Land-side Impermeable Wall (Frozen Soil Wall)

It is actually a frozen soil wall around the four crippled reactor units, intended to block the flow of groundwater and prevent its mixing with contaminated water.

The principal benefit of the frozen barrier compared with a physical barrier is that it avoids the challenges of building a wall around such underground obstacles as pipes, and creates a seamless barrier. Its effectiveness was demonstrated in tests held in March through April of 2014, when it maintained the ground temperature below 0 degrees Celsius.

The barrier is being funded by the government, with construction being undertaken by Kajima Corporation, one of the few entities that has developed the necessary technology, which it has used at numerous construction sites, especially tunnels, to block water penetration. The refrigerant is environmentally safe and the chilled brine will flow through the pipes to a depth of 30 meters, freezing the surrounding soil and forming a barrier around the reactor facilities. The circumference of the wall is approximately 1500 meters.

The wall is also designed to withstand even long-term interruptions of electricity, maintaining its effectiveness for approximately two months after the loss of power. It is one of several measures TEPCO is undertaking to reduce the amount of water that becomes contaminated on the site, thereby reducing storage needs and protecting the environment.

Installation of facilities required for 'ICE WALL' Construction was completed on February 9, 2016.

Activation was on March 31 of the same year.
No firm timetable has been announced, but it is expected that the entire process will unfold over a period of months.