Fukushima nuclear plant diverting groundwater to stem contamination

The operator of Japan's crippled Fukushima nuclear plant said yesterday it had begun a bypass system that diverts groundwater into the sea in a bid to reduce the contamination of the water with radiation.

The move is an attempt to stop tonnes of unpolluted groundwater flowing under the battered plant and mixing with water already there that is laced with radioactive isotopes.

Coping with the huge, and growing, amount of water at the tsunami-damaged plant is proving to be one of the biggest challenges for Tokyo Electric Power Co. (Tepco), as it looks to clean up the mess after the worst nuclear disaster in a generation.

As well as all the water used to keep broken reactors cool, the utility must also deal with the water that travels underground from mountainsides to the sea.

An extra 300 to 400 tonnes of groundwater becomes contaminated beneath the site each day.

For the past month Tepco has been pumping groundwater onto the hillside before it enters the plant site, and storing it in tanks.

Yesterday, engineers started releasing that water after it satisfied quality tests more rigorous than those put in place by the Japanese government or by the United Nations, Tepco said in a statement.