Core fission product volatilization, effect

In particular accident sequences with high-pressure, low-flow conditions the buildup of a significant vapor pressure of volatilized fission products in the reactor pressure vessel over the surface of the overheated core may limit the release rates (e. g. Taig, 1984). Since the release rates used in the codes have mostly been determined in experiments in which vapor pressures did not limit the release, this effect has to be taken into account in order not to overestimate the fission product volatilization rates to be expected in such accidents. 

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