REGDOC-2.5.6, Design of Rooms Where Unsealed Nuclear Substances are Handled - Consultation

Consultation has concluded

Consultation on REGDOC-2.5.6, Design of Rooms Where Unsealed Nuclear Substances are Handled is now closed. Thank you to everyone who submitted comments.

Regulatory document REGDOC-2.5.6, Design of Rooms Where Unsealed Nuclear Substances Are Handled provides requirements, guidance and a recommended approach for meeting the room design requirements under paragraph 3(1)(l) of the Nuclear Substances and Radiation Devices Regulations. It also provides guidance on performing shielding design analyses as a component of keeping doses as low as reasonably achievable (ALARA) pursuant to paragraph 4(a) of the Radiation Protection Regulations.

This document is the first version and supersedes GD-52, Design of Nuclear Substance Laboratories and Nuclear Medicine Rooms (May 2010).

The information in this document is consistent with modern national and international practices for addressing issues and elements that control and enhance nuclear safety. In particular, this document establishes a modern, risk-informed approach to the design of rooms where unsealed nuclear substances are handled.

Potential impacts

The CNSC welcomes information on the potential impacts to the regulated community or alternative approaches to meeting the document’s objectives. Interested stakeholders may provide information about the potential impacts of incorporating the requirements and guidance in this document into their operations. Comment on the potential impacts of this draft regulatory document

Consultation on REGDOC-2.5.6, Design of Rooms Where Unsealed Nuclear Substances are Handled is now closed. Thank you to everyone who submitted comments.

Regulatory document REGDOC-2.5.6, Design of Rooms Where Unsealed Nuclear Substances Are Handled provides requirements, guidance and a recommended approach for meeting the room design requirements under paragraph 3(1)(l) of the Nuclear Substances and Radiation Devices Regulations. It also provides guidance on performing shielding design analyses as a component of keeping doses as low as reasonably achievable (ALARA) pursuant to paragraph 4(a) of the Radiation Protection Regulations.

This document is the first version and supersedes GD-52, Design of Nuclear Substance Laboratories and Nuclear Medicine Rooms (May 2010).

The information in this document is consistent with modern national and international practices for addressing issues and elements that control and enhance nuclear safety. In particular, this document establishes a modern, risk-informed approach to the design of rooms where unsealed nuclear substances are handled.

Potential impacts

The CNSC welcomes information on the potential impacts to the regulated community or alternative approaches to meeting the document’s objectives. Interested stakeholders may provide information about the potential impacts of incorporating the requirements and guidance in this document into their operations. Comment on the potential impacts of this draft regulatory document

CLOSED: This discussion has concluded.

Can I submit my comments by email?

If you prefer to submit comments by email, please send your comments to cnsc.consultation.ccsn@canada.ca


Has consultation on REGDOC-2.5.6 closed?

Yes, consultation on REGDOC-2.5.6, Design of Rooms Where Unsealed Nuclear Substances are Handled closed on March 17, 2021. 


  • In section 4.5 it states that section F (dose estimates/shielding) is only required for high-level, containment-level and nuclear medicine - hot lab rooms. Is this correct? Specifically, does this mean that CNSC doesn't need dose estimates if we add a nuclear medicine injection room or a imaging room? I think this might be an oversight.

    Peter Petric asked 9 months ago

    Both room classifications “nuclear medicine – hot lab” and “nuclear medicine – other” require dose estimates. The text in this section with be modified to clarify this.

    Thank you for your question.