In 1986, the Chernobyl nuclear reactor in Ukraine (then still a part of the Soviet Union) exploded, dynamite-like, from a runaway nuclear chain reaction. The explosion was enough to destroy most of the reactor building, but that was it. The disaster that followed came not from the explosion but from the enormous amount of radioactive debris that was released. The number of excess cancers caused by this radiation is plausibly estimated at 24,000. Fortunately, many of these are thyroid cancers and are readily treatable.

Unlike...