Uranium giant Cameco has received approval to carry out engineering changes at its Port Hope uranium conversion plant in response to the discovery of contamination in groundwater last year.
The leak occurred after "corrosive chemicals and other liquids contacted the floor structures such as pits and trenches that were not well designed for holding liquids over extended periods," the company has previously said. This resulted in uranium and other process chemicals escaping through tiny cracks in the floor of the UF6 conversion building.
In addressing the problem, Cameco has already removed most of the floor of the building in question as well as 60 cm of soil from the areas leaks had been identified. A new concrete floor will be poured with leak-proof surface coatings before equipment is re-installed. A groundwater management unit is also to be added outside the plant to "contain, recover and treat affected groundwater," Cameco said.
Cameco has approval from the Canadian Nuclear Safety Commission to make these physical changes, but would require separate approval for final design, installation and subsequent operation.
Further regulatory work is required for Cameco to confim the conclusion of its preliminary risk assessment that the health and safety of employees and the public would not be affected by the groundwater contamination. The cost of the clean-up exercise is now put at C$15-20 million - up from an initial estimate of C$3 million. Cameco also intends to spend C$20-25 million on plant improvements.
At Port Hope, Ontario, shipments of uranium concentrate powder (U3O8) are converted in a chemical process to gaseous uranium hexafluoride (UF6) ready for enrichment at facilities around the world. It is the only such facility in Canada but has been offline since the discovery of the leaks. The target to begin operation again is the third quarter of 2008 at the earliest.
Cameco has covered its supply commitments, and intends to go on doing so, using stockpiles established for such purposes, by securing deferrals on UF6 deliveries from some customers, and purchasing replacement services from other converters.