Saturday, December 23, 2006

PBR advantages are attractive

Pebble bed reactor fuel spheres
    1. Pebble bed reactor (PBR) technology is safe; the reactor can not melt down. While today's reactors are safe due to multiple, redundant, engineered shutdown, cooling, and containment systems, the PBR is safe because the basic physics increases neutron absorption if the temperature rises.

    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.

    Thursday, December 21, 2006

    We can solve the US energy crisis

    MIT pebble bed reactor drawing

    The United States has an energy crisis, incorporating energy costs, global warming, and national security. A pebble bed reactor is a nuclear power plant that can generate electricity and hydrogen, eliminate carbon emissions, and cut US dependency on unstable oil producing nations.

    We'll introduce the pebble bed reactor in more detail later. Now let's recap some facts about US energy.

    Energy costs are high and rising, perhaps +40% in 2005. The price of gasoline surged through $2.00 per gallon, through $3.00, fell back to $2.00, and now hovers near $2.50. Much of the public agitation associated with $3 gasoline has waned, but the crisis is real as ever.

    US carbon dioxide emissions continue to rise at 2% per year. The US did not sign the Kyoto accord to reduce them because we don't have the energy structure and policy in place to do this. Meanwhile we contribute to global warming.

    80% of US energy comes from fossils

    Eighty percent of all US energy comes from fossil sources that include coal, petroleum, and natural gas. We do derive 11% of our energy from the 100 nuclear power plants that were constructed decades ago; none have been started since the 1970s. Only 1% comes from solar, wind, and geothermal energy.

    32% of US energy is imported

    We import just about as much energy as we expend in the transportation sector. The figures above are in quads, quadrillions of BTUs. Above is the 2005 energy flow diagram from the US Department of Energy. It's worth while to browse the extensive statistics available at the DOE Energy Information Administration.

    Of course billions of dollars flow to the oil producing nations such as Saudi Arabia, Iraq, Iran, and Nigeria. Much of this money in turn flows to fanatics and terrorists. Reducing our energy imports will improve national security.

    Imported energy also increases the trade deficit. On a micro scale, think of a car driving 60 miles per hour at 20 miles per gallon. That's 3 gallons an hour, or $9.00 per hour. Nearly two thirds of that money, $6.00 per 60 minutes, flows back to the energy suppliers. So just envision each automobile tailpipe pumping 10 cents per minute into the coffers of Saudi Arabia, Iran, Venezuela, etc.