Colloidal silica grout injection and radioactive wastes (JR)

PI: Joanna Renshaw University of Strathclyde.

Legacy disposal sites contaminated with radionuclides, such the Little Forest Legacy Site (LFLS) in New South Wales, Australia require long term management strategies. Due to costs and potential spread of contamination, in-situ containment/stabilization of radioactive wastes is often preferred to excavation and reconditioning. Using novel colloidal silica based grouts to immobilize radioactive wastes is a promising option due to its low cost, low injection viscosity and chemical inertness. However, little is known about the impact of the grouting process with these grouts on the geo-mechanical properties of the soil and wastes, and the environmental behaviour of radionuclides. In this project we will use X-ray Computed Tomography to investigate the geo mechanical properties of model soil and wastes and the behaviour of radionuclides of interest (e.g. Sr, Cs, U) before, during and after grout injection and setting. Finally, these experiments and analyses will be complemented by experiments performed with materials/solutions from the LFLS in order to inform on the best strategy for radioactive waste immobilization.