ML25233A295
| ML25233A295 | |
| Person / Time | |
|---|---|
| Site: | 99902049 |
| Issue date: | 09/04/2025 |
| From: | Holtec, SMR |
| To: | Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML25233A293 | List: |
| References | |
| 300-USNRC-112 | |
| Download: ML25233A295 (1) | |
Text
holtec.com l smrllc.com SMR-300 I&C Architecture Topical Report Overview September 4, 2025 Holtecs SMR-300 Technology Safe, Secure, Reliable, Flexible, Economical Clean Energy to Support the Worlds Energy Needs
holtec.com l smrllc.com l Page 2 Purpose of Meeting SMR-300 I&C Architecture Background Topical Report Division of Responsibility Licensing Strategy and Applicable Regulatory Guidance Topical Report Scope and Objective Submittal and Review Schedule Q&A Agenda
holtec.com l smrllc.com l Page 3 D3 Diversity and Defense in Depth DSRS Design-Specific Review Standard ESF Engineered Safety Feature I&C Instrumentation and Control LTR Licensing Topical Report MELCO Mitsubishi Electric Corporation MELTAC Mitsubishi Electric Total Advanced Control PSS Plant Safety System RT Reactor Trip SE Safety Evaluation Acronyms
holtec.com l smrllc.com l Page 4 To provide an overview of the LTR scope and objectives. The LTR will describe:
I&C architecture used on the SMR-300 design Compliance to applicable regulation LTR is generic and not site-specific Alignment on LTR submittal and review timeline Purpose of Meeting
holtec.com l smrllc.com l Page 5 Previous pre-application regulatory engagements include:
I&C Hazard Analysis Methodology, Feb 2023 ML23019A004 I&C D3 Evaluations, July 2023 ML23156A182 I&C ISG-04 Conformance Analysis, Aug 2023 ML23289A099 I&C Two Division Design Conformance to IEEE 603, Sept 2023 ML23296A001 SMR-300 Cyber Security Strategy, Aug 2024 ML24262A002 SMR-300 I&C Architecture Background
holtec.com l smrllc.com l Page 6 The SMR-300 I&C systems are based on digital platforms developed by MELCO.
MELCO received a SE for their MELTAC Platform LTR in 2018 (ML18260A211).
MELCO is expected to receive a SE for a revision to the MELTAC Platform LTR in 2025 (ML23167C168).
MELTAC Platform LTR covers the platform design and not the application use case for the SMR-300.
SMR-300 I&C Architecture Background
holtec.com l smrllc.com l Page 7 Topical Report Division of Responsibility MELCO (Supporting)
HOLTEC (SMR)
(Applicant)
NRC
holtec.com l smrllc.com l Page 8 SMR-300 is following 10 CFR Part 50.
LTR will list applicable regulations and demonstrate compliance No exemptions are being sought for the I&C architecture design DNRL-ISG-2022-01 Appendix A provides guidance for I&C content related to Part 50 construction permit applications.
The SMR-300 I&C design will follow the guidance in DSRS Ch. 7.
Unified framework that emphasizes fundamental I&C design principles:
Independence Redundancy Predictability and Repeatability D3 Generic for I&C, focused on digital I&C systems Licensing Strategy and Applicable Regulatory Guidance
holtec.com l smrllc.com l Page 9 The SMR-300 I&C Architecture LTR will describe the architecture design and configuration of the SMR-300 I&C systems.
Focus on the I&C Safety System (PSS) Architecture Non-safety systems are discussed to the extent necessary to demonstrate appropriate compliance with applicable regulatory requirements.
The objective of this report is to obtain an SE from the NRC concluding that the SMR-300 I&C architecture design is acceptable for reference in future SMR-300 licensing applications.
Topical Report Scope and Objective
holtec.com l smrllc.com l Page 10 The SMR-300 I&C Architecture LTR builds on the MELTAC Platform LTR.
Platform LTR covers topics that can be addressed at a platform level.
e.g., design of the communications networks Architecture LTR describes how the platform is applied to SMR-300.
Addresses some application-specific action items Architecture LTR will not duplicate or restate design concepts from the Platform LTR.
Topical Report Scope and Objective
holtec.com l smrllc.com l Page 11 The major topics of the SMR-300 I&C Architecture LTR include:
I&C architecture description Two division design Communications between safety and non-safety systems Evaluation of compliance to 10 CFR 50 requirements Evaluation of compliance to the fundamental I&C design principles Independence, redundancy, predictability and repeatability, D3 Includes evaluation of compliance to IEEE 603 and IEEE 7-4.3.2 This LTR is intended to be generic and not site-specific Does not cover site-specific protection logic Topical Report Scope and Objective
holtec.com l smrllc.com l Page 12 I&C architecture description will include:
Architecture block diagram Coincidence voting descriptions Bypass logic RT and ESF initiation RT and ESF reset Prioritization functions Topical Report Scope and Objective
holtec.com l smrllc.com l Page 13 Evaluation of compliance to the fundamental I&C design principles Independence:
RG 1.75 Criteria for Independence of Electrical Safety Systems RG 1.152, Criteria for Programmable Digital Devices in Safety-Related Systems of Nuclear Power Plants IEEE 603 Standard Criteria for Safety Systems for Nuclear Power Generating Stations IEEE 7-4.3.2 Standard Criteria for Programmable Digital Devices in Safety Systems of Nuclear Power Generating Stations Redundancy:
RG 1.53, Application of the Single-Failure Criterion to Safety Systems IEEE 379, Application of the Single-Failure Criterion to Nuclear Power Generating Station Safety Systems Topical Report Scope and Objective
holtec.com l smrllc.com l Page 14 Evaluation of compliance to the fundamental I&C design principles Predictability and Repeatability IEEE 603 Standard Criteria for Safety Systems for Nuclear Power Generating Stations Diversity and Defense in Depth:
BTP 7-19, Guidance for Evaluation of Defense in Depth and Diversity to Address Common-Cause Failure due to Latent Design Defects in Digital Safety Systems NUREG/CR-6303, Method for Performing Diversity and Defense-in-Depth Analyses of Reactor Protection Systems RG 1.62, Manual Initiation of Protective Actions Topical Report Scope and Objective
holtec.com l smrllc.com l Page 15 LTR submittal is expected October 2025.
SMR will request a 12-month review cycle to support Palisades SMR-300 construction permit application timeline.
Submittal and Review Schedule
holtec.com l smrllc.com l Page 16 Questions?
www.holtec.com l Page 17 Thank You Krishna P. Singh Technology Campus 1 Holtec Boulevard, Camden, NJ 08104 Tel: (856) 797-0900 l www.holtec.com holtec.com l smrllc.com l Page 17