The Decommissioning of the Denison Uranium Facilities in Elliot Lake

Abstract

The Denison uranium facilities consisted of the Denison, Stanrock and Can-Met mines. The Denison mine operated continuously from 1957 through to 1992, while the Stanrock and Can- met mines had discontinuous operations. Several other mines in the Elliot Lake area were also developed in the mid 1950's to supply uranium primarily to the United States Atomic Energy Commission. From the 1970s to the 1990s, the Denison mine supplied uranium to electrical power generating facilities; however, the cancellation of the Ontario Hydro contracts resulted in the closure of the Denison mine in 1992. All of the Denison uranium facilities were decommissioned between 1992 and 1998 and have been in a state of monitoring, care and maintenance since that time. The purpose of this paper is to describe the decommissioning activities for each site, the monitoring programs in place and water quality improvements that have occurred since decommissioning was completed.