Technical considerations at Ontario Hydro for disposal of radioactive waste

Ontario Hydro is currently carrying out studies for the disposal of low and intermediate level wastes generated at the CANDU nuclear generating stations. A screening study of a number of generic concepts led to selection of underground disposal concepts at shallow to intermediate depths for further studies. These concepts could be hosted in generally impermeable soil media such as clay and till and impermeable rock media such as limestone/shale, available in Southern Ontario geology. Although the concepts are considered adequate for majority of low and intermediate level wastes, the adequacy with respect to a segment of the waste containing large quantities of C-14, remains to be assessed in a broader context, with site specific data on hydrogeology, geochemistry and dispersion/dilution characteristics and the leaching properties of the wasteform, all of which are currently being studied. (orig./PW)