New technique against nuclear waste

2000/06/01 Elhuyar Zientzia Iturria: Elhuyar aldizkaria

• Ingurumena

The U.S. government is trying to push for a new technique for treating depleted waste generated in reactors, called "melted and diluted."

While most of the fuel used so far was reprocessed to separate uranium from the waste that could be used, the process has sparked debate, as uranium is used in the manufacture of nuclear weapons and minor radioactive waste contaminates the environment.

The technique developed by researchers at the Savannah River nuclear plant in South Carolina combines low-level uranium with depleted fuel to melt and form ingots. The U.S. Department of Energy defended this technique as the most appropriate technique for treating aluminum fuel in reactors.

In the experimental furnace the exhausted fuel and aluminum will be heated up to 850ºC, 200 ºC more than the melting point of the aluminum. This means a reduction in residue volume over 70%. The proportion of Uranium 235 decreases from 70% to 20%. The obtained ingots will be stored in the underground warehouse.

Natraj Iyer, responsible for the development of the new technology, says that this technology will allow to treat any fuel based on aluminum. However, it considers that there may be problems with what is generated in nuclear power plants, since most of the depleted fuels are zirconium alloys and the melting point exceeds 2,000°C.

Two British companies, British Nuclear Fuels and The UK Atomic Energy Authority, claim the new technique is expensive and impractical.