nuclear reactors, called Generation IV (GEN-IV) reactors, might be preferable to accelerator-generated spallation neutrons for transmuting radioactive waste. Consistent with its recommendation, the ATW Subcommittee changed its name to the Advanced Nuclear Transformation Technology (ANTT) Subcommittee, thereby de-emphasizing the role of accelerators in the U.S. transmutation program.
Most recently DOE decided that its GEN-IV and transmutation programs needed more coordination to maintain consistency between the two sets of technologies. To promote this coordination Congress established a new program in 2003 called the Advanced Fuel Cycle Initiative (AFCI), under which DOE is charged with developing both advanced fuels for GEN-IV reactors and technologies for spent fuels reprocessing and transmutation.
Research on transmuting radioactive waste is in its infancy, and there is much to be done to make it a reality.
The long-term storage, by which I mean the permanent burial, of highly radioactive waste from nuclear reactors is a major obstacle to exploiting fully the potential of nuclear energy. In the United States high-level waste from its roughly 100 civilian nuclear reactors is stored temporarily near the reactors at some 130 sites around the country until some long-term storage facility is commissioned. The most likely site for a permanent repository is Yucca Mountain in the state of Nevada, about 100 miles northwest of Las Vegas. The waste would be buried some 800 feet below the surface and about 1000 feet above the water table. The 5000-foot mountain is located in a desert region that receives about 6 inches of rainfall per year, most of which evaporates. Tentatively the spent fuel would be sealed inside containers made of a corrosion-resistant steel alloy containing nickel, chromium, molybdenum, and tungsten, and the spent fuel would be protected further by titanium drip shields.
The statement of the problem facing the long-term storage of high-level waste from nuclear reactors is as follows:
To be licensed by the U.S. Nuclear Regulatory Commission as a permanent repository for high-level waste from nuclear reactors, the containers to be used to encase the reactor waste at Yucca Mountain must be corrosion-resistant and leak-proof for 10,000 years.2
If the reactor waste is not transmuted, it will be highly radioactive for about hundreds of thousands of years.
In case of waste leakage after 10,000 years can we trust the geologic integrity of the site to prevent the waste from diffusing into the water table or other parts of the environment?
The goal of the U.S. transmutation program is to solve this problem by reducing the radioactivity of the high-level waste, in a period not to exceed 10,000 years,