The Nuclear Waste Management Organization (NWMO) in Canada said on Jan. 24 that just two communities, both in the province of Ontario, remain in contention to host an underground disposal facility for spent fuel from the nation’s nuclear power plants.

The locations are the township of Ignace in northwest Ontario and the municipality of South Bruce in southern Ontario. In a press release, the NWMO said it had reached agreements with landowners in South Bruce for sufficient access to their properties to conduct additional technical evaluations on the use of the area for the geologic repository.

The southern Ontario township of Huron-Kinloss is now out of the running, NWMO said.

“The two areas that we’re working in both have a fairly strong potential to be the host community. The issue will come down to a lot of dialogue with those communities, understanding more detail around the technical components, and then really getting an understanding where we might be best placed for this facility,” Laurie Swami, the organization’s president and chief executive officer, said in an interview Tuesday with RadWaste Monitor.

Borehole drilling and some environmental monitoring are expected to begin in South Bruce within a matter of months, according to the NWMO release. The organization remains on track to select the location for the disposal facility by 2023, Swami said.

The nonprofit Nuclear Waste Management Organization was formed by Canadian nuclear utilities in 2002 to select the site for the repository, then build and operate it. The project in total is expected to cost $24 billion CAD ($18.2 billion U.S.). It will bury a projected 5.2 million bundles of radioactive used fuel 500 meters underground. Construction of the repository is expected to last a decade, followed by 40 years to transport and emplace the spent fuel.

Site selection began in 2010 with 22 potential locations. The NWMO gradually whittled down the number of candidate sites through an extended screening and assessment process gauging the suitability of locations and the interest of the surrounding communities, including the First Nations.

The NWMO believes it will need 1,500 acres of land for the repository. The selected area in northwest Ontario is Crown land, which is effectively owned by the government. There would be a set process for acquiring that acreage, including an environmental assessment.

However, in southern Ontario the area is privately owned. By last week, the NWMO had sealed deals with multiple landowners for a total of 1,300 acres: either outright buying the land or signing an option for the property that would be executed if South Bruce is selected the repository.

“We announced our success last Friday. Since that time we have had many other landowners come forward to offer their land as well to be part of our development of a repository,” Swami said during a presentation at the Institute of Nuclear Materials Management’s Spent Nuclear Fuel Management Seminar in Alexandria, Va.

In the subsequent interview, Swami said she did not know offhand how much land had been bought and how much remains under option.

The organization still has years of technical evaluations and community interface remaining before selecting its preferred site.

Six boreholes will be drilled in the Ignace area. Three have been completed, one is being drilled, and two more should be drilled this year.

Drilling in the South Bruce region should begin in a matter of months, Swami said. Three are planned there, each to a depth of roughly 900 meters with a diameter of 85 millimeters, NWMO spokesman Bradley Hammond said by email Friday.

Boreholes allow for testing of rock and water samples to help in determining the best, safest location for disposal. That includes studying the porosity of the rock and the age of the water, along with looking for fractures or other major structures in the rock.

“There’s a number of things we look for, and of course we’re looking for very tight rock, so very little movement within the rock,” Swami said.

Beyond the boreholes, NWMO will conduct extensive site characterizations at each location, focusing on potential environmental impacts of the repository. It expects to spend another $250 million to $500 million (CAD) in coming years before site selection. Local approval, including from indigenous communities, is mandatory for a site to go forward.

Construction on-site will begin with a center for expertise that will provide a hub for technical and social research on the repository, along with a technology demonstration program.

The repository itself will involve surface facilities and then an underground footprint sized roughly 2 kilometers by 3 kilometers. The used fuel assemblies will be held within multiple engineered and natural barriers to prevent a radiation release: fuel pellets, fuel bundles, fuel containers, bentonite clay, and natural rock.

“As we’re getting closer to drilling in southern Ontario, as we narrow down further, we need to educate Canadians and Americans alike,” Swami said in her conference presentation. “You see articles around Michigan complaining that we were too close to the Great Lakes in our siting process, and we think that it’s important that we explain what the process is, explain the safety factors and how safe that these facilities will be.”

State and federal lawmakers from Michigan have expressed particular concern about plans for disposal of Canadian radioactive waste near the Great Lakes. That has generally focused on Ontario Power Generation’s planned geologic repository for low- and intermediate-level waste at its Bruce power plant in Kincardine, near Lake Huron. The Canadian government has not yet signed off on the plan, and members of the Saugeen Ojibway Nation were voting Friday whether to support the utility’s approach, Bloomberg reported.

The Michigan House of Representatives is currently considering a resolution urging Congress to “take every legal action possible” to keep the Canadian government from approving the utility’s plan.

Swami was senior vice president for decommissioning and nuclear waste management at Ontario Power Generation before joining the Nuclear Waste Management Organization in November 2016. On the NWMO’s repository siting, she noted that even the southern Ontario location at South Bruce is 30 kilometers from Lake Huron.