When people hear about nuclear waste, they usually think about spent fuel – the uranium that has powered nuclear reactors. Spent fuel is highly radioactive, but it makes up only three percent of the volume of nuclear waste worldwide. The remaining 97 percent is much less radioactive. Even so, all waste needs to be treated with care.
There are three main types of nuclear waste:
- Low-level waste: Every nuclear facility uses cleaning tools (such as mop heads) and protective clothing. These items almost never touch radioactive material, but they’re still treated as nuclear waste.
- Intermediate-level waste: These are reactor parts, such as water filters, that have been irradiated and become radioactive.
- High-level waste: This is spent fuel. When fuel is removed from a reactor, it is very hot, and still radioactive. Its radioactivity will slowly decline over time.
Canada’s nuclear energy facilities store different types of waste in different ways, depending on how hazardous they are:
- Most low-level waste is no more dangerous than regular garbage, but it goes into long-term storage as a precaution.
- Intermediate-level waste is kept in containers made of materials that block radiation (for example, lead). In storage, the radioactivity of these items slowly declines.
- High-level waste is placed in a pool of water for five to ten years, which allows it to cool. Then it goes into special storage containers made of thick concrete and steel. Over time, the level of radiation declines, but the fuel will remain too radioactive to be safe for direct exposure to people and the environment for many years.
Storage for the future
Storing waste on-site, above ground is safe, but requires ongoing monitoring and security. An alternative way to keep nuclear waste safe is to bury it deep in the ground, in dry rock that is safe from earthquakes.
A federal government panel has recommended that the government approve a plan to bury low- and intermediate-level waste at a site near Kincardine, Ontario. As well, the government has approved a nuclear industry plan to find a site to store spent fuel. The Nuclear Waste Management Organization is reviewing sites that have both the right geology and a willing host community.