TEPCO struggles to resume key water treatment system at Fukushima+

TOKYO, June 20 Kyodo -
Tokyo Electric Power Co. continued struggling Monday to figure out how to cope with difficulties in operating a newly installed water treatment system at its Fukushima Daiichi nuclear power plant, aiming to resume its full operation as early as Tuesday.
Smooth operation of the system, which is designed to remove highly radioactive materials from a massive amount of water accumulating at the station, is considered essential to containing the three-month-old nuclear crisis, as the utility plans to eventually recycle the water to cool the plant's damaged reactors.
But the newly installed system was halted at 12:54 a.m. Saturday, after becoming fully operational at 8 p.m. Friday, because the radiation level of a component to absorb cesium had reached its limit and required replacement earlier than expected, the plant operator said.
TEPCO has been analyzing why the component has not worked well and how to solve the problem, the firm's officials said.
While dealing with the tainted water, TEPCO said Monday it fully opened the doors of the No. 2 reactor building at the power station to lower humidity inside to enable people to work there, denying the move would have an impact on the environment.
The ventilation has helped reduce the humidity inside, the government's nuclear safety agency said, adding that the level declined to 58.7-89.9 percent from as high as 99.9 percent measured before the doors were opened.
If the level of humidity decreases to around 70 percent, people can work inside the building with full-face masks, which could allow TEPCO to start injecting nitrogen into the reactor to prevent a hydrogen explosion and adjust measuring equipment there, the Nuclear and Industrial Safety Agency said.
Meanwhile, a robot called ''Quince'' -- jointly developed by Japan's Chiba Institute of Technology, Tohoku University and other institutions -- will be sent to the Fukushima power complex, the agency said.
Quince is capable of operating in places where rubble is scattered and is believed to be able to measure levels of radiation inside buildings and depths of contaminated water, as well as obtain samples of such water, as it can climb wet and slippery steps, the agency added.