Research looks for results that ‘outlive us all’

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Ensuring forever-safe storage of Canada’s nuclear fuel waste is a complex choreography that requires cutting-edge science, judicious site selection, secure transportation and no small measure of public buy-in. And although many of the logistics are in other experts’ hands, Western has emerged as a significant player in the science of developing and testing storage technologies that won’t corrode, leak or release radiation.

Interdisciplinary teams of chemists, microbiologists, physicists, earth scientists and engineers are working on inter-related aspects of the problem to make Canada a world leader in responsible nuclear waste management that keeps radioactive materials safely stored for millennia.

That research was recently showcased as officials from the Nuclear Waste Management Organization (NWMO) paid a visit to Western for a high-level update on the progress of their work. The tours were also an opportunity for NWMO President and CEO Laurie Swami to meet with emerging and established researchers at the home of the organization’s longest-term university partner.

“It’s the institution we’ve had the longest relationship with and our largest investment through those 20 years,” Swami said. “Western is obviously an important part of our program.”

Since 1999, NWMO has invested millions of dollars at Western directly supporting technical research. Those funds allowed faculty to leverage further investments from the Natural Sciences and Engineering Research Council of Canada (NSERC), the Ontario Research Fund (ORF) and other research bodies.

The main emphasis of the research involves predicting and ensuring corrosion resistance in the copper-over-carbon-steel canisters that will entomb the spent fuel bundles in dense bentonite clay in a vault deep below the Earth’s surface.

Western’s challenge is to test and scientifically model how a planned 3-mm copper electroplated surface can be more durable than a 50-mm copper sheath other that other nuclear-energy countries such as Finland and Switzerland are developing to manage their waste.

Answers to these questions have implications that, in the words of one senior NWMO official, “will outlive us all.”

Canada has about three million bundles of fuel waste in surface storage, with each bundle about the size of a fireplace log. NWMO is responsible for a long-term solution intended to last a million years, and has proposed an engineered barrier system that includes placing them in sealed and electroplated canisters and embedding them in bentonite clay deep below surface in a dense limestone or granite repository.

Corrosion-proof electroplating is a key part of this multiple-redundancy system, Swami said.

“It’s really important that corrosion is prevented because we don’t want any of the used fuel (bundles) exposed. With the copper coating and the carbon steel vessel, we have a good barrier to prevent corrosion – it really demonstrates that the long-term safety for the used fuel in the underground environment will be protected, even with radiolysis, even under different environment conditions.”

The group toured labs supervised by Chemistry professors and researchers Clara Wren, David Shoesmith and Jamie Noel and heard from young researchers working both on different and inter-connected facets of the work.

Science Dean Matt Davidson said the research undertaken at Western’s labs “is a shining example” of solid science, teamwork and partnerships. “The relationship has already been a fruitful one.”

Within the research teams, there’s an almost equal number of males and females – a ratio that also makes for well-rounded research approaches and problem-solving, Swami noted.

Swami – an engineering chemist who has worked in power generation and nuclear waste management and decommissioning at the provincial and national level since 1986 – said it’s important to cultivate smart scientists of both sexes and to remove barriers junior women have to entering and growing in the field.

“Women do bring a different perspective, whether to research or collaboration or communication. They do bring a different perspective to bear on whatever the work is,” Swami said.

Her team is working to shift the balance change by growing “a complete pipeline” for women in the field, from junior hires through to senior managers and the board.

Wren added perceptions of women in nuclear science has “progressed a lot” during her combined 35 years working in the industry and in university research: “What we are recognizing is that the women are equally capable and in fact they bring different skills. Women tend to think at things in more inclusive ways, more interdisciplinary ways.”

Wren and her student researchers said some of their work, soon to be published in peer-reviewed journals, challenges assumptions of previous corrosion models.

“We have a better way of predicting how the corrosion might evolve over a long period of time and the environment the containers will be exposed to. I think we have a lot more confidence about how these containers will behave.”

Of the original 22 Canadian communities expressing interest as “informed and willing hosts” to the repository, NWMO has recently narrowed the list to three: Ignace in northwestern Ontario and the municipalities of Huron-Kinloss and South Bruce, near the Bruce Nuclear Generating Station.

By 2023, NWMO will have chosen one site, Swami said.

The safety analyses, extensive third-party review and public hearings are all “a fundamental part of the work” towards expected regulatory approval by the Canadian Nuclear Safety Commission, licencing by 2032 and operation by 2043, Swami said.

“From my perspective, the technical case is there. There’s still work to be done,” she said. “There’s obviously more studies to be done but we have the best technical solution for used fuel management in the long run. No question in my mind. What we really need to do is have all of the processes in place to make sure that communities feel confident, as I feel confident in the safety of the technology.

“We’re responsible for the long-term safe management of used nuclear fuel that will protect people and the environment essentially for forever, and so it has to be something that stands the test of time.”

Swami was appointed to the top NWMO role in 2016. She previously served as Senior Vice-President of Decomissioning and Nuclear Waste Management at Ontario Power Generation, where she oversaw OPG’s nuclear waste management facilities and led the file for OPG’s plans to build a deep geologic repository (now on hold) for non-fuel, intermediate- and low-level nuclear waste.