TEESWATER – The South Bruce Community Liaison Committee (CLC) met via Zoom on June 16 to receive the Aggregate Resource Study, the Deep Geological Repository (DGR) Conceptual Design layout, and a brief introduction to the Confidence in Safety Report.
Several presenters were on hand to discuss the studies and answer questions from members of the CLC and the general public, including Jeremy Taylor, central regional manager from R.J. Burnside & Associates, and Andrew Keir, president of Keir Corp.
The pair were joined by Nuclear Waste Management Organization (NWMO) employees Allan Webster, director, regulatory affairs and environmental assessment; senior engineer Dylan Luhowy; Dr. Paul Gierszewski, director, safety and technical research; Matthew De Los Santos, section manager, mining and repository engineering; Shanu Shaikh, design authority; and Andre (Chip) Lee, manager of mining and repository engineering for the presentations.
Gierszewski started the presentation with the introduction to the Confidence in Safety Report, referring to the ongoing analysis, like the rock core samples which they are testing for things like porosity or hydraulic conductivity or mechanical strength, adding, “if the site selected, there will be new studies that would be initiated, such as additional deep boreholes.”
Gierszewski said, “I want to be clear that we are at a point in the process of developing confidence.”
He spoke about what has already been done, such as borehole drilling. But, he said, “there are more things that we will do over the next few years as we progressively improve our understanding of the site.”
Much of their confidence in safety at the South Bruce site is based on the multiple-barrier system, which Gierszewski says is an internationally accepted approach, as well as the evidence of the suitability of the rock from recent studies.
The presentation slide said, “The Cobourg Formation is our preferred rock, and our boreholes found it right where it was expected at the site, at around 650m depth and surrounded by hundreds of meters of strong rock.”
“We are now measuring properties of this rock, but it looks good,” said Gierszewski.
Key points highlighted in the study include a favourable geological setting, the stability of the setting, the risk of future human intrusion into the repository if the site is amenable to geological characterization, a robust multiple-barrier system, the ability to construct and operate the repository safely, the ability to transport fuel to the site safely, and that the facility performance will meet regulatory criteria.
The expanded Confidence in Safety Key Points explanation can be read on the NWMO’s website.
“We’re at a point in the process, but what we’re assessing now is whether we think we have sufficient confidence in the likely outcome to proceed with the South Bruce site,” said Gierszewski. “We’re doing this separate … report now to support the discussion with the community on this, but we’re not stating that we have enough information at this point for a license to construct or operate.”
The presentation concluded, “Overall, based on the assessment results to date, the NWMO is confident that a deep geological repository could be constructed at the South Bruce site in a manner that would provide safe long-term management of Canada’s used nuclear fuel.”
Luhowy spoke about the aggregate resources study, how the aggregates would be used during construction and operations, the excavated rock management area, and best management practices and site water management.
The excavated rock management area, which will store rock removed during underground development, will mainly comprise the Cobourg limestone formation.
“It’ll be about two and a half million cubic meters of rock in total,” said Luhowy. “For construction, the base is prepared by grading with an impermeable liner installed as required underneath the pile. There will be perimeter ditches constructed and a stormwater management pond as well.”
Luhowy said that some of the aggregate generated by the project during construction may be used on-site, but “we just want to emphasize that no excavated material will be made available for outside commercial use.”
“But the possibility does remain open to the possibility of donating material to projects that might otherwise not be economic to undertake,” said Luhowy.
The study indicated that some of the resulting rock pile would be used in the decommissioning process and as back filler for the underground openings.
The pile of leftover rocks would then be landscaped and rehabilitated to blend in with the surroundings, capable of supporting a self-sustaining ecosystem.
Kier took over the presentation to discuss local aggregate resources, outlining how much would be needed and where they would possibly get the gravel.
“At the present time, within South Bruce, there are 33 licensed pits,” Kier said. “And the current annual production from those pits is about 450,000 tons. Now over the life of the project, the amount of aggregate that will be required is in the order of 1.9 million tons.”
Kier explained the possibilities of using licensed and undeveloped aggregate sites and going beyond the borders of South Bruce if necessary.
De Los Santos went over the facility’s conceptual design, saying, “we are currently underway with some pre-feasibility level or advanced class four estimate level engineering work packages, and that’s per the Association for Advancement of cost engineering.
“But, in the future, once site selection has been completed, we’ll progress with some detailed engineering work to tailor some of these pre feasibility study designs to our detailed site-specific characteristics and considerations.”
The summary of the conceptual design included an overview of surface facilities and used nuclear fuel lifecycle management from receipt on-site to underground emplacement, shaft sinking with water management techniques and technologies, and the underground lateral development sequence and phases over the lifecycle of the repository.
You can view the entire conceptual design at https://www.southbruce.ca/en/municipal-government/studies-and-reports.aspx.
Cory Bilyea, Local Journalism Initiative Reporter, Wingham Advance Times