TOKYO (Kyodo) -- Workers at the troubled Fukushima Daiichi nuclear power plant began work Sunday to remove highly radioactive water that has leaked and prevented restoration work that is necessary to stabilize Japan's prolonged nuclear crisis.
Toxic water has been found in the basements of the Nos. 1 to 3 reactor turbine buildings, as well as in nearby underground trenches connected to them. Transferring the water, totaling some 60,000 tons, to nearby tanks and other storage places is seen as vital to move ahead with the work to restore the key cooling functions for reactors damaged after the March 11 quake and tsunami.
The workers were to start soon with pumping out water filling a trench near the No. 2 reactor to a storage place they have secured inside the reactor's turbine building, as the level of the water is edging up, apparently because of steps taken to block the water from leaking into the Pacific Ocean, the government's nuclear safety agency said.
The water inside the basement of the No. 2 reactor turbine building and the trench connected to it is highly contaminated because it is believed to be originating from the No. 2 reactor core, the most dangerous of the three reactors where fuel rods have partially melted.
"As contaminated water with high concentration (of radioactive substances) will be moved, we would like to confirm the safety of the process," Hidehiko Nishiyama, a spokesman for the Nuclear and Industrial Safety Agency, said at a press conference in the morning.
A worker in his 30s was taken to a hospital as he complained of feeling sick around 11:10 a.m. after laying a hose pipe for the work from 9:30 a.m., but is conscious and was found to have no radioactive materials on him, plant operator Tokyo Electric Power Co. said.
Wearing a full-face mask, outerwear upon protective clothing, rubber gloves and high boots, the worker was exposed in the work to 4.84 millisieverts of radiation, which is below the limit of 5 millisieverts set for Sunday's work, said the utility known as TEPCO.
The water in the trench was to be transferred to a "condenser" inside the No. 2 reactor turbine building, where in normal operations steam created from the reactor is converted into water.
The condenser has a capacity to store 3,000 tons of liquid and work to empty the condenser finished Saturday.
Workers are also trying to open up a facility for nuclear waste disposal in the plant by continuing to dump relatively less contaminated water found inside the facility into the Pacific Ocean.
A total of 8,900 tons of water had been disposed of from the facility as of Sunday morning and TEPCO aimed to finish releasing the remaining 200 tons during the day.
The utility also flew a small unmanned helicopter to survey the plant, Nishiyama said.
(Mainichi Japan) April 10, 2011
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