Key Lake Extension Project

The Minister of the Environment has designated this project and the environmental assessment will continue under the former Canadian Environmental Assessment Act.

The Canadian Nuclear Safety Commission (CNSC) has received a project description from Cameco Corporation (Cameco) to extend the lifespan of the Key Lake milling operation in northern Saskatchewan by undertaking a variety of extension activities all within the area of the surface lease.

Cameco is proposing the following extension activities:

  • an increase to the approved storage capacity of the existing Deilmann Tailings Management Facility (DTMF);
  • an increase in the average annual production capacity of the Key Lake mill from 7.2 million kilograms of uranium (18.7 million pounds U3O8) up to an average annual production capacity of 9.6 million kilograms (25 million pounds U3O8) including any physical changes required to allow uranium processing and waste-handling and treatment systems at this higher production rate;
  • installation/modification of infrastructure and mill process equipment to permit receipt and treatment of a wider range of ore and waste rock types from other deposits; and
  • modification and conversion of the mill processes to use a strong acid strip solvent extraction, and to use hydrogen peroxide for uranium precipitation.

All activities would occur within the existing boundaries of the Key Lake Operation surface lease.

CNSC authorization is required for Cameco to carry out the proposed extension project. This requires an amendment to Cameco's Uranium Mill Operating Licence, pursuant to subsection 24(2) of the Nuclear Safety and Control Act (NSCA).

Before the CNSC can consider any licensing actions under the NSCA regarding Cameco's proposal, a screening level environmental assessment (EA) must be completed in compliance with the Canadian Environmental Assessment Act. The purpose of an EA is to identify the possible environmental effects of a proposed project, and determine whether these effects can be mitigated before the project is allowed to proceed.


Latest update

September 10, 2014 - The environmental assessment decision has been made.



Canadian Nuclear Safety Commission
Nicole Frigault, Environmental Review Specialist
280 Slater Street
P.O. Box 1046, Station B
Ottawa, Ontario K1P 5S9
Telephone: 343-542-7657 or 1-800-668-5284

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