Takeshi Takahashi says removing melted nuclear fuel will be difficult, but blames overheating fears on faulty thermometer
The manager of the Fukushima Daiichi power plant in Japan has conceded that removing melted nuclear fuel from the facility will be very difficult, but dismissed fears that one of the damaged reactors had started overheating again.
"Our main challenge is to now remove the nuclear fuel from the reactors," Takeshi Takahashi told a group of visiting journalists on Monday. "Technically it's a very difficult problem, but we want to take it step by step."
Takahashi, who became plant manager in December after his predecessor, Masao Yoshida, was diagnosed with cancer, apologised repeatedly for the turmoil the accident at the plant had caused the people of Japan, and thanked the international community for its support, according to a pool report provided from the power plant.
Three of Fukushima Daiichi's six reactors suffered meltdown in the hours after Japan's north-east coastline was destroyed by a magnitude-9.0 earthquake and tsunami on the afternoon of 11 March last year.
More than 100,000 people living near the plant have been forced to leave their homes, with many unsure when, or if, they will be able to return.
The government announced in December that the plant had reached "cold shutdown" – a safe state achieved when temperatures inside the reactors remain below boiling point and radioactive leaks are kept to a minimum.
But fears rose earlier this month that fuel inside the No 2 reactor had begun to heat up again, prompting the plant's operator, Tokyo Electric Power (Tepco) to inject more cooling water along with boric acid, which is used to prevent a nuclear chain reaction.
Asked repeatedly to explain the dramatic rise in temperature, Takahashi said the cause had been traced to a faulty thermometer, one of three inside the unit.
"The plant has reached a state of cold shutdown," he said. "We will now try to allow people to return to their homes as soon as possible."
Takahashi, who looked pale and exhausted, dismissed questions about the state of his health. His predecessor took early retirement at the end of last year to receive treatment for cancer of the oesophagus.
Tepco officials said Yoshida's diagnosis was not connected with his exposure to high levels of radiation in the early days of the crisis when, he later admitted, he and his colleagues were convinced they would die.
Evidence of the damage the quake and tsunami inflicted on the ageing plant remains more than 11 months on from the disaster.
Of the three reactors that went into meltdown, one is covered with tarpaulin and another appears intact, but the third is a mess of tangled metal. High radiation levels persist in areas close to the most badly damaged reactors.
About 100 new storage tanks, each capable of holding 1,000 tonnes of liquid, have been installed to store contaminated water from the reactor buildings. The water is then purified and used again to cool damaged fuel. The existing tanks will be full by April, Tepco said.
Yasuki Hibi, an engineer for a construction firm, said conditions at the plant had improved significantly in recent months, but added that workers were still limited to two three-hour shifts a day. "Radiation levels inside reactor No 3 are still too high for us to enter," he said.
About 3,000 people continue to work at the plant each day, according to Tepco. They monitor radiation, decontaminate workers and vehicles, prepare uniforms and equipment, and clear radioactive rubble and other material.
"The worst time was when radiation levels reached 250 millisieverts a year [a temporary upper exposure limit the government introduced soon after the accident]," said Kazuhiro Sakamoto, who hires workers and buys equipment for a Tepco affiliate. "We couldn't find enough people to do the work, and we could only work in two-minute bursts."