How NuScale Technology Works

Each NuScale Power Plant is self contained and each module operates independent of the other in a multi-module configuration. However, all are managed from a single control room.

The reactor pressure vessel (1) measures 45 x 9. It sits within a containment vessel (2). The integrated Reactor and Containment Vessel operate inside a water-filled pool (3) that is built below grade.

The NuScale reactor operates using the principles of natural circulation. No pumps are needed to circulate water through the reactor  Instead, the system uses a convection process. Water is heated as it passes over the fuel or core (4). 

As it is heated the water rises within the interior of the vessel.  Once the heated water reaches the top of the riser (5), it is drawn downward by water that is cooled passing through the steam generators (6).  The cooler water has a higher density.  It 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 and the Steam Generator system are kept separate.  As the hot water in the reactor system passes over the hundreds of tubes in the Steam Generators, heat is transferred through the tube walls. 

Water inside the tubes turns to steam.  The steam turns turbines (7) which are attached by a single shaft to the electrical generator.

After passing through the turbines, the steam losses its energy.  It is cooled back into liquid form in the condenser (9) then pumped by the feed water pump (10) back to the steam generator (6), where it begins the cycle again.