Publisher's Synopsis
Scientific Essay from the year 2017 in the subject Engineering - Nuclear Engineering, grade: 2, language: English, abstract: The paper presents results on the evaluation performed by the author for durationof two decades in various Nuclear Power Plants (NPP) safety projects. The focus is on the lessons learnt from the perspective of the evaluation of Safety Margins (SM) and Defense in depth (DiD). SM and DiD are two closely related concepts in the evaluation of NPP safety issues, that evolved in the last decades. They are again under scrutiny for potential adaptation to the lessons learnt from the operating experience andmajor accidents. One important direction in the review of the SM and DiD concepts is related to their better description and quantification, as well as the methodologies used to demonstrate compliance with the requirements in force for them. This review is also connected with the existing efforts to define better the SM in light with the extension of design conditions. The use of the complementary features of the deterministic and probabilistic methods, as well as of the feedback from operation for the evaluation of safety margins and the review / extension of the design conditions is illustrated for some examples from different projects in which the author took part. The paper presents some significant for the topic of SM and DiD from various projects. The paper presents aspects related to the process of evaluation of SM and DiD, the adopted strategies, the methodological approaches. The use of the complementary features of the deterministic and probabilistic methods and of the feedback from operation was one of the focusin all the projects. The results presented are for various projects, considered as cases significant for learning the lessons. This is a real cases experience in nuclear projects for a period of several decades. The paper is the main source with details for presentations in a story-telling format at IAEA conference.
