2011-04-19 15:56

TOKYO - The operator of Japan's crippled nuclear plant began pumping highly radioactive water Tuesday from the basement of one of its buildings to a makeshift storage area in a crucial step toward easing the nuclear crisis.

Removing the 25,000 tons of contaminated water that has collected in the basement of a turbine building at Unit 2 of the Fukushima Dai-ichi plant will help allow access for workers trying to restore vital cooling systems that were knocked out in the March 11 tsunami.

It is but one of many steps in a lengthy process to resolve the crisis. Tokyo Electric Power Co projected in a road map released over the weekend that it would take up to nine months to reach a cold shutdown of the plant. But government officials acknowledge that setbacks could slow the timeline.

The water will be removed in stages, with the first third of it to be handled over the coming 20 days, said Hidehiko Nishiyama of Japan's Nuclear and Industrial Safety Agency. In all, there are 70,000 tons of contaminated water to be removed from the plant's reactor and turbine buildings and nearby trenches, and the entire process could take months.

TEPCO is bringing the water to a storage building that was flooded during the tsunami with lightly contaminated water that was later pumped into the ocean to make room for the highly contaminated water. The operator also is trying to develop a system to decontaminate the incoming water so that it can be reused to cool the plant's reactors, Nishiyama said.

"We hope to gradually reduce contaminated water through that process," he said, adding that it would take "several months" to ready this system.

Once the contaminated water in the plant buildings is safely removed and radioactivity levels decline, workers can begin repairing the cooling systems for the reactors of Units 1, 2 and 3, which were in operation at the time of the tsunami. Workers must also restore cooling functions at the plant's five spent fuel pools, one each for Units 1-4 and a joint pool for Units 5 and 6, which were in a cold shutdown on March 11.

Cold shutdown is when a reactor's core is stable at temperatures below 100 Celsius.

With Japan's nuclear crisis dragging on, some residents who were evacuated from around the Fukushima plant, about 140 miles (225 kilometers) northeast of Tokyo, began moving out of school gymnasiums into temporary housing. Hundreds who have not found apartments or relatives to take them in began filling up inns at hot springs.

"The government has asked us to be ready to take in as many as 200 evacuees for the next four months at least," said Masaki Hata, whose family has run the Yoshikawaya Hot Springs Inn on the outskirts of Fukushima for seven generations.

Michiaki Niitsuma, a 27-year-old office worker, said he was glad to have a comfortable place to stay while he waited to go home.

"My kids got sick in the shelter. It was cold. It's much better here. It's a relief," he said.

In TEPCO's blueprint for stabilizing the reactors, the utility aims to cool the reactors and spent fuel pools and reduce radiation leaks over the next three months. Within 6-9 months, the goal is achieve a cold shutdown of the reactors and cover the buildings, possibly with a form of industrial cloth, to further tamp deter any possible radiation leaks.

Two remote-controlled robots sent into the reactor buildings of Unit 1 and Unit 3 on Sunday showed that radiation levels inside - up to 57 millisieverts per hour - were still too high for humans to realistically enter.

The US-made Packbots, which resemble drafting lamps on tank-like treads, also were briefly sent into Unit 2 on Monday, officials said, and the radiation level was found to be a much lower 4.1 millisieverts per hour.

But the high level of humidity inside the reactor building fogged up the robot's camera lens, making it difficult to see conditions inside. They were pulled out after less than an hour, officials said.

"We didn't want to lose sight of where the robot was and then not be able to retrieve it," TEPCO manager Hikaru Kuroda said.

The reason for the higher humidity wasn't clear, but it suggests that workers - if they were to go inside - also would have difficulty seeing through their masks, Kuroda said.