Tokyo Electric Power Company (Tepco) says there has been no new leak at the Fukushima nuclear power plant in Japan, but has yet to explain why radiation levels at a nearby water storage tank at the facility are 18 times higher than originally thought.

Tepco said radiation near the bottom of the tank measured 1800 millisieverts an hour – high enough to kill an exposed person in four hours. However the company added that water levels inside the tank had not changed, indicating there had not been a leak.

Fukushima aftermath
Last month Tepco said another storage tank at Fukushima – of the same design as the container causing concern at the weekend – had leaked 300 tonnes of radioactive water, possibly into the sea.

Japan‘s nuclear watchdog confirmed last week it had raised the severity of that leak from level 1, an “anomaly”, to level 3, a “serious incident”, on an eight-point scale used by the International Atomic Energy Agency for radiological releases.

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