Transport model for the nuclear decontamination of cementitious materials

This paper describes a transport model for the nuclear decontamination of cementitious materials by electromigration. The porous medium is assumed to be saturated and reactive with the radioelement of interest, cesium. The transport of ions is described by a Nernst–Planck equation, in the framework of a multi-species approach to the problem. The overall electrical field accounts for the electrical field applied externally, and for the membrane potential. Two extreme cases are detailed: irreversible cesium binding, and reversible cesium sorption. It is shown that cesium interactions with the solid phase have a strong effect on the decontamination rate. In addition, the influence of the initial cesium content in the pore solution and the relevance of accounting for the membrane potential in the transport equations, are discussed.