Part Two – Inside the Deep Geological Repository concept

Two area communities (Ignace and Ear Falls) are involved in the early stages of a site selection process for a deep geological repository to store Canada’s nuclear waste.

Conceptual design of a deep geologic repository for nuclear fuel. Image courtesy NWMO

The projected $16 billion project has its share of critics and supporters in the region dating back to Atomic Energy of Canada Ltd.’s research into the idea of storing spent nuclear fuel deep in the rock of the Canadian Shield in the 1970s.

Over 30 years and 2 million radioactive fuel bundles later, the concept lives on in a proposal put forth by the Nuclear Waste Management Organization (NWMO), the industry-funded organization charged with the task of developing the idea and finding a site for it.

Environmental group Northwatch hosted a discussion on the geological repository concept in Ignace, June, 29.

“From a northern Ontario perspective, we’re very concerned about the siting process and this repeated experience of having waste presented to northern communities as an economic option,” said Northwatch’s Brennain Lloyd. “Economically vulnerable communities are being put under pressure internally and externally, I think, to consider this.”

Waste: what exactly are we talking about?

After leaving a CANDU nuclear reactor, pellets of spent uranium 235 encased in zirconium-alloy bundles are stored in pools of water for a cool-down period of seven to 10 years. Fuel bundles are about the size and shape of a fireplace log, weighing 24 kilograms.

Sufficiently cool to move to dry storage, the fuel bundles are packaged in metal and concrete storage containers, silos or vaults.

Making the safety case

The idea is basically this: use a combination of natural and engineered barriers to isolate used nuclear fuel from humans and the surface environment for as long as the waste remains dangerous.

But how can one account for 1,000 or 1,000,000 years of future geological and socio-political circumstances that can affect the stability of the project.

“It’s a fair question,” says Mahrez Ben Belfadhel of the NWMO. “We’re not pretending that we can predict everything, that’s why the repository has multiple barriers, redundant safety functions. A big part of our site characterization is spent on looking at what has happened over the last million years. We study the history with one question in mind, ‘what was the stability of that site in the past?’. If we can demonstrate that the site has remained stable for 20 million years, we would consider that site amenable to a project like this.”

In a project where assumptions are made on a scale of geologic time and where multiple ice ages are taken into account, Director of the Environmental risk Assessment Division for the Canadian Nuclear Safety Commission Mike Rinker says that uncertainty must be overcome with multiple lines of reasoning as well as the ability to retrieve the waste should the concept not work out as planned.

“It’s just not possible for any of us to say ‘this is demonstrated to be safe’, but we can have multiple lines of evidence to lead us in that direction,” said Rinker,. “In the design of any facility you have to have the concept of retrieval. We have to put the onus on future generations to keep looking at this and asking whether these lines of evidence are still being supported. If not, then we can retrieve the waste and do something else.”

Seismic concerns

Rinker offers some insight into why northern Ontario seems to be ‘targeted’ for such a project. Stability.

He says most seismic activity in the Canadian Shield can be attributed to the slight rising of the underlying bedrock, which has been occurring since the end of the last ice age when weight of overlying glaciers retreated from the land.

“It’s about as stable as you get,” said Rinker. “It’s never zero, but the magnitude of what you would expect is pretty low. In the middle of these plates there’s no driving force to get a really large earthquake.”

Natural Analogs

The NWMO’s multiple barrier system involves encasing fuel bundles in a corrosion resistant copper container, placing them in a bore hole 500 metres below the surface. The bore hole is then surrounded by bentonite clay which isolates the container from moisture.

It’s an approach inspired by nature — mimicking the geological conditions of Saskatchewan’s Cigar Lake uranium deposit. Surrounded by flowing groundwater, a clay barrier has isolated the radioactive ore from the surface.

“It’s the richest uranium deposit in the world,” said Belfadhel. “It was formed 1.3 billion years ago in very porous sandstone, so groundwater has been flowing over it for millions of years. Despite that fact there is no sign of radioactivity at the surface. Scientist involved in the deep geological repository concept have studied this site to death.”

