10% of ice wall at Fukushima nuke plant not frozen yet

A circular underground frozen soil wall built around the crippled Fukushima Daiichi nuclear power plant of Tokyo Electric Power Co. (TEPCO) to prevent groundwater from flowing into the facility and being polluted with radioactive substances has hit a snag, with about 10% of the soil yet to freeze nearly two months after the shield went into use. The utility, which disclosed the situation on May 26, said it is considering additional work on the unfrozen portions. According to TEPCO, the flow of groundwater is fast at points of the wall containing much gravel, preventing the soil from being frozen. The company plans to take additional measures stopping groundwater inflows such as the injection of special chemical agents into these points. It is expected to report the measures on June 2 at a meeting of the Nuclear Regulation Authority’s panel supervising specified nuclear facilities. In the wall project, cylindrical pipes were inserted into soil, with subzero liquid circulated in the pipes, lowering the temperature and freezing the ground to shield groundwater from flowing into reactor buildings. The wall went into operation on March 31. (Translated by Kyodo News)