Impact des conditions évaporantes sur le transfert de l'iode en conditions accident grave

Titre du congrès :NURETH-12 (Nuclear Reactor Thermal Hydraulics) Ville du congrès :Pittsburgh Date du congrès :30/09/2007

During postulated severe accidents transfer of volatile iodine dissolved in containment water sumps to atmosphere can be fostered under pool evaporative conditions. Scarcity of representative data has resulted in semi-empirical models that relies on fitting parameters and still need of further validation. This paper presents a mechanistic model based on: the Two-Film model, the heat-mass transfer analogy and the surface renewal surface theory. Comparison to data from the SISYPHE program has resulted in an accurate response, the error band being 9-25% for the aqueous steady state concentration. Likewise, the model performance has been compared to others' in the literature and, in addition to yield similar results, some advantages have been highlighted: the mechanistic nature, the estimates conservatism, and the thorough documentation of model grounds and assumptions