The operator of the damaged Fukushima Daiichi nuclear power plant says part of an underground frozen earth wall around the plant’s reactor buildings may have melted and is considering repairing the structure.
The Tokyo Electric Power Company pours cooling water at minus 30 degrees Celsius into pipes in the wall.
The structure is intended to prevent groundwater from flowing into the buildings that are contaminated by radioactive substances. When the utility began to freeze the ground in March 2016, 500 tons of groundwater were contaminated every day.
According to TEPCO, the temperature in the wall on November 18 on the mountain side of reactor building No. 4 rose to 13.4 degrees Celsius. The temperature has been above freezing since mid-September.
The company says they also found water near part of the wall that should have frozen. It is said that underground spring water may have warmed the area and melted some of the soil.
TEPCO plans to start installing steel pipes and plates as early as next month to prevent possible groundwater from entering the frozen ground.
There was no change in the water level in the wall near the building and the structure as a whole retained its functions.