via NHK World / June 25, 2014 / The operator of the Fukushima Daiichi nuclear plant has found that radioactive water can now easily spread in a deep layer of groundwater. It says it will speed up construction work on a barrier aimed at preventing contaminated water from leaking into the ocean.
The deep layer of water is about 25 meters below the surface. Water there was found to be contaminated on June 4th, when 4,700 becquerels of tritium per liter were detected in a well near the No. 1 reactor building.
Following further study, officials of Tokyo Electric Power Company found that the water pressure in the layer was lower than that of a shallower layer. They say this makes it easier for contaminated water to spread in the deep layer. They suspect the radioactive water could be spilling into the ocean.
TEPCO officials say the ongoing construction of the barrier may be to blame for the lower pressure. The work involves drilling into the deep layer. The barrier is scheduled to be completed in the fall.
TEPCO officials say they will take more action to keep radioactive water from spreading in the deep layer.
This will involve fortifying holes in an underground frozen-soil wall. Those holes go through the layer and are filled with pipes. The frozen-soil wall is intended to keep groundwater from seeping into the facility and becoming contaminated.
SOURCE: NHK World