The Nuclear Futures Institute is pleased to highlight the publication of a recent research paper written by Dr Phylis Makurunje and Dr Simon Middleburgh. The paper is titled “Self-contained dual-scale composite architectures in spray dried zirconium diboride” and was published in the Ceramics International journal. See the full text here.
The paper showed the preparation of zirconium diboride microspheres as candidate nuclear fuel additives. The solid microspheres were prepared by spray drying and sintering. These ceramic microspheres would be dispersed in a fissile matrix (e.g., uranium dioxide) to give a new candidate composite nuclear fuel. Composite fuels aim to boost thermo-physical and thermo-chemical fuel stability during normal operation and in the event of expected operational occurrences (AOOs) or design-basis accidents.
The paper further demonstrated how complex structured microspheres – with self-contained dual-scale composite architectures – can also be obtained from spray drying. The novel architectures were characterised by scanning electron microscopy. The resultant architecture of the microspheres via the used process was largely determined by the differences in the binder quantity used during the manufacturing process. The architectures have potential utility in the accommodation of fission products expected during reactor operation.
The paper’s demonstration of spray drying of solid microspheres ushers a process of consideration for the manufacture of fuel kernels, besides sol gel and granulation. Additional architectures (self-contained dual scale) potentially enable more efficient accommodation of the fission products and property changes during reactor operation.
The figure shows the shapes of microspheres synthesised. Discussions regarding the mechanisms how the shapes are formed are found within the paper.
Spray drying has wide and established applications in pharmaceutical, food, and ceramic industries. The spray drying technique involves the spraying of a liquid stream into a chamber in which formed droplets collide with a hot stream of air that effects moisture evaporation. This drying of the droplets results in microspheres.
Summary
The paper’s demonstration of spray drying of solid microspheres ushers a process of consideration for the manufacture of fuel kernels besides sol gel and granulation. The solid microspheres architectures expand the conventionally accepted hollow (“shell”), partially hollow (“dimpled”) and shrivelled (“wrinkled”) architectures previously reported in literature. Self-contained dual-scale composite architectures in spray dried zirconium diboride highlights the potential that the synthesised microspheres have as nuclear fuel additives where the architectures might enable more efficient accommodation of the fission products and property changes during reactor operation.
This research was funded under the £46 m Advanced Fuel Cycle Programme as part of the Department for Business, Energy and Industrial Strategy’s (BEIS) £505m Energy Innovation Programme. SCM was funded through the Sêr Cymru II 80761-BU-103 programme by Welsh European Funding Office (WEFO) under the European Development Fund (ERDF).