Radiation levels in seawater jump near Japan nuclear plant

Apr 9, 2011, 1:12 GMT

Tokyo - The operator of a damaged nuclear power station in north-eastern Japan said radiation levels in seawater near the plant had risen, a news report said Saturday.

Tokyo Electric Power Co (TEPCO) said it found on Thursday 110 becquerels of radioactive iodine-131 per cubic centimetre in seawater samples collected near the northern part of the Fukushima Daiichi Nuclear Power Station, which was crippled by a March 11 earthquake and tsunami.

The figure was 2,800 times higher than the legal limit. At the same spot, the operator detected 600 times the standard Tuesday and 1,000 times Wednesday, the public broadcaster NHK said.

The operator also found a reading 9.3 times the limit off the coast of Minami-soma, 15 kilometres north of the plant.

TEPCO on April 2 discovered highly radioactive water was leaking into the Pacific Ocean from a crack at a concrete pit at the six-reactor power station. It was able to seal the leak Wednesday.

That same day, it began dumping about 9,000 tons of wastewater containing relatively low-level radioactive substances into the Pacific to free up space for the even more contaminated water that had been leaking into the sea. The massive amount of such contaminated water at the site had hampered work to stabilize the stricken plant, TEPCO said.

The government's Nuclear and Industrial Safety Agency instructed TEPCO to review its monitoring of seawater, NHK reported. The radioactive material found this week was likely to be carried northward by ocean currents, NHK reported, citing the agency.

To prevent further sea contamination, TEPCO started Saturday to put up a steel wall and fence near the plant. The operator is to plug a seawater intake system with seven steel sheets and a 120-metre-wide, curtain-like fence near the intake and two other locations, the Kyodo News agency reported.

The construction of the wall and the fence was being carried out as TEPCO was trying to ease mounting environmental concerns that the nuclear crisis has raised at home and abroad, Kyodo said.

Last month's disaster knocked out the reactors' cooling systems, leading to overheating, partial meltdowns, explosions, fires and radiation leaks.

The official death toll from the March 11 disaster stood at 12,876 Saturday with 14,865 people listed as missing, Japan's National Police Agency said.

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