The government has asked Tokyo Electric Power (TEPCO), the operator of the crippled Fukushima Daiichi nuclear plant, to freeze the soil around the reactor buildings to reduce the flow of the radioactive groundwater into the site. This is from a draft report by the Ministry of Economy, Trade and Industry based on the recommendation of a Tokyo-based general contractor.
Kajima Corp suggested a plan to create walls of frozen soil by inserting pipes into the soil that will then be injected with coolant to lessen the flow of the radioactive water. The walls are extremely watertight and can be quickly constructed, even if it is really just a short-term solution. They added that even if there is a sudden blackout, the soil will still remain frozen for several months. METI Minister Toshimitsu Motegi told Tepco President Naomi Hirose to start coming up with a plan based on the report’s recommendations, which favored the frozen ground solution over the other possible options, which includes clay walls. However, the costs for the frozen-soil walls will become higher over time because the pipes would have to be replaced eventually.
The recommended plan is to have the frozen-soil walls encircle the four buildings with the reactors, where around 400 tons of groundwater flow into the basements everyday, eventually making them radioactive. TEPCO has been trying to process the water, pumping them into tanks but the sheer volume of it is preventing them from actually working on the decommissioning of the reactors. They are hoping to create these walls between April and September 2015, and the estimation is that the seepage will be reduced from 400 to 100 tons.
[ via Radio Australia ]