The operator of Japan's crippled nuclear plant has begun pumping highly radioactive water from the basement of one reactor's turbine building to a makeshift storage area - a key step in stabilising the complex.
Removing the 25,000 tons of contaminated water which has collected in the basement of Fukushima Dai-ichi's Unit 2 will allow workers access to the reactors to restore vital cooling systems that were knocked out by the March 11 earthquake and tsunami which left more than 27,000 people dead or missing.
The step is one of many in a lengthy process to resolve the crisis.
Tokyo Electric Power Co projected in a road map plan released over the weekend that it would take up to nine months to reach a cold shutdown of the plants.
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 taking the water to a storage building which 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 is also trying to develop a system to decontaminate the incoming water so that it can be reused to cool the plant's reactors, Mr Nishiyama said.
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.
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 were also 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.