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On March 11th 2011, an earthquake hit the Pacific coast of Japan. The earthquake, known as the Great East Japan earthquake, was the most powerful known to have hit Japan. It triggered a powerful tsunami, and together the earthquake and tsunami killed over 15,000 people. The tsunami restricted the electricity supply to several reactors in the Fukushima Daiichi nuclear power plant, causing the reactors to stop functioning. This triggered the meltdown of nuclear fuel rods, explosions in the overheating reactors, and leakage of a huge amount of nuclear radiation. The nuclear disaster was rated as 7 – the most severe level of nuclear accident – on the International Nuclear and Radiological Event Scale.
The Fukushima Daiichi nuclear power plant, launched in 1971, had been in operation for around 40 years and had already deteriorated significantly with age. Before the tsunami, the Tokyo Electric Power Company (TEPCO) had postponed planned seismic strengthening works for the plant, despite the possibility of disaster in the case of earthquake having been pointed out. In any case, the magnitude of the Great East Japan earthquake was beyond the worst case assumptions of any seismic-resistant design. Considering these points, the Fukushima nuclear disaster can be understood as a man-made calamity. A large part of the responsibility lies with the government, which has both power over regulation and promotion of nuclear policy.
After the event, residents in the area surrounding the Fukushima power plant were provided with inadequate evacuation instructions and information about the nuclear accident. The division of responsibilities between the government, TEPCO and Japan’s prime minister was unclear and as a result the emergency response was not properly organised. Their evacuation plan and training was found to be useless, and SPEEDI, the network system which was supposed to monitor the scale of the emergency by predicting the spreading of radiation, did not function well.
Radioactive substances released from the nuclear power reactor have been spread across a very wide area. 160,000 residents of the Fukushima prefecture have been evacuated and most of them still live in temporary refugee accommodation with inadequate services for elderly and disabled people. The International Commission on Radiological Protection’s identified radiation exposure limit is 1 mSv/year. However, large areas in eastern Japan are above this level. The Japanese government has raised this limit to 20 mSv/year, four times as high as the limit for an occupational radiation worker. The government has now defined some areas within 20 km of the Fukushima nuclear power plant as no longer residential. However, there are high levels of pollution outside these defined areas, and disparities between the affected people inside and outside these areas in terms of compensation and support.
Tens of trillions of yen have already been spent on the removal of radioactive contamination with only limited success, and it is understood that the clean-up activities will have to continue for at least several decades. It is impossible to restore polluted nature back to its state prior to the nuclear accident. The clean-up operations also mean serious radioactive exposure for workers, and meanwhile 400 tons of water contaminated by radiation is dumped into the sea every day. Two years after the nuclear accident, the Fukushima situation looks set to get even worse before it gets better.