Spaltproduktablagerung im Primärkreis des HTR bei extremen Corekühlungsstörfällen am Beispiel des PNP-500

摘要

This report presents an analysis of the consequences for the High Temperature Reactor PNP-500 which occur during core cooling accidents. The consequences of the temperature transients and the fission product behaviour are considered for the primary circuit. The analysis shows that, even for an extremely delayed start of the afterheat removal system, the retention of caesium in the graphite of the fuel elements and of the bottom reflector reduces the release of the coated particles by more than two orders of magnitude. The plate out in the steam generator leads temporarily to a further, however, much smaller retention of the release flow.