Containment thermal hydraulics

The investigation of transient thermal hydraulic performance of nuclear reactor containments constitutes the topic of the present chapter. Standard nuclear thermal hydraulic equations and models, i.e. adopted for accident analysis in primary circuit and discussed in different chapters of the book, are applicable here. The main peculiarities of containment that requires specific consideration (and specific chapter) are the size, typically much larger than in primary circuit of nuclear reactor and the presence of non-condensable gases, noticeably air and hydrogen that unavoidably interact with steam-liquid two phase mixtures. Namely, the size and the shape of containment structures and compartments bring to specific parameter ranges, e.g. to characterize condensation and stratification phenomena, which require specific modeling. Therefore containment configurations are introduced first, then phenomena occurring following accident are discussed and applicable codes are listed. Unavoidably, as in any area of nuclear thermal hydraulic, validation of models and codes is necessary; then, we report experimental programs suited for code validation.