ISO 1709:2018 specifies the basic principles and limitations which govern operations with fissile materials. It discusses general nuclear criticality safety criteria for equipment design and for the development of operating controls, while providing guidance for the assessment of procedures, equipment, and operations. It does not cover specific quality assurance requirements or details of equipment or operational procedures.

ISO 1709:2018 does not deal with the issues associated with administrative criteria relating to nuclear criticality safety. These issues are covered by ISO 14943. It does not cover the effects of radiation on man or materials, unless the material properties affect nuclear criticality safety.

These criteria apply to operations with fissile materials outside nuclear reactors but within the boundaries of nuclear establishments. They are concerned with the limitations which are imposed on operations because of the properties of these materials which permit them to support nuclear chain reactions. These principles apply to quantities of fissile nuclides in which nuclear criticality safety is required to be established.

ISO 1709:2018 can also be applied to the transport of fissile materials outside the boundaries of nuclear establishments.