Study on cement monolith solidification for immobilizing intermediate level wastes from reprocessing plants

This study dealt with a cement monolith solidification process for intermediate level liquid wastes from fuel reprocessing plants. Yong Deng 525 type portland cement (Chinese product) and two simulated wastes (evaporator concentrate (NaNO3: 330 g/1, Na2CO3: 50 g/1, NaOH: 20 g/1), decladding waste solution (NaNO3: 280 g/1, Na2CO3: 40 g/1, NaOH: 80 g/1, NaA102: 100 g/1)) were chosen for the study. The two main aspects of the investigation were: evaluation of the properties of waste-cement mortars (fluidity, setting time, bleeding behaviour, temperature rise caused by hydration heat etc.) and characterization of the waste-cement products (compressive strength, leachability, radiation stability, thermal expansion, autogenous expansion, wet expansion, thermal analysis etc.). The study showed that the cement monolithic waste form solidification process is suitable for both the simulated evaporator concentrate and the decladding waste solution. (author). 3 refs, 16 figs, 2 tabs