Nuclear waste study breaks synchrotron record

04 July 2017

An experiment to study transformations in nuclear waste materials at the UK's Diamond Light Source has become the longest running synchrotron light experiment in the world after being in place for 1000 days.

Senior support scientist Sarah Day with Claire Corkhill of the University of Sheffield on the I11 beamline (Image: Diamond Light Source)

The research, led by Claire Corkhill of the University of Sheffield, has used Diamond's Long Duration Experimental (LDE) facility to investigate the long-term behaviour of cements used in nuclear waste storage and disposal.

"Understanding the rate at which hydration occurs in cement, a process that can take anywhere up to 50 years, is very important to help us predict the behaviours of cement in the long term," Corkhill explained.

"These cements are being used to safely lock away the radioactive elements in nuclear waste for timescales of more than 10,000 years, so it is extremely important that we can accurately predict the properties of these materials in the future. The unique facility at Diamond has allowed us to follow this reaction in situ, for 1000 days, and the data is already allowing us to identify particular phases that will safely lock away radioactive elements in 100 years' time, something we would otherwise not have been able to determine," she said.

Corkhill is monitoring changes in eight nuclear waste cement materials on Diamond's I11 beamline using the LDE. She is planning to return to Diamond to investigate the reaction of these phases with uranium, technetium and plutonium on the B18 X-ray absorption spectroscopy beamline. Results from the studies are being used to support the ongoing safety case development for the disposal of nuclear waste in a deep geological repository, according to UK governmental policy.

Diamond, at the Harwell Science and Innovation Campus near Didcot, is the UK's national synchrotron science facility. It is funded as a joint venture by the UK government through the Science and Technology Facilities Council in partnership with the Wellcome Trust. The LDE was commissioned in 2014.

Researched and written
by World Nuclear News