CSA N294:25

Preface This is the third edition of CSA N294, Decommissioning of facilities containing nuclear substances. It supersedes the previous editions published in 2019 and 2009. Changes to this edition include the following: a) guidance was added on the interaction between the various decommissioning plans; b) guidance was added on decommissioning plans for complex or multi-unit sites; c) communication of decommissioning plans, end-state objectives, and decommissioning timelines with Indigenous Nations and communities, and members of the public were clarified; d) a new annex providing guidance on design for decommissioning was added; e) titles were added at all clause levels for accessibility; f) guidance was provided on remediation, and facility and site characterization; g) revisions for alignment with regulatory documents; h) guidance was added on stabilization prior to decommissioning; and i) the application and level of detail of this Standard to new designs/facilities were clarified. This Standard was developed in response to a need for direction on decommissioning consistent with Canadian and international recommendations. It incorporates current best practices and existing regulatory requirements. This Standard also draws on the decommissioning experience of the Canadian nuclear industry. The CSA N-Series Standards provide an interlinked set of requirements for the management of nuclear facilities and activities. CSA N286 provides overall direction to management to develop and implement sound management practices and controls, while the other CSA Group nuclear Standards provide specific technical requirements and guidance that support the management system. This Standard works in harmony with CSA N286 and does not duplicate the generic requirements of CSA N286; however, it can provide a more specific direction for those requirements. Users of this Standard are reminded that additional and site-specific requirements might be specified by federal, provincial, or municipal authorities. This Standard should not be considered as a replacement for the requirements contained in the Nuclear Safety and Control Act and its Regulations or in other legislation, standards, or guides. This Standard was prepared by the Technical Committee on the Decommissioning of Nuclear Facilities, under the jurisdiction of the Strategic Steering Committee on Nuclear Standards, and has been formally approved by the Technical Committee. Scope 1.1 Inclusions This Standard applies to the decommissioning of nuclear facilities and locations where nuclear substances and radiation devices are managed, possessed, stored, or disposed. Notes: 1) Users are responsible for determining the extent to which this Standard applies to a given facility or location and for consulting the associated regulatory requirements. 2) Annexes H, I, J, and K contain recommended approaches for the decommissioning of mine waste rock and mill tailings, complex sites, facilities (other than Class I or II), and high-energy reactor facilities, respectively. 1.2 Exclusions This Standard does not apply to the decommissioning of facilities or equipment involving only a) naturally occurring radioactive material (NORM); b) technologically enhanced, naturally occurring radioactive material (TENORM); or c) radiation-emitting devices. Notes: 1) In Canada, radiation-emitting devices includes those consumer and medical devices (e.g., x-rays, microwaves, lasers) regulated under the Radiation Emitting Devices Act and similar industrial radiation-emitting devices regulated by the provinces. 2) This Standard provides guidance that might be useful for facilities and sites containing the materials and equipment specified in this clause. 1.3 Partial rehabilitation of a facility It might be necessary, for functional purposes (e.g., reuse of a building) or for the mitigation of risk and cost escalation, to rehabilitate part of a facility during operation (e.g., in a redundant building or mined-out pit). Though rehabilitation is not specifically addressed in this Standard, the methodology and principles of decommissioning may be applied to the rehabilitation of a portion of a facility. Note: Regulatory approval might be required for rehabilitation work. 1.4 Terminology In this Standard, "shall" is used to express a requirement, i.e., a provision that the user is obliged to satisfy in order to comply with the Standard; "should" is used to express a recommendation or that which is advised but not required; and "may" is used to express an option or that which is permissible within the limits of the Standard. Notes accompanying clauses do not include requirements or alternative requirements; the purpose of a note accompanying a clause is to separate from the text explanatory or informative material. Notes to tables and figures are considered part of the table or figure and may be written as requirements. Annexes are designated normative (mandatory) or informative (non-mandatory) to define their application.