Pre-application Process
The early regulatory timeline for an application for a proposed reactor facility is:
Each of the steps discussed below is an important component of the pre-application process.
Letter of Intent
A company’s letter of intent formally notifies the NRC an application is coming for a major licensing action on commercial nuclear power generation facilities at a specific site. The letter outlines the project’s scope (which may include advanced reactors or other energy systems) and the company’s projected timeline for the initial phases of development. The letter commits to engaging with the NRC throughout the pre-application and application processes and requests a project number for tracking NRC interactions with the application. While a letter of intent is voluntary, it does signify the seriousness of the applicant to the NRC staff.
Examples:
Project Number Creation/Electronic Billing
NRC staff create a project number to identify the applicant and to set up fee billing. A project number will also be issued, and fee billing started, even without a letter of intent, if the applicant requests NRC feedback on any subject or submittal.
Regulatory Engagement Plan
Applicants should develop a Regulatory Engagement Plan (REP). For more information, see the REP subpage.
Kickoff Public Meeting
A kick-off meeting is held to allow the applicant to introduce their project to the NRC staff as a whole and to the public.
Pre-Application Activities
The NRC encourages applicants to engage with the NRC staff early and often on their technology and facility design. The NRC guidance for pre-application engagements is found in Appendix A of the Interim Staff Guidance DANU-ISG-2022-05, “Review of Risk-Informed, Technology-Inclusive Advanced Reactor Applications—Roadmap,” that provides a list of the recommended pre-application topics. While this guidance focuses on non-light water reactor technologies, the document, especially the environmental sections, generally applies to all reactor technologies.
NRC pre-application activities mainly occur through three processes: white papers/technical reports, topical reports, and readiness assessments.
- White Papers/Technical Reports – white papers request NRC feedback on technical, programmatic, regulatory, or administrative topics that may involve challenging issues, describe new/novel approaches, involve policy issues that require Commission involvement, or are technical areas that applicant/vendors have little experience. Technical Reports address application-specific technical safety topics and are generally intended to support and augment information contained in the application, typically in the preliminary or final safety analysis reports.
- Topical Reports – requests NRC staff’s review and approval of singular, but critical, technical issues.
- Readiness Assessments - assess the readiness of a draft application, such as a design certification, combined license, early site permit, construction permit, or operating license.
Public Outreach Meeting
When the application’s submission date is near, a large public meeting is held in the vicinity of the proposed reactor site to introduce the project to the public.
Applications
Two significant decisions must be made when submitting an application for a reactor facility. The applicant must determine the:
- Type of license
- Regulatory pathway
License Types
Two types of licenses for nuclear reactors are identified in Sections 103 and 104 of the
Atomic Energy Act of 1954, as amended. The implementation regulations for the two types of licenses are found in 10 CFR 50.21, “Class 104 licenses; for medical therapy and research and development facilities,” and 10 CFR 50.22, “Class 103 licenses; for commercial and industrial facilities.”
- Class 103 – This license type is for a commercial reactor or industrial facilities. All electricity-generating reactor facilities today have this license type, as do facilities made to generate radioactive isotopes for commercial purposes.
- Class 104(c) – This license type is for a production or utilization facility useful in the conduct of the types of research and development activities related to:
- Nuclear processes;
- The theory and production of atomic energy, including processes, materials, and devices related to such production;
- Utilization of special nuclear material and radioactive material for medical, biological, agricultural, health, or military purposes;
- Utilization of special nuclear material, atomic energy, and radioactive material and processes entailed in the utilization or production of atomic energy or such material for all other purposes, including industrial or commercial uses, the generation of usable energy, and the demonstration of advances in the commercial or industrial application of atomic energy;
- The protection of health and the promotion of safety during research and production activities;
- The preservation and enhancement of a viable environment by developing more efficient methods to meet the nation‛s energy needs.
Additionally, per the Atomic Energy Act of 1954, as amended, class 104(c) facilities must also meet the requirement that not more than 75 percent of the annual cost of owning and operating the facility are devoted to the sale of nonenergy services, energy, or a combination of both nonenergy services and energy; and not more than 50 percent of the annual cost of owning and operating the facility are devoted to the sale of electricity. All other activities must be research and development or education and training.
Regulatory Pathway
As detailed in the DOE GAIN video series, there are currently two separate pathways to license a nuclear reactor under the regulations in 10 CFR. These two regulatory pathways are:
A third pathway is currently under development in the rulemaking process, but not yet available for use:

