MOX fuel behavior in the reactor
Civil plutonium management

The general aim is to use MOX fuel under the same conditions as UO₂ fuel. However, since its introduction into reactors in France in 900 PWRs, MOX has been irradiated for 3 annual cycles, whereas UO₂ fuel resides 4 cycles in reactors. This is known as "hybrid" management.

Future management called "MOX Parity" aims to manage MOX fuel like UO₂ fuel. It is therefore necessary to increase MOX discharge depletion by bringing its maximum burnup (average burnup of the most loaded assembly) to the same value as that of UO₂: 52 GWj / t since 1998.

The economic stakes are high, as achieving parity between UO₂ and MOX fuels will enable both types of assembly in the same load to be managed in the same way, and avoid the more complex "hybrid" management in operation. In addition, the increase in depletion favors MOX, which, like UO₂,...