IGNACE - There is a lot of controversy surrounding the Nuclear Waste Management Organization’s action plan to store radioactive waste in an underground repository in the Wabigoon – Ignace area.
And, rightly so. The public should be cautious when there are plans to put a highly volatile and deadly by-product of energy into the luscious green space in Northern Ontario.
However, the debate around this issue is way more complex than a simple slogan of “Say No to Nuclear Waste,” a slogan the Nuclear Waste Management Organization’s Mobile Learn More Centre hopes to address.
“It’s like a rolling classroom; in a way, it gives us a chance to walk people through the exhibit and 3D models and tell the story of used nuclear fuel,” Vince Ponka, regional communications manager, NWMO, explains. “Right from the beginning of the fact that they are small ceramic pellets and the process, it goes through in an actual reactor, and then when it comes out of the reactor when we get involved, and then it becomes the used nuclear fuel. Then we start talking about the potential project to create a deep geological repository to store Canada’s used nuclear fuel.”
At the moment, there are 3.1 million used nuclear fuel bundles being stored in Canada. Canada’s nuclear power plants generate 90,000 fuel bundles a year.
When used nuclear fuel bundles are removed from a reactor, they are placed in a water-filled pool heated once again to dispel any leftover radioactivity. After seven to 10 years, the bundles are placed in dry storage containers, silos, or vaults.
Dry storage has been in use around the world since the 1980s.
According to NWMO, dry storage containers are made of reinforced high-density concrete about 510 millimetres (20 inches) thick and are lined inside and outside with a 12.7-millimetre-thick steel plate.
“When used nuclear fuel comes out of the reactor, it goes into cooling pools for about 10 years, and during those 10 years, it loses 99 per cent of its radioactivity, but to lose that final one per cent, it takes hundreds of thousands of years, and it’s dangerous to human and the environment in that time.”
These bundles of used nuclear fuel are stored in above-ground waste facilities where the waste containers have a 50-year shelf life before they are inspected once again to see if there are any damages to the containers.
And suppose that doesn’t cause enough worry. In that case, these facilities are located near densely populated areas at nuclear reactor sites in Ontario, Quebec, and New Brunswick and Atomic Energy of Canada Limited's places in Manitoba and Chalk River Laboratories in Ontario.
Although these dry storage containers are heavily monitored, the 50-year shelf life isn’t sustainable for storing the amount of nuclear waste Canada generates.
Since the early 2000s, governments worldwide have been coming together to find the best possible solution to safe nuclear waste storage.
Nearly every nuclear country has concluded after 30 years of research that the safest approach is a deep geological repository for the storage of nuclear waste.
A geological repository uses a multiple barriers system. A system that is designed in a way to keep everything isolated.
Starting with the geosphere (the bedrock on which the repository is built into), the natural clay barrier, the copper coated and carbon steel container to house the used nuclear fuel, the Zircaloy fuel bundle, and the uranium dioxide.
The bedrock where the repository will be situated. Not only with the bedrock be stable and predictable over long periods, but the bedrock is also deep enough underground that surface waters, plants, animals, and humans will not be able to come in contact with any toxic chemical.
Ponka explains, “this rock we’ve studied is called the Revell Batholith, and a batholith is this egg-shaped rock that’s 45 kilometres long and roughly 4 kilometres deep. It’s this one chunk of rock that is more than 3 billion years old. We know from studying the microscopic amount of water at depths that this rock has been undisturbed for 4 billion years. This water is so old that we know there has been no interaction with surface water, so we have confidence that will continue.”
Jeff Binns, Associate Scientist, NWMO, also explains, “their properties kind of stack up on top of each other and work together with the surrounding rock to ensure safety. The rock is the sets the chemistry and temperature, and the barriers that are housed within that behave predictable and the stability to make sure there is no leaking.”
Bentonite Clay, a substance found in kitty litter, will surround the used fuel container as a fail-safe. Much like kitty litter, when water comes into contact, it expands. Therefore, if any microscopic bits of water get into the repository, the clay will swell, preventing the water from getting closer to the used nuclear containment.
“So active ingredient in the Bentonite Clay is a mineral called montmorillonite, and if you were to shrink yourself down to the microscopic level it occurs in a bunch of sheets, and in-between these sheets there is a lot of sodium, a little bit of calcium, and as water comes in, it replaces the sodium and calcium with water, and it causes those sheets to expand. Because it’s confined within the space of the rock, there is nowhere for it to actually swell,” Binns said.
Therefore, the clay slows the water as it gets absorbed, making the container hard to get wet and rust.
The Nuclear Waste Management Organization is taking every step possible with a massive amount of research going into this project to ensure the safe storage of used nuclear fuel will not affect the environment and the inhabitants.
Nevertheless, there is still a lot more work before any plans to build a repository near Ignace.
Therefore, if you are in the Kenora area from Tuesday, May 24 to Friday, May 27, the Mobile Learn More Centre will be at the Lake of the Woods Visitor Discovery Centre.
For more information on Nuclear Waste Management, go to https://www.nwmo.ca/.