Highly radioactive water is building up in tunnels underneath at least three reactors at the Fukushima Daiichi nuclear power plant, impairing the ability of workers to reestablish power connections at the facility.
Officials of the Tokyo Electric Power Co., which owns the facility, also said that tests last week found trace levels of plutonium in soil outside the plant, an indication that the containment vessel of reactor No. 3, the only one that is fueled with plutonium, may have been breached.
Plutonium is highly carcinogenic if breathed in or ingested. Company officials said the element was found in samples at five separate sites on the grounds of the facility, suggesting that contaminated water from reactor No. 3 had seeped into the soil. No. 3 is fueled with a mixture of plutonium and uranium.
Engineers have run a new power line to the plant from the electrical grid, but they cannot reconnect the earthquake-damaged plant’s cooling systems until the water is pumped out of the tunnels. The water is so radioactive, however, that plant authorities fear simply releasing it directly into the environment and are exploring ways to capture and store it.
Experts say it could take days to weeks to work out a way to remove all the water safely, further slowing efforts to bring the stricken facility fully under control. Efforts to pump out the water are proceeding while workers continue to pump water into the plant’s reactors to keep them cool and prevent a meltdown.
Pools of water burned two workers last week when they stepped into the water and it seeped into their boots. The workers suffered radiation burns on their legs and were hospitalized, but they were scheduled to be released from the hospital on Monday.
On Sunday, plant officials erroneously said the water was releasing radiation 1,000 times higher than permitted, but on Monday they said it was four times higher than permitted levels.
The water was also found in trenches used for wiring and pipes outside the reactor buildings. Engineers said the level of radioactivity in the water was 1 sievert per hour. A 30-minute exposure to that level would trigger nausea and potential hair loss; a 4-hour exposure would probably be lethal within a month.
Engineers are not sure where the radioactive water is coming from, but say they fear that the reactor containment vessels at units No. 2 and No. 3 have, at the least, been cracked, allowing some radiation to seep out.
If the plutonium escapes, it would be a much bigger problem than if the uranium escapes.
The head of the U.S. Nuclear Regulatory Commission, Gregory Jaczko, arrived in Tokyo on Monday to meet with Japanese authorities and to get a first-hand look at the situation, according to a statement from the U.S. Embassy.
Yukiya Amano, head of the International Atomic Energy Agency, called Monday for an international summit in Vienna to discuss the situation in Japan, possibly in June. Referring to Fukushima, Amano said: “The difficult situation has not been overcome and it will take time to stabilize the reactors. Radioactivity in the environment, foodstuffs and water is a matter of concern in the vicinity of the Fukushima plant and beyond.”
Times wire services contributed to this story.