Zur technischen Gestaltung von passiv sicheren Hochtemperaturreaktoren

Abstract

In future, a rising consumption of primary energy, especially fossil energy, is expected. Serious climatic changes will result from a continous ejection of CO$_{2}$ into the atmosphere. At this background, the humanity can not resign at the utilisation of nuclear power. By their construction, high temperature reactors can be designed to avoid catastrophic effects an the enviroment at any accident condition. This statement is verified by a discussion of inherent safety mechanisms like negativetemperature coefficient, delayed neutrons and passive afterheat removal from the core without surpassing fixed temperature limits. It is shown, that passive save HTR's of any core power can be realised, if one choose a plate- or ring-shaped geometry. The utilisation of a burst protected prestressed reactor pressure vessel guarantees the integrity of the core structures, which is absolutely necessary to realise passive afterheat removal. This vessel construction limits also the amount of air, which possibly can enter the core under accident conditions and corrode the hot graphite structures. These corrosions, which may be caused also by other fluids entering the core, can be limited or most favorable be avoided developing corrosion protected graphitical structures e.g. fuel elements and reflectors