About Those Accidents

Abstract

A nuclear power plant is undergoing an emergency shutdown procedure known as a “scram” when there is an unusual vibration and the coolant level drops precipitously. Subsequent investigation by a shift supervisor reveals that X-rays of welds have been falsified and other problems exist with the plant that could potentially cause a core meltdown that would breach the containment building and cause an explosion. However, the results of the investigation are squelched and the plant is brought up to full power. The shift supervisor takes the control room hostage but is then shot by a SWAT team as the reactor is scrammed. A meltdown does not actually occur. No, this did not really happen, but these events—portrayed in the movie The China Syndrome —evoked a scenario in which a nuclear core meltdown could melt its way to China and contaminate an area the size of Pennsylvania. It also exposed a nuclear power culture that covered up safety issues rather than fixing them. It made for a compelling anti-nuclear story that scared a lot of people. And then a real core meltdown happened, 12 days later. The worst commercial nuclear power reactor accident in US history began on Three Mile Island, an island in the Susquehanna River three miles downstream from Middletown, Pennsylvania (hence its name). Two nuclear reactors were built on this island, but one of them (TMI-1) was shut down for refueling while the other one (TMI-2) was running at full power, rated at 786 MWe. At 4:00 a.m., what should have been a minor glitch in the secondary cooling loop began a series of events that led to a true core meltdown, but no China syndrome occurred and there was little contamination outside the plant. Nevertheless, it caused panic, roused anti-nuclear sentiment in the country, and shut down the construction of new nuclear power plants in the United States for decades. The nuclear reactors at Three Mile Island were pressurized water reactors (PWR), the type of reactor that Admiral Rickover had designed for power plants in US Navy nuclear submarines.