COLLEGE STATION - Disposal of nuclear waste has always been a hot topic, but a Texas A&M University chemist's new approach could lead to new waste treatment procedures - and even a boost to nuclear medicine.
A main component of President George W. Bush's energy policy is to increase use of nuclear energy. However, according to Abraham Clearfield, a professor of chemistry at Texas A&M, "to accept this part of Bush policy, the general public must be confident that nuclear waste disposal will be effectively dealt with."
One of the most common ways to dispose of highly radioactive waste is to use devices similar to water softeners called ion exchangers, which are either inorganic - mineral-type - compounds or synthetically produced organic resins.
An ion exchanger usually contains a harmless element such as sodium, present in ordinary salt, which is exchanged for a harmful element such as cesium 137, present in radioactive waste, says Clearfield.
Clearfield has been developing inorganic ion exchangers for more than 30 years. He has been studying their role in nuclear waste for 10 years in collaboration with Pacific Northwest National Laboratories and the Savannah River Site, a weapons research facility based in South Carolina.
Nuclear waste coming from nuclear weapons plants is made of highly radioactive elements, mainly strontium 90, cesium 137 and plutonium 239 and 240, as well as other less radioactive elements.
The highly radioactive waste is either extracted by a solution that does not mix with the waste solution - a process called solvent extraction - or is removed by ion exchangers. The high-level wastes are then to be immobilized in a special glass, placed inside steel drums and buried about 1,000 feet deep in salt mines, in sites to be designated. The remaining low-level waste may then be encased in cement and stored on site at Hanford, Wash., and the Savannah River Site, S.C.
The inorganic ion exchangers remove cesium and stro
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Contact: Patrice Pages
patrice-pages@tamu.edu
979-845-4618
Texas A&M University
18-Jun-2001