Practical Phase 1 guidance helps governments plan nuclear safety infrastructure, using lessons from six Member States. This publication provides countries considering embarking on a nuclear power programme with essential information and practical examples of the key activities to be carried out during Phase 1 of developing a nuclear safety infrastructure, as well as lessons learned from analysing the experiences of six IAEA Member States. This publication aims to support governments in making an informed decision to launch their first nuclear power plant, bearing in mind that such a decision requires a firm and long-term commitment to maintaining the activities that are necessary for establishing and maintaining a robust safety infrastructure throughout all subsequent phases of the programme.