Surprise finding by PhD student could improve future handling of nuclear waste
29 Sep 2016
A researcher at the University has made a surprise finding after observing variations of a chemical bond with a radioactive metal called thorium – and this newly revealed stabilising relationship could one day contribute to improving nuclear fuel management
Elizabeth Wildman, a PhD student in the research group led by Professor Steve Liddle, has reported compounds where unusual forms of phosphorus - known as the Devil’s element - are stabilised by thorium, the chemical element named after the Norse god of thunder.
The finding has been published in the leading multi-disciplinary journal Nature Communications in an article entitled ‘Thorium Phosphorus Triamidoamine Complexes Containing Th-P Single and Multiple Bond Interactions’.
“This has been an exciting experience and I am delighted my work has been recognised in this way,” said Elizabeth Wildman. “It seems the Norse god of thunder has tamed the Devil’s element.”
Thorium – an actinide element that is radioactive – can be used as a nuclear fuel in the nuclear power industry. Reactors that use thorium are operating on what is called the Thorium-Uranium (Th-U) fuel cycle.
Professor Steve Liddle, Co-Director of the Centre for Radiochemistry Research at Manchester, said: “Nuclear power could provide energy security for the UK and produce far less carbon dioxide than fossil fuels, but the waste it produces is potentially very dangerous if not handled properly.
“In order to find ways of reducing the volume of nuclear waste and recycle unspent fuel, research has focussed on developing our understanding of how radioactive actinide elements interact with elements from around the periodic table that they could come into contact with in the fuel cycle.
“This could potentially help improve extraction and separation technologies and evidence is emerging that the role of ‘softer’ elements, such as phosphorus and sulphur, could be important in these processes.
“In recent years the overwhelming amount of chemistry research looking at the interaction and bonding of the actinides with other elements has focussed on uranium.
“However, in order to fully understand the behaviour of these elements we need to not only understand them in isolation but also be able to compare them to one another by preparing families of compounds where only the metal is varied.
“Apart from uranium the only other actinide element that can be handled routinely is thorium, but surprisingly little has been done with this element.”
This latest study from Professor Liddle’s research group looked at how ‘soft’ elements such as phosphorus can interact with thorium in unusual bonding environments.