The discussion about AGW is a distraction from the discussion of pros/cons of alternative energy sources to fossil fuels. If one understand the limitations of the alternatives, it appears nuclear is the best alternative.
The US pressurized enriched (Uranium 238 enriched with 235) reactor design was selected as the standard as it produces plutonium which is required for nuclear weapons.
Thorium is roughly four times as abundant as uranium and does not produce significant amounts of plutonium.
India is a developing a commercial heavy water thorium reactor (the hydrogen in heavy water, deuterium has an extra neutron).
http://energyfromthorium.com/2010/07...ntist-readers/The thorium fuel cycles produce almost no plutonium, and fewer higher-isotope nasties, the long-lived minor actinides. Thorium is much more abundant than uranium, and the reduced plutonium output eases proliferation concerns. The energy output per tonne is also attractive, even though thorium isn't itself a fissile material.
Thorium reactors are also safer, with the fuel contained in a low-pressure reactor vessel, which means smaller (sub-500MWe) reactors may be worth building. The first Molten-Salt Breeder prototype was built at Oak Ridge in 1950, with an operational reactor running from 1965 to 1969. Six heavy-water thorium reactors are planned in India, which has the world's largest thorium deposits.The design has also had its champions in Europe, but planning restrictions and a continent-wide policy obsession with conservation and renewables have seen little commercial action. But that might change.
A private company founded by Kazuo Furukawa, designer of the Fuju reactor, called International Thorium Energy & Molen-Salt Technology Inc (iThEMS) aims to produce a small (10KW) reactor within five years. Furukawa is aiming for a retail price of 11 US cents per kWh (6.8p per kWh).
Just to put that into perspective, the UK's feed-in tariff ranges from 34.5p/kWh for a small wind turbine to 41.3p/kWh for a retro-fitted solar installation, making a personal LFTR much more attractive than an additional garage. Just tell them you've got an enormous solar panel.
The objective for energy cheaper than from coal is $0.03/kWh and a capital cost of $2/watt of generating capacity. How can the liquid fluoride thorium reactor produce energy cheaper than from coal?
Fuel costs. Thorium fuel is plentiful and inexpensive; one ton worth $300,000 can power a 1,000 megawatt LFTR for a year – enough power for a city. Just 500 tons would supply all US electric energy for a year. The US government has 3,752 tons stored in the desert. US Geological Survey estimates reserves of 300,000 tons, and Thorium Energy claims 1.8 million tons of ore on 1,400 acres of Lemhi Pass, Idaho. Fuel costs for thorium would be $0.00004/kWh, compared to coal at $0.03/kWh.
Capital costs. The 2009 update of MIT’s Future of Nuclear Power shows new coal plants cost $2.30/watt and PWR nuclear plants cost of $4.00/watt. The median of five cost studies of molten salt reactors from 1962 to 2002 is $1.98/watt, in 2009 dollars. The following are fundamental reasons that LFTR plants will be less costly than coal or PWR plants.
Pressure. The LFTR operates at atmospheric pressure, without a massive reactor vessel pressurized to 160 atmospheres, and without a large containment dome needed to contain any accidentally released radioactive materials propelled by pressurized steam. One concept for the smaller LFTR containment structure is a concrete building below grade, with a concrete cap at grade level to resist aircraft impact.
Safety. PWRs are safe because of defense in depth – multiple, independent, redundant systems engineered to control faults. LFTR’s intrinsic safety keeps such costs low. A molten salt reactor can’t melt down because the core is already molten — its normal operating state. The salts are solid at room temperature, so if a reactor vessel, pump, or pipe ruptured the salts would spill out and solidify. There is no explosion potential because the pressure in the reactor is atmospheric. If the temperature of the salt rises too high, a solid plug of salt in a drain pipe melts and the fuel drains to a dump tank; the Oak Ridge researchers turned the reactor off this way on weekends.