Gentilly 1 declared free from nuclear fuel

Tuesday, 8 July 2025

Gentilly 1 - a 250 MWe steam-generating heavy water reactor with vertical pressure tubes, light water coolant and heavy water moderation - operated intermittently from 1972 to 1978. A decommissioning programme was initiated in 1984 to bring the facility to a safe shutdown state. Since then, the facility has been in a state of safe, long-term storage with ongoing monitoring. Operations at the site are conducted under a licence issued to Canadian Nuclear Laboratories (CNL) by the Canadian Nuclear Safety Commission (CNSC). The Gentilly 1 site is now partially decommissioned and is licensed as a waste facility, the Gentilly-1 Waste Management Facility (G1WF).

The facility is owned by Atomic Energy of Canada Limited (AECL), which has contracted CNL to manage and operate its sites. The facility is adjacent to the Gentilly 2 plant, which was shutdown in 2012.

CNL has now completed the transfer of used fuel from G1WF to Chalk River Laboratories, "safely removing a major nuclear liability and clearing the way for the next steps in the decommissioning and environmental remediation of the facility".

"The efficient and safe completion of this important project reflects the deep expertise CNL has developed through years of complex, technical work in nuclear material management," said Mark Chapman, CNL's senior director of the fuel programme. "The project required detailed planning and coordination, including the development of specialised fuel-handling systems, and enhancements to storage infrastructure at CRL."

As outlined in CNL's comprehensive Integrated Waste Strategy, the fuel is now securely stored in modern purpose-built canisters at the Chalk River Laboratories – where it will remain until the Nuclear Waste Management Organization's planned long-term disposal facility for used nuclear fuel becomes available. CNL said its strategy is "aligned with Canada's national policy to reduce the number of waste sites by centralising the safe and secure storage of fuel waste".

"The successful delivery of this project is a reflection of the expertise, dedication, and collaboration across our entire organisation,” said CNL President and CEO Jack Craig. "It demonstrates CNL's commitment to safety, environmental stewardship, and the responsible management of Canada's nuclear legacy."

CNL submitted an application in July 2024, to the CNSC to amend the current licence for the facility to permit decommissioning. The CNSC has announced a public hearing in writing, scheduled for July 2026, to consider the proposed amendment for the Gentilly-1 Decommissioning Project. The amendment would authorise CNL to proceed with decommissioning all remaining buildings and structures at the site to achieve a brownfield end state.