Deep Geologic Repository, Tiverton, Ontario

On behalf of Ontario Power Generation (OPG) the Nuclear Waste Management Organization has undertaken geoscientific studies to support an Environmental Assessment process related to the proposed development of a Deep Geologic Repository (DGR) for long-term management of Low and Intermediate Level Radioactive Waste (L&ILW) generated at OPG owned facilities at the Bruce site located near, Tiverton, Ontario, 225 km northwest of Toronto. As part of these studies straddle-packer hydraulic testing has been conducted in multiple deep boreholes to characterize formation hydraulic conductivities within the 840 m thick Paleozoic age sedimentary sequence underlying the site. This paper describes the design of custom testing equipment, test-methodology, and analysis approach. Preliminary results are presented describing extremely low-permeability and underpressured formations within the Ordovician sedimentary bedrock sequence that will host and overlie the proposed DGR. RÉSUMÉ Au nom d’Ontario Power Generation (OPG), le Société de Gestion des Déchets Nucléaires a entrepris des études géoscientifiques pour supporter un processus d’analyse environnementale liée au développement envisagé d’un stockage en couches géologiques profondes pour la gestion à long terme de déchets de faible activité et de moyenne activité, produits aux sites qui appartiennent à OPG, au site Bruce situé près de Tiverton, Ontario, à 225 km au nord