Underground ice wall at Fukushima nears completion

New York Times : Since being damaged during a 2011 earthquake and tsunami, Japan’s Fukushima Daiichi nuclear plant has experienced a number of problems, including the flow of contaminated groundwater into and out of the facility. To try to stem that flow, the Tokyo Electric Power Co (TEPCO) has spent the past two years building an underground ice wall. The Landside Impermeable Wall consists of more than 1500 pipes about 30 meters in length and sunk into the ground at 1-meter intervals. Filled with a brine solution and supercooled to -30 °C, the pipes are expected to freeze the soil around them and create an icy barrier. Following installation earlier this year, the wall was activated in two stages, part in March and the rest in June. Because it can take several months for the soil to completely freeze, TEPCO is still awaiting the results. The plan has been criticized for its high cost and technical complexity.