Consideration of molten core coolability in containment from a viewpoint of severe accident management

摘要

In order to retain the molten core in the reactor cavity, water injection is considered as one of the severe accident management measures. However, it is not certain that the molten core is cooled by the water and there is a possibility of energetic steam explosion. In this paper phenomena and effects of various parameters on the molten core coolability and steam explosion are described with uncertainties based on a review of previous studies and our ALPHA experimental results. Possible, advantages and disadvantages are discussed for various water injection modes and a possible best estimated method based on the state of the art knowledge is proposed.