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According to the Organisation for Economic Co-operation and Development, Canada has, by far, the world’s most nuclear waste per capita, and the second-most total nuclear waste. And yet we don’t have nuclear arms, use nuclear power for only 14 percent of our electricity, and have a strong anti-nuclear movement (British Columbia even has a no-nuke policy). So where is all this waste coming from?
The answer lies not just in the particulars of Canada’s nuclear energy sector, but also in what defines “waste.” By the Canadian Nuclear Safety Commission’s definition, any material that contains a radioactive nuclear substance and has no use is defined as nuclear, or radioactive, waste.
To begin, Canada has one of the world’s largest uranium reserves, and more uranium (nearly a fifth of the global total) has been mined here than anywhere else. Our first uranium refinery opened in Port Hope, Ontario in 1932; northern Saskatchewan’s uranium mines currently provide 18 percent of the world’s supply. This enormous amount of uranium mining, refinement, and processing leaves a residue of uranium tailings, a radioactive sand.
Alongside this abundance of natural material, Canada was one of the first countries to use nuclear power, dating back to Chalk River, Ontario’s first operational reactor in 1947. Today, even though nuclear energy provides a small fraction of our electricity, we have the world’s third-highest per capita use of electricity (after Iceland and Norway), so our 14 percent is significant. From 1957 until May 2009, we also produced nearly half of the world’s medical isotopes through the National Research Universal reactor in Chalk River, a process that depends on highly enriched uranium. (Alison Motluk investigated Canadian isotope production in The Walrus’s April 2011 issue.) Canada’s long nuclear history amounts to more accumulated nuclear waste than most other countries (only the US has more.)
Combine all of the above, and we still get only a tiny part of the explanation for our nuclear waste. The largest piece of the puzzle lies in our particular nuclear technology. Our homegrown CANDU reactors use natural uranium, which contains only about 0.7 percent of the U-235 particle required for nuclear fission. Most other nuclear countries have light water reactors that require low-enriched uranium, in which the proportion of U-235 has been increased to 3-5 percent. The waste exiting from CANDU reactors is higher volume but less dense in radioactive particles than the waste exiting from light water reactors. Since nuclear waste is usually measured by volume rather than density, Canada comes out on top.
A more accurate cross-country comparison would measure the leftover radioactive particles per mega-watt hour of generated energy. In such a comparison, the amount of radioactive particles left over from a nuclear reaction in a Canadian reactor to produce, say, 1,000 mega-watts of electricity, is likely about the same as the amount of radioactive particles left over from a reaction in a light water reactor.
Finally, all the uranium our CANDU reactors use ends up as spent fuel (counted as waste), but this still contains 99 percent of the original uranium particles and can be reprocessed to feed nuclear reactors again. We don’t do that, because the technology for reprocessing spent fuel bundles remains prohibitively expensive. (In other countries, many reprocessing plants have shut down in the last decade.) It remains much cheaper to use natural uranium.
For now, Canada’s spent nuclear fuel is stored by our power companies — with oversight by the Nuclear Waste Management Organization — whose plans for long-term storage include retrievability. When Canada starts running low on natural uranium (sometime within this century), we may turn to reprocessing spent fuel bundles to feed its reactors. In the meantime, small communities in Southern Ontario are competing for the chance to host and manage the storage of 48,000 tonnes of radioactive waste for thousands of years, in exchange for the several hundred jobs expected to spring up as a result.
There’s debate about how dangerous this stuff really is. On the one hand, a mere splashing of 6 litres of mildly radioactive “heavy water” onto the factory floor of the New Brunwick’s Point Lepreau plant caused a full evacuation last December. On the other, uranium is a naturally radioactive material; un-enriched, it already has a half-life of 4.5 billion years. The pro-industry Canadian Nuclear Association argues that toxic heavy metals like mercury and arsenic, common non-nuclear industrial waste, last forever, whereas most of the radioactive material in used fuel bundles will decay to the level of original uranium ore in about 500 years. Jeremy Whitlock, nuclear scientist and manager at AECL Chalk River Laboratories, states that “All the waste from fifty years of nuclear electricity in Canada would fit on a soccer field piled to the height of a player. To put this volume of waste into perspective, it is approximately equal to half the volume of garbage (domestic and commercial) generated by the city of Toronto on one day.”
The Walrus thanks Fred Boyd of the Bulletin of the Canadian Nuclear Society, independent nuclear consultant Garry Fowles, Bill Garland at McMaster University’s Department of Engineering Physics, and Jeremy Whitlock at AECL Chalk River Laboratories.
Alina Konevski is an online editorial intern at The Walrus.