Cameco reported July 20 that during a construction project it discovered uranium and evidence of other production-associated chemicals in the soil beneath its Port Hope uranium hexafluoride (UF6) conversion plant. The company said “the affected area appears to be within, and near, the perimeter walls of the UF6 plant based on the preliminary information available at this time. Ongoing subsoil investigations are expected to provide additional information. Cameco has suspended operations at the UF6 conversion plant and a thorough investigation is being conducted. The chemicals are in a contained area so public health and worker safety are not affected.”

The discovery was made in an area being excavated within the building to install new equipment. Cameco and third-party experts are investigating to determine the source of the chemicals. In addition, holes are being drilled around the area and the soil and groundwater are being tested to ascertain the area affected. All regulatory authorities have been notified.

Due to the nature of soil at the plant, Cameco expects the ground water flow rate, with the chemicals, to average approximately 40 to 60 m/y. The perimeter of the plant is about 70 m from the edge of the property. This provides ample time to address, contain and mitigate the affected area. Cameco has monitoring wells around the property to detect chemicals in the area. These wells are checked quarterly and reported to the regulator annually. The last scheduled samples were taken in April and did not indicate potential issues. Cameco has arranged for additional samples to be taken.

Full production of UF6 will likely be suspended for a minimum of two months until Cameco has determined the source of the chemicals and developed appropriate plans. There is no cost estimate for this activity available at this time. Uranium dioxide (UO2) conversion and other activities at the site are not affected. The company says it is assessing the impact of this situation on its production forecasts and will provide a revised forecast in its second quarter report. It “plans to meet scheduled deliveries for the remainder of the year based on existing inventory.”