Japan building giant ice wall at Fukushima after all as TEPCO gets go ahead

Japan’s nuclear authority will allow Fukushima's nuclear power plant operator, TEPCO, to build an underground ice wall isolating radioactive water build-up. This is despite earlier concerns that the wall might cause the ground to sink.

The Nuclear Regulation Authority (NRA) no longer has reservations about the 32 billion yen (US$314 million) government-funded project, in which a giant “wall of ice” is to be built around the crippled Fukushima No. 1 nuclear plant’s four reactors, Kyodo news agency reported.

The plan, which involves 1.5 kilometers of pipes with coolant powerful enough to make the earth around it freeze, earlier raised concerns that it could cause trouble by making the ground near the reactors less stable.

TEPCO officials have, however, persuaded NRA experts that the ground around the ice wall may sink only up to 16 mm, posing no threat to its stability.

“I think we have been able to confirm today the scale of ground sinking, which is what we have most feared as side effects of building the wall,” NRA Commissioner Toyoshi Fuketa told Kyodo.

While accepting the operator’s explanation, the NRA still has issues to discuss with TEPCO, which include ways to accurately measure the level of radioactive water accumulating inside the reactor buildings.

The issue of contaminated groundwater seeping through the ground and into the ocean has for years been one of the major problems faced by TEPCO.

Some 350,000 tons of water have already accumulated in tanks beside the plant, which are becoming increasingly difficult to maintain. A water purification system was introduced a year ago, but has suffered constant malfunctions and is currently in shutdown. The system is capable of cleaning up to 750 tons of water a day.

TEPCO recently rerouted water flows around the plant straight into the ocean in an attempt to prevent them from being contaminated.

Earlier in April, the manager of the stricken Fukushima nuclear power plant, TEPCO’s Akira Ono, admitted that the company still doesn't have “full control” over radioactive leaks in some parts of the plant.

TEPCO is now hoping that the giant ice wall will isolate the problem. While this engineering solution has been used before, such as for preventing the flooding of Russia’s St. Petersburg underground system, the Fukushima ice wall may be the first project of such a large scale.