a technology which has been quietly used in marine nuclear reactors for years. This competes with the oxide fuels ordinarily used in civil LWRs and that the French have developed to make mixed-oxide (part U, part Pu) fuels. Problem with that is that quality MOX fuel is made of U and Pu alloyed in a high-energy ball mill but that makes nano particles that are highly effective at getting in your lungs and causing cancer. That is a problem with casting too, but making MOX fuel means you need to pick up fuel pellets with gloves and carefully stuff them in a tube whereas you don’t have to get anywhere near a cast fuel rod.