Up & Atom

The NRC (or the Commission) issued a proposed rule on February 26, 2026 to regulate commercial fusion under its byproduct material framework rather than as a traditional nuclear power reactor. These regulations aim to provide regulatory certainty at a pivotal commercialization phase for fusion, reducing ambiguity and regulatory burdens for capital providers and developers. The proposed rule implements the Commission’s 2023 decision to select the byproduct material pathway instead of utilizing facility or hybrid approaches.

Key Takeaways

The NRC’s proposed rule does the following:

• Regulates fusion under a byproduct material framework, which is performance-based, technology-inclusive, risk-informed, and less prescriptive than regulations for power reactors
• Focuses on hazards related to radiological materials, which supports a performance-based, flexible licensing path
• Requires license applications to address design, radiation protection, materials handling, organizational safety, training, maintenance, and accounting, with room for alternative approaches
• Requires environmental review, but often via an Environmental Assessment (EA); the more detailed Environmental Impact Statement (EIS) will be required only where warranted
• Includes no new export controls

Background

Fusion developers have long faced a threshold question of how technology will be regulated. In 2009, the NRC asserted that it has regulatory jurisdiction over commercial fusion energy devices where the device would be of significance to the common defense and security or could affect the health and safety of the public. However, the Commission directed the NRC staff to wait until the commercial deployment of fusion technology became more predictable before expending significant resources to develop a regulatory framework. The NRC staff considered the following three regulatory pathways:

1. Regulate as a utilization facility (like a fission reactor)
2. Regulate under the byproduct material framework
3. Adopt a hybrid approach

The NRC emphasizes that fusion and fission are fundamentally different because the fusion process does not involve fissile material or a self-sustaining chain reaction, and the process would cease if confinement were lost. The NRC does not expect that fusion facilities will generate decay heat requiring engineered emergency cooling, which allows the NRC to shift the regulatory focus to radiological materials management. Key hazards for fusion include tritium fuel, neutron activation products in structures, and activated dust and components; these hazards align with risks currently managed by materials licensees. Because these risks fit existing materials regulatory practices, the Commission concluded fusion is more appropriate within Part 30 of its regulations (10 CFR Part 30) and thereby adopted the second option.

This choice to regulate under the byproduct material framework is advantageous for developers because it is performance-based, technology-inclusive, risk-informed, and ultimately less prescriptive than power reactor licensing under Parts 50 or 52 of the NRC’s regulations. By framing the regulatory approach as a materials issue, the NRC’s proposed rule reduces the risk for project financing and preserves technology flexibility.

Core Provisions of the Proposed Rule

The proposed rule would add a formal definition of “fusion machine” and update the definition of “byproduct material” to include radioactive material generated by, or made radioactive by use of, a fusion machine, resolving jurisdictional uncertainty as required by Section 205 of the ADVANCE Act of 2024. A “fusion machine” means “a machine that is capable of—(1) transforming atomic nuclei, through fusion processes, into different elements, isotopes, or other particles; and (2) directly capturing and using the resultant products, including particles, heat, or other electromagnetic radiation.”

The proposed rules would establish a tailored license application process for fusion machines at 10 CFR Section 30.32(k). Applicants must describe the fusion machine design, radiation protection systems, radioactive material handling and inventory controls, organizational and radiation safety structure, training, inspection and maintenance plans, and radioactive material accounting methodology. The proposed rule would preserve design flexibility by allowing alternative technical approaches if applicants demonstrate safe operation. It also would amend recordkeeping requirements to cover production, requiring licensees to keep records showing production, receipt, transfer, and disposal, with retention periods specified, and recognizes the complexity of calculating total quantities (including production and decay), allowing computational methods as discussed in draft guidance. The NRC’s regulatory engagement will center on radiological risk management rather than the traditional power reactor-style safety analysis.

An applicant must submit an environmental report unless a categorical exclusion applies. Where an environmental report must be prepared, the NRC will prepare either an EA if it expects no significant impacts with a potential Finding of No Significant Impact (FONSI) or an EIS if an EA cannot support a FONSI or if the Commission directs that an EIS be prepared. An EIS, however, is not prepared by default and will be required only where warranted.

