The leaching in deionized water of sulfate and chloride ions from cement-based matrices of varying dosification (mixture of ordinary Portland cement and Boiling Water Reactor (BWR) evaporator concentrate solutions) were studied at the temperatures of 20°C and 40°C. The changes of the composition of both the extracted pore solution and the solid phases were characterized to see the possible related dissolution-precipitation processes of the cement hydrated aluminate and the competition established between both the sulfate and the chloride ions binding capacity.