This report provides guidance on the planning for decommissioning and on the provision of relevant features at the design and construction stages of nuclear power plants. Most of the information presented is equally applicable, however, to planning and implementing the decommissioning of research reactors and prototype reactors. The report will be useful in the context of backfitting and refurbishment of existing facilities. Contents: 1. Introduction; 2. Policy and strategy considerations; 3. Radiological protection and optimization considerations; 4. Planning for decommissioning; 5. Documentation and records; 6. Basic design aspects; 7. Design features to facilitate decommissioning; 8. Conclusions; Annex I: National experience; Annex II: Problems encountered during decommissioning; Annex III: Case study on the evaluation of decommissioning facilitating features; Glossary.