Amorphous SiO2 ambigels as hosts for simulated PWR multicomponent nuclear waste

In this work we report the synthesis of high specific surface area amorphous silica ambigels and their applications as hosts for immobilizing simulated pressurized water reactor multicomponent nuclear wastes. Three batches consisting of five ambigels each were subjected to different pre-sintering heat treatment and different immersion times in the waste as part of a factorial composite design of experiment. We have produced high specific surface area ambigels (> 300 m2/g), which after immersion in the simulated nuclear waste decreased its area in almost 70%, reaching over 46%, on average, waste loads. We also found that none of the two factors, temperature and immersion time, affected the waste load gain for the tested ranges.