Fuel performance modelling of nitride fuels

Nitrides have been identified as a candidate fuel for fast reactors due to the better thermal conductivity, compatibility with sodium and, in the case of aqueous fuel reprocessing, higher solubility in nitric acid compared to conventional oxide fuels. The physical properties and vaporisation behaviour of actinide nitrides and (Zr,Pu)N fuels are reviewed. The extent of transport of gaseous nitride species are predicted from kinetic calculations using the FAC SIMILE code and an appropriate model for the fuel pellet system. The assessed thermophysical data recommendations are incorporated into the oxide fuel performance code TRAFIC and a nitride version developed, NITRAF. Results from fuel pin calculations are presented; these include temperature profiles and the evolution of fuel-clad mechanical interaction