Nanoporous materials could prevent radiation damage in nuclear reactors
05 May 2015
Man-made sponge-like materials might provide a new way of solving important engineering challenges for future generations of nuclear reactors.
Scientists are investigating the use of man-made sponge-like materials as a new way of solving important engineering challenges for future generations of nuclear reactors, such as the accumulation of gas, which can lead to structural weakness.
Now, a joint research project by the Universities of Huddersfield and Surrey has been awarded an Engineering and Physical Sciences Research Council (EPSRC) grant of £678,000 towards the cost of a three-year, £856,000 project entitle: Radiation damage in nanoporous nuclear materials.
The project is headed by Dr Jonathan Hinks, a Senior Research Fellow at the University of Huddersfield, and he will be aided by the computer modelling expertise of Professor Roger Webb of the University of Surrey.
The computer modelling will complement experimental data gathered at Huddersfield using the latter's Microscope and Ion Accelerator for Materials Investigations (MIAMI) facility.
Major problems can be caused by the displacement of atoms – by high-energy neutrons – and the accumulation of gases – from nuclear decay and fission events – in the materials used in the construction of nuclear reactors.
A solution is to dispel defects and gas atoms so that the material is able to recover from the damage – in effect, repair itself – and an ideal way to do this is to create surfaces that act as 'sinks' where this can happen.
“Surfaces are fantastically good at getting rid of these problems and nanoporous material has huge amounts of surface because the entire substance is made like a sponge, meaning the surface-area-to-volume ratio is massive,” says Dr Hinks. “With a cube of solid material you have a lot of volume, but your only surface is its six sides. However, if a substance is all surface, you have plenty of opportunity to get rid of your problems.”
Nanoporous material is formed from structures as little as 10 nanometres in width. The proposal to use it in nuclear reactors is a very recent development, and now Dr Hinks and his collaborators will gather valuable data by observing strands of the material under bombardment using MIAMI’s ion beam as a safe means of simulating neutron irradiation.
But could a material with a sponge-like structure have sufficient strength to be used for nuclear components? Dr Hinks says studies have suggested that the mechanical properties of nanoporous materials are very similar to those of their bulk equivalents. “You wouldn’t necessarily have it as a barrier layer, but for structural materials inside reactor cores, nanoporous materials are strong enough,” he adds.