This book encompasses many different topics in the field of nuclear safety and answers the need for an accessible introductory text to complement industry guidance. It focuses on the principles and applications of nuclear safety, guiding the reader through the 'why' and the 'how' of constructing a nuclear safety case. The theory is enhanced by the provision of examples on how safety cases may tackle a particular problem. Each nuclear site licensee has its own way of undertaking nuclear safety although there is much common ground. The book adopts a consensus approach to the various methodologies used in the industry and armed with such knowledge, an individual should have a good grounding for the application of nuclear safety in the manner required for their industry. Introduction to Nuclear Safety describes why we pursue nuclear safety, including the legal, financial and moral reasons. The fundamental concept of reducing risks to as low as reasonably practicable in the nuclear industry is discussed and the safety case life-cycle from design to commissioning to operations and decommissioning is described. Typical safety case methodologies are also discussed. In considering the applications of nuclear safety, examples of how to undertake an assessment are given. Producing a safety case is not solely a theoretical exercise; it must be implemented and adopted for use within the plant. Therefore, the book describes how safety case documents can be utilised within the plant. The book assumes only a relatively basic knowledge of physics, engineering and mathematics but the interested reader can find more detailed texts in the bibliography.