Criticality safety studies for plutonium–uranium metal fuel pin fabrication facility

This study focuses on the criticality safety during the fabrication of fast reactor metal fuel pins comprising of the fuel type U–15Pu, U–19Pu and U–19Pu–6Zr in the Plutonium–Uranium Metal fuel Pin fabrication Facility (PUMP-F). Maximum amount of fissile mass which can be handled safely during master alloy preparation, Injection casting and fuel slug preparation following fuel pin fabrication were identified and fixed based on this study. In the induction melting furnace, the fissile mass can be limited to 10.5 kg. During fuel slug preparation and fuel pin fabrication, fuel slugs and pins were arranged in hexagonal and square lattices to identify the most reactive configuration. The number of fuel slugs which can be handled safely after injection casting can be fixed to be 53, whereas after fuel fabrication it is 71.

► Criticality safety limits for PUMP-F facility is identified.
► The fissile mass which can be handled safely during alloy preparation is 10.5 kg.
► The number of fuel slugs which can be handled safely during injection casting is 53.
► The number of fuel slugs which can be handled safely after fuel fabrication is 71.