Material removes radioactive gas from spent nuclear fuel

’This is one of the first attempts to use a MOF for iodine capture,’ said chemist Tina Nenoff of Sandia’s Surface and Interface Sciences Department.

The process reduces the volume of high-level wastes, which is said to be a key concern of the Sandia researchers. ’The goal is to find a methodology for highly selective separations that result in less waste being interred,’ said Nenoff.

Part of the challenge of reprocessing is to separate and isolate radioactive components that can’t be utilised as fuel. The Sandia team focused on removing iodine from spent fuel.

It studied known materials, including silver-loaded zeolite — a crystalline, porous mineral with regular pore openings, high surface area and high mechanical, thermal and chemical stability. Various zeolite frameworks can trap and remove iodine from a stream of spent nuclear fuel, but need added silver to work well.

’Silver attracts iodine to form silver iodide,’ Nenoff said. ’The zeolite holds the silver in its pores and then reacts with iodine to trap silver iodide.’