After spending years convincing skeptics of nuclear power’s importance, Bret Kugelmass, founder and CEO of Last Energy, says the conversation has shifted. “For the first half decade, I had to explain why nuclear matters,” he told TechCrunch. “Now people just say, ‘Of course nuclear is part of the solution.’”
Last Energy is developing small modular reactors (SMRs)—compact nuclear power plants designed for mass manufacturing to reduce costs. Its commercial reactors are designed to generate 20 megawatts of electricity, enough to power around 15,000 homes.
The company recently closed a $100 million Series C funding round led by the Astera Institute, with participation from AE Ventures, Galaxy Fund, Gigafund, JAM Fund, The Haskell Company, Ultranative, Woori Technology Investment Co., and others. The raise comes amid strong investor interest in nuclear energy, driven in part by surging power demand from data centers. In recent months, Google-backed X-energy raised $700 million, Antares secured $96 million, and Aalo Atomics raised $100 million for its prototype reactor.
What differentiates Last Energy is its design philosophy. Rather than developing an entirely new reactor concept, the company is adapting a proven pressurized water reactor design originally developed decades ago for the NS Savannah, the world’s first nuclear-powered merchant ship. While that reactor was significantly smaller, Last Energy’s modernized version is engineered to deliver 20 megawatts of electricity.
As a first step, the company is building a 5-megawatt pilot reactor at a site leased from Texas A&M. The latest funding will fully finance this pilot and support the rollout of its first commercial units. Last Energy aims to bring the pilot reactor online next year, with commercial-scale production targeted for 2028.
The reactors are designed to be sealed for their entire operating life. Each core is encased in around 1,000 tons of steel, eliminating the need for on-site servicing. The reactors will arrive fueled with six years’ worth of uranium, and heat from fission will be transferred through the steel casing to water pipes that generate steam for power production.
At the end of its operating life, the reactor will remain on site, with the steel enclosure serving as a permanent waste cask, removing the need for separate disposal infrastructure. Kugelmass believes this approach, combined with manufacturing scale, can significantly reduce the cost of nuclear power over time.
“We don’t think in ones and twos,” he said. “We think in tens of thousands.”