Japan will seek to halve the amount of radiation in residential areas around the Fukushima No. 1 nuclear plant and cut children’s daily radiation dose by 60 percent over the next two years, according to an emergency decontamination policy document.
The plan is to be endorsed Friday by a government task force dealing with the nuclear crisis triggered by the March 11 earthquake and tsunami.
The government under the plan will take responsibility for securing final disposal sites for contaminated soil but will stress the need for temporarily storage locally.
To achieve the goals set in the emergency plan, the government will lead decontamination activities to scale down areas where radiation exposure is expected to top 20 millisieverts a year, such as within the 20-km no-entry zone around the plant, it said.
Local governments can request the cleanup of contamination if safety is assured.
Reactors spewed less
The amount of radioactive substances emitted into the atmosphere from the Fukushima No. 1 nuclear plant is now estimated at 570,000 terabecquerels, down from an earlier estimate of 630,000 terabecquerels, the chairman of the Nuclear Safety Commission said.
Given a large margin of error in an estimate of this kind, however, the figure “may change greatly” as more data on the nuclear accident become available, Haruki Madarame said Wednesday.
The Nuclear Industrial and Safety Agency has made its own estimate that the total amount of radioactive substances released into the air from the plant is 770,000 terabecquerels.
In the Chernobyl nuclear accident of 1986, an estimated 5.2 million terabecquerels of radioactive substances were discharged into the atmosphere.
The earlier estimate was revised based on new data on the release of radioactive substances in the four days from March 12, when the first of a series of explosions occurred at the plant.
According to the recalculated estimate by the Japan Atomic Energy Agency, 130,000 terabecquerels of iodine-131 and 11,000 terabecquerels of cesium-137 were emitted into the air from March 11 through April 5, Madarame said.