Metal fuel (alloy of U-Pu-Zr) is identified as a suitable candidate for future Indian Nuclear Fast Breeder Reactor program. Metal fuel fabrication is carried out by Injection Casting (IC) method where molten metal is forced into quartz moulds and allowed to cool. IC is a suitable method to cast smaller diameter and longer length slugs with minimal defects and it employs induction heating to melt metals in a graphite crucible. In high temperature induction heating systems, the induction coil is cooled by circulating water through the coil made from hollow copper tubes, traditionally. Water cooled coils must be completely avoided in nuclear fuel casting applications due to safety concerns. Further, as zirconium has lesser density, it does not easily mix with other elements homogeneously in molten state.

In this seminar talk, methods to reduce coil temperature without using water and to increase heating system efficiency will be presented. Besides, different induction stirring techniques will be discussed that aim to achieve homogeneous distribution of Zirconium on cast slug. The proposal of use of direct AC/AC converters to address the high supply current THD associated with conventional induction heating power supplies and to generate required stirring forces within molten metal will also be presented.