Part 50
The regulations in 10 CFR Part 50 discuss a two-step process for receiving a license to operate a nuclear reactor. The first step of that process is a construction permit, that when issued, permits the applicant to build the facility but not operate.
To obtain a construction permit, the applicant must submit a:
- Preliminary Safety Analysis Report
Describes the preliminary design and safety features of a proposed nuclear reactor facility.
- Environmental Report
Describes the impacts of the proposed facility on the environment and how the facility meets all applicable environmental laws and regulations
- Antitrust and other Financial Information
The NRC will review each of the documents to determine that they provide reasonable assurance of adequate protection of public health and safety and to promote the common defense and security and to protect the environment. Once the process for construction permit reviews are complete, including multiple steps such as
ACRS review and a hearing, the permit is issued and the applicant may start building the facility.
During the construction of the facility, the applicant finalizes the design and submits an application for an Operating License.
An Operating License application includes many additional technical documents, including:
- Final Safety Analysis Report
Describes the installed design and safety features for the facility. Updates to the Environmental Report, if applicable
- Technical Specifications
Establishes the facility-specific requirements for plant operation, specifically the safety limits, limiting safety system settings, limiting control settings, limiting conditions for operation, surveillance requirements, design features, and administrative controls.
- Fire Protection Plan
- Security Plans
- Emergency Preparedness Plan
- and a multiple others…
Once the facility construction is complete, and the NRC completed its review without open items, the operating license can be issued.
The two-step Part 50 license process provides flexibility for the applicant because no design information provided by the applicant in a construction permit application is considered final (unless the applicant requests so) and can be modified during the construction process. This modified design or changed information will be presented in the operating license application for NRC review and approval before the facility can start operation.

Part 52
Combined License
The second regulatory pathway for obtaining a license to operate a nuclear reactor facility is detailed in Part 52 of 10 CFR. This process, called a combined license (COL), requires all required facility information to be submitted at the very beginning. This process reduces the risk for applicants, in comparison to the Part 50 license process where a design change from the construction permit to the operating license application may not be approved by the NRC. However, because all information is provided at the beginning, Part 52 applications reduce flexibility for applicants because many proposed changes during the construction process may require NRC approval. Once a COL is approved, construction can start and many construction verifications, called ITAAC, are completed by the COL holder to verify that the plant was constructed and will operate as designed.
COL applications must be submitted as a class 103 license. Class 104(c) licenses for research and test reactors must be submitted through the Part 50 licensing process.
Part 52 contains the additional types of licensing processes described below. These additional approvals may be applied to a COL application to shorten the NRC review of the application.
Design Certification
The NRC may approve and certify a standard nuclear plant design through a rulemaking, independent of a specific site. The design certification is valid for 15 years. A design certification application must contain proposed inspections, tests, analyses, and acceptance criteria (ITAAC) for the standard design. The application must also demonstrate how the applicant complies with the Commission’s relevant regulations.
Standard Design Approval
The NRC staff may provide advance approval of major portions of a nuclear plant design, but not the entire design, thereby preventing re-opening the review for that portion for future COL applications. This approval of this partial design is not certified through rulemaking, so it may not be a permanent approval if circumstances change (i.e., industrial codes updates, changes in laws or regulations, etc.).
Early Site Permit
The NRC may approve one or more sites for a nuclear power facility, independent of an application for a construction permit or combined license. In reviewing an early site permit application, the NRC staff will address site safety issues, environmental protection issues, and plans for coping with emergencies, independent of the review of a specific nuclear plant design.
Manufacturing License
The NRC may approve the ability of an applicant to manufacture a nuclear power reactor at a location that is different from the final operating location of that facility. That final location must be a site for which either a construction permit under Part 50 or a COL has been issued.
Additional basic information on Part 50 and Part 52 licensing frameworks can be found on the Backgrounder on Nuclear Power Plant Licensing Process page and in the document, “A Regulatory Review Roadmap For Non-Light Water Reactors”. Even though this document title mentions non-light water reactors, a majority of the content is applicable for light-water designs.

Part 53
A third proposed pathway for licensing reactors, Part 53, focuses on the new technologies found in advanced reactors and is currently under development for issuance in 10 CFR. The current status for Part 53 can be found on the Part 53 webpage.
