The depth and breadth of the treatment is such that the book may be used as a text book for graduate and post-graduate courses, and will also be useful to those involved in decommissioning projects and radioactive waste management practices, such as project managers, engineers, health physicists and regulators. Although the general perception is that decommissioning is nothing more than dismantling and demolition of existing facilities, the book demonstrates that there are more to it and there are challenging technical issues to face. The book has been divided into three parts. Part One (Radiation Science) is the enabling part covering radiation, biological effects of radiation, radiological protection, and statistical methods. These subject matters are used and referred to throughout the rest of the book. Part Two incorporates the whole aspect of decommissioning covering decommissioning planning, regulatory aspects in decommissioning, project management, safety aspects, environmental impact assessment, decontamination and dismantling techniques etc.The last part includes radioactive waste management covering regulatory aspects, treatment and conditioning, storage and transportation, waste disposal etc.