Gasaustausch zwischen einem Helium enthaltenden Behälter und der Umgebung über ein nach unten abgehendes Rohr und dessen Relevanz für den HTR Modu

摘要

After a fracture of the fuel charge tube {$arnothing$ = 65 mm) of a HTR-Modul-Reactor a rapid depressurization of the primary circuit occurs and thereafter a long-range gas exchange between primary circuit and containment takes place. Experiments related to the problem of gas exchange between a vessel and the environment via a vertically installed tube were carried out. For the calculation of the gas exchange rates a computer code was developed, which takes into account all mechanisms influencing the exchange rate in the experiment. The calculated values were in good agreement with the experimental results. The transformation of the results to a HTR-Modul shows that the gas exchange rate in the case of a charge tube fracture is only determined by gas expansion and contraction in the primary circuit. Therefore the amount of air entering the primary circuit is very small.