Section Synopsis
Pages: 110The provided text summarizes geological findings for a proposed Deep Geological Repository (DGR) site, asserting that the granitoid rock at the location is sufficiently voluminous, homogeneous, and competent. It identifies a preferred repository depth of approximately 750 meters, situated between inferred fracture zones. The proponent concludes that the site's bedrock exposure is favorable for study and that there is no evidence of geological hazards such as landslides or liquefaction affecting the project.
Community Assessment Narrative
The text presents a highly confident outlook on the geological suitability of the site, yet it relies on several qualifiers that merit closer scrutiny. The use of the term 'inferred' regarding fracture zones (FZs) suggests a level of uncertainty in the subsurface mapping that contrasts with the definitive claim of rock 'homogeneity.' In geological terms, the presence of large-scale structural features like FZs inherently contradicts the description of the rock as homogeneous, indicating a potential bias in how the proponent characterizes the site's complexity. Furthermore, the assertion that there is 'no evidence' of risks like landslides or liquefaction is a negative proof; the absence of evidence in 'studies to date' does not necessarily equate to the absence of risk over the long-term lifecycle of a nuclear waste repository.
Transparency is also limited by the vague reference to 'studies to date' without citing specific methodologies or data sets. This lack of supporting detail makes it difficult for independent reviewers to validate the claim that the volume of competent rock is 'sufficient.' The tone, while professional, leans toward a confirmatory bias, emphasizing favorable conditions (minimal overburden, good exposure) while potentially downplaying the technical challenges of positioning a DGR between inferred structural failures. The narrative would be strengthened by a more balanced discussion of geological uncertainties and the specific criteria used to define 'competent' and 'sufficient' in the context of long-term radioactive waste containment.
Corrective Measures & Recommendations
The proponent should provide a detailed inventory and summary of the 'studies to date,' including geophysical surveys, borehole data, and peer-reviewed geological assessments. This documentation must clarify the degree of uncertainty associated with 'inferred' fracture zones and provide a 3D geological model demonstrating the spatial relationship between these structures and the proposed repository footprint. Without this, the claim of 'sufficient volume' remains an unsubstantiated technical assumption that could lead to significant design changes or safety concerns if subsurface conditions differ from surface inferences.
Additionally, the proponent should conduct and present a comprehensive long-term seismic and geomorphological stability analysis. While the text dismisses risks like liquefaction and landslides based on current evidence, a DGR requires stability over thousands of years. The proponent must justify how current surface observations and 'minimal overburden' translate to long-term subsurface stability, specifically addressing how potential seismic events or climate-induced changes could reactivate inferred fracture zones or impact the integrity of the granitoid host rock at the 750-meter depth.
On 16 February, 2026 the Impact Assessment Agency of Canada (IAAC), with input from the Canadian Nuclear Safety Commission (CNSC), published a Summary of Issues (SOI) for the proposed Deep Geological Repository (DGR) for Canada’s Used Nuclear Fuel Project, put forward by the Nuclear Waste Management Organization (NWMO). The SOI identifies the key issues that IAAC considers relevant to the federal integrated impact assessment process for the project. NWMO’s response to the SOI will assist IAAC in determining whether an impact assessment is required under section 16 of the Impact Assessment Act. If an impact assessment is required, the issues outlined in the SOI—together with NWMO’s response—will help shape the scope of the assessment and inform the continued development and finalization of the Integrated Tailored Impact Statement Guidelines and associated plans.
Alignments to IAAC Summary (SOI)
The community findings from Melgund Township demonstrate a high degree of alignment with the "Physical and Biological Environment" section of the IAAC Summary of Issues (SOI), particularly regarding "Geology, geochemistry, and geological hazards." The Township’s concern regarding the proponent’s reliance on "inferred" structural features directly supports the IAAC’s identified need for a "detailed understanding of the rock formation" to determine technical suitability. While the IAAC SOI broadly flags "structural stability" and the "presence of faults and fractures" as key issues, Melgund’s analysis provides specific technical weight to this requirement by identifying that current surface-level inferences are insufficient for a project of this magnitude.
