Visit the 325 MWe General Atomics GT-MHR   http://gt-mhr.ga.com/ 

(This is a commercial product.  It's best if I let them do the talking.)

GT-MHR
(General Atomics)
Synonyms: Gas Turbine Modular Helium Reactor, Freedom Reactor (Entergy trademark)
Approximate Capacity (electric): 285 MWe
Reactor Type: High temperature gas-cooled reactor (HTGR)
NRC Design Certification Status: Pre-application review.
Supporting Generating Companies: Entergy (development only)
The GT-MHR is an HTGR developed by the U.S. firm, General Atomic. The most advanced plans for GT-MHR development relate to building reactors in Russia to assist in the disposal of surplus plutonium supplies. Parallel plans for commercial power reactors would use uranium-based fuels enriched to as high as 19.9 percent U-235 content. This would keep the fuel a fraction below the 20 percent U-235 enrichment that defines highly-enriched uranium. The U.S. utility, Entergy, has participated in GT-MHR development and promotion and uses the name "Freedom Reactor" for the design.  A proposed research version of the reactor has been proposed for the University of Texas Permian Basin and affiliated institutions for Andrews County, Texas.  Because coolant temperatures arising from HTGRs are much higher than from light water reactors, the design is viewed as a potential source of commercial heat. Particular attention has been paid to the design's potential to produce of hydrogen from water. The GT-MHR is considered, among many other designs, as a potential contender for the US Department of Energy's Next Generation Nuclear Plant (NGNP) program.
Further Information:  http://gt-mhr.ga.com/  http://en.wikipedia.org/wiki/GT-MHR  http://www.nei.org/doc.asp?catnum=3&catid=711