As the industry regulator the Canadian Nuclear Safety Commission (CNSC) usually waits for a license application to get involved in the discussion around a proposed nuclear facility. Yet they’ve already opened channels to communities and the public who are asking questions about the repository concept.

“There are a lot of different aspects to this project, a lot of things that the NWMO has to present so that we can assess its safety,” says CNSC Director of Wastes and Decommissioning, Don Howard. “We’re collaborating with other countries because there’s some things that we’re not quite sure about either. We’re doing research to ensure that we’re in a position that when we review this stuff it seems logical and reasonable to move forward with it. At the end of the day the buck stops with us.”

Transporting waste

While there are over one million shipments of radioactive material per year on Canada’s highways, high-level nuclear waste is not routinely moved in Canada for lack of a destination.

With the advent of a repository, Canada would benefit greatly on the experience of France, the United Kingdom, the United States and Sweden who transport high-level waste on a frequent basis.

Among 3,000 shipments of used nuclear fuel in the U.S. over the past 40 years there have been nine transport accidents — none of which saw the packages release their radioactive contents into the environment.

The philosophy behind the safe transport of high-level waste is to keep the radioactive material inside its robust packaging despite any conceivable eventuality.

Repackaged for transport at Ontario’s power facilities, a load of four tonnes of used nuclear fuel is loaded into a stainless steel cask with walls nearly 30 centimetres thick and a lid attached by 32 bolts.

The transport casks must meet extreme performance requirements to simulate accident conditions. Packages are dropped from nine metres onto an unyielding surface; dropped one metre onto a rigid vertical bar (to test penetration), engulfed in flames to a temperature of 800 degrees Celsius for 30 minutes and immersed in water to a depth of 15 metres for 8 hours.

Northwatch’s Lloyd says the container testing isn’t rigourous enough to satisfy her of their safety.

“Given the consequence of a release, which under accident scenarios could mean complete container collapse, I’d like to see something much more rigourous than putting it under a relatively shallow depth under water for a half an hour. It doesn’t seem like a tough enough test from a practical perspective.”

The transport of nuclear materials is regulated by both Transport Canada and the Canadian Nuclear Safety Commission.

“Internationally it has and is being done,” says the CNSC’s Don Howard. “We’re not doing something brand new here.”

Part 1 — The Broad Strokes

The idea of storing nuclear waste far underground in the bedrock of the Canadian Shield is hardly a new idea in Northwestern Ontario.

From the Dryden Observer archives, January 1980 — an early article discussing Atomic Energy Canada Ltd.’s early research efforts into the deep geological repository concept.

In fact, much of the early testing in developing the very concept of the deep geological repository was done in nearby places like Atikokan, or Lac Du Bonnet across the Manitoba border, close to the now decommissioned Whiteshell Laboratories — a centre for nuclear research from 1963 to 1998.

Shortly after Atomic Energy of Canada Ltd. was asked by the Canadian government in the late 1970s to demonstrate whether used nuclear fuel could be safely disposed of in the rock of the Canadian Shield, Dryden Observer newspaper pages of the day frequently featured stories of the AECL’s exploits on the leading edge of geological science and engineering.

While work continued on a used nuclear fuel disposal option, the Three-Mile Island incident (1979) and Chernobyl disaster (1986) replaced the public’s fascination with increasing wariness towards the nuclear industry throughout the 1980s.

In 1989, AECL’s concept of a deep geological repository was submitted for a federal environmental assessment panel review chaired by former deputy minister of environment Blair Seaborn.

Following nearly a decade of review and public consultation, the Seaborn panel deemed AECL’s plans to be ‘technically acceptable’, though they concluded that the widespread support of Canadians for storing radioactive waste underground had not been demonstrated.

