Today it is exactly 40 years since the Three-Mile-Island nuclear accident shocked the world. It became a turning point for US nuclear developments, and by extension for global nuclear expansion. In my own country, Sweden, it paved the way for a referendum about the future of nuclear power. In Austria, which had already had a referendum a year earlier, it confirmed that the decision to abandon nuclear energy was a reasonable one. In Germany, the US accident added fuel to an already fierce struggle for the future of the country’s energy supply. No country remained unaffected by Three Mile Island.
Nuclear engineers dryly refer to the accident as a “partial core meltdown”. But it was a “dry” accident in another sense too: there was not enough water available to cool the plant’s second reactor. Thousands of pages have been written seeking to come to grips with the accident. But from a purely technical point of view it is actually very easy to understand what went wrong: there was a valve in one of the cooling loops that had accidentally been left closed at a time when it should have been open. So nothing mysterious really. And this is, when one looks closer, nearly always the root of nuclear accidents and incidents worldwide: some prosaic, everyday technical component is out of order: a valve, a pipe, a pump, a diesel generator, or something like that. Not the nuclear reactor as such.
The implication, as far as historical studies of nuclear energy is concerned, is clear: if we want to understand nuclear disasters, we need to liberate ourselves from the nuclear historian’s normal obsession with nuclear reactors and nuclear reactions and, instead, target the more traditional or “conventional” technologies that make up most of any nuclear power plant: pumps, pipes and valves – or, as in the case of Fukushima, dikes and seawalls.
By the way, the best account of the Three-Mile-Island accident is (still) the first chapter of Charles Perrow’s classical book “Normal Disasters” (1984).