Safety of fusion power plants from fundamental to current state of the art

Since the beginning, magnetic fusion adopted safety and environmental aspects as central elements
for the development of a future fusion power plant (FPP). First the lecture introduces fundamental phrases such as safety, reliability and security which relevant for a safety assessment and valid for all technological systems. Based on this methods and approaches are presented to quantify a “safe state” or vice versa to measure the risk. This in turn requires computation of the probability of a failure by an adequate system description for which the most relevant approaches are sketched. Here either deductive methods as the Fault Tree Analysis (FTA) or inductive, qualitative procedures as the Failure Mode Effect Analysis (FMEA) are most frequently used. Also the approach to apply a Master logic Diagram (MLD) is explained. Fusion reactors have to be licensed as any other nuclear installation according to individual nation frameworks and laws. In this context exemplary the German regulations are briefly explained, before in a next step the procedures for a safety demonstration are described. One central
element therein is the protection, which is described by the dose limits, and another one of monitoring denoted as dosimetry. ... mehrThe fundamentals of both are outlined. Based on these fundamentals the fusion reactor safety concept is explained and compared to nuclear power plants (NPP). Some result of a study generated for the German Ministry based on previous safety reviews for different fusion power plant concepts are shortly described. The FPP
safety concept follows the NPP defence in depth principle, however, taking into account the physical and engineering differences such as the radiologic inventories, the stored internal energies, the power densities and potential release paths, necessitating other safety systems in a FPP. Finally, some challenges for the systematic safety assessment currently executed in the context of the EUROFUSION program for DEMO are formulated.