Furnace slag can dilute and stabilise plutonium wastes

The researchers, from Sheffield University’s Faculty of Engineering, have shown that mixing plutonium-contaminated waste with blast furnace slag and turning it into glass reduces its volume by 85-95 per cent. It also locks in the radioactive plutonium, creating a stable end product.

According to the university, this approach could also be applicable to treating large volume mixed wastes generated during the eventual clean-up of the damaged Fukushima plant.

‘The overall volume of plutonium contaminated wastes from operations and decommissioning in the UK could be upwards of 31,000 m³, enough to fill the clock tower of Big Ben seven times over,’ said lead researcher, Prof Neil Hyatt. ‘Our process would reduce this waste volume to fit neatly within the confines of just one Big Ben tower.’

The current treatment method for non-compactable plutonium contaminated wastes involves cement encapsulation, a process which typically increases the overall volume. 

In a statement Prof Hyatt said, ‘If we can reduce the volume of waste that eventually needs to be stored and buried underground, we can reduce the costs considerably.  At the same time, our process can stabilise the plutonium in a more corrosion resistant material, so this should improve the safety case and public acceptability of geological disposal.’