Radioactivity rises in seawater near Japan’s Fukushima Daiichi nuclear plant

TOKYO — Radioactivity levels soared in the seawater outside the troubled Fukushima Daiichi nuclear plant, safety officials reported Saturday, igniting fresh concerns about the spread of highly radioactive material and the risks involved in completing an already dangerous job.

Samples taken 360 yards offshore from the plant Friday showed radioactive iodine levels 1,250 times the legal safety limit. Earlier in the week, the levels of iodine-131 in the water had been closer to 100 times the limit.

As of Saturday, some signs of progress were evident at the plant: Fresh water was being pumped in to cool the first three nuclear reactors, rather than seawater, which can ultimately impair the cooling process. And the lights were turned on in the control room of the second reactor.

But work was slowed as the Tokyo Electric Power Co., which owns and operates the plant, turned its attention to cleaning up stagnant, highly contaminated water found in turbine rooms outside the reactors.

“This is currently one of our largest problems,” said Hidehiko Nishiyama, deputy director general of the government’s Nuclear and Industrial Safety Agency, at a news conference Saturday night.