Part 53 – Risk-Informed, Technology-Inclusive Regulatory Framework for Commercial Nuclear Plants

Safely Enabling Flexibility, Efficiency, and Innovation

On this page:

• Introduction
• Background
• Major Features of Part 53
• Reference Information

Introduction

Title 10 of the Code of Federal Regulations (10 CFR) Part 53 establishes a risk-informed, performance-based, and technology-inclusive regulatory framework as an alternative for the licensing and regulation of commercial nuclear plants. This framework leverages risk insights and features a prominent role for probabilistic risk assessment (PRA), other systematic risk evaluations (SREs), or combination thereof—an approach largely based on the U.S. Department of Energy (DOE) cost-shared and industry-led Licensing Modernization Project (LMP) methodology. Part 53 enables –

• Flexibility: design and operational features can be tailored to meet the needs of an application
• Efficiency: use of risk insights allows a focus on issues most important to safety and applicability of requirements reduces the need for exemptions
• Innovation: supports any technology and provides a variety of licensing options to meet applicants’ deployment models

Risk-Informed

• Provides a holistic approach that explicitly considers risk insights using flexible methods (i.e., PRA, other SREs, or a combination thereof) to assess and manage risks.
• Supports leveraging safety margins and focusing on those aspects of a design and its operation that are important to protecting public health and safety.

Performance-Based

• Promotes efficiency and innovation by allowing applicants to propose design features to meet safety objectives and achieve safety outcomes rather than prescribing specific methods or processes.

Technology-Inclusive

• Provides a broad and flexible regulatory framework that can be used for any reactor technology, any size reactor, and any commercial end-use.

Background

Many factors contributed to the initiation and development of Part 53 including decades of policy development, regulatory initiatives, legislative direction, and stakeholder interactions.

The NRC has long recognized that the licensing and regulation of a variety of nuclear reactor technologies presents challenges because the existing regulatory framework has evolved primarily to address the light-water reactor (LWR) designs that compose the current operating fleet. The NRC has had many interactions with designers of various reactor technologies under development, sometimes collectively referred to as advanced reactors. The interactions have informed the development of policies and guidance, including the LMP methodology, to support the potential licensing of new and different types of reactor facilities, some of which may not use LWR designs.

The NRC issued its Advanced Reactor Policy Statement to provide all interested parties, including the public, with the Commission’s views concerning the desired characteristics of advanced reactor designs. The NRC further described its early efforts to establish a technology-inclusive approach to the regulation of nuclear reactors in the advance notice of proposed rulemaking published in 2006. The NRC acknowledged in its “Report to Congress: Advanced Reactor Licensing,” issued August 2012, that “while the safety philosophy inherent in the current regulations applies to all reactor technologies, the specific and prescriptive aspects of those regulations clearly focus on the current fleet of LWR facilities.”

The passage of the Nuclear Energy Innovation and Modernization Act (NEIMA) directed the NRC to complete a rulemaking establishing a technology-inclusive regulatory framework for optional use by commercial advanced nuclear reactor applicants seeking new reactor licenses. The Accelerating Deployment of Versatile, Advanced Nuclear for Clean Energy (ADVANCE) Act of 2024 later amended NEIMA and reinforced the need for a regulatory approach capable of accommodating a variety of innovative nuclear technologies.

Major Feature of Part 53

Major provisions of this final rule include the following:

• Flexible use of risk methodologies: 10 CFR 53.450 includes explicit consideration of risk through the use of PRAs, other SREs, or a combination thereof to generate risk insights and to assess and manage those risks.
• Generally licensed reactor operators (GLROs): For self-reliant mitigation facilities, GLROs are allowed to perform duties under the provisions of a general license that is effective without the filing of an application with the Commission or the issuance of licensing documents to a particular person (see §§ 53.800 through 53.820).
• Alternative siting criteria: 10 CFR 53.530 provides an alternative to the NRC’s preference for siting reactors in areas of low population density which allow siting in areas of higher population densities or within a densely populated center containing more than about 25,000 residents based on assessments of societal risk in comparison with societal benefits.
• Factory loading of fuel into manufactured reactors: 10 CFR 53.620 includes provisions that allow for the loading of fuel into a manufactured reactor at the manufacturing site for subsequent transport to a commercial nuclear facility that will operate pursuant to a combined license or operating license.
• Expanded use of consensus codes and standards: 10 CFR 53.440 allows the use of generally accepted codes and standards to be tailored to the safety significance of structures, systems, and components (SSCs), such as the use of non-nuclear codes and standards for SSCs composed of commercial grade components.
• Departure from the single failure criterion: The single failure criterion in Appendix A to 10 CFR Part 50 relates to the loss of capability of a component to perform its intended safety functions, without explicitly considering the component’s risk significance or its importance to the overall safety case. The single failure criterion is not a requirement under 10 CFR Part 53 because a holistic risk-informed approach, including risk evaluations, defense-in-depth considerations, and performance monitoring, ensures that performance objectives are met with appropriate consideration of reliability and consequences.
• No traditional aircraft impact assessment requirement: Applicants under 10 CFR Part 53 perform a comprehensive assessment of their reactor design, which includes assessment of a full spectrum of unplanned events. As such, the systematic evaluations of internal hazards, external hazards, and security threats under 10 CFR Part 53 and 10 CFR Part 73 sufficiently address the potential loss of large areas of the plant and applicants will have considered how to mitigate the broader potential plant impacts that may result from an event such as the impact of a large aircraft. Other regulations such as the siting requirements under 10 CFR Part 100 also address hazards from aircraft accidents to determine whether those hazards should be considered in the design basis.
• Reduces the future need for regulatory approvals: The risk-informed approach for managing plant equipment and programmatic controls provides opportunities to improve regulatory efficiency.
• Functional containment: This concept can be implemented under Part 53, which as described in SECY-18-0096, is taken as a barrier or a set of barriers taken together, that effectively limits the physical transport of radioactive material to the environment.
• Reduced staffing levels: Allows for new technologies involving concepts of operations that are more conducive to customizable licensed operator staffing requirements.
• Remote operations: Removal of the “onsite” limitation to include activities performed both within the owner-controlled area as well as operations and maintenance duties performed at remote facilities where safety-significant systems and components are expected to be operated within the design basis of the commercial nuclear plant.
• Load following: 10 CFR 53.740 allows for, with appropriate measures in place, plant output to automatically change to match expected demand in response to externally originated instructions or signals.
• First-of-a-kind (FOAK) licensing provisions: Allows an application for either a standard design approval or a standard design certification to reference appliable licensing-basis information that supported issuance of an operating license or combined license under Part 53 (see 10 CFR Part 53, Subpart H).
• Standardized design benefits: Finality of standard design approvals and information requests extends to a standard approval referenced in a standard design certification application (see 10 CFR Part 53, Subpart H).
• Fitness for Duty: A new risk-informed, performance based, and technology-inclusive alternative framework in 10 CFR Part 26, “Fitness for Duty Programs,” that introduces flexibilities for conducting drug testing and the use of innovative drug and alcohol screening technologies, and accommodates a wide variety of sites, including those with small staff sizes and that are remotely located.
• Physical Security: A new performance-based and technology-inclusive alternative security framework in 10 CFR Part 73, “Physical Protection of Plants and Materials,” that includes the use of graded and flexible performance requirements for protection of licensed activities at commercial nuclear plants.

Reference Information

• Key documents related to the Part 53 rulemaking, including the proposed rule, associated draft guidance documents, and stakeholder comments, can be found at Regulations.gov under Docket ID NRC-2019-0062