The Nuclear Futures Institute’s new Yamato DL410 spray dryer was recently delivered at the Dean Street MERLIN lab. The equipment will be used in preparing spherical beads of nuclear fuels. The effort is part of the Advanced Fuel Cycle Programme (AFCP), which is led by the National Nuclear Laboratory (NNL) and part of the Department for Business, Energy and Industrial Strategy’s (BEIS) £505m Energy Innovation Programme.

The process starts with nuclear fuel formulations being prepared into a slurry with appropriate additives.  The slurry is pumped into the spray dryer unit and is atomised (sprayed into a stream of fine droplets) by a nozzle. During atomisation, the droplets contact a flowing hot gas stream as they fall down the chamber. Contact with the hot gas solidifies the droplets as the carrier liquid evaporates.

In addition to slurry properties, atomisation and drying medium conditions are known to affect the morphology of the granulates. The multiple factors that influence granulates physical, chemical and mechanical properties are summarised below.