Passive autocatalytic recombiners (PAR) is the only used method for hydrogen removal from the containment buildings in modern nuclear reactors. Numerical models of such devices, based on the CFD approach, are the subject of this paper. The models may be coupled with two types of computer codes: the lumped parameter codes, and the computational fluid dynamics codes. This work deals with 2D numerical model of PAR and its validation. Gaseous hydrogen may be generated in water nuclear reactor systems in a course of a severe accident with core overheating. Therefore, a risk of its uncontrolled combustion appears which may be destructive to the containment structure.
In this review, research carried out on sorption-enhanced steam methane reforming (SESMR) process is presented and discussed. The reactor types employed to carry out this process, fixed packed bed and fluidized bed reactors, are characterized as well as their main operating conditions indicated. Also the concepts developed and investigations performed by the main research groups involved in the subject are summarized. Next the catalysts and CO2 sorbents developed to carry out SE-SMR are characterized and the relationships describing the reaction and sorption kinetics are collected. A general approach to model the process is presented as well as results obtained for a calculation example, which demonstrate the main properties of SE-SMR.