Using reactor grade plutonium in PWR: CORAIL and IMF options

Abstract

In nuclear reactors, plutonium is continuously being produced due to the presence of U-238 in the fuel. The need of the hour is to look for the ways to utilize this plutonium to overcome the uranium fuel shortages in future. To utilize the plutonium inventory from these reactors, Mixed Oxide fuel (PuO2+UO2) has become a well known option. One of the options to use this MOX fuel is the CORAIL assembly in which one-third of the assembly at the periphery is occupied by the MOX rods and rest of the assembly is having UO2 rods. This option almost has a zero mass balance because the plutonium produced in the UO2 rods is compensated by the burning in MOX rods. On the other hand, Inert Matrix Fuel (IMF) is an option to use this, in which no plutonium source is present. The results have showed that IMF is a better option among these two fuel options but at the expense of lesser temperature coefficients values (MTC and ITC). Control material worth is higher in IMF than CORAIL which is important from the safety point of view. In this paper both options have studied based upon the reactor physics aspects.