The US Nuclear Regulatory Commission has certified the design for the US’s first-ever small modular nuclear reactor. NRC established a rule allowing NuScale reactor to be used within the US beginning on 21 February 2023. The rule paves the way for companies to construct reactors that require less space, capital, and labor than their conventional counterparts. The design is courtesy of Oregon-based NuScale Power, which has been working to certify a small modular reactor design since 2007. At the NuScale’s core are up to 12 power modules, natural circulation light water reactors that each consisting of a reactor core, a pressurizer, and two steam generators housed in steel. Each of these power modules generates 160 megawatts of thermal output and 50 megawatts of electrical output. The lower portion of each power module is submerged in a below-ground pool that functions as a heat sink, thus precluding the need for emergency diesel generators for power outages or water injectors to cool the reactor after an accident. The NuScale reactor is the seventh nuclear reactor design to achieve certification in the US. The others are all considered conventional nuclear reactors. SMRs are significantly smaller than their conventional predecessors, making them more suitable for geographical locations in which large nuclear plants would not be possible. Their size also translates to easier construction and lower upfront costs, while their modular design allows them to be deployed incrementally as energy demand fluctuates.