Modelling of bituminized radioactive waste leaching. Part II: Experimental validation

This paper presents experimental work aiming at studying the behaviour of leached bituminized waste materials and the development of a saline solution-filled pore structure (called permeable layer) in the materials. Standard leach tests are performed on two synthetic BW materials containing different soluble salt contents and leached by solutions of varying chemical activities. The water uptake and the sodium nitrate leach rates are measured continuously during the tests. Porosity profiles are obtained from ESEM image analyses performed on the same BW samples leached during periods of varying durations. These experimental results provide a precise description of the internal structure of BW materials during leaching. The impact of the leaching duration, of the soluble salt content, and of the chemical activity of water in the leachant on the overall behaviour of leached BW materials is by this way assessed and compared to the theoretical trends presented in Part I of this paper.