Attenuation of particles through leak paths

Particulates of sodium oxide were passed through narrow leak passages. The particulates impacted on the walls and built up plugs which eventually stopped the flow. Conditions under which plugging occurs were determined. Material which did pass through the leaks was increased in size because of agglomeration on the wall followed by detachment. The data shows that radioactive particulates escaping through leaks following a hypothetical FBR accident will tend to plug the leaks in both the reactor vessel and the containment building. Also, the particulates will generally increase in size so as to be nonrespirable.