Article ID Journal Published Year Pages File Type
1727878 Annals of Nuclear Energy 2016 11 Pages PDF
Abstract

•The coolability of porous debris beds was investigated in an experimental study.•Dryout heat flux was measured for six different debris bed geometries.•Heap-shaped debris beds had 47–73% greater dryout heat flux than a top-flooded bed.•It was shown that the bed height has to be taken into account, in addition to the shape.•The significance of post-dryout conditions in the overall coolability was discussed.

The coolability of porous debris beds consisting of a simulant of solidified corium was investigated in an experimental study. The focus was on the effects of the geometrical shape of the debris bed and multi-dimensional flooding on the dryout heat flux. Dryout heat flux (DHF) was measured for six variations of the debris bed geometry, one of which was a classical, top-flooded cylinder and five that had more complex geometries. The complex geometries included conical and heap-shaped beds which can be considered prototypic to reactor scenarios. It was found that the multi-dimensional flooding related to heap-like geometries increases the DHF compared to top flooding by 47–73%. It was emphasized that the debris bed height has to be taken into account when assessing the coolability of realistic geometries: the heap-like geometry increases the dryout heat flux by facilitating multi-dimensional infiltration of water into the bed, but it also decreases the dryout power by having a greater height. The measured DHF increase represents a limit for the debris bed height, because if the increase in bed height is greater than the DHF increase, the direct benefit from the multi-dimensional flooding is lost. In addition, post-dryout conditions and their significance in the overall coolability of multi-dimensionally flooded beds were discussed.

Related Topics
Physical Sciences and Engineering Energy Energy Engineering and Power Technology
Authors
,