Highly radioactive water filling an underground trench at the troubled Fukushima No. 1 nuclear power plant are expected on Sunday to be moved to a nearby storage inside the No. 2 reactor turbine building, local media reported.

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, where fuel rods have partially melted, Kyodo News reported.

The water in the trench is planned to be moved to a "condenser" inside the No. 2 reactor turbine building. The condenser has a capacity to store 3,000 tons of liquid.

Radioactive water was found in the basements of the Nos. 1 to 3 reactor turbine buildings, and the nearby trenches connected to them. The water totaled about 60,000 tons.

Removing the water to nearby tanks and other storage places is considered vital to the attempt of restoring the key cooling functions at the reactors.