I visited nuclear generating stations in France and I asked them roughly the same question, such as what happens if, like it occurred in Three Miles Island or in Tchernobyl, control is lost over the nuclear chain reaction? I was told that they have large amounts of heavy water above the reactor that can be readily dumped over it and that will completely stop the nuclear reaction. Do we have the same thing here?
On November 9th, 2006. See this statement in context.