Research and Development to Improve Containment for the Next Generation of Pressurised Water Reactor Plants

Abstract

In recent years politicians and scientists have increasingly demanded that, on account of the serious consequences resulting from a core meltdown accident, future nuclear power plants should include additional safety features. This requirement has been taken up by the industry and improved containment concepts for future pressurised water reactors (PWRs) are being considered and appropriate R&D studies on severe accident loadings conducted. These include the estimation of loads which might result from an energetic in vessel steam explosion, high pressure failure of the reactor pressure vessel, or dynamic hydrogen combustions. Conservative estimates of the upper limits of loading are presented. Complementary investigations concentrate on reliable, long term removal of the decay heat from the core melt after an accident, and from the accident atmosphere in the containment. In this context, two core melt cooling concepts (core catchers) are presented which can serve as innovative elements in future PWR plants. The general goal of these studies consists in contributions to be made to the development of a containment which will not allow significant radiological consequences for the environment, even under the extreme conditions of severe reactor accidents.