The government on Feb. 23 gave the Mainichi Shimbun and other members of the press their first look at fully installed equipment to create a wall designed to freeze soil around the Fukushima No. 1 Nuclear Power Plant and prevent groundwater from flowing into buildings.
A refrigeration machine and pipes will create a wall of frozen soil around 1.5 kilometers in length, encircling reactor Nos. 1 through 4. A total of 1,568 pipes were inserted into the ground at a depth of around 30 meters to freeze the surrounding soil.
Work on the wall began in June 2014, and it was completed earlier this month on Feb. 9. Since permission is required from the Nuclear Regulation Authority before starting operations, however, the process of freezing the pipes has not yet begun.
Once the soil surrounding the entire area has been frozen, the government and Tokyo Electric Power Co. (TEPCO) say the amount of groundwater flowing into the premises can be reduced from a total of around 150 metric tons per day to some 50 tons.
The pipe fittings, which each have a diameter of around 50 centimeters, were positioned to encircle the reactor buildings, which are presently undergoing decommissioning. The pipe rods to be frozen were then placed into the ground 1 meter apart from one another.
Utilizing 30 freezers placed in two buildings at a high elevation, the coolant to be poured into the frozen pipes will first be chilled to a temperature of minus 30 degrees Celsius. After being circulated, the coolant will then again be returned to the refrigeration machine for cooling.
When revealing the wall to reporters, the government also showed them an incineration facility for miscellaneous solid waste. The facility will be used to dispose of materials used during the decontamination process, such as protective attire. The facility plans to burn some 66,000 cubic meters of waste that has accumulated since the nuclear disaster, in order to reduce the volume down to one-tenth of existing levels.
TEPCO aims to begin operating the incineration facility sometime in March.