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Advanced Reactors (non-LWR designs)

Advanced Reactor Activities

Non-LWR Vision and Strategy, Implementation Action Plans, and Overview of Activities

The staff has developed a vision and strategy to assure that the NRC is ready to review potential applications for non-light water reactor (non-LWR) technologies effectively and efficiently. The staff described the vision and strategy in "NRC Vision and Strategy: Safely Achieving Effective and Efficient Non-Light Water Reactor Mission Readiness," which was published in the Federal Register on July 21, 2016, for stakeholder input. The NRC updated its Vision and Strategy Document to reflect stakeholder feedback in December 2016.

To achieve the goals and objectives stated in the NRC's vision and strategy, the NRC has developed implementation action plans (IAPs). The IAPs identify the specific activities the NRC will conduct in the near-term (within 5 years), mid-term (5-10 years), and long-term (beyond 10 years) timeframes. The NRC released its draft IAPs to obtain stakeholder feedback during a series of public meetings held between October 2016 and March 2017. The staff also briefed the Advisory Committee on Reactor Safeguards (ACRS) on March 8 and 9, 2017. The staff considered the ACRS comments and stakeholder feedback in the final Near-Term, Mid-Term and Long-Term IAPs which were issued on July 12, 2017.

The staff issued SECY-20-0010, "Advanced Reactor Program Status" on January 30, 2020. This paper provides the status of the NRC staff's activities related to advanced reactors, including the progress and path forward on each of the implementation action plan (IAP) strategies. It also provides an overview of the various external factors influencing the staff's activities to prepare for possible licensing and deployment of advanced reactors.

As required by Sections 103(b) and 103(c) of the Nuclear Energy Innovation and Modernization Act (NEIMA), the NRC prepared two reports to Congress regarding (1) expediting and establishing stages in the licensing process for commercial advanced nuclear reactors; and (2) increasing, where appropriate, the use of risk-informed and performance-based evaluation techniques and regulatory guidance in licensing commercial advanced nuclear reactors within the existing regulatory framework. These reports were sent to Congress on July 12, 2019.

In addition, consistent with Section 103 of NEIMA, staff has begun efforts to establish a "Risk Informed, Technology-Inclusive Regulatory Framework for Advanced Reactors" for optional use by applicants for new commercial advanced nuclear reactor licenses by December 31, 2027. The staff presented its proposed plan for this rulemaking to the Commission for approval in SECY-20-0032 dated April 13, 2020.

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Advanced Reactor - Summary of Integrated Schedule and Regulatory Activities

Summary of Integrated Schedule and Regulatory Activities (updated 06/10/2020)
Thumbnail image of Gantt Chart entitled Integrated Schedule of Regulatory Activities for Advanced Reactor consisting of an image of an excel spreadsheet with color-coded items

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Flexible Licensing Processes for Advanced Reactors

The NRC's review and licensing processes are flexible and allow interactions related to a wide variation in design development and deployment strategies. Based on interactions with stakeholders, the NRC determined that guidance would be beneficial to assist non-LWR developers in planning regulatory interactions. To address this need, the NRC developed guidance for its flexible regulatory review processes within the bounds of existing regulations, including the use of conceptual design reviews and staged-review processes in the document, "A Regulatory Review Roadmap for Non-Light Water Reactors." The "roadmap" is also intended to help designers prepare technology- or design-specific regulatory engagement plans. Regulatory engagement plans define desired outcomes from various interactions between the designer and the NRC, considering factors such as the resources available to the designer and the NRC and the coordination of regulatory issues with other aspects of the overall program for developing and deploying non-LWR designs. Regulatory engagement plans also define the timing and scope of regulatory interactions in order to align with stakeholders activities related to plant design, research and development, finance, public policy, and the fuel cycle. The NRC released a draft roadmap document in October of 2016 to support discussions with stakeholders during several public meetings. The staff incorporated stakeholder feedback, and guidance related to standard design approvals and prototype reactors into the final roadmap, which was issued on December 26, 2017.

