Safety and control area series – Physical design

Safety and control areas

The Canadian Nuclear Safety Commission (CNSC) is responsible for evaluating how well licensees meet regulatory requirements and expectations.  CNSC staff consider the performance of programs in 14 different SCAs. For the next several months, we will be publishing a series detailing each SCA and its significance for the CNSC and its licensees. This feature article will focus on the physical design SCA. For a general overview on all SCAs and their functional areas, visit the CNSC's safety and control areas Web page.

What is physical design?

When building a new house, all safety aspects, including robust design reviews and approvals, are essential to creating a home that is both sturdy and safe. Likewise, Canada's nuclear industry applies physical design requirements to all aspects of nuclear facilities, equipment and locations. The primary goal of these requirements is to ensure that structures, systems and components (SSCs) are able to meet and maintain their design basis as new conditions and information arise over their lifecycle and taking changes in the external environment into account.

CNSC staff review the physical design of SSCs and design modifications to verify that the design complies with all applicable codes, standards and regulations. This SCA also requires the licensee of each nuclear power plant to implement and maintain a comprehensive design program.

The design process

Safety starts and ends with a strong design. Before a shovel even hits the ground, safe conduct of licensed activities takes place. This happens during the design phase. A potential licensee can only start construction of a new facility once CNSC staff have diligently reviewed the proposed facility's design to ensure that it meets regulatory requirements. While most SCAs cover licensee processes, physical design narrows the focus to the actual equipment, grouped under these specific areas:

  • Design governance: How will the licensee approach defence in depth, lifecycle management, quality assurance and accidents?
  • Site characterization: siting, exclusion areas, geology and seismology
  • Facility design: structures, systems and components as a whole
  • Structure design: buildings, control rooms, soil and containment
  • System design: reactor core and coolants, instrumentation and control
  • Component design: generators, turbines, pipes, valves and cables

To obtain approval for a proposed project, a licensee must demonstrate to the Commission's satisfaction that its facilities and equipment will be designed to operate successfully, sustainably and safely over time and under a range of both predictable and unpredictable conditions. After a project has been approved, CNSC staff undertake compliance verifications both through onsite inspections and desktop reviews of licensee submissions.

CNSC staff conducting an inspection at the Point Lepreau nuclear power plant

CNSC staff conducting an inspection at the Point Lepreau nuclear power plant.

What's next?

The CNSC's current physical design SCA was recently updated following an extensive internal consultation to determine the full range of subjects that should be covered under this SCA. CNSC staff also considered how to logically group these subjects to provide flexibility to address the full range of nuclear facilities and activities, from the use of small gauges to the operation of nuclear power plants. This SCA will continue to seek improvements as part of the CNSC's commitment to never compromise safety.