Methodology for Analysis of Internal Influences on NPP Safety

The foundations for NPPs safe operation are laid down at the design stage; therefore, the main task of this stage is the most complete consideration of safety requirements and principles in the project. The existing experience in the design of NPPs for foreign customers shows that both safety standards and national regulatory documents of a number of countries impose detailed requirements for deterministic safety analysis of internal influences, the source of which is inside the building: fires, explosions, projectiles, falling loads, flooding, etc. At the same time, the methodological issues of performing deterministic safety analysis of internal influences are not sufficiently developed either at the level of national standards or at the level of safety guidelines. The presented analysis methodology is aimed at improving the regulatory documentation for the NPPs safety justification and is developed on the basis of regulatory requirements in the field of nuclear safety in various countries and summarizing the experience of performing the deterministic safety justification of domestic and foreign projects.