This project associates SCK•CEN, as a centre of excellence in research reactor fuel development/qualification and in radioisotope production, and IRE, a global supplier of radiopharmaceuticals, not in the least fission generated 99Mo. Besides support for the ongoing development of UAl2 based targets in existing projects at SCK•CEN, the PhD project aims at advancing the qualification of identified candidate U compounds (previous thesis work on this was interrupted, but has yielded promising results for certain compounds) for use as fissile materials in radioisotope targets, studying the production and processing characteristics on fresh materials. With the constraints of target production and processing in mind, the project aims at fabrication of a set of selected candidate targets, with and without added Mo in the meat to simulate the fission Mo generated and radioisotope extraction tests. In the process of attempting to reach these technological goals, basic properties of the candidate materials (crystal structures, thermodynamic properties, transformation kinetics, etc.), with their intrinsic scientific importance and merit, will need to be carefully assessed through the use of a variety of available techniques (eg. XRD, TEM, EPMA, thermal interaction, TGA-DTA, etc.).
For the production of these targets, powder metallurgical methods are used, in which an alloy or compound is formed in an arc furnace, crushed and mixed with Al powder, pressed into a compact and rolled out between Al sheets to form a mini fuel plate. Many aspects of this processing were studied in the previously initiated PhD and rolled platelets are already available, but the methodologies will need to be perfected. The established relation with Argonne National Lab will allow an exchange of know-how and a possibility for production of samples if necessary. Eventually, the production of LEU based targets and test irradiations can be envisaged, but it may be more useful to work with IRE on the dissolution studies of as-produced targets with Mo addition. Because of the short irradiation times, the differences in dissolution response is minimal, except for the decay heat input, which can be simulated using electrical heating.
Year 1 : literature study, review of data from previous PhD and characterisation of available materials, compound synthesis and powder metallurgy up to compact
Year 2 : target rolling, advanced characterisation of compounds (TGA-DSC, crystallography, thermal interaction Al with uranium compound), initialisation of dissolution testing on compacts with heat treatment
Year 3 : continuation of dissolution studies, Mo addition to targets and extraction, characterisation of rolled targets and optimalisation of process
Year 4 : writing PhD, LEU target manufacturing