Officials said that as Hagibis-triggered rainfall caused rivers to flood, bags filled with debris collected during the Fukushima decontamination efforts were swept into the Furumichi River after the facility was flooded, the Asahi Shimbun reported on Sunday.
The discovery was made by workers this week after the rain fell over the weekend.
About 2,667 bags were being stored at the Fukushima waste site. They didnt have sheets placed over them for protection from the rain and wind.
Six bags were found shortly after with their contents intact, officials told NHK. Officials warned that other bags may have gone downstream.
Authorities said the bags will have little impact on the environment if they are released into the river.
The decontamination process involved removing soil, leaves, plants, and other debris that contain radioactive substances released in the 2011 meltdown that was triggered by a large earthquake and tsunami.
Meanwhile, CNN reported that some 72 people died in Japan due to Hagibiss impacts. Fukushima Prefecture had the highest number of casualties in the storm.
Running Out of Space
The utility company operating Fukushimas tsunami-devastated nuclear power plant said last month that it will run out of space to store massive amounts of contaminated water in three years, adding pressure on the government and the public to reach a consensus on what to do with it.
Three reactors at the Fukushima Dai-ichi plant suffered meltdowns in a massive 2011 earthquake and tsunami that devastated northeastern Japan.