The decontamination work in Fukushima Prefecture is expected to produce 14 million cubic meters of waste such as soil and plants.
A law stipulates that these materials will have to be disposed of outside the prefecture by 2045.
The cost estimate by a group of researchers is based on the assumption that more than 90 percent of the decontamination waste will be recycled in public works and other projects.
The researchers say that 8 percent of the waste needs to be disposed of at a cost of at least 3.7 billion dollars. This figure includes the construction of disposal sites and transportation.
They say the cost will increase if the waste is not fully recycled.