Decontamination of Radioactive Waste
In the changing world of power generation, nuclear power plays a central role in Canada. Ontario alone sees 60% of its energy needs met by nuclear power and the province houses the vast majority of Canada’s nuclear power stations. The economic benefits of Canada’s nuclear capabilities are many fold: 60,000 jobs created directly and indirectly, over $6.5 billion in revenue, $1.5 billion generated in federal and provincial tax, and about 50% of the global market share in radioactive isotopes. Beyond the massive economic output, the environmental benefits of nuclear power are also widely touted, saving millions of tonnes of carbon dioxide emissions.
Continued reliance on and future development of nuclear energy depends heavily on the safe containment and disposal of radioactive material from our reactors. The Nuclear Waste Management Organization (NWMO) of Canada in collaboration with the Nöel lab at Western University, works to ensure the safe disposal of spent nuclear fuel – the most radioactive component of the nuclear power generation process.
Also of critical importance is the safe containment of radioactive structural components of the reactor itself. The lifespan of a nuclear reactor is finite but can be extended by servicing and renovating the plant; these steps, however, require that certain radioactive structural components be replaced. The safe containment of these radioactive components requires an entirely different approach from what is used to dispose of fuel, but of equal importance to ensure the safety and noncontamination of surrounding environments and bodies of water.
At the end of a reactor’s life, the process of nuclear decontamination and decommissioning is a decades-long process with various protocols depending on the radioactivity levels of the reactor components. The volume of these components is vast and far exceeds that of the spent fuel bundles; as Ontario Power Generation (OPG) plans for the eventual decommissioning of its reactors, maximizing safety and containing costs of disposal is of principal importance.
Clara Wren and her research group in the Department of Chemistry at Western University are working alongside OPG to find new ways to decontaminate such massive volumes of radioactive waste from future decommissioned plants. One method being developed by the Wren group is laser ablation, which uses high-intensity near-infrared lasers to scour radioactive oxides from the surfaces of metal components.
Traditional methods of containment include chemical decontamination, which creates secondary radioactive waste, and concrete encasement, which is extremely inefficient for such large amounts of waste. Beyond laser ablation, the Wren group is developing geopolymers made from recycled coal slag as a superior alternative to concrete for the long-term encasement of certain types of radioactive waste.
The novel waste containment methods being developed by the Wren lab are designed to reduce costs and environmental impact from the lengthy process of reactor decommissioning while providing superior results to current, state-of-the-art methods. As the Wren group works alongside OPG, these new technologies will ensure both Canada’s enduring global leadership in nuclear power generation and the safety of our communities and environment.
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