US firm gets funds to make mini nuclear reactors using old ship design

Last Energy Inc., an Austin-based startup, has raised $100 million in a Series C funding round led by Astera Institute to advance its development of small modular nuclear reactors (SMRs). The company plans to use the funds to complete a 5-megawatt pilot reactor, supported by the U.S. Department of Energy, and accelerate commercialization of its 20-megawatt steel-encased microreactors. These reactors are designed to be mass-produced using off-the-shelf components and factory-style manufacturing, aiming to provide reliable, low-carbon power to approximately 15,000 homes per unit. The startup’s reactor design is based on a decades-old pressurized water reactor concept originally used in the NS Savannah, the first nuclear-powered merchant ship, but updated for modern applications. The reactors are sealed within about 1,000 tons of steel, operate without on-site servicing, and come fully fueled with six years of uranium. This sealed design allows the reactor to remain on site at