Although 34.5 billion yen ($309 million) in taxpayer money has funded an “ice wall” to keep out groundwater from the Fukushima No. 1 nuclear power plant site, the frozen barrier may not be meeting hopes and expectations.
In particular, the wall has been vulnerable to heavy rain brought by typhoons.
Reducing the volume of radiation-contaminated water is vital to proceeding with the removal of melted fuel from the reactors at the Fukushima No. 1 plant so it can be decommissioned.
But officials of Tokyo Electric Power Co., the operator of the plant, are still not completely sure if the ice wall is performing as designed.
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The estimated volume of groundwater that has leaked into the reactor and other buildings was 190 tons a day at the start of 2016, but it had decreased to 110 tons a day by early October.
However, the situation changed dramatically when two typhoons passed by in late October.
The groundwater level rose rapidly and the average daily flow of groundwater into the building basements for October was estimated to be 310 tons. That was close to the 400 tons that was flowing into the building basements before any measures were implemented to deal with the contaminated water.
There was no realistic expectation of building a ice wall that would keep out all groundwater because the pipes had to be buried in a way that would avoid underground piping from the reactors that were already in place. That meant there were underground portions that could not be frozen.
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Another measure that is receiving more attention of late is pumping up groundwater from the 42 wells located around the reactor buildings and releasing it into the ocean. TEPCO plans to double the number of pumps and processing capacity of decontamination facilities by early 2018.
But other measures will likely have to be considered before work can begin to remove melted fuel from the reactor cores. The first step would be to remove as much as possible the highly radioactive water that remains in the reactor building basements. Such water poses a huge risk to the workers who will have to enter the buildings to remove the fuel.
Read more at Fukushima ‘ice wall’ linchpin not living up to high hopes
