Atomic Energy of Canada Limited


AECL, CNL and AtkinsRéalis team up to bolster Canada’s strategic heavy water supply in support of CANDU technology

Chalk River, ON – May 13, 2024 –Atomic Energy of Canada Limited (AECL), Canadian Nuclear Laboratories (CNL), and AtkinsRéalis are pleased to announce that they have signed a Memorandum of Understanding (MOU) to explore opportunities to collaborate on heavy water production. The agreement comes amidst renewed interest in domestic nuclear energy production in Canada, including the potential deployment of large-scale nuclear power reactors in Ontario, which may require significant volumes of heavy water to operate, depending on the design selected.

As the owner and operator of Canada’s national nuclear laboratories, AECL and CNL collectively maintain the necessary expertise, technology, facilities and intellectual property (IP) necessary for the production, management and upgrading of heavy water, a form of water that is used as a moderator and coolant in Canada’s current fleet of CANDU® reactors. These capabilities complement those at AtkinsRéalis, an international leader in the nuclear industry and steward of CANDU technology that has introduced a next-generation CANDU reactor. Known as the CANDU® MONARKTM, the 1,000 MW nuclear reactor would require the use of heavy water in its operation, like other CANDU reactors, and represents the only large-scale reactor developed domestically in Canada.

“Alongside our client, AECL, CNL is thrilled to enter into this MOU with AtkinsRéalis, an agreement that leverages our extensive expertise and resources in heavy water production, and which acts as a meaningful step forward in the deployment of home-grown, large-scale nuclear power here in Canada,” commented Jack Craig, CNL’s President and Chief Executive Officer. “As operator of AECL’s Chalk River Laboratories, which is the birthplace of the CANDU reactor, CNL is well-versed in this technology, and we play a significant role in ensuring its safe and reliable operation around the world. The CANDU reactor design is a proven technology and CNL will continue to support the technology now and into the future, which includes establishing the necessary heavy water inventory and production capabilities.”

“I am pleased that AECL, CNL and AtkinsRéalis are collaborating and working together to advance heavy water production for CANDU reactor technology. CANDU technology is uniquely positioned to contribute to important national objectives such as decarbonization, energy security, economic growth and maintaining Canada’s Tier-1 nuclear nation status,” said Fred Dermarkar, President & Chief Executive Officer of AECL.

“CANDU technology, as Canada’s only domestically developed large scale nuclear technology, is a source of national pride,” said Joe St. Julian, President, Nuclear, AtkinsRéalis. “We are honoured to continue stewarding and enhancing its reputation as a leading global nuclear technology. A reliable supply of heavy water will also safeguard the supply of the global isotope market with cancer-fighting nuclear medicine, as CANDU reactors— with Ontario’s supplying 50% of the world’s supply of Cobalt 60 — are the only commercial scale reactors that can produce such medical isotopes while also producing power at the same time.”

According to terms of the MOU, the organizations will explore opportunities to work together, along with additional strategic partners whose expertise could accelerate technologies, to either produce or upgrade heavy water that could be used in the commissioning and operation of new CANDU reactors in Canada. All three organizations recognize that the construction of CANDU reactor new builds would require significant volumes of heavy water, a need that would require the construction of new facilities in Canada. They also have a shared interest in advancing this technology towards deployment that goes beyond commercial opportunities, recognizing that it contributes to important national policy objectives in Canada, including decarbonisation, energy security, economic growth and maintaining Canada’s position as a leading nuclear nation. In addition to the current collaboration, AECL and CNL intend to play a leadership role in additional initiatives to support the success of this nascent industry in Canada.

“As the owner of CANDU intellectual property licensed to Candu Energy Inc. and owner of Canada’s national nuclear laboratory at Chalk River, Ontario, managed and operated by CNL, AECL is committed to seeing its CANDU technology and the unique capability of its national laboratory leveraged for the benefit of Canadians,” commented Grant Gardiner, EVP, Business Strategy & Development. “We believe establishing a secure, domestic and economically viable supply of heavy water is vital to the continuing success of CANDU technology and are proud of the unique capability that our national laboratory brings to this effort.”

Heavy water is a form of water in which the normal hydrogen is replaced by a heavier form of hydrogen called deuterium. In the case of CANDU® reactors, heavy water has two applications – first, it is used as a moderator to slow the speed of neutrons during the fission process, which allows operators to regulate the reactor’s power output. It is also used as a coolant, circulating throughout the reactor core to cool it down and keep it to the desired temperature. Leveraging AECL’s facilities and IP, CNL is a world leader in the production, management and upgrading of heavy water.

“The deployment of large-scale nuclear power in Canada is an enormous undertaking, and will require extensive alignment and coordination between organizations, industries, public officials and regulators from across the country,” added Jack Craig. “Heavy water is one key piece of the larger puzzle, and AECL and CNL are working together to play a leadership role in this process, ensuring that the broader industry is working towards a shared vision, and that the necessary inventory and production capabilities are in place to supply these reactors. CNL looks forward to leveraging our world-leading expertise, experience and CNL-managed, AECL-owned IP in heavy water production and upgrading to support the deployment of new CANDU reactors in Canada with AtkinsRéalis. By doing so, we will strive to make Canada the leader in the global heavy water market.”

For more information on AECL, please visit If you’d like to learn more about CNL, including its work related to heavy water production and management, please visit For additional details on AtkinsRéalis and the CANDU® MONARKTM, visit


About Atomic Energy of Canada Limited
Atomic Energy of Canada Limited (AECL) is a federal Crown corporation with a mandate to drive nuclear opportunities for Canada. Working through a government-owned / contractor-operated (GoCo) model that is executed by its contractor, Canadian Nuclear Laboratories, AECL enables nuclear science and technology through its Chalk River Laboratories, Canada’s largest research complex, and by engaging with academia and private industry to advance nuclear innovation. It is committed to advancing reconciliation with Indigenous peoples. It also manages the Government of Canada’s radioactive waste responsibilities. AECL continues to own the intellectual property for the CANDU® reactor technology and is accountable for deriving optimal benefit from this technology for Canada.  Read more on AECL at


About CNL
As Canada’s premier nuclear science and technology laboratory and working under the direction of Atomic Energy of Canada Limited (AECL), CNL is a world leader in the development of innovative nuclear science and technology products and services. Guided by an ambitious corporate strategy known as Vision 2030, CNL fulfills three strategic priorities of national importance – restoring and protecting the environment, advancing clean energy technologies, and contributing to the health of Canadians.

By leveraging the assets owned by AECL, CNL also serves as the nexus between government, the nuclear industry, the broader private sector and the academic community. CNL works in collaboration with these sectors to advance innovative Canadian products and services towards real-world use, including carbon-free energy, cancer treatments and other therapies, non-proliferation technologies and waste management solutions.

To learn more about CNL, please visit


About AtkinsRéalis
Created by the integration of long-standing organizations dating back to 1911, AtkinsRéalis is a world-leading professional services and project management company dedicated to engineering a better future for our planet and its people. We create sustainable solutions that connect people, data and technology to transform the world’s infrastructure and energy systems. We deploy global capabilities locally to our clients and deliver unique end-to-end services across the whole life cycle of an asset including consulting, advisory & environmental services, intelligent networks & cybersecurity, design & engineering, procurement, project & construction management, operations & maintenance, decommissioning and capital. The breadth and depth of our capabilities are delivered to clients in key strategic sectors such as Engineering Services, Nuclear, Operations & Maintenance and Capital. News and information are available at or on LinkedIn.


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Jeremy Latta
Director, Communications and Government Reporting