Nuclear Materials Science
Fig 1 shows a cross-sectional image of a Zr/Ti
mesoporous structure prepared by a ‘sol-gel’
templating method.
Research conducted under the Nuclear Materials Science theme builds on the capability of engineering materials and processes for the nuclear fuel cycle.
The development of separation materials and process technologies are vital components of the fuel cycle especially in the field of reprocessing. The tasks performed within this research theme fall into three areas:
- Development of selective adsorbent materials;
- Pyroelectrochemical reprocessing of spent nuclear fuel;
- Nano-scale materials in nuclear applications.
Development of selective adsorbent materials
In attempts to reduce radioactive waste volumes, separation techniques are used to contain or recycle components in spent fuel. At ANSTO, porous metal oxides are being investigated as potential adsorbent materials as nuclear wasteforms. Research within the Nuclear Materials Science group is focused on developing novel porous oxide materials in the form of beads for separation columns.
Pyroelectrochemical reprocessing of spent nuclear fuel
CV for Zr4+ (0.0445 mol/kg) in LiCl - KCl
eutectic molten salt at 450 °C.
WE: W 1mm dia. wire (S = 0.325 cm2);
CE: - GC rod; REF, Ag/AgCl; [AgCl] = 0.75mol/kg.
Click here for larger image
The current technology employed in the nuclear fuel cycle for the recovery and recycling of spent fuel involves hydrometallurgical processing. For next generation (Gen IV) reactors, pyroelectrochemical processing appears to have several advantages over the hydrometallurgical route in terms of recycling and separating. The reprocessing of Uranium, Thorium and fission products in molten halide salts are of particular interest for reprocessing of high-level waste streams from these reactors to reduce the waste volume for final disposal.
Research is focused on understanding the electrochemistry of zirconium and its speciation in LiCl-KCl and LiF-CaF2 eutectic molten salts within the Gen (IV) and molten salt reactor. The presence of zirconium ions in the melt interferes with the recovery of minor actinides (MA). Therefore, it needs to be selectively electrodeposited and characterised.
The electrochemical reduction of Zr4+ in LiCl - KCl eutectic molten salt is being investigated using transient techniques such as cyclic voltammetry (CV), figure 1, at elevated temperatures of 450, 500 and 550 °C. This figure shows the reduction of Zr4+ at 450 °C which proceeds through an initial adsorption process followed by two reaction steps independent of the temperature.
A partner in this research activity is the ACSPET (Actinide reCycling by SEParation and Transmutation) program which is a FP7 EURATOM Collaborative project (www.acsept.org).
Nano-scale materials in nuclear applications
Research within the Nuclear Materials Science group is focused on understanding the performance of nano-structured materials subject to radiation. The impact of nano-scale oxide-based materials are being investigated as passive barrier layers to reduce corrosion/oxidation and as novel coatings for surface decontamination.
Key contact:
Gerry Triani, Group Leader, Nuclear Materials Science
ANSTO Institute of Materials Engineering
PMB 1, Menai NSW 2234, Australia
Phone: +61 2 9717 9070
Email: gerry.triani@ansto.gov.au