Efforts to repair the cooling systems at the No. 2 and No. 3 reactors at the Fukushima Dai-Ichi nuclear plant are being delayed by the need to drain radioactive water from the floors, Tokyo Electric Power Co. said.
Tests found radiation levels at 100,000 times the normal level in the No. 2 reactor at the plant, and the reactor may be leaking water, Vice President Sakae Muto said at a briefing broadcast on the Internet.
The company plans to put the radioactive water into condenser tanks. Those tanks are probably already full, so crews must find a way to drain them, company officials said at a briefing today.
“I think it is high,” Muto said of the radiation level in the pool of water at the No. 2 unit.
The cooling pool at the No. 2 reactor, used to store spent nuclear fuel, appears to be full of water, the company said. The pool at the No. 4 reactor is likely full, the company said. The pools need cooling water to keep the rods from melting and releasing radiation into the air.
The radiation level at the No. 2 reactor was measured at 1,000 millisieverts an hour, Japan’s nuclear safety agency said. That’s higher than the dose that would cause vomiting, hair loss and diarrhea, according to the World Nuclear Association.
“They’re finding quite high levels of radiation fields, which is impeding their progress dealing with the situation,” said Richard Wakeford, an expert in radiation epidemiology at the U.K.’s Dalton Nuclear Institute in Manchester. At reactor 2, “you’d have a lot of difficulty putting anyone in there.”
Tepco said it needs to drain the water to determine where it came from. Muto said it is possible it came from the fuel in the reactor.
Tepco initially said the radioactivity in the No. 2 reactor was caused by iodine-134, and was 100 times higher than the last report. The company corrected that information at its news conference, without specifying what element was causing the radiation levels.
The company will “make our greatest effort not to repeat such a mistake,” Muto said.
Efforts to gain control over the damaged plant have been hampered by radiation leaks, forcing repair work to be suspended and engineers to rotate shifts.
Two men who were exposed to radiation had “significant” skin contamination on their legs, the International Atomic Energy Agency said.
“In the first eight days you were in a cycle where you’re trying to deal with the decay heat,” Robin Grimes, a professor of materials physics at Imperial College in London, said by phone. “Now, 90 percent of that energy has decayed away, so there is no longer a risk of something suddenly happening; things are going to change much more slowly.”
Soil samples have been taken and will be tested for plutonium, Chief Cabinet Secretary Yukio Edano said at a briefing in Tokyo.
“I’ve said the situation won’t immediately improve, and high radiation water is one of the unexpected things that I had said might occur,” Edano said at a briefing in Tokyo yesterday. “We want to continue cooling, and establish a direction toward ending the situation.”
The number of dead and missing from the March 11 earthquake, tsunami and subsequent aftershocks reached 27,110. The government is struggling to help hundreds of thousands of people left homeless or without essential services or food.
The tsunami disabled backup cooling systems at the six-reactor Fukushima complex, leading to fires and explosions at some of the reactors.
Radiation in drinking water was found in one out of three Tokyo water purification plants based on samples taken yesterday, the Tokyo metropolitan government said. Two out of three facilities detected radioactive levels the previous day.