NuScale takes a modular approach for building its power plants. Each NuScale Power Module is a self-contained and operates independently of the other modules in a multi-module configuration. However, all modules are managed from a single control room. Using light water reactor (LWR) technology, the NuScale Power Module is cooled by natural circulation, is entirely self-contained and is installed underwater and underground to maximize safety.

The reactor (1), 65' x 9', sits within a containment vessel (2). The reactor and containment vessel operate inside a water-filled pool built below grade. The system uses a convection process, rather than using pumps to circulate water. Water is heated as it passes over the core (3). As it heats up, the water rises within the interior of the vessel. Once the heated water reaches the top of the riser (4), it is drawn downward by water that is cooled passing through the steam generators. The cooler water has a higher density and is pulled by gravity back down to the bottom of the reactor where it is again drawn over the core. Water in the reactor system is kept separate from the water in the steam generator system to prevent contamination.

The basic NuScale Power Module has a thermal capacity of 160 MW_t and electrical capacity of more than 45 MW_e. An 80' x 15' cylindrical containment vessel module contains the reactor and steam generator—a 650-ton unit as shipped from the fabrication shop. Cost is projected to be less than $5,000/kW. The module uses standard LWR fuel in a 17 x 17 configuration, each assembly 2 meters (~ 6 ft) in length, on a 24-month refueling cycle with fuel enriched less than 4.95%.

Our design offers the DOE a plant with innovative new safety features and true scalability from 45MW to 540MW—making it adaptable to fit multiple potential applications. This FOA emphasizes the importance of an SMR technology’s ability to withstand severe natural phenomena, such as a Fukushima-type event. Our plant is designed to safely shut down and self-cool indefinitely in such an event, without AC or DC power or additional water requirements.

—John Hopkins, NuScale’s chairman and CEO

The NuScale design was initially developed in 2000 under a DOE-funded research program and demonstrated in a one-third scale electrically heated test facility in Corvallis, OR, starting in 2003.

NuScale was the first US-based SMR vendor to begin discussions with the US Nuclear Regulatory Commission and has been engaged in pre-application efforts since 2008.

NuScale Power has the backing and technical assistance of Fluor Corporation, a multi-billion-dollar global engineering firm with more than 60 years in the nuclear new-build market. Fluor has designed, built or provided construction support for 20 nuclear units in the US, and provides a full range of procurement and other services to nuclear plant operators worldwide.