Japan’s government said the nuclear crisis at a quake-damaged power plant isn’t getting worse as radiation levels rise in sea water used to cool over-heating fuel rods.
“There’s no doubt we have been able to prevent the situation at the Fukushima Dai-Ichi plant from getting worse,” Chief Cabinet Secretary Yukio Edano said in Tokyo yesterday. “The situation doesn’t permit us to loosen our grip.”
Tokyo Electric Power Co., the plant’s operator, started using pumps to drain water from the turbine building in the No. 1 reactor and store it in tanks. Radiation readings of between 200-300 millisieverts per hour were found in water at the No. 2 unit, Hidehiko Nishiyama, a spokesman at Japan’s Nuclear and Industrial Safety Agency, said yesterday. That is equivalent to the maximum-permitted exposure for workers battling to contain the crisis.
Repair work at the site of the worst nuclear disaster since Chernobyl has been hampered by explosions and radiation leaks. Tepco, as the utility is called, is studying how much water is in the No. 2 and No. 3 reactors before attempting to drain them.
Tepco switched on the lights in the control room of its No. 2 reactor yesterday, Vice President Sakae Muto said at a press conference in Tokyo. The utility already turned on lights at its No. 1 and No. 3 reactors.
“We are not ready to comment on the schedule to turn on other facilities,” Muto said. “We need to connect a power cable to a cooling pump, which is located in the turbine housing where the water pool was found. We need to drain the water on the basement floor first.”
Muto said he can’t confirm that water from Tepco’s reactors is flowing into the sea.
The company is also starting to switch to fresh water for its cooling efforts of spent fuel rods and the reactor core to prevent further salt corrosion. Tepco stopped dousing sea water on a pool containing spent fuel rods in the No. 1 reactor after radiation levels rose to 200 millisieverts per hour, Kyodo News reported, without citing anyone.
“I was relieved to see the statements about freshwater pumping,” said David Weaver, professor of nuclear physics at Birmingham University in the U.K. “That means they’re in less of an emergency situation, though it’s still difficult and there may be a downturn again.”
Tepco switched to using fresh water to cool the No. 2 reactor at 10:10 a.m. local time, and began draining excess water from the turbine building of the No. 1 unit, Muto said. The company is considering a similar operation on the No. 2 and No. 3 turbine houses, he said.
Radioactive nuclides including cesium-136 and yttrium-91 were found in water at the turbine building of No. 1 reactor, the nuclear agency said in a statement on its website. Three workers were exposed to radiation on March 24 after stepping in water at the No. 3 unit, which indicated a possible leakage from the reactor core, the agency said.
Iodine levels measured in sea water close to the plant on March 25 were 1,251 times the legal limit, Nishiyama said. Those levels are not harmful to health, he said.
Prime Minister Naoto Kan will appoint Sumio Mabuchi, a former land and transport minister, as an adviser on the nuclear crisis, Edano said. Mabuchi, 50, is a former engineer at Mitsui Construction Co.
Tepco plans to drain residual sea water after dumping almost 4,500 tons on the No. 3 unit and 835 tons on No. 4, according to government data. Fresh water may be used to cool the pool containing spent fuel rods at the No. 3 and No. 4 reactors tomorrow, Nishiyama said.
The nuclear agency said it doesn’t believe there is a physical crack in the pressure or containment vessels, which surround the core of the No. 3 reactor. Leakage may be coming from pipes connected to the reactor.
The March 11 quake, Japan’s biggest, and subsequent tsunami left the plant without power needed to cool nuclear fuel rods. The government has advised more people living close to the nuclear site to evacuate because basic goods are in short supply, while assuring them that radiation levels hadn’t risen in the area.
Radiation readings between 20 kilometers (12 miles) and 30 kilometers from the plant are falling, according to the Nuclear Safety Commission of Japan.
“At evacuation centers, we have a short supply of gasoline and oil for heaters,” Fukushima prefecture public relations officer Keiichi Sakamoto said by phone yesterday. “We want fuel so badly.” The crippled plant is about 220 kilometers north of Tokyo.
The prefecture estimates that about 136,000 people lived between 20 kilometers and 30 kilometers from the plant and most have left, Sakamoto said. The rest remain under orders to stay indoors.
“The infrastructure is starting to recover, as some local lines are in service,” Sakamoto said. “What we need but we don’t have is underwear for women and babies.”
The death toll from the quake and tsunami rose to 10,489 as of 9 p.m. local time, with 16,621 people missing, according to the National Police Agency in Tokyo.
The spread of radiation to food and water supplies prompted bulk-buying of bottled drinks even as the government said the health threat remained minimal.