Radiation Damage in Nanoporous Nuclear Materials

Materials in nuclear reactors are bombarded by neutrons. This can result in atoms being knocked off their lattice sites creating crystalline defects and in transmutation events which can create helium atoms. These processes can cause the physical properties of the material to deteriorate. In order to run a nuclear reactor safely it is vital to have materials which can perform under these extreme conditions. Furthermore, it is important to understand the physics behind the response of materials to radiation in order to predict how they will behave in-service and to develop new technologies.

One way to control the defects and helium which are created by neutron irradiation is to engineer a material with features which are designed to safely store them. The perfect such feature is a surface because it can never become saturated. Nanoporous materials have a structure like a nanoscale sponge and so have very high surface-area-to-volume ratios. Recently, nanoporous materials have been shown to have very good radiation tolerance and so have been proposed as candidates for use in nuclear applications. However, research so far has been limited to materials which are not suitable for use in nuclear reactors.

This research project will investigate nanoporous iron, nickel, zirconium, molybdenum, tungsten, silicon carbide and zirconium carbide. These materials all have properties which means they can be used in nuclear reactors. In order to explore the effects of irradiation, the Microscope and Ion Accelerator for Materials Investigations (MIAMI) facility at the University of Huddersfield will be used. The MIAMI facility incorporates a transmission electron microscope which allows materials to be observed on the nanoscale and an ion accelerator so the sample can be irradiated at the same time. The experiments will be combined with computer simulations to help explain the results in terms of the fundamental underlying atomistics.

The knowledge and understanding acquired from the experiments and the computer modelling will then allow nanoporous materials to be designed which are ideally suited for use in nuclear applications.