audit team will consist of the following NRC staff from NRR.
NAME DIVISION BRANCH Role Kevin Roche Division of Advanced Reactors and Non-power Production and Utilization Facilities (DANU)
Advanced Reactor Licensing Branch 2 (UAL2)
Project Manager Maggie Chauhan DANU UAL2 Project Manager Hanh Phan DANU Advanced Reactor Technical Branch 2 (UTB2)
Audit Leader, Lead Technical Reviewer Kristy Bucholtz DANU Advanced Reactor Technical Branch 1 (UTB1)
Technical Reviewer Ben Adams DANU UTB1 Technical Reviewer Logistics:
The NRC staff will conduct the audit virtually from the NRC Headquarters in Rockville, Maryland via TEUSAs established electronic portal. Audit meetings will be held virtually, using Microsoft Teams, or via other, similar platform. These meetings will be scheduled on an as needed basis after the entrance meeting and once the NRC staff has had the opportunity to read any documents placed in the online reference portal. The audit will begin May 20, 2025, with the issuance of this audit plan and continue as necessary, with activities occurring
intermittently during the audit period.
To improve the efficiency of the audit, TEUSA and the NRC staff have discussed the use of the online reference portal (i.e., Watchdog), established by TEUSA, that would allow the NRC staff limited read-only access to the material and other technical information placed in the portal by TEUSA. Use of the online reference portal is acceptable provided that TEUSA establishes measures to limit access to specific NRC staff (e.g., based on NRC e-mail addresses or the use of passwords which will only be assigned to the NRC staff directly involved in the audit on a need-to-know basis), and to make the documents view-only (i.e., prevent NRC staff from saving, copying, downloading, or printing any documents). The conditions associated with the online reference portal must be maintained throughout the audit process. The NRC staff who should initially be granted access to the portal are those listed in the Team Assignments section above. As needed, the NRC Project Manager may provide TEUSA with the names of additional NRC staff who are added to the audit team and should subsequently be granted access.
When the NRC staff determines that any information on the portal is relevant to the safety determination, the NRC staff will request that TEUSA to place that information on the docket. The NRCs licensing project manager will inform TEUSA via routine communications when the NRC staff no longer needs access to the portal.
Deliverables:
The NRC staff will develop any RAIs or confirmations of information, as needed, which will be provided to TEUSA via separate docketed correspondence. At the completion of the audit, the audit team will issue an audit summary within 90 days after the exit meeting but will strive for a shorter duration. The audit summary will be declared and entered as an official agency record in ADAMS.
If you have questions regarding this audit, please contact me via email at Kevin.Roche@nrc.gov.
Sincerely, Kevin Roche, Project Manager /RA/
Advanced Reactors Licensing Branch 2 Division of Advanced Reactors and Non-Power Production and Utilization Facilities Office of Nuclear Reactor Regulation Date: May 20, 2025 Project No.: 99902076 cc:
dokeefe@terrestrialusa.com dlove@terrestrialusa.com KEVIN ROCHE Digitally signed by KEVIN ROCHE Date: 2025.05.20 13:09:11 -04'00'
Package:
Audit Plan: ML25118A101 NRR-106 OFFICE NRR/DANU/UAL2:PM NRR/DANU/UAL2:PM NRR/DANU.UTB1: BC NAME MChauhan KRoche GOberson DATE 4/30/2025 5/15/2025 5/2/2025 OFFICE NRR/DANU/UAL2: BC NAME SPhilpott DATE 5/9/2025