NRC approves 77-megawatt reactor while nuclear waste storage remains unsolved

On June 24, 2025, the Nuclear Regulatory Commission approved NPNuScale Power's updated design for a 77-megawatt small modular reactor (SMR) — the company's second design certification, following its initial certification of a 50-megawatt design in 2022. The certification means the design is pre-approved for use at any U.S. site, cutting future project licensing time by up to 30 months by eliminating repetitive safety reviews for individual deployments.

Small modular reactors are nuclear reactors designed to be built in factories and shipped to sites in modules, rather than custom-constructed on-site the way traditional large reactors are. The 77-megawatt scale is roughly one-tenth the capacity of a conventional commercial reactor. Proponents argue SMRs can be deployed faster, at lower upfront cost, and in smaller communities — including data center campuses and industrial sites — that don't need a full gigawatt of power.

The June 2025 certification came under pressure from the Department of Energy and the Trump administration, which had made nuclear power expansion a priority in the context of surging AI data center electricity demand. DOE had proposed streamlining safety review requirements in ways critics said cut corners. NRC commissioners who voted for the certification said the existing safety standard was maintained; environmental and nuclear safety advocates disagreed.

The U.S. has no permanent solution for storing high-level nuclear waste. The Yucca Mountain facility in 🎰Nevada — the only site ever designated for permanent underground nuclear waste storage — has been blocked since 2010, when the Obama administration withdrew the license application after Nevada's congressional delegation and state officials mounted sustained opposition. All U.S. commercial nuclear waste — roughly 90,000 metric tons of spent fuel — sits in temporary on-site storage at reactor sites across the country.

NuScale's commercial viability has faced significant challenges despite its regulatory approvals. In November 2023, the company canceled its first commercial project — a proposed six-reactor plant serving the 🏜️Utah Associated Municipal Power Systems — after projected costs more than doubled from $58 per megawatt-hour to $119 per megawatt-hour. That cancellation left NuScale's U.S. commercial pipeline essentially empty, making the June 2025 certification a regulatory achievement for a technology with no currently scheduled U.S. customer.

The 77-megawatt design certification does not mean a reactor will be built. Under U.S. law, a company seeking to build a nuclear reactor also needs a site-specific Combined License (COL) — a separate NRC process that evaluates geological conditions, evacuation planning, population density, and other site-specific factors. Getting a design certified is step one of a multi-step process. No U.S. site has yet applied for a COL for any NuScale reactor.

Internationally, NuScale is in discussions with clients in Romania, Poland, and several other countries. Romania's Nuclearelectrica and the U.S. Trade and Development Agency signed an agreement in 2023 to develop an SMR site at Doicești — a project backed by U.S. government financing through the Export-Import Bank and the International Development Finance Corporation, with over $3 billion in committed support.

The certification was welcomed by nuclear energy advocates as proof that advanced reactor design can receive regulatory approval in the United States. But it also drew attention to the gap between regulatory approval and actual deployment: the U.S. nuclear industry has not brought a new commercial reactor online since Vogtle Unit 4 in 🍑Georgia in 2024 — a project that was seven years late and roughly $20 billion over budget.