The purpose of this report is to provide an overview of the current knowledge in the field of radioactive waste disposal, limiting itself to the essential topics in this field. It covers the basic principles associated with the state of the art of near surface and deep geological radioactive waste disposal, including examples of prudent practice, and provides basic information on performance assessment methods. Contents: 1. Introduction; 2. Background information; 3. Nature and function of natural barriers; 4. Engineering barriers; 5. Siting and site characterization; 6. Repository concepts and operation; 7. Performance assessment of disposal systems; 8. Regulatory and institutional aspects; 9. Conclusion.