History of Nuclear in Canada

Canada’s nuclear sector began in the 1940s in Chalk River, Ontario with early scientific research into atomic energy. Over the decades, this research evolved into a fully integrated nuclear sector encompassing electricity generation, medical isotope production, uranium mining, fuel fabrication, nuclear research laboratories, and a comprehensive federal regulatory system.

Canada developed its own reactor technology — CANDU (Canada Deuterium Uranium) — which uses natural uranium fuel and heavy water as a moderator and coolant. CANDU reactors became the foundation of Canada’s commercial nuclear power fleet and were exported internationally.

Throughout the second half of the 20th century, nuclear facilities were established in several provinces, creating long-term host community relationships that continue today.

Evolution of Regulation

Originally regulated under the Atomic Energy Control Act, Canada’s nuclear oversight framework was modernized in 2000 with the introduction of the Nuclear Safety and Control Act.

This legislation established the Canadian Nuclear Safety Commission (CNSC) as Canada’s independent nuclear regulator, separating promotional and regulatory functions and strengthening transparency, public participation, and environmental protection requirements.

The CNSC regulates all nuclear facilities and activities in Canada, including uranium mining, milling, fuel fabrication, reactor operations, isotope production, waste management, transportation, security, and safeguards.

Why History Matters for Host Communities

For nuclear host communities, understanding this historical evolution provides important context for:

• current safety and regulatory standards
• public perception of nuclear energy
• long-term facility operations and refurbishment cycles
• environmental remediation and decommissioning activities
• Canada’s international nuclear commitments

The nuclear facilities operating today are part of a regulatory and technological system shaped over decades of scientific advancement, policy development, and community engagement.