Mechanical Behavior of SNR-300 Reactor Vessel Components Under Postaccident Heat Removal Conditions

Within the framework of the licensing procedure for the SNR-300 nuclear power plant in Kalkar, Federal Republic of Germany, it is verified that the reactor vessel and its internal component parts withstand the loadings resulting from a hypothetical core disruptive accident (HCDA). The resultant high temperatures at the areas in contact with molten nuclear fuel are sufficiently reduced by the decay heat removal chain so that these component parts can withstand the mechanical forces resulting from the dead weight of the fuel and the adjacent component parts. The finite element method is used for determination of strain resulting from mechanical loadings and thermal expansion for the strength test and for evaluation of the component parts concerned according to the applicable rules for this type of accident, taking into consideration criteria and stress limit values.