Operators of Japan’s earthquake-damaged nuclear plant say highly radioactive water has been detected for the first time outside one of the plant’s reactor buildings.
The power company’s announcement came hours after Chief Cabinet Secretary Yukio Edano said water from the plant’s number 2 reactor appears to have been in contact with melted-down fuel rods inside the reactor’s core. He said it is a top priority to prevent the contaminated water from seeping into the ground water system.
The discovery is the latest setback for crews that have been struggling to repair cooling systems at the plant since they were destroyed by a devastating earthquake and tsunami more than two weeks ago.
More than 10,800 people have been confirmed dead since the quake and 16,200 are missing, according to national NHK television. It said 193,000 people are living in evacuation centers, down from about 300,000 last week.
At a press conference Monday, Edano said some residents are placing themselves at risk by returning to homes inside a 20-kilometer evacuation zone surrounding the Fukushima nuclear plant. He said the government hopes to allow some evacuees to visit their homes for limited periods to collect belongings, but urged them not to enter the zone before that.
Radiation levels of water inside the plant’s number 2 reactor remain dangerously high, and Edano said the water seems to be coming from inside the plant’s pressure chamber where it has been exposed to melted-down fuel rods in the reactor’s core. That would confirm suspicions that the reactor suffered at least a partial meltdown, and that water is escaping from the pressure chamber.
The power company said Monday that water found in a utility trench outside the number two reactor building was emitting radiation at a rate of more than 1,000 millisieverts per hour. Officials said that is about the same level as the water inside the building, which was reported Sunday to be 100,000 times higher than normal.
Officials said the water comes to about 1 meter from the top of the trench, which runs to within 55 meters of the Pacific Ocean. They say there is no evidence that any has leaked into the sea, though high levels of radiation have been measures in seawater around the plant for the last three days.
Water has also been found in similar trenches at the number 1 reactor, where the radiation level is far lower, and at the number 3 reactor. Plant crews have not been able to measure the radiation level in that trench.
The discovery complicates the efforts of workers to remove radioactive water from the basements of several reactor buildings before they resume the critical process of reconnecting electrical lines to the pumps that will keep the plant’s fuel rods from overheating.
Two workers were taken to a hospital last week after suffering burns to their feet while wading in the radioactive water at the number 2 unit.
Edano said the highest priority is to make sure the radioactive water does not make its way into the ground water system.
Officials are also worried by high levels of radioactive iodine detected in the ocean to the east of the plant for the past three days. They said Monday that the radioactivity appears to be moving northward up the coast.
Radiation from the plant, which lost its cooling systems during the March 11 earthquake and tsunami, has also been detected in milk and vegetables in a wide area around the plant and in tap water as far away as Tokyo, 220 kilometers to the south.