Tepco Water Treatment Hopes Elude

The Japan Times - June 21, 2011

Tokyo Electric Power Co. continued struggling Monday to restart a newly installed water treatment system at its crippled Fukushima No. 1 nuclear plant, aiming to resume full operations Tuesday.

The treatment system is designed to remove highly radioactive materials from the massive amounts of water accumulating at the plant, thus its full operation is vital for efforts to contain the three-month-old nuclear crisis, because Tepco hopes to eventually recycle the water to cool the plant's damaged reactors.

But the new 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 much earlier than expected, Tepco officials said.

Tepco has been trying to ascertain why the component didn't work as hoped and is probing ways to solve the problem, company officials said.

Tepco meanwhile said Monday it fully opened the doors of the reactor 2 building to lower the humidity inside so workers can enter the site, and denied this would have a negative impact on the environment.

The ventilation helped reduce the humidity, the nuclear safety agency said, adding that it declined to between 58.7 and 89.9 percent from as high as 99.9 percent before the doors were opened.

If the humidity falls 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 blast and adjust measuring equipment there, the Nuclear and Industrial Safety Agency said.

Meanwhile, a robot called Quince jointly developed by Chiba Institute of Technology, Tohoku University and other institutions will be sent to the Fukushima complex, NISA said.

Workers await results

While authorities slam Tokyo Electric Power Co. for exposing workers to excessive radiation — especially internal exposure — around 1,400 Tepco workers are still waiting for the results of their checkups.

About 3,700 people worked at the Fukushima No. 1 power plant from the time the March 11 disasters struck to the end of that month, but detailed checks for internal radiation exposure had only been completed on around 2,300 of them by late May.

Hidehiko Nishiyama, a spokesman for the Nuclear and Industrial Safety Agency, said one of the reasons they haven't been able to get the checkups done quickly is that the utility doesn't have enough whole body dosimeters, which are designed specifically to measure radioactivity within the human body.

The situation is serious because the nuclear crisis is still unfolding and a large number of people are risking their lives to get the plant under control.

Internal radiation exposure can increase the incidence of cancer and leukemia dramatically.

http://search.japantimes.co.jp/cgi-bin/nn20110621a3.html