cost us. "So, why is it that things have gone wrong? For a start, "Christopher Hinton, interviewed 1974 "When Calder Hall was opened, we were leadingthe world by three years ... I can only feel terribly sad, becauseI've seen that lead... thrown away I find it difficult to put it any otherway."In America, the enormousnuclear plants ordered in the sixties were nearing completion. The engineers incharge were beginning to discover the trap they had set themselves by failingto redesign the containment. If a molten core could not be contained, then theemergency systems to prevent a meltdown would have to work, whateverhappened. The engineers had to anticipate everything that could possibly gowrong. In the enormous complexity of the plants, this was proving impossible.Robert Pollard, reactor engineer, AEC 19691976 One of the main things we began to discover is thatour theoretical calculations... did not have a strong correlation with reality. While theregulations required emergency cooling systems pumps and valves we didn't really have any basis forknowing that those pumps and valves would actually prevent a meltdown of the reactor, becausethe degree of complexity of trying to predict what will happen inside a huge reactor in the midstof a pipe-break... we couldn't make any judgements because we didn't have any facts on whichto make judgements.During the winter of 1971, aseries of tests of emergency core cooling systems [using water] were performed at the AEC'sprivate testing site in Idaho. Accidents were simulated in a small model of areactor. In each case, the emergency systems worked, but the water failed tofill the core. Often, it was forced out under pressure. Despite this, both theindustry and senior members of the AEC argued that the full-sized safetysystems were safe enough.[Robert Pollard] I think what happened was... the federal governmentand the nuclear industry decided that the absence of proof of danger was almost as good asproof of safety. In other words, even though we had done experiments that cast doubt on whetherthe safety systems would actually work if we had an accident, we still had that backup [of] "Well, maybe an accidentwon't happen while we continue to work to perfect the design of theemergency system[s]." Now, we couldn't announce to the public that we having told the public that the plants were safe [] now had to disclose to them [that] we were wrong and [that] [] all these safetysystems we told [them] about [] might not do anygood... my goodness, the uproar would've been... we all probably would've been fired, there would've been theend of this wonderful technology from [our] standpoint [] and we justcouldn't... admit that we had been wrong; plus, of course, you understand with this one experiment [that] it didn't prove the emergencysystems wouldn't work in all circumstances.28th March 1979,PennsylvaniaOn March 28, 1979, a seriesof human and mechanical errors at the Three Mile Island plant exposed the core.It reacted with steam and produced hydrogen, which exploded. None of theemergency teams could understand what was going on inside the reactor. Then,suddenly, this helicopter [from which (presumably) the footage onscreen wasshot] detected a largeradioactive cloud drifting towards the