Abstract: According to the present disclosure, road surface state information (road surface frictional force) is acquired and monitored together with road surface temperature information, road surface moisture information, and road surface salt concentration information of each road to determine whether to spray a deicing agent and whether to re-spray a deicing agent as a subsequent process depending on whether to satisfy not only a road surface temperature condition, a road surface moisture condition, a road surface salt concentration condition, but also the road surface state condition of road freezing.

Abstract: The present invention provides a porous cooling block for cooling corium, comprising: a base part that includes a plurality of pores; a plurality of porous cooling blocks that include a channel part that communicates with some of the plurality of pores of the base part; a sacrificial part that covers the exposed upper surfaces of the porous cooling blocks; and a cooling-water supply unit that supplies cooling water to the porous cooling blocks. Corium is cooled by using steam or cooling water discharged from the porous cooling blocks. Therefore, the corium can be cooled and solidified in the shape of a porous form. Further, the cooling water is uniformly supplied to one surface formed by the cooling block on the whole, thereby easily cooling the corium.

Abstract: The present invention provides a porous cooling block for cooling corium, comprising: a base part that includes a plurality of pores; a plurality of porous cooling blocks that include a channel part that communicates with some of the plurality of pores of the base part; a sacrificial part that covers the exposed upper surfaces of the porous cooling blocks; and a cooling-water supply unit that supplies cooling water to the porous cooling blocks. Corium is cooled by using steam or cooling water discharged from the porous cooling blocks. Therefore, the corium can be cooled and solidified in the shape of a porous form. Further, the cooling water is uniformly supplied to one surface formed by the cooling block on the whole, thereby easily cooling the corium.