THE U.S. ENVIRONMENTAL PROTECTION AGENCY HAD A novel idea: For power plants and sources relying on devices to control air emissions, rather than attempt to monitor the actual physical emissions...
Face-Off: The Renaissance of Nuclear Power
is its energy density. The heat value of uranium used in a light water reactor is 500,000 megajoules per kilogram. For high-Btu content coal, the value is 30 megajoules per kilogram. Residual oil is about 50 megajoules per kilogram; natural gas comes in at 40 megajoules. For wood (biomass), the heat content is on average 16 megajoules per kilogram. 4
The extraordinary heat content of uranium translates into significant environmental and economic benefits. For example, a 1,000-MW power station will consume more than 3 million tons of coal each year. If it is a nuclear power plant, the physical resource requirements are 24 tons of UO2 enriched to about 4 percent U235. This in turn requires 200 tons of natural uranium processed from 25,000 to 100,000 tons of uranium ore. 5 Even at the high end of 100,000 tons, this translates into a resource extraction ratio of 30 to 1 in favor of uranium. Similar statistical ratios can be generated comparing uranium with oil, natural gas, and biomass.
In truth, the ratio is much higher in uranium's favor. Much uranium and nuclear fuel comes from secondary sources, including other mineral mining operations and material from dismantled Russian nuclear warheads. Also, most of the uranium ore mined today comes from rich mines in Canada and Australia. Uranium is a relatively abundant element, with only one commercially practical application: generating electric power. Fossil fuels, possibly excepting coal, can have multiple applications that in part explain their higher price on a Btu basis, i.e., they have a larger potential market.
Fuel density also results in a smaller footprint for nuclear power plants and supporting facilities. Nuclear power plant sites can be more compact than similar-sized fossil stations. Also the transportation and supporting facilities to supply fuel are much smaller for nuclear power plants; large connecting rail, barge, and pipeline facilities are not necessary, and neither are fuel storage yards or tanks. The reduced need for supporting facilities also increases the flexibility to site nuclear power plants, including at more isolated and secure locations. By contrast, renewable energy facilities such as windmills and solar power plants require enormous chunks of real estate-an inevitable result of their being extremely energy diffuse.
While much is made of nuclear waste, it is small and manageable compared to other fuel forms. The 24 tons of UO2 after it is irradiated is extracted and stored, and ultimately will be encased in a repository. If processed, the amount of material that would go to the repository would be less than 700 kilograms, a small fraction. A coal-fired power plant would produce about 7 million tons of CO 2 each year, as much as 200,000 tons of SO 2 and other emissions such as NO X, and mercury. 6 While oil- and natural gas-fired power plants produce less emissions than coal plants, they are nevertheless significant.
Air emissions bring up the subject of global warming. Nuclear power plants are emission free. In 2001 nuclear power plants were the source of more than 76 percent of all emission-free generation in the United States.