Environmental Reviews Should Empower Nuclear Energy, Not Stall It

Environmental regulation is meant to prevent harm. But in the case of nuclear energy, it often indirectly causes it.

Overly narrow or outdated environmental reviews delay or block the deployment of zero-emission nuclear infrastructure, undermining both climate goals and more direct environmental impacts. What’s worse, many reviews ignore the consequences of doing nothing. Inaction is treated as benign, even when it results in increased emissions and pollution stemming from continued reliance on fossil fuels.

That cannot continue. As Congress has made clear through recent reforms to the National Environmental Policy Act (NEPA) and the ADVANCE Act, federal agencies must not only improve the efficiency of environmental reviews, they must also take a more realistic view of the alternatives. That means acknowledging the environmental and public health costs of denying or delaying clean energy projects.

Smarter Reviews, Better Tools

NEPA reviews have long served as a vital guardrail, ensuring that federal decisions don’t result in unchecked environmental damage. Agencies use a tiered approach to environmental reviews under NEPA falling into three main categories, each differing in scope, complexity, and resource demands. The Nuclear Regulatory Commission (NRC), in theory, regulates each project based on the potential environmental impact of the proposed action.

A Categorical Exclusion (CATEX) is the simplest form of review. An action may be "categorically excluded" from a detailed environmental review if the action does not "individually or cumulatively have a significant effect on the human environment." An Environmental Assessment (EA) is a more detailed study conducted to determine whether a full review is necessary; if no significant impact is found, the agency can issue a Finding of No Significant Impact (FONSI). If significant impacts are expected, or if uncertainty remains, the agency must complete a full Environmental Impact Statement (EIS): an extensive, time- and resource-intensive review that thoroughly examines potential environmental effects and alternatives.

The NRC can do a better job of triaging its environmental review process and put more projects into the appropriate lower-threshold buckets, but it also must reform its own regulations. Currently, the NRC is required to perform an EIS for new commercial reactors in 10 CFR 51.20. The NRC needs to change the regulation to comply with the NEPA amendments and select the appropriate level of review.

The NRC could make significant headway in expediting the review process without sacrificing the environment by simply being able to perform an EA when appropriate. EAs are faster, leaner, and often sufficient for projects that are unlikely to result in significant environmental impacts. They can only be used when the agency issues a Finding of No Significant Impact (FONSI), but when applicable, they dramatically reduce review time and resource use.

The NRC’s own data supports this: the EA for the Hermes 2 test reactor was completed in under a year, with 40% fewer staff hours and 60% fewer pages than the Hermes EIS. Now, this example is representative of a new design that is only a test reactor on a known piece of land, but the result is the same; there are no indications in the process that it would not have been successful for a commercial facility on a new site.

In recent years, the NRC has begun to use EAs for a growing number of advanced or non-commercial reactors, as well as for restart licensing, such as the Palisades plant in Michigan. But these examples remain exceptions.

But there is no reason EAs shouldn’t be the default for advanced reactors, license renewals, or projects at previously reviewed sites. These are cases where environmental impacts are already well-characterized or largely unchanged. During a recent Advisory Committee on Reactor Safeguards (ACRS) meeting, NRC staff were questioned about why review time was only reduced by 30% when using an EA for a license renewal, especially when the underlying documentation was up to date. In such cases, the savings should be much greater. EAs for restart projects, in particular, should be limited to evaluating new or significantly changed impacts since the last EIS, rather than rehashing settled issues.

In some cases, even an EA may be unnecessary. For very small reactors or experimental facilities, a CATEX may be sufficient. For example, as microreactor development accelerates, the NRC should finalize a clear definition for microreactor categories and establish new categorical exclusions where justified.

And even when an EIS is necessary, the NRC can reduce work hours and review time by using a Generic Environmental Impact Statement (GEIS). A GEIS can address environmental impacts common across multiple project types. By addressing common environmental impacts generically, rather than on a case-by-case basis for each reactor, a GEIS significantly streamlines the environmental review effort. A site-specific Supplemental Environmental Impact Statement (SEIS) is still required to address unique or less common issues at each specific location. Put together, both would likely require less working time and project delay than a stand-alone EIS.

Used effectively, a GEIS reduces duplication and increases predictability. GEISs have long been used for license renewals; there’s no reason they shouldn’t be applied to new applications as well.

The new Generic Environmental Impact Statement for Licensing of New Nuclear Reactors (NR GEIS) is expected to be publicly published in June 2026. According to the NRC’s regulatory analysis, the NR GEIS can help save 43% of the working hours (15,000 hours reduced to 8,500 hours) and approximately $30 million for the NRC (assuming there are 20 applications during a 10-year period after rule issuance, i.e., 2026-2036). The NR GEIS has the potential to significantly reduce NEPA review effort if appropriately implemented. Industry groups, NGOs, and NRC staff support the wide use of NR GEIS for new applications and the continued use of GEIS for subsequent renewals.

