Orano Canada

CLS techniques provide powerful toolkit for modelling arsenic at McClean Lake.

By Paige Buckberger

McClean lake tailings pond.

Helping to reduce the impact of environmentally harmful chemicals

October 2022

Northern Saskatchewan is home to large deposits of high-grade uranium, which Orano Canada mills to provide a source of energy to their customers. More than 99% of the world’s uranium is used as fuel for nuclear power plants – a very small portion is used to produce medical isotopes or as fuel for research reactors.

In a long-standing relationship with the Industry Services group at the Canadian Light Source, Orano has been able to monitor and assess the overall environmental impact and safety of its JEB Tailings Management Facility (TMF), which it has operated at McClean Lake in Northern Saskatchewan since 1997.

A major environmental concern posed by uranium mining and milling is the accumulation of environmentally harmful chemicals in the tailings created by the extraction of uranium – such as arsenic. The Orano McClean Lake mill approach to uranium tailings production ensures that the iron to arsenic ratio is appropriate and that the pH is adjusted for the precipitation of a stable iron arsenate solid in the tailings. Using this effective system, the produced mine tailings can be sampled, and the results modeled, to predict that there will be no significant downstream impacts.

The CLS provides detailed information on arsenic in trace amounts – a task not easily completed by conventional methods and one which has been vital to gaining approval by regulators. Additionally, through this significant collaboration not only has effective tailings management been achieved by Orano Canada, but a proactive approach to looking at the geochemistry of mine tailings while in operation has been made possible.

With the full-service capabilities of the Industry Services group, analysis work has been conducted seamlessly. From radioactive sample preparation to collecting and analyzing synchrotron data – the CLS has proven to be an invaluable resource in support of Orano’s operations.

Recent changes in global tailings standards to protect from failures in the geotechnical aspects of dams have only added value to the existing partnership between Orano and Industry Services. The proactive approach that has been established provides the ability to discover potential hazards to the environment as they are being produced, reducing the likeliness of environmental injury being discovered after it may already have taken place.

CLS techniques have provided Orano Canada with the toolkit to form a detailed geochemical model for arsenic, as well as proactively monitor the production of potentially environmentally hazardous chemicals in their mine tailings produced at the McClean Lake mine and milling site in northern Saskatchewan. The continuation of this existing relationship will not only protect from future environmental hazards but set high standards of production quality among the mining and milling community.