“I dunno, shoot it into the sun with a railgun?”
“Drop it into a volcano?”
“I don’t care, just as long as it’s not in our backyard”
It’s surprising what some people suggest when the topic of long-term storage of Canada’s nuclear waste comes up around the bonfire.
With nearby Ignace being one of nine communities actively participating in a decade-long site selection process for a deep geological repository (DGR), that conversation is happening more and more in Northwestern Ontario. Yet, for the nuclear industry, communicating the specifics of Canada’s plan to store nuclear waste is a challenge like no other.
It’s a challenge rooted in overcoming a palpable sense of fear triggered by the word ‘nuclear’, the cartoonish notion of sloshing barrels of glowing green goo that can dissuade many from learning more about the actual plan.
“Often times folks who come into an open house might have a certain picture of what this is all about in their head and it’s actually not what they’re thinking,” said Nuclear Waste Mangement Organization’s Director of Social Research, Jo-Ann Facella. “When they see what it is, their mind can open up and maybe they say I need to learn more about this before I make a decision.
It’s a good process because then maybe they tell their neighbour who won’t come to an open house, ‘Y’know what? It’s not what you think. It is worth learning something about this’.”
Ignace has entered Step 3 of Phase 2 of the NWMO’s Preliminary Assessment which will see more detailed studies and community engagement activities. The NWMO hopes to have identified a preferred site by 2023 and make a project siting selection by 2030.
Facella says taking the time to get informed on the project, ask questions and satisfy your doubts and fears is worth considering.
“People also worry about the idea that the decision’s already been made and it didn’t involve them,” said Facella. “Well, the decision hasn’t been made and it will involve you. There’s a big, open transparent process, the time frame isn’t this year or next year or even the year after that. The more people who are involved, the better the decision that will be made.” An idea born in the north
The proposed solution to the question of how to deal with Canada’s mounting stockpile of nuclear waste was actually pioneered in the Northwest at Atomic Energy of Canada Limited research stations in Atikokan and across the Manitoba border at Whiteshell. When the plan was completed in 1989, an independent environmental assessment panel (The Seaborn Commission) spent nearly a decade studying and consulting the public on the idea of a deep geological repository.
In 1998 the Seaborn Commission determined that the DGR concept was technically sound but found that the idea had not proven acceptable to the public. In order for a deep geological repository project to move forward, the panel demanded that any project must satisfy the equally important social component and clearly demonstrate the informed and willing consent of the community that would eventually play host to it. It marked the birth of the Nuclear Waste Management Organization (NWMO) the agency charged with the task of finding a site to host the DGR, a $16-24 billion project which could break ground as early as 2040.
Adaptive-Phased Management in a nutshell
The approach to securing high-level nuclear waste for an indefinite period involves a system of multiple barriers to isolate spent nuclear fuel from the environment.
At its most basic level the uranium fuel pellets themselves take the form of a high-density ceramic pellet which will not readily dissolve in water.
Fuel bundles (about the size of a fireplace log) consist of sealed corrosion resistant zircaloy tubes containing the fuel pellets. Throughout their 18-month span in a CANDU reactor, a single fuel bundle provides enough energy to power 100 homes for one year. After a 10 year cool down period underwater, used fuel bundles are moved to dry storage casks. Canada is currently storing 2.6 million used fuel bundles in seven locations across Ontario and Quebec.
Deep underground 48 used fuel bundles are loaded into a large pill-shaped corrosion resistant steel container, engineered strong enough to withstand the pressure of the overlying rock from a three-kilometer thick glacier in a future ice-age. The container works in concert with a buffer box made from high density bentonite clay — a powerful barrier to water flow. Formed from volcanic ash, bentonite swells if exposed to water, also making it an excellent material to seal the entrance to each placement room in the DGR.
A fifth and final barrier exists in the geosphere itself – the half kilometre of rock that will protect the repository from disruption of water flow and human intrusion. The repository will exist at a depth of approximately 500m (1,640 feet) in a rock environment selected for its low permeability.
Groundwater – a common concern
While moisture and corrosion over large periods of geologic time are key concerns of project engineers, how the project will interact with groundwater seems to be of equal concern to those within the communities being studied.
“It’s a common theme in people’s concerns,” said Sarah Hirschorn, NWMO’s Section Manager for Geoscientific Site Evaluations. “Generally in the kind of areas we’re looking you have the top 200-300 metres is one (groundwater) system and below that you have another system where the water is millions or billions of years old and often very salty in the pore spaces of the rock at those depths. In a site that would be suitable for a repository you wouldn’t have any younger or newer water in those areas — they are two very separate systems. It’s quite disconnected from what people traditionally consider an active groundwater system.”
While mines can run much deeper than 500m yet see plenty of groundwater interaction, Hirschorn says the difference with a repository has everything to do with site selection — searching for uniform dry, ‘boring’ rock where the natural diffusion of groundwater measures in the centimetres over millions of years. Seeking a site devoid of mineral and groundwater resources is another strategy to keep long distant generations ahead from disturbing the site.
“Part of the reason there are mines is because of economic minerals deposited there because of water moving through over geologic time,” said Hirschorn. “You’re usually mining in rock with fractures and features we would find unsuitable for a repository.”
Of the areas participating in the project’s site selection process, including Blind River/Elliot Lake, Central Huron, Hornepayne, Huron-Kinloss, Manitouwadge, South Bruce and White River — Ignace is the area of study furthest from the current waste storage facilities.
According to NWMO’s Jo-Ann Facella, the project is not particularly sensitive to the distance that the waste has to travel to reach a repository.
“The (transportation) cask is designed to protect it irrespective of the distance travelled. The effort is really to put it in the cask and to take it out of the cask. There are many factors that are part of the siting process, such as the safety of the rock and the ability to form a partnership
(with the community). Sometimes in communities we hear, ‘do we have no chance because we’re farther away?’ But that’s not the way the process works at all.”
Used nuclear fuel bundles are transported in extremely robust transportation packages designed to meet international standards. The reusable package, featuring 30 cm thick walls of solid stainless steel can transport 192 used fuel bundles, weighing 35 tonnes when loaded. The package can endure a drop of nine metres (30 feet) onto reinforced surfaces, repel puncture, maintain its integrity during 30 minutes of an 800 degree Celcius fully-engulfing fire, as well as immersion in water to 15 metres and far beyond for up to eight hours.
THE DRYDEN BSERVER. By: Chris Marchand – 14 April 2016