JAPAN’S NUCLEAR AUTHORITIES have detected the presence of plutonium in the soil outside the troubled Fukushima I nuclear power plant.

The findings – reported by Japan’s Kyodo news agency – would all but confirm that radioactive material has leaked from the plant, and from the number 3 reactor in particular.

Reactor 3 was the only one of the six reactors at Fukushima I to contain plutonium, and operators had feared that the integrity of the inner core reactor had been breached after black smoke was seen coming from the reactor last week, and radiation levels shot up over the weekend.

The containment building at reactor 3 had been destroyed following a hydrogen explosion on the day after the March 11 tsunami, with further damage caused by subsequent fires.

Japan’s nuclear watchdog had been treating the problems at reactor 3 as a matter of relative urgency given that reactor 3 was the only one to use the ‘MOX’ fuel – plutonium mixed with low-enriched uranium.

For now, however, the plant’s operator TEPCO has insisted that the level of plutonium found in the soil is not harmful to human health.

The presence of the highly radioactive element in the soil does, though, confirm that enough damage was caused to reactor number 3, and to its containment facilities, for the nuclear material at the reactor’s core to escape the plant itself.

The developments came a few hours after China said it had detected a miniscule amount of radioactive material over its south-eastern coastal areas, though Xinhua quoted China’s nuclear authorities as saying the presence of iodine-131 was not enough to require any preventative measures for safeguarding human health.

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