Frozen Wall Unfinished

Tokyo Electric Power Company, the owner of broken First Fukushima Nuclear Power Plant, announced that construction of the underground frozen wall around the plant was finished. While TEPCO argues that certain amount of the flow of underground water is blocked by the wall, some experts doubt that effect. What exactly was that expensive great wall of ice for?

With an endorsement from the government of Japan on the policy, TEPCO started the construction of the wall one year and seven months ago. The cost was estimated to be ¥34.5 billion, which would be procured from national budget. While the wall was installed around the plant for 1.5 kilometers long by August, except 7 meters on the hillside, TEPCO announced that the wall was completed this month, because they confirmed that the last part of 7 meters was stably frozen.

The frozen wall project is to install 1568 piles with 30 meters length in underground around the plant and freeze the soil by injecting cold liquid at -30°C into each pile. The frozen soil is supposed to build a wall in underground to block the stream of water flowing into the site, where highly contaminated water remains. Increase of contaminated water causes a problem of decontamination. Chairman of TEPCO, Takashi Kawashima, carelessly referred to a possibility of dumping the contaminated water into the sea.

Before the project started, there was a flow of natural water amounting 400 tons a day into the site. TEPCO reconfirmed that the flow was reduced as low as 100 tons in October. The power company argued that the effect of frozen wall was obvious. However, the original estimation of the effect was as low as tens of tons a day. The result has not reached the target.

TEPCO has also built 40 wells called sub-drain that enables drawing underground water. Or it paved the surface of the plant site to avoid penetration of rainwater into the soil. Some members of Nuclear Regulation Authority suppose that the effect of frozen wall can be limited, requiring further verification of the effect.

The frozen wall project started for appealing that the contaminated water produced in broken nuclear power plant could completely be under control. However, new contaminated water is still produced everyday. Although the project worked for an argument that they would not stand still doing nothing, the actual solution has not been found. It costs ¥1 billion a year to maintain the wall. How long TEPCO or the government can keep on saying that they are doing something on it?