Development of durable cementitious materials for use in a nuclear fuel waste disposal facility

This paper describes the work on cement paste development and short-term leaching tests in Standard Canadian Shield Saline Solution (SCSSS) in the presence of bentonite at 1500C. It has been found that: (1) supplementary cementing materials such as silica fume or fly ash could significantly improve the properties of sulfate resistant portland cement (SRPC), in particular, permeability to water and pore size distribution; (2) the addition of bentonite suppressed the normal tendency of the pH of groundwater to increase rapidly in the presence of cement; (3) the presence of bentonite increased the release of potassium ions from the cements; and (4) SRPC blended with 20% silica fume resulted in a groundwater pH lower than that of SRPC, with and without bentonite. Moreover, its cumulative fraction of release of potassium was significantly lower than that of SRPC