Investigations on the behaviour of structural parts of PCRVs as a basis for specific HTR design criteria

Abstract

The paper gives a survey on the investigations carried out by the authors' firm within a research activity carried out with a couple of competent institutions. In the course of these works design criteria for Prestressed Concrete Reactor Vessels (PCRVs) are elaborated or actualized. Starting with some general considerations about permissible concrete stresses from the load carrying capacity and serviceability point of view, the paper deals with investigations on the need to limit the temperatures in the prestressed concrete structure. The influences of effects of accidents in coherence with the transient heat up of the insides of walls and penetrations of a PCRV are briefly discussed. A main topic within the research concerns the question of how to fix the criteria for the analysis of the limit state of ultimate load. Calculations of top caps of PCRVs with large penetrations done so far, regarding non-linear material behaviour in the general three-dimensional case are presented. After that investigations on the question of how to treat the standtube area of a PCRV in the ultimate load analysis regarding the different material behaviour in the compression and tension zone are presented. The paper concludes with a discussion of some parametric studies on the relations between the different types of ultimate load models and the geometry of the prestressed concrete structure.