Furthermore, Melgund Township’s critique of the proponent’s dismissal of geological hazards—specifically landslides and liquefaction—aligns precisely with the IAAC’s category of "Destabilization of geology and induced geological hazards." The IAAC SOI explicitly lists landslides and liquefaction as concerns that could affect long-term containment. Melgund’s assessment validates the inclusion of these risks by pointing out a critical gap in the proponent’s logic: treating a current lack of evidence as proof of long-term stability. This supports the IAAC’s requirement for the proponent to address how project activities might induce such disasters over the repository's multi-generational lifespan.
A significant alignment is also found in the realm of data transparency and project description adequacy. The Township’s observation regarding vague references to "studies to date" without specific citations mirrors the concerns listed in Annex A of the IAAC SOI under "Project description." The Agency noted public concerns regarding the "clarity and transparency" of the proponent’s documentation. Melgund’s findings provide a concrete example of this lack of transparency, noting that reviewers cannot verify claims of rock competence without access to the underlying source data and geophysical surveys.
Recommendations
The working group recommendations emphasize that the proponent must move beyond qualitative assertions of "homogeneity" and provide a quantitative, data-driven 3D geological model. This model should explicitly map the spatial relationship between the proposed 750-meter repository footprint and the "inferred" fracture zones. By requiring a detailed inventory of geophysical surveys and borehole data, these recommendations directly address the IAAC’s "Suitability of host rock" issue. Providing this level of detail is the only way to resolve the uncertainty identified by both the community and the Agency regarding whether the host rock can truly provide containment for thousands of years.
Additionally, it is recommended that the proponent conduct a formal geomorphological and seismic hazard assessment that accounts for long-term environmental changes, such as glaciation or climate-induced shifts. This recommendation is designed to bridge the gap between the proponent’s current surface observations and the IAAC’s concern regarding "Long-term containment of waste" and "Seismicity." By demanding a justification for how subsurface stability is maintained over millennia, the community ensures that the "Destabilization of geology" issues identified in the SOI are addressed with scientific rigour rather than unsubstantiated technical assumptions.
Key Claims
Underlying Assumptions
Critical Observations & Gaps
Analysis Table| Issue Identified | Implication | Information Required |
|---|---|---|
| Reliance on 'inferred' structural features for site positioning. | If the 'inferred' fracture zones are incorrectly mapped, the structural integrity of the repository could be compromised. | High-resolution 3D seismic imaging and borehole verification data. |
| Vague reference to 'studies to date' without specific citations or data summaries. | The validity of the entire geological assessment cannot be verified by reviewers without knowing the source data. | A comprehensive list of references and a summary of the data supporting the claims of rock competence. |
| Contradiction between 'homogeneous' rock and the presence of 'structural features.' | The term 'homogeneous' may be an oversimplification that masks localized geological complexities relevant to waste containment. | A quantitative definition of homogeneity and data on the frequency and scale of minor fractures within the 'homogeneous' blocks. |
| Absence of evidence for landslides or liquefaction is treated as evidence of absence of risk. | Dismissing hazards based on 'no evidence' may overlook low-probability but high-impact long-term geological events. | A formal geomorphological and seismic hazard assessment covering the projected lifespan of the repository. |
Working Group Recommendations
Challenge the statement that there is 'no evidence' of landslides or liquefaction by requiring a forward-looking geohazard assessment that models slope stability and ground integrity over the repository's full lifecycle.
Request the specific geophysical datasets and borehole logs used to map the 'inferred' Fracture Zones (FZs) and demand a quantitative definition of rock 'homogeneity' relative to these structural features.
Understanding the Impacts of Nuclear Waste on our Community
This digital archive houses the public comments submitted to the Impact Assessment Agency of Canada regarding Project 88774: The Nuclear Waste Management Organization Deep Geological Repository (DGR) for Canada's Used Nuclear Fuel Project. The impact assessment is led jointly by the Impact Assessment Agency of Canada and the Canadian Nuclear Safety Commission. This archive preserves community perspectives, concerns, and observations shared during the assessment process, particularly in relation to Melgund Township, Northwestern Ontario and the communities of Dyment and Borups Corners who are the closest and most impacted of all in the process.