Investigation of Hypothetical Water Ingress Accidents at THTR 300

[Automatically extracted and translated] In the licensing process of nuclear power plants, questions about the behavior of the plant in hypothetical accidents are often addressed. Hypothetical means that these are accidents that do not need to be considered in the design of a nuclear power plant due to their low probability of occurrence. In the licensing process of the THTR (Thorium High-Temperature Reactor), the question was raised about the behavior of the plant in hypothetical water ingress accidents. To provide a well-founded answer, it was necessary to analyze the course of water ingress accidents and estimate their probability of occurrence. It was also necessary to examine whether accidents with massive water ingress actually fall into the hypothetical range. Furthermore, among the hypothetical water ingress accidents, those had to be identified where the strongest pressure stresses and thermal shock loads on the primary circuit components must be expected.