In this resource, science writer Robert Pool examines the first two decades of the evolution of nuclear power, in particular the thinking that went into ensuring public safety. From today's perspective, knowing what we do now about the dangers of nuclear power, in large part from the meltdown events at Three Mile Island and Chernobyl, Pool argues that the Atomic Energy Commission -- the responsible agency -- overemphasized development at the expense of safety.

The initial mandate given to nuclear engineers was to consider all possible scenarios in which things might go wrong in nuclear reactors and to design them so that no harm would befall the public in the event of accidents. This eventually changed so that risk evaluations were made according to the probability of a certain type of accident occurring and its consequences. With the philosophical shift came acceptance that some types of accident could happen (perhaps once in a thousand years), and that some measure of harm would follow (perhaps one death per event). Thus, a "safe" reactor was one that was very unlikely to have an accident, rather than one engineered for complete safety. This acceptance of even the slightest risk, Pool seems to suggest, explains the public's early -- and lasting -- uneasiness about nuclear power.

Unlike fossil fuel plants, which run at full power until something breaks with little danger to the public, Pool points out that nuclear power plants are far more complex and major accidents can be triggered by little things. With so many components interacting, accidents can happen in so many different ways that they are in essence an inevitable consequence of the technology, not just anomalies.

When reading the excerpt from Pool's book, it is important to keep in mind that his analyses and conclusions are among the many expressed in the ongoing debate over nuclear power safety.