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Industry-Led Licensing Modernization Project

The NRC engaged with the Licensing Modernization Project (LMP) led by Southern Company, coordinated by the NEI, and cost-shared by DOE. The interactions between the NRC staff and LMP resulted in the submittal of NEI–18–04, Revision 1, "Risk-Informed Performance-Based Guidance for Non‑Light Water Reactor Licensing Basis Development," on August 26, 2019. The guidance focuses on identifying licensing basis events; categorizing and establishing performance criteria for structures, systems, and components; and evaluating defense in depth for advanced reactor designs. The staff issued SECY-19-0117, "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," on December 2, 2019. In this notation vote paper, the staff discussed potential policy issues associated with the LMP methodology and recommended that the Commission find that the use of the methodology described in NEI 18-04 is a reasonable approach for establishing key parts of the licensing basis for non-LWRs. The Commission's Staff Requirements Memorandum dated May 26, 2020, found that using the methodology is a reasonable approach to support the licensing of non-light water reactors. The NRC published Regulatory Guide 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," in the Federal Register on June 9, 2020.

The following table provides reports related to the LMP demonstration and pilot activities that have been submitted to date.

Date Design
September 2019 Fluoride-Cooled High Temperature Reactor Licensing Modernization Project Demonstration
September 2019 Molten Salt Reactor Experiment (MSRE) Case Study Using Risk‐Informed, Performance‐Based Technical Guidance to Inform Future Licensing for Advanced Non‐Light Water Reactors
August 2019 Westinghouse eVinci Micro Reactor
Licensing Modernization Project Demonstration
December 2018 PRISM Sodium Fast Reactor
Licensing Modernization Project Demonstration
September 2018 OKLO's DG-1353 Pilot
August 2018 High Temperature, Gas-Cooled Pebble Bed Reactor
licensing Modernization Project Demonstration

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Advanced Reactor Content of Application Project

The purpose of the advanced reactor content of application project (ARCAP) is to develop technology-inclusive, risk-informed and performance-based application guidance. The ARCAP is broader and encompasses the industry-led technology-inclusive content of application project (TI-CAP). These projects build on the outcome of the Licensing Modernization Project.

The ARCAP guidance is intended to be used for an advanced reactor application for a combined license, construction permit, operating license, design certification, standard design approval, or manufacturing license. The industry-led TI-CAP's purpose is to develop the content for specific portions of the safety analysis report (SAR) that would be used to support an advanced reactor application. The TI-CAP portion of the SAR will be informed by the guidance found in in NEI 18-04, Revision 1, "Risk-Informed Performance-Based Technology-Inclusive Guidance for Non-Light Water Reactor Licensing Basis Development."

ARCAP is a longer-term effort that will support the 10 CFR Part 53 rulemaking effort. NRC staff has developed the "Non-Light Water Reactor Review Strategy Staff White Paper," dated September 2019, to provide internal guidance for the review of non-LWR applications in the near-term.

The following table provides reference to ARCAP-related activities that have been provided to date.

Date Design

January 2020

NRC Staff Comments on Technology Inclusive Content of Application Project Definition of Fundamental Safety Functions for Advanced Non-Light Water Reactors – Draft Report Revision B
November 2019

Technology Inclusive Content of Application Project for Non-Light Water Reactors Definition of Fundamental Safety Functions for Advanced Non-Light Water Reactors - Draft Report Revision B

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Advanced Nuclear Reactor Generic Environmental Impact Statement (GEIS)

The NRC intends to develop a GEIS for advanced nuclear reactors with a small generating output and correspondingly small environmental footprint in order to streamline the environmental review process for future small-scale advanced nuclear reactor (ANR) environmental reviews. The purpose of an ANR GEIS is to determine which environmental impacts could result in essentially the same (generic) impact for different ANR designs that fit within the parameters set in the GEIS, and which environmental impacts could result in different levels of impacts requiring a plant-specific analysis.  Environmental reviews for small-scale advanced nuclear reactor license applications could incorporate the ANR GEIS by reference and provide site-specific information and analyses in a Supplemental Environmental Impact Statement (SEIS), thereby streamlining the environmental review process.

In SECY-20-0020, the staff informed the Commission that it plans to use a technology-neutral plant parameter envelope (or PPE) approach to bound small-scale ANR projects. For the purposes of the ANR GEIS, the staff considers a "small-scale" ANR as having the potential to generate up to approximately 30 megawatts thermal per reactor with a correspondingly small environmental footprint. The actual bounding thermal power level of the ANR and the environmental footprint used in the ANR GEIS are topics to be determined during the scoping process for the GEIS.

