Recently, the U.S. Nuclear Regulatory Commission (NRC) approved the first small modular reactor (SMR) design certification application and NuScale Power is expected to become the first manufacturer to build a new small modular nuclear power plant in the United States.
This is the seventh design approved by the NRC since its inception in 1974 and a SMR, as the name suggests, refers to a small, modular nuclear reactor designed by NuScale to enable large-scale manufacturing of light water reactors in factories and then transported to onsite to build a nuclear power plant relatively quickly and easily.
At the end of April 2018, NuScale obtained a first stage design certification review from the US Nuclear Energy Regulatory Commission. Now, it has obtained approval and is expected to become the first small modular nuclear reactor nuclear power program in the United States.
NuScale small nuclear reactors are light water reactors. Compared with heavy water reactors, light water is cheaper and has high deceleration efficiency. Each reactor is about 20 meters high, 2.7 meters in diameter, and each has a capacity of about 77MW. A single control room can operate 4~12 small nuclear reactors at a time, so the capacity of the whole power plant falls between 308~924MW.
Similar to many SMRs, NuScale emphasizes safety. In an emergency, it can be safely shut down without human operation or power requirements. After the feedwater and steam outlet valves are closed, a second set of valves opens, allowing steam to escape from the reactor. The core is depressurized into a containment vessel surrounding the reactor and the steam condenses and returns to the core, repeating the cycle.
This design, NuScale says, allows the plant to remain in a stable and safe shutdown state, providing a last line of defense for the giant water tanks and concrete containment that house the reactor modules if any catastrophic problems arise.
The first NuScale small modular nuclear power plant is expected to start generating electricity in 2029 and six reactors at the Idaho National Laboratory will come online in 2030 with a total capacity of about 462 MW, of which utility companies have already completed a large part of a 40-year power purchase contract.