Ice wall planned for containment of Fukushima groundwater contamination

The Atlantic : TEPCO, the Japanese utility company in charge of the Fukushima-Daiichi nuclear plant that is still working to repair the damage from the 2011 earthquake and tsunami, appears to have settled on a plan to shield groundwater from the facility’s nuclear contamination. The site is on a slope where an estimated 400 tons of groundwater each day mixes with contaminated coolant water and then washes out to sea. TEPCO’s goal is to install a 30-m-deep ice wall stretching 1400 m around the damaged reactors. Underground ice walls are regularly used for protecting shaft mines and tunneling projects and have been tested for containing nuclear contamination. The technique works by sinking steel pipes, spaced at regular intervals, into the ground down to the bedrock. The pipes are then pumped with coolant that absorbs heat from the ground as it cycles through the system. Over time, ice forms around the pipes and slowly spreads until the ice columns from each pipe merge into a solid wall.