Because small-scale advanced reactors are not specific to only one reactor design and could be sited anywhere in the United States that meets NRC siting requirements, the NRC decided to pursue a technology neutral approach using a PPE.  The PPE will consist of a table of bounding values or parameters for different reactor designs located on a site. In addition, a table of values representing the site parameter envelope (e.g., size of site, quantity of water used, demographics) will be developed to describe the affected environment. The ANR GEIS will evaluate the impacts of a reactor that fits within the bounds of the PPE on a site that fits within the bounds of the site parameter envelope to determine the environmental impact.

A future application that references the ANR GEIS will need to demonstrate that its project is bounded by the analysis in the ANR GEIS and that there is no significant new information affecting the evaluation. If the project is bounded by the ANR GEIS and there is no significant new information, the NRC will incorporate by reference the ANR GEIS and no further analysis would be needed. The application will also need to analyze the site-specific resources not resolved generically in the ANR GEIS. If impacts to a resource have not been resolved generically by the ANR GEIS, the site-specific SEIS will evaluate the impacts to the resource.

Below is the schedule for the GEIS.

April 30, 2020 – Federal Register notice of intent to prepare GEIS and conduct scoping (85 FR 24040)

Scoping comment period ends – June 30, 2020

May 1, 2021 – Draft GEIS issued for comment
May 1, 2022 – Final GEIS issued

Advanced Nuclear Reactor GEIS Scoping Meeting Slides.

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NRC-DOE Joint Initiative - Non-LWR Design Criteria

In July 2013, the US Department of Energy (DOE) and the NRC established a joint initiative to address a key portion of the licensing framework essential to advanced reactor technologies. The initiative addresses the "General Design Criteria for Nuclear Power Plants," Appendix A to 10 Code of Federal Regulations (CFR) 50, which were developed primarily for LWRs, by adapting them to the needs of advanced reactor design and licensing. The initiative is being accomplished in two phases. Phase 1, completed by DOE, consisted of reviews, analyses and evaluations resulting in a report issued by the DOE in December 2014 titled, "Guidance for Developing Principal Design Criteria for Advanced (Non-Light Water) Reactors." Phase 2 of the initiative, managed by the NRC, involved review of the Phase 1 DOE work products issuance of regulatory guidance resulting from the review.

On April 7, 2016, the NRC issued the, "Draft - Advanced Non-LWR Design Criteria - April 2016," for informal public comment. The informal public comment period closed on June 8, 2016. After consideration of stakeholder input, the NRC issued draft regulatory guide DG-1330, "Guidance for Developing Principal Design Criteria for Non-Light Water Reactors" for formal public comment. DG-1330 was published in the Federal Register on February 3, 2017, for a 60 day public comment period. The public comment period closed on April 4, 2017. The NRC considered the public comments and held a public meeting for further discussion on August 24, 2017. The staff considered the public comments and stakeholder interactions in preparing the final RG 1.232. On April 3, 2018, the NRC issued the, "Final RG 1.232," along with the, "Public Comment Resolution Table." Final RG 1.232 was published in the Federal Register on April 9, 2018.

The issuance of this new NRC regulatory guidance is expected to provide the following benefits:

  • reduced regulatory uncertainty for advanced reactor developers,
  • improved guidance for NRC staff reviewing advanced reactor license applications, and
  • improved timeliness and efficiency of licensing activities for both applicants and NRC staff.

The following table lists the meetings that NRC has conducted with external stakeholders in connection with the initiative:

Date Description
08/24/17

Public Meeting on Non-LWR Design Criteria

10/11/16

Public Meeting on Non-LWR Design Criteria

02/25/15

Non-Public Seminar Modular HTGR Technology and Safety Design Approach

02/18/15

Non-Public Seminar Sodium-Cooled Fast Reactor (SFR) Technology and Safety Overview

01/21/15

Public Meeting to Discuss the DOE Report, "Guidance for Developing Principal Design Criteria for Advanced (Non-Light Water) Reactors."

