Tokyo Electric Power Company Holdings announced on Thursday that highly radioactive water had leaked from a treatment machine at the Fukushima Daiichi nuclear power plant. Fortunately, no injuries were reported, and radiation monitoring indicated no impact on the surrounding environment.
The leak was discovered by a plant worker during routine valve checks on Wednesday morning at the SARRY treatment machine, designed to remove cesium from contaminated water. Although the machine was undergoing maintenance work at the time, it was not in operation.
Approximately six tons of radioactive water, equivalent to the volume of two standard backyard swimming pools, leaked through an air vent, forming a pool of water on an iron plate outside the machine and seeping into the surrounding soil. However, TEPCO reassured that no radioactive water escaped beyond the plant compound.
The exact time the leak started remains unclear, but TEPCO stated that no issues were identified during an inspection conducted the day before. Investigations revealed that the leak may have resulted from valves being inadvertently left open during a flushing procedure with filtered water. Ten out of sixteen valves that should have been closed were found to be open during this process, and the leak ceased once the valves were closed.
Fortunately, radiation levels in the vicinity of the plant and within gutters on the compound remained stable, indicating no increase in radiation levels.
This incident occurred within the context of TEPCO’s contentious wastewater discharge project, initiated in August, which involves releasing treated water into the ocean. Since the Fukushima Daiichi plant’s devastating triple meltdowns following the 2011 earthquake and tsunami, such discharges have sparked opposition from fishing groups and neighbouring countries, including China, which imposed a ban on Japanese seafood imports.
This recent leak follows a separate incident a few months ago at the Advanced Liquid Processing System (ALPS) treatment facility, where four workers were accidentally sprayed with radioactive liquid waste during cleaning operations. Although two workers required brief hospitalization due to skin contamination, none exhibited signs of radiation poisoning.
Efforts to contain and mitigate such incidents remain paramount as TEPCO continues its decommissioning efforts at the Fukushima Daiichi nuclear plant.