This week TEPCO officials at a meeting with officials from the Nuclear Regulation Authority in Japan admitted that the ice wall they promoted as an impermeable barrier to prevent groundwater from entering the crippled reactor buildings and mixing with highly radioactive water has failed to work as billed and is technically incapable of blocking off groundwater.
The Fukushima Daiichi nuclear power plant continues to be overwhelmed by enormous amounts of contaminated groundwater that is generated every day as it mixes and interacts with contaminated water in the basement of the reactor buildings. Currently 400 tons of groundwater flows into the damaged reactor buildings every day and mixes with the highly radioactive water in the basements.
TEPCO had developed the ice wall and installed subdrain wells around the reactor buildings to pump up the contaminated groundwater, treat it, and discharge it into the Pacific Ocean, in the hopes that it would reduce the amounts of contaminated water generated every day. The wall consists of a series of underground refrigeration pipes that freeze the soil around them.
Before installation of the wall, TEPCO described the project to the public, saying, “We will create an impermeable barrier by freezing the soil itself all the way down to the bedrock that exists below the plant. When groundwater flowing downhill reaches this frozen barrier it will flow around the reactor buildings, reaching the sea just as it always has, but without contacting the contaminated water within the reactor buildings.”
The ice wall began operating in March of this year, but has not yet made a meaningful impact on reducing the amount of groundwater that enters the reactor buildings.
Experts are concerned that the increasing levels of highly radioactive water in the reactor buildings could escape into the local environment in the event of heavy rainfall or a tsunami.