Experimental Investigation on the Retention of Soluble Particles by Pool Scrubbing

Abstract

In the late stage of a severe loss-of-coolant accident, the pressure in the containment building of a nuclear power plant could rise beyond the design limits and thus endanger its structural integrity. Therefore, to avoid pressure failure, it may be necessary to perform controlled venting of the containment. During the event of an accident, a large amount of fission and activation products are released into the containment as airborne particles (aerosols). These particles are filtered during the venting process, usually with the help of wet filters, in order to keep risks to the surrounding environment to a minimum. Consequently, the knowledge of the retention processes in a water reservoir (pool scrubbing) is of central importance for such filtered containment venting systems and for reactor concepts in which water reservoirs are used for pressure reduction (e.g., condensation chamber of a boiling water reactor (BWR)). Investigations on pool scrubbing are carried out in the severe accident aerosol behavior (SAAB) test facility at the Juelich Research Center in the framework of a national project (“severe accident aerosol behavior-II”). SAAB is a unique large-scale facility with the ability to perform a great variation of experiments using various measurement tools. The influence of numerous parameters, such as the height of the water pool, solubility of aerosols and concentration on the retention capacity, is investigated by means of separate effect studies on both insoluble and soluble particles. This technical brief gives a detailed overview over the facility and includes example results of the first test series with soluble particles including cesium iodine (CsI).