Question

Describe what went wrong at Three Mile Island, Chernobyl, and Fukushima.

Short answer

The Three Mile Island accident was caused by a combination of equipment malfunctions, design-related problems, and operator errors. The Chernobyl disaster was due to a flawed reactor design operated with inadequately trained personnel and caused an explosion and fires that released large amounts of radioactive particles. The Fukushima disaster was due to a massive earthquake and tsunami, which disabled the power supply and cooling of the reactors, leading to their overheating, nuclear meltdowns, and release of radioactive contamination.

Step-by-step solution

Describe Three Mile Island accident

The Three Mile Island accident in 1979 was a partial meltdown of reactor number 2 of Three Mile Island Nuclear Generating Station (TMI-2) in Dauphin County, Pennsylvania. A combination of equipment malfunctions, design-related problems, and operator errors led to a loss of coolant and a partial meltdown of the reactor's core. Despite the severity of the accident, the reactor vessel remained intact, and the surrounding population was exposed to only minimal radiation.

Describe Chernobyl disaster

The Chernobyl disaster in 1986 at the No. 4 reactor in the Chernobyl Nuclear Power Plant near the city of Pripyat in Ukraine was the worst nuclear power plant accident in history. The explosion and fires released large amounts of radioactive particles into the atmosphere, which spread over much of Western USSR and Europe. The cause of the disaster was a flawed reactor design that was operated with inadequately trained personnel. The immediate and long-term death toll, though disputed, is high and the environmental damages persist.

Describe Fukushima accident

The Fukushima Daiichi nuclear disaster in 2011 was caused by a 9.0 magnitude earthquake and a consequent tsunami, which disabled the power supply and cooling of three Fukushima Daiichi reactors. This caused the reactors to overheat, leading to nuclear meltdowns, hydrogen-air explosions, and the release of radioactive contamination. The disaster is the most significant nuclear accident since Chernobyl.