Atomic Energy of Canada Limited


Waste Primer

AECL owns most of Canada’s low-level radioactive waste.

Why AECL has radioactive waste

Since AECL opened for business in 1952, we have driven Canada’s nuclear research and development. We built prototype nuclear reactors to demonstrate that CANDU reactors could generate electricity. We also developed medical isotopes to detect and treat cancer. Both processes created radioactive waste that is stored safely and responsibly.

Nuclear reactors generate electricity without creating greenhouse gas emissions. Today 15% of Canada’s electricity comes from nuclear energy. Almost all of it is generated in Ontario, with the remainder generated in New Brunswick.

Medical isotopes from Canadian nuclear reactors have been used more than one billion times around the world to detect and treat cancer.

Creating medical isotopes and clean energy can’t be done without also creating radioactive waste.

All radioactive waste creates danger – but how much depends on the type of waste involved. Waste like used nuclear fuel will remain highly dangerous to people and the environment for generations far into the future. On the other hand, some types of waste have very low radioactivity, like workers’ protective clothing, mops, and rags. The hazard they pose today will fade away over a few hundred years, if not sooner.

AECL’s waste includes the legacy by-products of seven decades of nuclear science and research. Most of it is contaminated soil, or demolition debris from laboratory buildings. AECL also owns fuel used in prototype and research reactors, as well as reactor parts, filters and other items used in nuclear research and development.

AECL’s waste also includes radioactive materials were left behind by other organizations using obsolete waste-management practices. In 2015, AECL agreed to move them into storage and disposal as part of the Port Hope Area Initiative.

How dangerous is it?

Radioactive waste is dangerous if you’re exposed to it. If it’s contained and isolated, it isn’t dangerous at all.

Radiation harms humans by changing the cells in human tissue, which can lead to cancer, pregnancy complications, and death. Over decades of research, we’ve come to understand radiation and how to manage it safely.

Safe management means different things, depending on where the radiation comes from.

The fuel used in nuclear power stations is very dangerous. It needs to be managed well into the future. But other radioactive waste is simply soil contaminated by practices used years ago – and no longer. This type of waste is less dangerous. Even so, it still needs to be contained and isolated, so that humans, plants, and wildlife remain safe.

In fact, nearly 99 per cent of Canada’s radioactive waste is contaminated soil, rubble from demolished laboratory buildings, and cleaning items like rags.

This is “low-level waste.” It requires minimal isolation. Within a few hundred years, if not sooner, its radioactivity will fade to the point that it no longer threatens humans and the environment.

Only 0.5 per cent of Canada’s radioactive waste exists as used fuel, removed from reactors at nuclear generating stations. This waste is highly radioactive and generates heat. Today the stations safely store this waste in concrete containers. The stations are working together to build a storage centre deep underground that will hold used fuel long into the future.

The remaining 0.6 per cent of Canada’s radioactive waste is “intermediate-level waste.” It includes used reactor parts, and chemicals used to help reactors work better. Like used fuel, it needs long-term management, but it won’t need as much protection against heat.

It’s interesting to note that the danger from all radioactive waste fades eventually to levels that are safe — unlike types of toxic industrial waste that remain dangerous forever.

How much waste does AECL have?

We own most of Canada’s radioactive waste.

Type AECL Share (%)
Low-Level Waste 95
Intermediate-Level Waste 12
High-Level Waste 2.0

Note: The numbers in this chart are based on Natural Resources Canada’s Radioactive Waste Inventory, which is updated every three years.

What will AECL do about its waste?

It’s important to know that all AECL’s waste—and all of Canada’s—is stored safely. It presents no danger to the humans or the environment.

When the nuclear generating stations build permanent underground storage for their used fuel, we’ll send our used fuel there.

For mid-level waste from our research and prototype reactors (Chalk River, Whiteshell, Douglas Point, NPD and Gentilly-1), we’ll build our own storage above ground at Chalk River. When Canada builds underground storage for mid-level waste, we’ll store ours there.

Together, the two underground storage sites will hold about one per cent of Canada’s radioactive waste. The remaining 99 per cent will be isolated and contained near the Earth’s surface.

For AECL, this means three containment mounds.

One mound, just east of Toronto at the Port Granby site in Clarington, has already been filled and capped. It holds about 1.3 million cubic metres of waste. AECL is working in partnership with the local municipalities and First Nations to transform the surrounding lands into a nature reserve.

Another mound, at Port Hope, is being filled now. It can hold 1.7 million cubic metres of waste. AECL expects to cap it around 2030.

A third mound has been proposed for AECL’s Chalk River Laboratories. If it is approved by Canada’s independent nuclear regulator, this mound would store low-level waste from nearly eight decades of nuclear research and development. Unlike the other mounds, this one would remain open for another 40 years or more. That’s because the research and development work at Chalk River continues.

Today nuclear scientists are working on new reactors, a new cancer treatment, and new ways to improve nuclear safety and security.

The proposed Chalk River mound would let them continue their work knowing that the waste they create will go into disposal safely.