Yet, finalized institutional reforms have been slow to follow. It took the NRC a year after the NEPA amendments to make recommendations to the Commission. Those recommendations remain under consideration. Its issuance came just over a month before the ADVANCE Act was signed into law. Notably, Section 506 of the ADVANCE Act required the NRC to report on its efforts to “facilitate efficient, timely, and predictable environmental reviews of power reactor applications under section 103 of the Atomic Energy Act of 1954, including through expanded use of categorical exclusions, environmental assessments, and generic environmental impact statements.” That will require fixing the NRC’s NEPA practices.

The NRC’s January 2025 report to Congress, as mandated, was a step in the right direction. The report explicitly called for expanded use of EAs, particularly for follow-on projects at previously licensed sites or retiring coal plants where a FONSI is likely. And yet policies are still pending decision and implementation. Commissioner Crowell’s March 2025 vote did support broader use of EAs and GEISs, while calling for meaningful public engagement to be preserved. Chairman Wright similarly emphasized narrowing the scope of reviews to avoid unnecessary delays. But coming up on two years since the NEPA amendments were signed into law, and almost one year since the ADVANCE Act, NRC staff and stakeholders are still waiting for recommendations and decisions from the Commissioners.

No Action Isn’t Neutral

Environmental reviews typically overlook what happens if a project does not move forward. That “no-action alternative” is now central to NEPA, which was amended in 2023 to require that agencies consider the negative environmental impacts of not implementing a proposed action. In the very real case of retiring brownfield sites, repowering with a nuclear project will produce a large net-positive impact. Ignoring the net-positive impacts or ignoring the environmental benefits altogether is against the spirit and letter of NEPA.

In the context of nuclear energy, the consequences of delay or denial are considerable and measurable. The NRC must evaluate the full range of potential environmental, public health, and societal impacts associated with both the proposed alternatives and the no-action alternative. The NRC must also consider the overall benefit to society of each project when it comes to the environmental review, in compliance with the ADVANCE Act Section 501 and the newly revised NRC mission statement.

When the NRC prepared a SEIS for license renewal at California’s Diablo Canyon plant, it concluded that extending operations would have only a small environmental footprint. The review ignored the downsides of shutting the plant down: greater reliance on natural gas, higher greenhouse gas emissions, increased energy prices, and reduced grid reliability. These considerations should have been central to the analysis.

Likewise, the draft Environmental Assessment for restarting Palisades, a shuttered reactor in Michigan, correctly concluded that restarting the plant would not significantly harm the environment. The review correctly understood that alternative facilities would require additional time and cost, no matter what kind. However, the review did not fully evaluate other factors that contribute to the costs and benefits of alternative options. The review could have gone further in quantifying what would happen if the restart were denied.

In the case of the Palisades, the nuclear plant provided 15% of Michigan’s clean generation before its closure. Consumers Energy, the regional utility and previous owner of Palisades, stated that it would compensate for the lost generation through energy demand reduction, expanded renewable energy deployment, and the acquisition of natural gas power plants. Since Palisades’ closure, Michigan has relied mainly on increased natural gas. The Indeck Niles Energy Center, utilizing two natural-gas-fired combined cycle turbines, came online July 1, 2022, and Michigan officials touted that “[i]t would more than replace the Palisades.” In 2023, exactly a year after the closure of the Palisades, Consumers Energy began operating the Covert Generating Station, a power station with three natural gas-fired combined cycle turbines. The company has since planned major upgrades to its natural gas infrastructure. The replacement of the Palisades clean generation with natural gas increased Michigan’s greenhouse gas emissions by at least 2.8 million metric tonnes, contributing to over 4% of Michigan’s annual reported greenhouse gas emissions.

The same blind spots appear in the NRC’s draft NR GEIS. The NR GEIS aims to streamline environmental reviews for future nuclear technologies, but it lacks clarity on how to evaluate what happens when new reactors aren’t built. For a rule meant to speed deployment, failing to grapple with that core trade-off is a major oversight.

Bring Environmental Reviews Into the 21st Century

The ADVANCE Act mandated the NRC to modernize its regulatory framework; reforming the environmental review process must be a central focus.

The NRC's January 2025 report to Congress, recent Commission votes, and industry examples all point to the same conclusion: the agency must make broader use of EAs, GEISs, and CATEXs. At the same time, the agency must stop treating the no-action alternative as neutral. Reviews that fail to account for trade-offs constrain efficient and modernized licensing.

Environmental review is a critical safeguard, and it should remain so. But the NRC can uphold high environmental standards while modernizing the process to ensure it is proportionate, predictable, and aligned with today’s energy and climate imperatives. A smoother and more structured environmental review process is needed to enable the next generation of nuclear energy.