Nuclear waste disposal remains a critical hurdle for global energy expansion

The resurgence of nuclear power as a cornerstone of national energy strategies has been accompanied by a persistent and unresolved challenge regarding the management of radioactive waste. As governments across the globe seek to diversify their energy portfolios and reduce dependence on fossil fuels, the issue of waste disposal has emerged as a significant barrier to the sector’s continued growth. While the technology for generating electricity from nuclear fuel is well established, the safe and permanent containment of the by-products remains a complex task with no universally accepted solution. This discrepancy between the expansion of nuclear capacity and the lag in waste management infrastructure poses a strategic risk to the long-term viability of the industry.

Nuclear waste is categorised into three distinct levels of radioactivity, with the majority of material consisting of low-level items such as contaminated tools and work clothing. These materials account for the bulk of the waste volume but represent a small fraction of the total radioactivity. High-level waste, which comprises spent fuel, presents the most significant technical challenge. Although it constitutes only about three per cent of the total volume of waste produced by nuclear energy operations, it contains approximately 95 per cent of the radioactivity. This high concentration necessitates robust containment methods that can ensure safety over geological timescales, as the material remains hazardous for thousands of years.

Despite the high radioactivity of spent fuel, the volume of waste generated by nuclear power plants is relatively small compared to other energy sources. This is due to the high energy density of nuclear fuel, which allows for the generation of large quantities of electricity from minimal material. For instance, a conventional one gigawatt nuclear plant, capable of supplying electricity to over one million people, produces only around three cubic metres of vitrified high-level waste annually. This efficiency means that while the waste is difficult to manage, the physical quantity is manageable, provided that appropriate storage solutions are available.

In Canada, the Nuclear Waste Management Organisation has developed a test site in Oakville to demonstrate the feasibility of deep geological storage. The facility utilises automated systems to stack blocks of bentonite clay into rock tunnels, encasing copper-coated steel containers that hold the spent fuel. These containers are designed to withstand extreme pressures, including those equivalent to being buried under a three-kilometre-thick glacier or submerged at depths exceeding six kilometres. The final repository is planned for the town of Ignace, located 1,600 kilometres northwest of the test site. It is expected to be buried at a depth of approximately 750 metres within the hard rock of the Canadian Shield. Upon completion, targeted for around 2040, the facility will be capable of storing nearly six million bundles of spent fuel from Canada’s four nuclear power plants.

Similar deep geological repositories are under development in Finland, Sweden, and Japan, indicating a growing global consensus on this disposal method. However, the United States has fallen behind its international peers due to significant political and public opposition. The U.S. government selected Yucca Mountain in Nevada as its first geological repository site in the 1980s, becoming the first country to submit a licence application for such a facility. Despite this early start, the project has been stalled by concerns over geological risks, including the proximity of an active volcano and the site’s location above the water table. Political opposition, particularly from Nevada Senator Harry Reid, who placed the project on hold in 2007, has further impeded progress.

The U.S. Department of Energy has since explored alternative sites in Utah, Idaho, Louisiana, Oklahoma, and Tennessee, but Yucca Mountain remains the only legally designated option for permanent storage. The current administration would need to pass new legislation to change this designation. Meanwhile, the United States has accumulated approximately 95,000 metric tonnes of nuclear waste that requires management. As the global nuclear renaissance continues, governments must address the waste issue by constructing safe disposal facilities alongside new power projects to ensure the long-term sustainability of the energy source.