Canadian experience in appraisal of uranium resources additional to reserves

Since the establishment of the Uranium Resource Appraisal Group (URAG) at the Department of Energy, Mines and Resources (EMR), the Geological Survey of Canada (GSC) has been engaged in periodic, systematic quantitative appraisals of Canadian uranium and thorium resources additional to reserves, i.e. Estimated Additional Resources I (EAR I), Estimated Additional Resources II (EAR II) and Speculative Resources (S), with biennial full, and alternate years interim, reports to URAG. These appraisals, conducted by the GSC Mineral Resource Appraisal Secretariat (MRAS), include: (a) geological analyses of exploration activities in Canada conducted by industry; (b) assessments of uranium and thorium resources of uranium-bearing domains; and (c) estimates of resources, additional to reserves, in identified uranium deposits. The appraisals are based upon field, laboratory and office research on uranium occurrences, on studies in close liaison with exploration and mining companies, with provincial professionals, universities, and with other EMR agencies. The quantification of the resources is conducted by diverse methods, including geological extrapolation, crustal abundance approach, modified MIMIC (Mining Industry Model for Inventorization and Cost Evaluation) and subjective probability estimations. These quantification methods are described in an Instruction Manual ''Methods for the Estimation of Undiscovered Uranium Resources'' to be published by the International Atomic Energy Agency (IAEA). Results of the studies are incorporated in the biennial publication ''Uranium in Canada: Assessment of supply and requirements'' (EMR Report EP-3), in the Nuclear Energy Agency - Organization for Economic Cooperation and Development/IAEA ''Red Book'' and in ''Fact Sheets'', distributed by EMR annually to exploration and mining companies operating in Canada. Findings pertaining to regional and local geology and to conceptual models are published in GSC Current Research and IAEA publications, which provide timely information for the professional public. 20 refs, 5 figs