Treating spent nuclear fuel for disposal

Argonne's electrometallurgical treatment process is a revolutionary approach to the disposition of "sodium-bonded" spent nuclear fuels. This is a metallic fuel and is bonded with elemental sodium. Because sodium reacts with air and water, the fuel has to be treated to remove and neutralize the sodium before it can be disposed of in the ground. The treatment process converts the sodium into sodium chloride, common table salt, and seals the radioactive materials in a ceramic that is impervious to air and water.

The National Research Council (NRC) has reviewed Argonne's three-year demonstration of the electrometallurgical treatment program and concluded that "no technical barrier" exists to further use of the technology. The NRC panel also recommended that the Department of Energy consider this technology for expanded use beyond sodium-bonded metallic fuel. This would allow electrometallurgical treatment to be used as an alternative to current fuel management technologies.

The process uses an electrorefining technique to separate uranium, inert materials and radioactive wastes from spent nuclear fuel. This greatly reduces the volume of high-level waste and could save taxpayers millions of dollars in disposal costs.

Before preparing the waste for disposal, the electrometallurgical process removes the useful uranium from the fuel. The remaining waste takes one of two forms: a ceramic or a metal alloy. The ceramic waste is produced by heating and compressing a composite of borosilicate glass and zeolite, a mineral that binds the fission products within its structure. The metal alloy is made from the remains of the stainless-steel cladding that encased the fuel while it was in the reactor and noble or "non-reactive" metals produced as a byproduct of the fission reaction. The process reduces concerns about nuclear proliferation by keeping the plutonium in the waste bound up at all times with highly radioactive waste products that render it useless for weapons.

For more information about Argonne's electrometallurgical technology and other nuclear reactor safety and technology programs, visit the following Web pages: