On the fundamental aspects of the molten core cooling strategy

Fundamental mechanisms behind the molten core cooling strategies, which include flooding of water onto the molten core spread in a reactor cavity, cooling of a debris bed immersed in a pre-flooded reactor cavity, external cooling of the molten core in a vessel, and cooling of molten core by water injected from below, are revised with the aid of major findings from the results of recent world wide research to provide a view on the development of an effective severe accident management strategy and a proper implementation of a dedicated engineered safety feature for a high power reactor. Above mentioned strategies are discussed in an integral manner with a view that improvements are necessary to provide a proper level of defense-in-depth against the hypothetical severe accidents. (author)