TOKYO – Japanese workers have entered the No 1 reactor building at the crippled Fukushima Daiichi nuclear plant for the first time since a hydrogen explosion ripped off its roof a day after the devastating earthquake and tsunami.
High radiation levels inside the building have prevented staff from entering to start installing a new cooling system to bring the plant under control, plant operator Tokyo Electric Power (Tepco) has said may take all year.
The March 11th magnitude 9.0 earthquake and tsunami killed about 14,800 people, left some 11,000 missing and destroyed tens of thousands of homes.
It also knocked out the cooling systems at the Fukushima plant, 240km (150 miles) north of Tokyo, leading to the worst radiation leak since the 1986 Chernobyl disaster.
Two Tepco staff and 11 contractors worked for 1½ hours, moving in and out in small groups to connect duct pipes to ventilators that will filter out 95 per cent of the radioactive material in the air, a company spokesman said.
“Things are moving forward steadily . . . our final goal is to bring them to a cold shutdown. As a first step towards that, we were able to go inside the building and this is a major point,” Tepco official Junichi Matsumoto said. “While they were going inside the reactor building for the first time . . . they did not go inside as so-called suicide squads.”
The ventilator system was now running and would be operated for two or three days. If the radiation level dropped after that, workers would start to install the cooling system, company officials indicated.
Tepco also said in a report to the Nuclear and Industrial Safety Agency that there was no possibility of another hydrogen explosion at the No 1 reactor due to progress in filling the containment vessel, an outer shell of steel and concrete that houses the reactor vessel, with water.
Workers have been trying to fill the reactors with enough water to bring the fuel rods to a cold shutdown and if the agency approves the report, Tepco would increase the rate at which it is pumping in water to accelerate the process.
Meanwhile, the temperature of the No.3 reactor, now about 240 degrees, has been rising and needed to be watched, said Hidehiko Nishiyama, deputy director-general of the Nuclear and Industrial Safety Agency.
Sea sediment with radioactivity 10,000 times higher than usual was found near the plant, Mr Nishiyama said.
“The possibility of a new leak is not zero, but we do not have firm data,” the deputy director general said. – (Reuters)