Small modular reactors and our ecosystems - engagement, transparency & trust; summary of a workshop held at McMaster University, Canada.

Purpose: Globally, governments are launching national programs, demonstration projects and industrial partnerships to bring small modular reactors (SMR) to market as lower-carbon, more flexible forms of nuclear power. Current international assessments suggest the first wave of commercial projects will be built in the 2020s, followed by broader deployment. It is anticipated that SMR could provide roughly a quarter of new nuclear capacity added worldwide by 2050. Siting of reactors is expected to be distributed and distinct from traditional large-scale dedicated centers; for example, close to cities and in remote environments. Unique safety concerns exist for these sites, and concerns go beyond solely traditional radiation protection and involve the impacts of infrastructure on site which extend beyond concerns associated with conventional large nuclear facilities. These include cradle-to-grave assessment of uranium mining, milling and transport, worker accommodation, and both human and environmental disruption. Waste associated with cooling, operation, and decommissioning is also an issue. This requires monitoring potential sites appropriately to establish comprehensive ecosystem baselines. Conclusions: This paper summarizes and expands the discussion of a group of experts who gathered to discuss the environmental risks and potentials of SMR in addressing Canada's climate goals, energy security, industrial and economic development. Experts were from areas including radiobiology, radioecology, radiation protection, engineering, regulatory authority and Indigenous community leadership. Discussions focused on scientific and governance principles that should inform the potential proliferation of multiple SMR, including design, siting, and assessment of their environmental impacts. This paper is derived from discussions among participating experts and reflects perspectives expressed by various contributors. While the paper aims to synthesize key themes that emerged during discussions, it does not represent the views of all participants, nor does it reflect a consensus position. Views expressed should not be interpreted as official positions of any participating organization, institution, or regulatory body.