Pebble bed reactor fuel spheres
2. PBR’s are cooled by helium gas, which is chemically inert and not radioactive, so the high temperature helium gas can directly power turbines to generate electricity at 45 percent efficiency, compared to typical 33 percent efficiencies.
3. The 900 to 950 degree Celsius heat enables efficient thermo-chemical production of hydrogen and disassociation of water into hydrogen and oxygen. Although hydrogen per se is unlikely to be a fuel of the future, it is readily combined with recycled CO2 such as from coal power plants to create methanol. Methanol is a suitable fuel for internal combustion engines and fuel cells, and unlike hydrogen it can be distributed through the existing infrastructure of pipelines and gas stations used today for petroleum derived fuels, says Nobel-prize winning chemist George Olah in his 2006 book, “Beyond Oil and Gas: The Methanol Economy.”
4. PBR’s are modular, costing about $200 million for a 100 megawatt unit. Utility companies can add modules as demand increases and investment capital becomes available, rather than risking a 2 billion expenditure for a 1,000 megawatt large power plant. The ROI will be in the 15-25 range, provided Congress provides a path through the legal gauntlets that discourage capital investment in nuclear power.
5. PBR’s can be built in factories, shipped by truck and rail, and assembled on site. This permits production line economies, strong quality controls, and continuing improvements.
6. China has a pilot PBR running. China has announced firm plans to build a full size 190 megawatt PBR which if successful will be expanded by 18 further modules creating a 3,600 megawatt power station in Rongcheng, China. South Africa is also building a PBR which they hope to have operational by 2012.
7. The U.S. is funding some basic research on Generation IV reactors, e.g. PBR’s at Idaho National Laboratories, but no funds have been appropriated to build a pilot plant, although the 2005 Energy Policy Act authorizes $1.25 billion for this.
I'll treat these topics in depth in future posts.