Modernized Combined Electrolysis and Catalytic Exchange

The construction of a Modernized Combined Electrolysis and Catalytic Exchange (MCECE) facility is being proposed at the Atomic Energy of Canada Limited (AECL), Chalk River Laboratories site. The associated project activities will be carried out by Canadian Nuclear Laboratories (CNL), the organization responsible for the operations of all AECL sites, including the Chalk River Laboratories (CRL) site where this project is proposed.

CNL has significant operating and design experience in the Electrolysis and Catalytic Exchange field. This has been proven through CNL's successful design and operation of the Combined Electrolysis and Catalytic Exchange Upgrading and Detritiation (CECEUD) Test Facility at CRL from 1998 to 2001; this facility is now in a safe shutdown state. A modernized CECE facility will process used heavy water, removing contaminants, resulting in clean and reusable heavy water. The removed tritium will be safely stored in Immobilized Tritium Containers and kept in an existing tritium vault at the Chalk River site that is monitored in accordance with CRL's current licence conditions. By processing used heavy water through the CECE, CNL will be able to recycle the materials, with potential reuse in the nuclear and other industries. The key benefit is reducing AECL's inventory of contaminated heavy water.

The proposed MCECE Facility is a modification to the CECEUD Test Facility and is within the CRL licensing basis. As such, the proposed MCECE will require physical design and layout considerations that meet the requirements of the Class I Nuclear Facilities Regulations, which include but are not limited to, hazard identification and safety analysis, deterministic analysis of the effects of the environment on the facility (e.g. extreme weather) and the effects from malfunctions within the process facility.

The site for the proposed facility is on heavily disturbed land, in the developed portion of the CRL site with an approximate footprint of 2400m2. The physical activities associated with the project do not include any tree clearing, nor the construction of new access roads or anticipated impact on biodiversity. Prior to site preparation and construction, CNL's Environmental Protection Program will assess the project site to ensure compliance with regulatory requirements, including under the Migratory Birds Act and/or the Species at Risk Act.

As with all non-routine activities at AECL site, an Environmental Effects Review is currently being conducted to assess potential adverse environmental effects caused from the proposed activities.  All comments from Indigenous groups and the public will be considered by AECL, when making a determination of the significance of the environmental effects under Section 82 of the Impact Assessment Act. All construction and operations activities associated with the MCECE will be conducted in accordance with the environmental policy that directs the management and operation of CNL and all applicable legislation.

AECL would like to invite comments from the public. Written comments must be submitted prior January 29 2024


Latest update

The Public Comment period on the project is now closed.  Atomic Energy of Canada is considering comments received to help inform its determination on whether the carrying out of the project is likely to cause significant adverse environmental effects.




Corporate Communications
Mitch MacKay, Director, Corporate Communications
286 Plant Road
Chalk River, Ontario K0J 1J0
Telephone: 1-800-364-6989

  • Location

    • Chalk River Nuclear Laboratories Ltd., Chalk River, Ontario (Ontario)
  • Nature of Activity

    • Building and Property Development
  • Assessment Status

    In progress
  • Start Date

  • Proponent

    Atomic Energy of Canada Limited
  • Authorities

    • Atomic Energy of Canada Limited
  • Assessment Type

    Project on federal lands
  • Reference Number


This map is for illustrative purposes. The markers represent the approximate locations based on available data. More than one marker may be identified for a given assessment.


Nearby assessments

...within 200 kilometres
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