In March 2023, Tepco discovered corroded tanks with peeling paint during a routine inspection of the decommissioned Fukushima Daiichi nuclear power plant. The company has confirmed that corrosion has been detected on the inner walls of tanks used to store treated radioactive water. While Tepco states that the tanks’ structural integrity is not compromised, some older tanks installed over a decade ago are showing signs of corrosion. Despite opposition from local fishermen and China, Tepco started releasing treated wastewater into the sea in August 2023. All radioactive elements except for tritium have been filtered out of the water, which is considered harmless by authorities. Inspections of tanks containing treated water are carried out annually to detect any abnormalities since it is impossible to inspect their interiors without the use of underwater robots.