The following table provides access to documents, and correspondence between the NRC and DOE in connection with the initiative:

Date Description
09/15/15 Response to NRC Staff Second Set of Questions on the U.S. DOE Report, "Guidance for Developing Principal Design Criteria for Advanced Non-Light Water Reactors"
08/17/15 Questions on the U.S. Department of Energy Report, "Guidance for Developing Principal Design Criteria for Advanced (Non-Light Water) Reactors."
07/15/15 Response to NRC Staff Questions on the U.S. Department of Energy Report, "Guidance for Developing Principal Design Criteria for Advanced (Non-Light Water) Reactors."
06/05/15 NRC Staff Questions on the U.S. Department of Energy Report, "Guidance for Developing Principal Design Criteria for Advanced (Non-Light Water) Reactors."
01/15/15 NRC Letter to DOE, "Initiative Regarding U.S. Nuclear Regulatory Commission Licensing Strategy for Advanced Reactor Technologies."
12/08/14 DOE Letter to NRC, "Joint Initiative Regarding U.S. Nuclear Regulatory Commission Licensing Strategy for Advanced (Non-Light Water) Reactor Technologies."
07/09/13 NRC Letter to DOE, "Initiative Regarding U.S. Nuclear Regulatory Commission Licensing Strategy for Advanced Reactor Technologies."

Updates relative to the Phase 2 portion of the initiative are also available by subscribing to the NRC GovDelivery Subscription service.

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Advanced Reactor Training Materials

The NRC contracted with the Oak Ridge National Laboratory (ORNL) to develop a 12-module training course on molten-salt reactors (MSRs). The course provides background on various MSR concepts presently under development, including a history of earlier MSR projects, descriptions of conceptual designs, and expected technical and regulatory challenges. The NRC also contracted with Argonne National Laboratory and Idaho National Laboratory to develop training courses for fast reactors and high-temperature gas-cooled reactors. The training materials for molten salt reactors, fast reactors, and high-temperature gas-cooled reactors are publicly available.

The NRC contracted with Brookhaven National Laboratory (BNL) to prepare a Regulatory History of Non-Light Water Reactors. This report describes the history of licensing non-LWRs with a focus on regulatory policy and licensing beginning with the Atomic Energy Commission and transitioning to the NRC's past and current activities. This background information is a valuable knowledge management tool for NRC staff and member of the public.

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Testing Needs and Prototype Plants

On June 16, 2017, the NRC issued a preliminary draft document, "Nuclear Power Reactor Testing Needs and Prototype Plants for Advanced Reactor Designs." This document described the relevant regulations governing the testing requirements for advanced reactors, described the process for determining testing needs to meet the NRC's regulatory requirements, clarified when a prototype plant might be needed and how it might differ from the proposed standard plant design, and described licensing strategies and options that include the use of a prototype plant to meet the NRC's testing requirements. The document was discussed during periodic public meetings on advanced reactor topics. The staff considered stakeholder feedback and issued the final paper as part of the regulatory review roadmap in December 2017.

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Advanced Reactor Workshops

In 2015, the NRC and the U.S. Department of Energy (DOE) began co-hosting a series of Advanced Reactor Workshops. The first workshop was held on September 1-2, 2015, 2015 and included presentations and discussions on roles and responsibilities of the NRC and DOE, previous experience licensing non-LWR designs, critical gaps and needs in research and development that need to be addressed, and suggestions for improvements in the licensing of non-LWR designs. The second workshop was held on June 7-8, 2016 and focused on exchanging information from NRC, DOE, industry and included presentations and discussions on strategies for advanced reactor development and deployment, recent initiatives; and advanced reactor fuel development, qualification, and challenges. The Third workshop in this series was held on April 25 and 26, 2017. The NRC has now transitioned from this workshop format to more frequent periodic stakeholder meetings to focus on specific topics of interest as discussed below.

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Advanced Reactor Reference Materials

