Decommissioning of Rio Algom's quirke and panel mines waste management facilities

With the completion of the production for British and American long-term uranium supply contracts in 1989/90, Rio Algom Limited, Elliot Lake Division, was faced with little hope for future contracts due to the low grade nature of the operations and a depressed uranium market. On January 24, 1990, Rio Algom Limited announced the pending closure of two of its three underground uranium mines, namely Quirke and Panel Mines which actually ceased operation on August 31, 1990. This paper addresses the proposed decommissioning of the two mines. The regulatory regime is presented together with an overview of all legislation related to uranium mine closure, decommissioning and, in particular, the compliance requirements of the AECB (Atomic Energy Control Board)-the lead regulatory agency. The primary concerns to be addressed in the closure of the Elliot Lake operations are the potential long-term production of acidity from the oxidation of the pyrite in the tailings together with the release of radioactive material. The closure plan for the tailings management areas has been developed to specifically address these tow issues. In the preparation of the plan, Rio Algom addressed several closure options prior to selecting permanent flooding of the tailings. These options and the reasons for selecting open-quotes flooded tailingsclose quotes are described. The decommissioning process is now in progress and is described in detail, particularly addressing those issues of concern to both the regulatory agencies and the Company. The present situation together with the company's expectations for the future are presented