Fusing science and communications, 2002-to present

Still considered by the federal government on its technical merits to be the most promising approach, 2002’s Nuclear Fuel Waste Act set Canada on a clear long-term path towards the development of an underground repository. The Act resulted in the formation of Nuclear Waste Management Organization (NWMO) an industry-funded entity tasked with moving the plan forward with a focus on the ‘ethical and social domains’ of the project.

By 2007, the NWMO had refined their approach into a detailed decade-long, nine-step site selection process.

Learning from other countries’ failures to consult surrounding communities, like Nevada’s widely-opposed and highly-politicized Yucca Mountain Nuclear Waste Repository, the NWMO is looking for both geological suitability and a demonstrated willingness on the part of the host community to interact and be an active partner in the project.

Communities can drop out of the selection process at any time they wish.

“There is no technical urgency for this to happen by a certain date,” says the NWMO’s Michael Krizanc. “We consider ourselves a research and public engagement organization. We’re not driven by a date. What we’re driven by is that Canadians have said that this generation has an obligation to take action now. We have set that the earliest the repository could go into operation is 2035. The intent is that by then, all of the money that is required for this will be in place.”

Funded jointly by Ontario Power Generation, Hydro-Quebec and New Brunswick Nuclear Power Corporation via trust funds for long-term management of spent nuclear fuels, the 10-year construction project is expected to cost as much as $16 billion and up to $26 billion over its lifespan.

A variety of Canadian Shield communities have responded to the NWMO’s call for initial assessment screenings including Ignace, Ear Falls, Red Rock, Schreiber, and Hornepayne.

In northern Saskatchewan the communities of Creighton, English River First Nation and Pinehouse have also undergone initial assessment screenings.

From a pool of promising candidates, two communities will be chosen for detailed site studies, each costing an expected $100 million.

The social element

So why don’t they just find a piece of remote Crown Land with few social entanglements to burden the process?

“There’s no piece of land that people don’t have an involvement or association with,” says Krizanc. “If Aboriginal peoples don’t have Treaties on lands, they have claims that cover most of Canada. You can’t just go digging holes.”

Krizanc adds that the NWMO’s approach is to foster a mutually beneficial relationship with a community and a region — draw upon it for labour during construction and operational phases, contribute to the economy and even work with community members to support local business development to support the facility.

“Based on international experience, when you go to a site and say, ‘I want to build a repository here,’ it will not work,” said Mahrez Ben Belfadhel of the NWMO. “That’s exactly what happened in the U.S. (Yucca Mountain) — the government owned the site and they spent billions studying it. But at the end of the day, the people who were there were opposed to it from day one and they never let go until (Barack) Obama decided to stop the project. It was a purely political decision.”

Significant First Nations consultation is expected to play a key role in any successful site selection process, says NWMO’s Joanne Facella, who adds the process will not resemble what currently happens with conflict-prone mineral exploration practices in Ontario.

She adds an ‘informed and willing’ social component is crucial.

“Unlike a mine, where you’re looking for minerals there’s lot of choices where you can put this from a technical safety point of view,” said Facella. “So, why not put it in a place where people are prepared to accept it?”

Communicating the details of the project can be a challenge. Jamie Robinson says there is much to absorb, though getting to know the details of the deep geological repository concept reduces the ‘fear factor’.

“When we do our open houses, we do find that some people come in a little hot under the collar and very concerned about this issue and things they’ve heard,” said the NWMO’s Jamie Robinson. “When they spend 45 minutes to an hour with us going through and understanding the issue — they’re still not jumping up and down saying it’s the best thing for the community but at least their temperature has gone down. A lot of people get wound-up thinking that the community has already made up its mind and that’s not the case. This is a long, long process. It’s a community decision, not a political decision.”

Next week’s installment of this series will ‘get technical’ delving into the details of the deep geological repository project itself, the nature of nuclear fuel, and perspectives from a variety of groups in regards to  the safety of transporting and storing spent nuclear fuel safely over long-periods of time.

By Chris Marchand