Date Issued Topic Author Affiliation
06/30/20 Human Factors Considerations for Automating Microreactors Sandia National Laboratories
05/31/20 Technical Letter Report on The Assessment of Tritium Detection and Control in Molten Salt Reactors: Final Report Argonne National Laboratory
04/01/20 Technical and Licensing Considerations for Micro-Reactors Sandia National Laboratories
03/31/20 Model Materials Controls and Accounting Plan for Pebble Bed Reactors Oak Ridge National Laboratory
02/05/20 Regulatory Review of Micro-Reactors – Initial Considerations Brookhaven National Laboratory
01/30/20 Simplified Approach for Scoping Assessment of Non-LWR Source Terms Sandia National Laboratories
08/09/19 Hazards Associated with Molten Salt Reactor Fuel Processing Operations Presentation Oak Ridge National Laboratory
08/07/19 Metal Fuel Fabrication Safety and Hazards Presentation Pacific Northwest National Laboratory
06/30/19 Review of Hazards for Molten Salt Reactor Fuel Processing Operations Oak Ridge National Laboratory
06/28/19 Metal Fuel Fabrication Safety and Hazards Final Report Pacific Northwest National Laboratory
06/19/19 Advanced Reactor Siting Policy Considerations Oak Ridge National Laboratory
06/10/19 NRC Regulatory History of Non-Light Water Reactors (1950-2019) Brookhaven National Laboratory
03/31/19 Advanced Non-Light-Water Reactors Materials and Operational Experience NUMARK Associates
03/31/19 Technical Gap Assessment for Materials and Component Integrity Issues for Molten Salt Reactors Oak Ridge National Laboratory
11/30/18 Molten Salt Reactor Fuel Qualification Considerations and Challenges Oak Ridge National Laboratory
08/21/18 Phenomena Important in Liquid Metal Reactor Simulations Brookhaven National Laboratory
05/09/18 Phenomena Important in Modeling and Simulation of Molten Salt Reactors Brookhaven National Laboratory

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Non-LWR Analytical Code Development

In support of IAP Strategy 2, the staff prepared a three-volume report to describe computer code needs, current capabilities, and gaps relevant to non-LWR confirmatory and future (beyond initial licensing) safety analysis. The reports identify candidate computer codes, the decision criteria and technical rationale applied to the selection process, and specific development activities needed to address known gaps. On May 1, 2019 and September 17, 2019, the staff briefed the Advisory Committee on Reactor Safeguards (ACRS) Future Plant Design Subcommittee on its plans for development of codes for non-LWR analysis. On October 3, 2019, the staff briefed the ACRS full committee on the role of computer codes in regulatory activities and needs for advanced reactor reviews and codes the staff intends to develop. On November 4, 2019, the ACRS transmitted a letter containing its conclusions, recommendations and constructive feedback on the staff's code development strategies. On January 30, 2020 the NRC published the final version of these reports taking into account ACRS and stakeholder feedback.

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Periodic Stakeholder Meetings

The NRC holds periodic stakeholder meetings to discuss non-LWR topics of interest. The following table lists the meetings that NRC has conducted to date in connection with this initiative:

Date Description
6/18/20
6/12/20
6/11/20
5/07/20
4/22/20
4/02/20
02/20/20
12/12/19

10/10/19
08/15/19
06/27/19
03/28/19
02/07/19
12/13/18
09/13/18
07/26/18
06/14/18
05/03/18
02/01/18
12/14/17
11/02/17
09/28/17
08/03/17
06/22/17
05/3-4/17
03/22/17
02/02/17
12/15/16
10/25/16
07/27/16

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Pre-Application Activities

Below is a summary of non-LWR reactor designers that have formally notified the NRC of their intent to engage in regulatory interactions. There are several more potential pre-applicants that participate in various industry activities that could be added to this list once they formally engage with the NRC.

Developer Pre-application information RIS response Technology
General Atomics General Atomics N/A Helium-Cooled Fast Reactor
X-Energy LLC XE-100 1/16/2018 Modular High Temperature Gas-Cooled Reactor
Kairos Power LLC Kairos Power Fluoride Salt-Cooled, High Temperature Reactor (KP-FHR) 3/14/2018 Molten Salt Reactor
Terrestrial Energy USA Ltd Integral Molten Salt Reactor (IMSR) 1/25/2019 Molten Salt Reactor
TerraPower, LLC Molten Chloride Fast Reactor (MCFR) 6/4/2017 Molten Salt Reactor
Westinghouse Electric Company eVinci 6/18/2019 Micro Reactor

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Related Documents

Over the years, a number of Commission papers and Commission Policy statements have been written on various topics related to licensing of advanced reactors. The staff has assembled a collection of these documents spanning from 2001 to the present. The staff has also assembled a list of stakeholder position papers identifying stakeholder documents that communicate opinions to the staff on technical or policy issues.

Page Last Reviewed/Updated Wednesday, June 24, 2020