Proposal for the continued operation of the national research universal (NRU) reactor at Chalk River Laboratories

Start date: December 13, 2004
Type: Screening
CEAR reference number: 04-01-8269
Proponent: Atomic Energy of Canada Limited (AECL)
Location: Chalk River, Ontario

Latest Update

• August 11, 2005 - CNSC Announces its Decision on the Environmental Assessment of AECL's Proposed Continued Operation of the National Research Universal (NRU) Reactor at Chalk River Laboratories
• April 11, 2005 - Environmental Assessment Guidelines issued by CNSC

Project Description

The Canadian Nuclear Safety Commission (CNSC) has received an application from Atomic Energy of Canada Limited (AECL) for authorization for the continued unchanged operation of the National Research Universal (NRU) Reactor at Chalk River Laboratories. This authorization would require an amendment to AECL's Nuclear Research and Test Establishment Operating Licence pursuant to section 24 of the Nuclear Safety and Control Act (NSCA). The reactor is a Class 1A nuclear facility under the Class 1 Nuclear Facilities Regulations.

The NRU reactor began operating in 1957. It is a research reactor that is licensed to operate at power levels of up to 135 megawatts. It produces about 60% of the world's supply of molybdenum-99, a critical isotope used for medical diagnoses, as well as other radioisotopes.

In 1996, AECL informed CNSC (then known as the Atomic Energy Control Board) that operation of the NRU reactor would not continue beyond December 31, 2005. It was expected that the Canadian Neutron Facility (CNF) would replace the research capability of NRU. However, the CNF is not ready to replace the NRU. In 2003, AECL advised CNSC that they intended to continue operation of the NRU reactor beyond December 2005. It should be noted that the project subject to an environmental assessment under the CEAA, is the uninterrupted continuation of the operation of the NRU reactor in an identical manner.

Before the Commission makes its decision on AECL's application, an environmental assessment must be completed in compliance with the Canadian Environmental Assessment Act. The purpose of an environmental assessment is to identify the possible environmental effects of a proposed project, and to determine whether these effects can be mitigated before the project is allowed to proceed.

Further Information

CNSC maintains a public registry of documents related to its Environmental Assessments. Lists and copies of documents may be obtained upon request. For questions or information related to this environmental assessment, please contact:

For questions or information directly related to the environmental assessment of this project, contact the CNSC.

CNSC regulates the use of nuclear energy and materials to protect health, safety, security and the environment and to respect Canada's international commitments on the peaceful use of nuclear energy.