Tokyo Electric Power Co. said Sunday another reactor of its quake-hit Fukushima nuclear power plants had lost its cooling functions, while at least 15 people at a nearby hospital were found to have been exposed to radioactivity.
The utility supplier notified the government early Sunday morning that the No. 3 reactor at the No. 1 Fukushima plant had lost the ability to cool the reactor core. The reactor is now in the process of releasing radioactive steam, according to top government spokesman Yukio Edano.
It was the sixth reactor overall at the Fukushima No. 1 and No. 2 plants to undergo cooling failure since the massive earthquake and ensuing tsunami struck Japan on Friday.
The disaster raised fears over radioactive leaks from the plants after cooling systems there were hampered, most seriously at the No. 1 reactor.
An explosion Saturday at the No. 1 plant blew away the roof and the walls of the building housing the No. 1 reactorís container.
The government and nuclear authorities said there was no damage to the steel container housing the troubled No. 1 reactor, noting that the blast occurred as vapor from the container turned into hydrogen and mixed with outside oxygen.
Tokyo Electric Power has begun new cooling operations to fill the reactor with sea water and pour in boric acid to prevent an occurrence of criticality. Chief Cabinet Secretary Edano said in a press conference Sunday morning that there had been no major changes in the results of monitoring radioactivity near the No. 1 reactor.
Following the explosion, the authorities expanded from 10 kilometers to 20 km the radius of the evacuation area for residents living in the vicinity of the Fukushima plants.
The Fukushima prefectural government said Saturday that three people had their clothes contaminated with radioactive substances while fleeing from the No. 1 nuclear plant.
The Fire and Disaster Management Agency said Sunday that 15 people were found to have been contaminated at a hospital located within 10 km from the No. 1 reactor. Edano said there was a possibility that nine people who fled on a bus had been exposed to radioactivity.