Tokyo Electric Power Co. have reported that containers holding contaminated water at the Fukushima nuclear power plant could trigger a hydrogen explosion, due to leaks in at least 10% of the containers.
There are estimated to be around 1,300 containers at the plant.
They store waste water from the ALPS (advanced liquid processing system) equipment that removes radioactive substances from contaminated water.
The containers, which are made of polyethylene, are 1.8 meters high and have diameters of 1.5 meters.
The first leak was discovered in a lid on April 2.
TEPCO began inspecting others to see if they had similar problems. Of the 278 it had examined by May 20, it found 26 had some sort of leak or were bleeding from their lids.
The operator said the leaks and bleeding were likely caused by hydrogen and other types of gases that resulted from the water’s exposure to high levels of radiation.
Such gases appear to have accumulated in sediment at the bottom of the containers, expanding the volume of the liquid.
An NRA official said the accumulating hydrogen poses a potential danger.
“If the concentration level is high, a spark caused by static electricity could cause a container to explode,” the official said.
Although all the lids of the containers were supposed to be fitted with pressure-release valves to allow gasses to escape, TEPCO’s survey found that one did not have the mechanism.
Further review of the delivery records for the containers showed there may be as many as 333 that are also defective, a TEPCO official said.