Decommissioning is the last step in the lifetime management of an authorized facility and it must be considered during the design, construction, commissioning and operation of such facilities. This publication provides guidance on how to comply with requirements for the safe decommissioning of nuclear power plants, research reactors, and other nuclear fuel cycle facilities. It addresses all the aspects of decommissioning that are required to ensure safety including: roles and responsibilities, strategy and planning for decommissioning, conduct of decommissioning actions and completion of decommissioning. It is intended for use by those working in policy and strategy development, planning, implementation and regulatory control of decommissioning.