Follow-up readings of designated waste in Miyagi Prefecture, which includes radioactive materials from the Fukushima No. 1 Nuclear Power Plant disaster, showed that the amount of waste that exceeded existing standards for the concentration of radioactive materials had decreased to about one-third of the previous figure, the Ministry of the Environment said on Feb. 17.
Shinji Inoue, state minister of the environment, relayed the news to Miyagi Gov. Yoshihiro Murai at the Miyagi Prefectural Government office. It is expected that there will be a resulting impact upon the plan for disposal sites for the waste within the prefecture, which is an issue that has run into difficulties.
State Minister Inoue commented, "It will be ideal if we can concentrate (the waste) at one single location within the prefecture." He indicated that three municipalities within the prefecture are being considered as possible candidate sites for construction (of the waste facility).
Designated waste is waste whose radiation levels exceed 8,000 becquerels per kilogram, and includes tainted rice straw. Some 3,404 metric tons of such waste is presently being temporarily stored within the prefecture on farmers' properties and other locations.
The follow-up measurements, which were conducted between August of last year and January of this year, revealed that the total amount of the waste whose radiation levels exceeded the existing standards had fallen to a total of 1,090 tons.
It is thought that the reduction is due to factors including the natural attenuation that has occurred along with the passage of time since the nuclear disaster.
The environment ministry announced this month that in cases where the concentration of radioactive substances within waste materials has decreased to a level below that of existing standards, such waste would be removed from the category of designated waste.
While the national government is responsible for the disposal of designated waste materials, it is possible for municipalities to dispose of the materials as regular waste once this designation has been lifted.