Evaluating Bedrock Stability and Geological Risks at Revell
This article is part of a series exploring the views and perspectives of youth, artists and community members working with the Melgund Integrated Nuclear Impact Assessment Project. This initiative is a climate entrepreneurship and arts-based community recreation program, developed through community consultation, engagement participation in the integrated impact assessment process for the NWMO’s proposed Deep Geological Repository for nuclear waste fuel.
What is Proposed
The Nuclear Waste Management Organization (NWMO) proposes to host a Deep Geological Repository (DGR) for Canada’s used nuclear fuel within the northern portion of the Revell batholith. This geological formation is a 2.7-billion-year-old rock unit approximately 40 km in length and 15 km in width. The proponent claims that the site provides a sufficient volume of homogeneous and competent granitoid rock to host the repository at a depth of approximately 750 meters. They assert that the repository can be strategically positioned between larger-scale structures, currently identified as fracture zones, within a rock unit that geophysical models suggest extends to a depth of nearly 4 km.
Underlying Assumptions
- The Revell batholith is relatively uniform in its composition and exhibits a low degree of deformation and fracturing.
- Current geophysical modeling accurately reflects the depth and thickness of the host rock without the need for extensive deep-crustal seismic validation.
- The six existing deep boreholes provide a representative sample of the geological conditions across the entire project site.
- Fracture zones are sufficiently isolated to allow for the safe positioning of the repository between them.
- Overburden thickness in wetland areas, though currently inferred, will not significantly impact construction or surface-water interactions.
Community Assessment
Our community-driven review of the Initial Project Description has identified several areas where the geological narrative requires deeper scrutiny. A primary concern is that structural features and fracture zones are currently “presently inferred” rather than fully characterized. For the community, this distinction is vital; inferred zones represent the highest risk for potential containment failure, as they are the primary pathways for radionuclide migration. Furthermore, the current borehole density is notably low for a project of this magnitude. Relying on only six boreholes for a 40km x 15km area may fail to capture localized geological anomalies that could disqualify specific locations. We also observe that the overburden in valleys and wetlands is only inferred to be several metres thick. Without site-specific geotechnical drilling in these sensitive areas, there is an increased risk of unforeseen surface-to-subsurface water interactions that could impact the long-term stability of the site.
Path Forward
To improve the technical rigor of the assessment and ensure public safety, we recommend that the proponent implement a high-density borehole drilling program and advanced seismic reflection surveys. This is necessary to transition from “inferred” fracture zones to a verified, high-resolution structural map. Understanding the precise geometry and connectivity of these fractures is essential to justify the claim that the repository can be safely isolated. Additionally, a comprehensive analysis of the overburden in wetland areas must be conducted to address potential groundwater recharge impacts. Finally, a sensitivity analysis of the 3D geophysical model should be provided to demonstrate how variations in rock density or undetected minor faulting might alter the current interpretation of a “homogeneous” rock mass.
About the Integrated Assessment Process
The federal Impact Assessment Agency of Canada (IAAC) has formally launched the integrated impact assessment process for the proposed Deep Geological Repository (DGR) for Canada’s Used Nuclear Fuel Project, a major national infrastructure initiative led by the Nuclear Waste Management Organization (NWMO).
The proposed underground repository is designed to permanently contain and isolate used nuclear fuel in a secure geological formation. Wabigoon Lake Ojibway Nation and the Township of Ignace have been selected as host communities for the project. The site is located approximately 21 kilometres southeast of Wabigoon Lake Ojibway Nation and 43 kilometres northwest of Ignace, Ontario, near Highway 17.
According to project materials, the repository would provide permanent storage for approximately 5.9 million bundles of used nuclear fuel. The full lifecycle of the project is expected to span roughly 160 years, including site preparation, construction, operations, closure, and long-term monitoring.
Integrated Federal Review
Major nuclear projects in Canada are subject to an integrated assessment process jointly led by the Impact Assessment Agency of Canada and the Canadian Nuclear Safety Commission (CNSC). This “one project, one review” approach is intended to streamline regulatory oversight while ensuring rigorous evaluation of environmental, health, social, economic, and Indigenous rights impacts.
Under this framework, IAAC oversees the impact assessment requirements under the Impact Assessment Act, while the CNSC regulates nuclear safety under the Nuclear Safety and Control Act. The CNSC will issue the initial site preparation licence and manage all subsequent nuclear licensing for the project’s duration.
The integrated assessment also includes a focus on potential impacts on Indigenous Peoples, including rights, land use, cultural practices, health, and socio-economic conditions. Where potential adverse effects are identified, the process is intended to identify mitigation measures to reduce or avoid harm.
Public Comment Period Now Open
The first public comment period for the project is currently open and will run until February 4, 2026. During this phase, the public is invited to provide feedback on the Summary of the Initial Project Description submitted by the NWMO. Submissions received during this period will inform IAAC’s summary of issues, which will guide the next stages of the impact assessment. All comments submitted become part of the public project record and are posted to the federal Impact Assessment Registry.
This plain-language summary is provided by ECO-STAR North and Art Borups Corners to support public engagement.
Disclaimer: The views and perspectives expressed in this article are solely those of the independent arts program led by ECO-STAR North and Art Borups Corners. They do not reflect the official positions of the Nuclear Waste Management Organization (NWMO) or the Government of Canada.
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