Advanced Reactors Sub-Arena

Advanced reactors comprise one of four sub-arenas that the staff of the U.S. Nuclear Regulatory Commission (NRC) identified in considering which areas of the reactor safety arena to target for greater use of risk information. This page summarizes the following aspects of this sub-arena with expanding menus:

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List of Risk-Informed and Performance-Based Activities

This list shows the ongoing licensing initiatives, projects, and activities that the staff of the U.S. Nuclear Regulatory Commission (NRC) has targeted for greater use of risk information in the Advanced Reactors Sub-Arena within the Reactor Safety Arena:

Advanced Reactor Content of Application Project

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In FY 2023, the NRC staff published the following documents for public comment:

  • DG-1404 Revision 1 Guidance on TICAP for Non-Light Water Reactors
  • DANU-ISG-2022-01 ARCAP Roadmap Interim Staff Guidance.
  • DANU-ISG-2022-02 ARCAP Chapter 2 Site Information.
  • DANU-ISG-2022-03 ARCAP Chapter 9 Normal Effluents.
  • DANU-ISG-2022-04 ARCAP Chapter 10 Occupational Dose.
  • DANU-ISG-2022-05 ARCAP Chapter 11 Organization and Human-System Consideration.
  • DANU-ISG-2022-06 ARCAP Chapter 12 Post-construction Inspection, Testing, and Analysis Program.
  • DANU-ISG-2022-07 ARCAP Risk-informed Inservice Inspection and Inservice Testing.
  • DANU-ISG-2022-08 ARCAP Risk-informed Technical Specifications.
  • DANU-ISG-2022-09 ARCAP Fire Protection for Operations.

See the Advanced Reactor Content of Application Project public webpage for an updated listing of public meeting and publicly available documents.

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Technical Assistance for Research on Innovative Methods and Technologies to Enhance Seismic Safety for Design and Construction of Commercial Reactors

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The staff reviewed and evaluated the Nuclear Energy Institute (NEI) 18 04, Revision 1, "Risk-Informed Performance-Based Technology Inclusive Guidance for Non-Light Water Reactor Licensing Basis Development," issued August 2019, and RG 1.233, "Guidance for a Technology-Inclusive, Risk-Informed, and Performance-Based Methodology to Inform the Licensing Basis and Content of Applications for Licenses, Certifications, and Approvals for Non-Light Water Reactors." After reviewing and evaluating the American Society of Civil Engineer (ASCE) standards ASCE 1-22 (Draft), "Standard for Geotechnical Analysis, Design, Construction, Inspection and Monitoring of Nuclear Safety-Related Structures,” ASCE 4-16, “Seismic Analysis of Safety-Related Nuclear Structures," and 43-18 (Draft), "Seismic Design Criteria for Structures, Systems, and Components in Nuclear Facilities," the NUREG/CR 7253, "Technical Considerations for Seismic Isolation of Nuclear Facilities," NUREG/CR 7254, "Seismic Isolation of Nuclear Power Plants using Sliding Bearings," and NUREG/CR 7255, "Seismic Isolation of Nuclear Power Plants using Elastomeric Bearings," the staff drafted two pre-decisional regulatory guides: "Technology-Inclusive, Risk-Informed, and Performance-Based Methodology for Seismic Design of Commercial Nuclear Plants" and "Seismically Isolated Nuclear Power Plants." These two draft regulatory guides are associated with the development of 10 CFR Part 53 rulemaking that has not been finalized. These pre-decisional, draft regulatory guides are publicly available now (ML22276A149 and ML22276A154) and will be finalized based on public feedback and the Part 53 rulemaking.

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Risk-Informed Review of Small Modular Reactor (SMR) Designs

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In preparation for the submittal of the NuScale standard design approval application (SDAA), the NRC staff collected preliminary risk insights in support of a graded review of the SDAA. These risk insights were leveraged by the NRC staff in its early review of the standard design approval application by: (1) identifying focus areas for the review; (2) grading the review scope and schedule; and (3) supporting decision-making during the acceptance review of the application. The SDAA was accepted and docketed for review in July 2023. As part of its safety review, the NRC staff is continuing to leverage risk insights. In addition to facilitating an effective review, these insights, in conjunction with the use of an integrated team of reviewers from different subject areas, are being actively used to support the resolution of challenging technical issues. This use of risk insights in all aspects of the NuScale SDAA review is aligned with the implementation of the lessons learned from the NuScale design certification application review and is an example of being a more modern risk-informed regulator.

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Non-Light Water Reactor Licensing Modernization

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No Update

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Risk-informed Emergency Planning Zone Size Evaluation

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The final rule package was published in the Federal Register on November 16, 2023 and became effective December 18, 2023.

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Advanced Reactor Regulatory Framework

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On March 1, 2023, the NRC staff submitted SECY-23-0021, "Proposed Rule: Risk-Informed, Technology-Inclusive Regulatory Framework for Advanced Reactors (RIN 3150-AK31; NRC-2019-0062)," to the Commission for consideration. The NRC staff released several iterations of preliminary proposed rule language to support numerous opportunities for public engagement (see the Part 53 public website for a complete list of public meetings). Additional details related to the Part 53 rulemaking schedule and major milestones can be found on the NRC's rulemaking website.

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Physical Security for Advanced Reactors

The U.S. Nuclear Regulatory Commission (NRC) is developing specific physical security requirements for advanced reactors, which refers to light-water small modular reactors and non-light-water reactors. The NRC is proposing a limited-scope rulemaking that would provide a clear set of alternative, performance-based requirements and guidance for advanced reactor physical security that would reduce the need for exemptions to current physical security requirements when applicants request permits and licenses. This rulemaking would provide additional benefits for advanced reactor applicants by establishing greater regulatory stability, predictability, and clarity in the licensing process.

Additional information is available at the Advanced Reactors web page.

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Regulatory Guidance on Advanced Non-LWR PRA Acceptability

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Regulatory Guide 1.247 "Acceptability of Probabilistic Risk Assessment Results for Non-LWR Risk Informed Activities" was issued for trial use in March 2022. The staff will continue gaining experience with the implementation of the RG and new risk-informed application reviews. The length of the trial period is yet to be determined. The trial period will depend on a number of ongoing activities such as accruing lessons learned from the implementation of the RG and continued development of PRA standards. Also see Endorsement of ASME/ANS RA-S-1.4 Probabilistic Risk Assessment Standard for Advanced Non-Light Water Reactor Nuclear Power Plants website.

Risk-informed Tools for Advanced Non-LWR Component Performance

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A graphite modeling tool was developed within Idaho National Laboratory’s (INL) finite element framework MOOSE. Within MOOSE, the graphite tool was made available within Grizzly which focusses on thermo-mechanical behavior modeling. The graphite tool itself has three main pieces. The first piece focusses on thermo-mechanical modeling of graphite, which includes the effects of irradiation. The second piece models the effects of degradation of the graphite from oxidation, and the final piece implements the probabilistic structural failure criteria provided in III-5 of the ASME BPVC. A technical letter report, TLR-RES/DE/REB-2022-11, was published which provides an overview of the graphite tool. The graphite tool is under constant development and currently looks to develop functionality to model degradation effects prevalent in a molten salt environment.

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Page Last Reviewed/Updated Wednesday, February 21, 2024