Heavy rain in Japan has caused more problems in Fukushima. At least 82 large bags filled with radioactive waste from decontamination efforts were washed away when the Niida River river overflowed in the Fukushima prefectural village of Iitate, which was entirely evacuated following the March 2011 nuclear accident.

Ministry of the Environment officials said the bags contained grass and tree parts from decontamination work at places including local farmland. No evidence of leaks of the waste has been found. While 37 one cubic-metre bags were later recovered, the heavy machinery used for the retrieval operation was unable to enter certain areas due to flooding, hampering recovery of the remaining bags.

The bags were being kept outdoors at the locations where the decontamination took place so that they could later be transported to a temporary storage facility. However, they were swept away in the river current. Mudslides and flooding damage were also confirmed at five locations in Iitate and the prefectural town of Kawamata where the decontamination waste is temporarily being stored, but there has been no evidence of leakage of the waste.

Earlier Tokyo Electric Power Co (Tepco) said that, following the storms, rainwater had intermittently overflowed from a drainage channel at the Fukushima NPP and spilled directly into the sea. Tepco is now checking the radioactive levels of rainwater samples taken from the channel. Radioactive rainwater was first found spilling into the sea from the channel in February. As a stopgap measure, Tepco built a barrier at the channel’s far end to pump up water before it reached the sea. Work, which began in May, to reroute the drainage channel so that the rainwater does not leak outside the plant’s port has yet to be completed. The channel repeatedly floods during heavy rains.