For waste, the NRC recognizes fusion may produce activation products not contemplated in the 1980s low-level waste tables and proposes two paths. Waste must either be analyzed and labeled within existing classifications or disposed of at a facility with a site-specific intrusion assessment showing inadvertent intruder dose at or below 0.5 rem per year. This approach aims to avoid licensing delays while maintaining safety.

Although byproduct material security requirements in Part 20 and Part 37 continue to apply, the NRC notes that tritium is not considered a risk‑significant radionuclide for Part 37 purposes and that activation products from fusion may not be listed in Appendix A to Part 37. For radionuclides not listed, the NRC will determine on a case‑by‑case basis whether additional security measures are warranted (e.g., via license conditions or orders), particularly where structural materials create new radionuclides of concern through activation.

The NRC does not propose new export controls for fusion machines, keeping primary jurisdiction with the US Department of Commerce (DOC) and aligning with international safeguards frameworks. The NRC maintains control over tritium and other byproduct material for export.

The NRC also is not proposing changes to requirements for decommissioning and financial assurance on the grounds that the existing regulations already provide the needed flexibility based on the quantity of radioactive material remaining at the facility at the end of life. The NRC notes that current regulations already offer fusion machine applicants a clear pathway to determine the appropriate level of financial assurance for decommissioning their facility and to fund decommissioning using a financial instrument that aligns with their business model and needs.

Implications for Investors and Developers

By regulating fusion facilities under byproduct material rules rather than as power reactors, the NRC is reducing the traditional burdens of Part 50 of its regulations. The framework is technology-inclusive and performance-based, preserving design optionality across multiple confinement approaches.

Key benefits of the NRC’s approach include:

• The proposal materially reduces the risk for financing by framing the regulatory approach as a materials regulation challenge and preserving technology flexibility
• Environmental review will be required but will not automatically trigger an EIS, which can streamline the permitting process and reduce the permitting timeline relative to large reactors
• Waste disposal appears manageable under the proposed flexible pathways options for activation products
• Export controls remain under DOC’s jurisdiction, supporting the administration’s international partnerships and supply chain strategies; the timing aligns with anticipated late-2020s demonstrations and early-2030s deployments, reinforcing commercial planning assumptions

When structuring projects under the proposed rule (or providing comments on the implications of the proposed rule on project development), developers should consider the following:

• The performance-based nature of Part 30 suggests diligence should prioritize radiation protection systems, tritium handling, and activation product management as central underwriting risks
• The framework’s technology inclusivity permits many different approaches without incurring substantial regulatory disadvantage by architecture; developers may benefit from modular and mass-manufacturing strategies
• License application materials aligned with 10 CFR § 30.32(k) would include detailed design descriptions, radiation protection systems, material accounting, organizational safety structures, training programs, and maintenance plans
• Developers should consider how activation product streams would map existing waste classes and identify disposal facilities capable of site-specific intrusion assessments at the 0.5 rem per year threshold; because activation products may challenge legacy waste classifications, securing relationships with disposal facilities capable of site-specific assessments will preserve schedule certainty
• Siting strategies should account for NEPA review scope by selecting locations likely to support EA-level reviews and by engaging early with state and local stakeholders to streamline environmental data collection; early definition of radioactive material accounting methodologies and tritium inventory controls can accelerate NRC review and build investor confidence in operational controls
• Export planning should leverage the stability of DOC-led controls to develop international supply chains and demonstration partnerships, with compliance frameworks aligned to current safeguards

Next Steps

Comments on the proposed rule are due by May 27, 2026. The NRC seeks comments on the clarity of its Section 30.32(k) application process, the thresholds for determining the appropriate environmental review, proposed waste pathways, and alignment with other NRC guidance documents. The NRC has also released for comment draft licensing guidance in NUREG-1556, Volume 22 (Consolidated Guidance About Materials Licenses: Program-Specific Guidance About Fusion Machine Licenses).

The NRC will conduct at least one public meeting to discuss the proposed rule and to facilitate public comments.

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