NuScale Modular 40 MWe Reactors

NuScale Power is an offshoot of an Oregon State University project financed by Idaho National Labs. The company employs over 40 highly trained professionals, and is working with Kiewit Constructors to develop modular manufacturing and construction plans for NuScale's small reactors.

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. __NuScale
The nuclear reactor and steam generator, also known as the Nuclear Steam Supply System (NSSS), is a self-contained assembly of reactor core and steam generator tube bundles within a single pressure vessel. Throughout the design, every effort was made to employ existing off-the-shelf technologies to minimize, and in many cases eliminate, the need for additional research and development. The primary coolant (water) is moved by natural circulation, eliminating the need for primary coolant pumps and external power. The NSSS and the passive safety heat removal systems are housed within the compact steel containment.

The reactor module, consisting of the containment and its contents, can be entirely fabricated at existing manufacturing facilities in the U.S. As a result, construction can be done on a significantly compressed schedule. Compared to a typical PWR plant, the NSSS parameters are much lower. Thermal rating of the reactor is several times smaller. Coolant pressure and steam pressure is about 50% lower than that of a typical PWR. The power generation system is greatly simplified. It implements a turbine-generator set and condensate/feedwater pump. The entire turbine-generator can be replaced with a spare unit for overhaul. Additionally, NuScale plants will use nuclear fuel assemblies similar to those in today’s commercial nuclear plants. The only difference is the length of the fuel assemblies (6 feet for a NuScale system instead of the traditional 12 feet) and the number of assemblies in the reactor. __NuScale

NuScale is caught in the same Obama Twilight Zone as the rest of the US energy sector.  Despite promises to rejuvenate the US nuclear industry, Obama has done nothing more than talking.  The necessary steps for anyone serious about reforming government energy obstructionism would involve a much needed reform of the US Nuclear Regulatory Commission -- the greatest governmental roadblock to a safer and more abundant US nuclear energy future.

Secondarily, reforming the US tort system and regulatory system to shorten the time of construction of nuclear plants, and to make it harder for frivolous lawsuits to halt expensive projects in the middle of planning and construction.

Obama will take neither of the above steps, because he is not serious.  He is a clownish psychological neotenate, indoctrinated into a quasi-religious dogma of third-world-liberation leftism by his late mother.