The Potential of Thorium for Safer, Cleaner and Cheaper Energy
September 26, 2014
Nuclear energy promised to generate low-cost electricity safely, with fewer environmental and health problems from air and water pollution than fossil-fueled power plants. For a number of reasons, that promise has not been fulfilled, write Xinyuan Zou, research associate and Joe Barnett, senior director of policy research at the National Center for Policy Analysis.
However, in addition to new designs for uranium-fueled reactors, efforts are underway in a number of countries to develop commercial nuclear reactor designs that could solve many of the problems encountered with existing uranium-fueled nuclear power plants. This new generation of reactors will be fueled by thorium (Th-232) instead of uranium (U-235).
Thorium-fueled reactors have a number of advantages over uranium reactors, including less potential for nuclear proliferation and less waste.
- Thorium is three times as abundant in the Earth's crust as uranium, and there are thorium-bearing ores identified in many countries.
- Currently operating nuclear reactors are inefficient in extracting energy from uranium. Only about 3 percent of the uranium in the rods is consumed before the rods must be replaced, due to the buildup of fission byproducts in the rods.
- Fission byproducts in liquid thorium salts, by contrast, can be removed and reprocessed to produce additional fuel stock, while the reactor continues to operate.
Thorium-based reactors have been shown to be more economical than uranium-fueled reactors. In contrast to conventional light water reactors using uranium, according to a 2013 report from the Bellona Foundation:
- The capital costs of thorium reactors would be lower than conventional nuclear reactors; a 1 gigawatt (GW) thorium power plant would cost at most an estimated $780 million in comparison to capital costs currently of $1.1 billion per GW for a uranium-fueled reactor.
- Less manpower would be required to operate the plant; for a 1 GW power plant, staffing costs may decrease from $50 million to $5 million.
- Less radioactive waste is produced, perhaps one-tenth as little, by volume; thus, nuclear waste disposal for a 1 GW thorium power plant would cost an estimated $1 million or even less per year.
There are technical challenges in designing an efficient thorium-fueled nuclear reactor, but current development efforts underway will likely lead to a commercially practical system. The relative abundance, greater safety and lower cost of thorium-fueled systems could help fulfill the promise of nuclear power.
Source: Xinyuan Zou and Joe Barnett, "The Potential of Thorium for Safer, Cleaner and Cheaper Energy," National Center for Policy Analysis, September 2014.
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