Experience at Chernobyl showed that the main long term radiological consequence to the population will probably be external exposure from radiaoctive fallout deposited on the ground. The present text provides an overview of the methodology and technology available for cleaning up large areas and gives preliminary guidance on the planning, implementation and management of such cleanups. Contents: 1. Introduction; 2. Purposes of the report; 3. Scope; 4. Planning the cleanup; 5. Managing the cleanup; 6. Characterizing the affected area; 7. Deposition of contamination on surfaces; 8. Characterizing the contamination; 9. Stabilization of contamination; 10. Decontamination techniques and equipment; 11. Interdiction of an area; 12. Application of cleanup technology to situations involving high radiation fields; 13. Loading and transporting large volumes of wastes; 14. Disposal of large volumes of wastes; 15. Radiation protection and safety; 16. Conclusions and recommendations; Annex A. The cleanup after the accident at the Chernobyl nuclear power plant.