Decommissioning Process at Canadian Nuclear Laboratories

Abstract

Canadian Nuclear Laboratories (CNL) is Canada’s premier nuclear science and technology organization and has nuclear sites located in different provinces within Canada. Some of the sites are under decommissioning and some have both operational and decommissioning activities. There are various challenges in conducting safe, compliant and efficient decommissioning activities in CNL’s sites.CNL developed and implemented a Decommissioning Process, which is based on fundamental principles of decommissioning and industry best practices with the goal of achieving excellence in decommissioning. The process applies to all decommissioning activities throughout the lifecycle of a facility until the final end-state is achieved, including any required environmental remediation of soils and affected lands at a site. The Decommissioning process is divided into six process steps, which align to the respective guidelines and standards, such as the Canadian Nuclear Safety Commission (CNSC) Guideline G219 and Canadian Standards Association (CSA) Standard N294. The process utilizes a graded approach based on the individual site or facility licences, regulatory requirements, level of risk and hazards present, and complexity of activities being performed using both engineering and management judgment to determine the extent of compliance required. This graded approach provides varying levels of rigor and formality when applying controls dependent on the level of hazards present, the potential environmental impact involved and the consequence of failure. This method ensures that the depth of details required and the magnitude of resources needed for decommissioning are aligned with each facility’s programmatic importance, regulatory requirements and potential safety, health, security and environmental impacts.This paper provides an overview of the CNL’s Decommissioning Process and describes the process grading criteria that have been developed based on the complexity, event consequence, desired mitigation approach, and health, safety, security, and environmental requirements.