Dissolution behavior of Fast Reactor MOX nuclear fuel pellets in nitric acid medium

Abstract The fundamental information required for designing a continuous FBR MOX spent fuel dissolution system is the intrinsic kinetics of dissolution of the MOX fuel under typical PUREX process conditions. The influence of parameters such as Pu content of the MOX pellet, nitric acid concentration, intensity of mixing and reaction temperature, on the dissolution behaviour of PFBR MOX fuel pellets in nitric acid was investigated. The results clearly bring out the preferential rapid dissolution of UO2 over PuO2 from the same MOX pellet. This behavior was found to be inversely proportional to all the above-mentioned influencing parameters except for the Pu content of the pellets in which case it is directly related. These results will pave way for better understanding of the dissolution mechanism of MOX fuel under typical PUREX process conditions.