On March 28, 1979, when a supposedly ""impossible"" accident took place at Three Mile Island reactor No. 2, Daniel Ford was immediately involved as Director of the Union of Concerned Scientists. Here, he explains--with insight, exactitude, and no anti-nuke rhetoric--what really happened at TMI-2, why it happened, and how it was handled. In the process, he fundamentally contravenes the claims of the Nuclear Regulatory Commission and the nuclear industry regarding the safety of nuclear power. That supposedly ""incredible"" incident, the uncontrolled meltdown of a reactor core, was ""at most, an hour away"" at TMI-2. Ford clearly demonstrates, indeed, that the NRC's list of incredible accidents is a sham; given the policies of the NRC and the nuclear industry, such accidents are not only credible but inevitable. What did stagger belief about TMI was the ineptitude and utter confusion of the NRC senior staff during the emergency, the multiple failures of simple plant equipment (such as valves and meters), the faulty design of the reactor and control room, the poorly educated and superficially trained operators, the haphazard maintenance procedures, and a host of other problems that brought the reactor to the edge of a meltdown. But even more disturbing is what Ford calls the ""paper trail."" Quoting from internal memos, testimony, and interviews, Ford shows that NRC staff, the manufacturers of the reactor, and Metropolitan Edison officials knew months and even years before March 28, 1979, of severe design defects in the reactor and control room. Yet, with ample warnings, they did nothing to correct the defects, or even to warn the operators about possible problems. Through his scrutiny of the TMI emergency, Ford sharply calls into question the basic assumptions and philosophy under which the nuclear power program has been operating. It is the entire system--not the operators, not just Met Ed, not just the NRC--that was responsible for TMI. And in the absence of substantial changes following TMI, the question Ford leaves us with is simply and aptly, how long before another serious accident? An exceptionally clear-sighted and clear-headed presentation, sections of which appeared in The New Yorker.