Environmental Remediation in Affected Areas in Japan(Dec., 2018 Ministry of Environment, Japan)
Progress in decontamination
Air radiation levels in the prefecture have significantly decreased compared to April, 2011. Decontamination of prefectural land has been completed in all areas except for the Difficult-to-return zone.
|Special decontamination area
|The "former planned evacuation zones" where the annual integral dose may exceed 20 milisievert (mSv) and the "former warning zones" located within 20 km of the Fukushima Daiichi Nuclear Power Station.
|Priority contamination survey area
|Municipality including areas where the annual additional exposure dose exceeds 1 mSv
|Municipalities where the decontamination plan is in effect
|Municipality where a decontamination plan was drawn up and is in progress
Progress in decontamination in all the municipal areas to be decontaminated (36 municipalities)
Actual progress in decontamination compared to planned number by the end of FY2017(March 2018)
In Fukushima Prefecture, some areas are decontaminated by national governmental agencies and other areas are by municipal agencies.
What is decontamination?
Decontamination is to reduce the amount of radiation received in the living areas by removing radioactive materials or by burying them underground.
Reduction of environmental radiation dose involves decontamination achieved by a combination of three methods, "removal", "blocking", and "keeping it away at a distance."
- "Removal" of soil and vegetation contaminated with radioactivity
- The removed soil and vegetation contaminated with radioactivity are then covered with uncontaminated soil "to block" the radiation.
- These removed contaminated materials are taken away from where people are living.
Decontamination methods and the effects
*Decontamination Activities in Tamura City
Wiping off rooftop and walls
Wiping off a gutter
High pressure water cleaning of a drain pipe
High pressure water cleaning of paved road
Mowing and removal of sludge
Removal of crushed stones and topsoil, and covering with clean soil
*Before & After the Decontamination Work in Tamura City
Effects of Decontamination in SDA
The chart shows the air dose rate average in each category (aggregated data of measuring points).
Residential areas include schools, parks, cemeteries, and large-sized facilities, farmland includes orchard, and forests includeslopes, grasslandand lawn.
Post-decontamination monitoring was implemented after 6 months to a year after the decontamination work. The latest result of post decontamination monitoring in municipalities were summarized
・Monitoring before decontaminationNov.2011 -Nov. 2016
・Monitoring after decontaminationDec. 2011 -Dec. 2017
・Post decontamination monitoringOct. 2014 -Aug. 2018