Kevin P. Shea

An Explosive Reactor Possibility

The Nuclear Regulatory Commission has commissioned a study to test a newly proposed hypothesis which may show how steam explosions of containment-shattering proportions could develop as a result of core-melt accidents, and that there might be a far greater likelihood of such an event than was previously believed. An explosion sometimes results from an extremely rapid heat exchange when a large amount of molten material is plunged into a large volume of colder liquid. The sudden transfer of heat energy from the hot liquid to the cold liquid is accompanied by the development of a pressure wave, the force and magnitude of which are determined largely by the quantities of the liquids involved and the rate of energy release. If the hypothesis proves valid, the risk involved in continuing to operate the 50 or so commercial reactors in the U.S. may be so great as to require their immediate shutdown. It might also require a halt in construction in reactors of current design, a shift to a different kind of reactor technology, or a complete redesign of light-water-reactor safety systems. (MU)