Frozen Soil Barrier ('Ice Wall') Activated to Isolate Reactor Buildings

After years of construction, TEPCO activated the ¥34.5 billion (approx. $320 million) frozen soil barrier (commonly called the 'ice wall') on March 31, 2016. The barrier uses a network of ~1,568 pipes sunk 30 m into the ground, circulating coolant at -30°C to freeze the surrounding soil into an impermeable barrier around the four reactor buildings. The NRA approved partial activation. While the wall reduced groundwater inflow significantly, critics argued it never fully achieved the groundwater isolation promised, and that contaminated water generation continued at reduced but still significant rates.