Leaking containers at Japan’s crippled Fukushima Daiichi nuclear power plant are at risk of possible hydrogen explosions, according to Japan’s nuclear regulator. The Fukushima facility, owned and operated by the Tokyo Electric Power Company (Tepco), was hit by an earthquake and tsunami in 2011 that caused meltdowns in three of the plant’s six nuclear reactors.
Asahi Shimbun said that just under 10% of recently inspected containers holding contaminated water at the nuclear plant in northeast Japan were found to be leaking radioactive water. The leakages, discovered during inspections by Tepco, were thought to be caused by a build-up of hydrogen and other gases due to radiation contamination.
The discovery was reported to the Nuclear Regulation Authority (NRA), and one unnamed official at the regulator told Asahi Shimbun that a spark from static electricity could cause a container to explode if the gas concentration level was high enough.
Officials at Tepco said that the risk of an explosion was believed to be minimal, and a series of measures were being undertaken urgently to fix the faulty storage containers. These include removing the leaking water, installing absorption materials, controlling water levels inside the concrete encasement and ensuring no fire or spark source was near to the containers.
Company officials made the discovery while inspecting 278 of the plant’s 1,307 containers and found that 26 had a leakage from their lids. The gases are thought to have accumulated in the sediment at the base of the containers, prompting the volume of the liquid to expand and overflow.
Tepco said there was no sign of radioactive water escaping beyond the confines of the concrete structures that encase the leaking containers.
Tepco has faced serious difficulties storing the contaminated water flushed over the damaged reactors to keep them cool enough to prevent further radioactive releases. Leakages, technical problems and storage space issues have undermined the utility’s claims to be successfully managing the cleanup and decommissioning of the plant.