Up & Atom


The NRC released a draft white paper discussing options to streamline its regulatory licensing process for microreactors. Specifically, the NRC Staff is “considering strategies to streamline the license review process by maximizing standardization and finality through the use of design certification, standard design approval, and topical report approvals” under 10 CFR Part 52, and is focusing on the following areas:

  • Enhanced standardization of the design (e.g., through using bounding design parameters in early site permits, bounding site parameters in design certification, and a minimal set of site-specific design features)
  • Using a manufacturing license to gain potential efficiencies at the combined construction and operating license (COL) stage, accompanied by other regulatory requirements, such as possession of special nuclear material and transportation
  • Strategies to review operational matters (e.g., technical specifications and operational programs) at the design stage, either as part of the design approval (to the extent allowed under Commission policy), through topical reports, or through a design-centered review approach, in which the Staff would review operational matters for the first micro-reactor application of a particular design and apply that review to similar subsequent applications
  • Rulemaking efforts to streamline the environmental reviews of advanced reactor applications


Microreactors are typically defined as a subset of advanced non-light water reactors that have small site footprints. In October 2020, the NRC issued SECY-20-0093 to address certain regulatory and policy issues associated with licensing microreactors. The new draft white paper is a follow-up to that SECY and to additional stakeholder feedback, which the NRC intends to use to “support potential commercial deployment of micro-reactors, including so-called fission batteries” which will “allow for the deployment of large numbers of such reactors.”

NRC Recommendations

The Staff proposes working toward standardization in several areas, mostly under 10 CFR Part 52: the design certification (DC) process, the COL process, operational programs, manufacturing licenses, possession and transportation of special nuclear material, external hazards and siting, and environmental reviews.

Design Certification and COL Processes      

The Staff found that it could maximize standardization through DC and COL processes under the following conditions:

  • No site-specific design features are relied on for safety.
  • COL action items are not used.
  • Bounding site parameters, including hazard parameters, are selected during design to minimize review at COL stage.
  • Operational programs are reviewed, if appropriate, at the design stage.
  • COL applications are fully standardized.
  • The advanced nuclear reactor generic environmental impact statement (ANR GEIS) is leveraged to streamline the environmental review.

Operational Programs

The Staff divided operational programs into two groups: Group 1, which consists of programs that are material to the adequacy of design, such as technical specifications and design quality assurance; and Group 2, which consists of programs that are not material to the adequacy of design, such as emergency planning and security.

Regarding Group 1, the Staff found that “neither 10 CFR Part 52 nor the [Atomic Energy Act] precludes resolution of Group 1 requirements through design certification” and that the “regulations in 10 CFR Part 52 do not require the design certification to include information on the inservice inspection or inservice testing programs.” Of note, the Staff pointed out that it did not give the same degree of finality to Group 1 requirements when it completed the advanced boiling water reactor design certification rule more than two decades ago. The Staff also noted that, although it “is exploring options to provide finality to technical specifications at the design certification stage to further streamline the COL review,” this change “to the degree of finality provided in a design certification for Group 1 programs would constitute a policy change and would require Commission approval.”

Regarding Group 2, the Staff found that the Commission would “need to settle several significant policy questions” to resolve these requirements through design certification. The Staff also said that it is considering addressing these policy issues as part of the ongoing 10 CFR Part 53 rulemaking effort, but that under the current regulatory framework, “to streamline micro-reactor licensing, a vendor may address Group 2 programs in a topical report(s) proposing standardized operational programs.”

Manufacturing Licenses

We have been urging the adoption of manufacturing licenses to streamline the NRC licensing process, so we are pleased to see the Staff place some focus on this option. The Staff found that manufacturing licenses “could be incorporated into licensing strategies that cover stationary micro-reactors built in a factory and transported to a licensed site, with no fuel loaded at the manufacturing site,” which would “reduce the need for site-specific inspections and verifications.” It also found, however, that “separate licenses will be necessary for transporting a fueled reactor from a manufacturing facility to a preapproved site and for initial testing and performing preoperational testing of a reactor with fuel in a manufacturing facility,” and that “scenarios involving starting and testing a reactor in the factory under a manufacturing license are beyond the current scope of the 10 CFR Part 53 rulemaking, because an OL or COL would be required for operation of a reactor at the manufacturing site.

Possession and Transportation of Special Nuclear Material

The Staff also noted that certain vendors are considering manufacturing and assembling reactor components, fueling the reactor in a factory, transporting the fueled reactor to approved sites, and possibly transporting the reactor containing spent nuclear fuel back to the factory. Such vendors would have to consider other applicable regulations located at 10 CFR Parts 30, 40, 70, 71, 73, and 74, as well as certain Department of Transportation regulations.

External Hazards and Siting

The Staff also outlined external hazards and siting requirements that could be streamlined. The Staff noted that if a “design certification identifies parameters that the design is insensitive to or that can be bounding for a number of predetermined COL sites, then this will eliminate or reduce the level of effort required at the COL stage.” The Staff also included a helpful hazard screening flow diagram.

Environmental Reviews

To meet requirements set out by the National Environmental Policy Act (NEPA) and other statutes, the Staff must perform a review under 10 CFR Part 51. The Staff listed several options for streamlining the environmental review for microreactors, including the following:

  • The recent issuance of guidance to applicants and NRC Staff on the conduct of environmental reviews for advanced non-LWRs and microreactors
  • Development of a GEIS for advanced nuclear reactor applications
  • A proposed rulemaking to codify the generic findings of the ANR GEIS
  • A potential rulemaking to streamline 10 CFR Part 51, including a potential revision to allow the NRC to prepare an environmental assessment for certain types of reactor applications rather than an environmental impact statement

Morgan Lewis will continue to follow the Staff’s efforts to streamline the licensing process and will report on future updates.