Effects of the Core Heat-Up Accident on the Strength of the Liner in the Area of the Armor Pipes in the High-Temperature Reactor PNP 500

[Automatically extracted and translated] In considering the core heat-up accident, triggered by the failure of cooling in the PNP 500 reactor under pressure, the problem arises whether the liner in the area of the prestressed concrete container ceiling is so impaired in its strength by the armor pipes that its strength is no longer guaranteed. In particular, the pipes on the edge are endangered in this incident by mechanical, and the pipes in the center by thermal stresses, thus affecting the liner in these areas. This work shows that 12 hours after the onset of the incident, the armor pipes are permanently deformed, but the necessary strength of the liner is still given. Therefore, when considering the core heat-up incident, it can be assumed that the liner does not fail.