1. Noteworthy points of environmental remediation work in Fukushima
〇After the earthquake
- The infrastructure was damaged
(Especially in the evacuation area, infrastructure repair was delayed)
- Decontamination method with water is impossible as the building is damaged
〇It took a long time to start decontamination work
- To obtain the consent of the residents
(temporary storage yards, Decontamination method)
〇The optimum decontamination method can not be selected
- Adopt same decontamination method in the same area for fairness
〇Issues of treatment and disposal of waste
- Most waste is transported to an intermediate storage facility regardless of contamination level
- Final disposal location is undecided
〇Residents' requests were given priority over scientific basis
- The content of decontamination implementation was ultimately determined by Political judgment.
〇Extensive decontamination - The entire area where residents live

2. Points of selecting decontamination technology
based on experience(reflection) in Fukushima
〇Contamination situation
- Type of radionuclide
- Level of contamination
- Timing of decontamination（Whether it is immediately or after a while）
〇Regional characteristics
- Soil properties(Sandy or clay-like, etc.)
- Usage form of land(Farmland or ground, park, etc.)
- Evacuation situation of residents
〇Evaluation criteria
- Resident requirements
- Target of radiation dose
- Regulation value(Radiation dose, contamination level,…)
- Rationale for cost calculation（decontamination and Waste disposal)
- Amount of generated waste
- Presence of waste disposal site
- Magnitude of environmental impact
- Size of decontamination area
- Decontamination schedule(Short term or long term)
- Required Infrastructure Status
- Easiness of equipment preparation
- Worker skills

3. 〇In case of Post-accident sites
・ It is more convenient to organize the objects to be decontaminated than to organize by methods .
・ Based on the EURANOS database, add the knowledge gained in Fukushima there as a case study.
・Regarding knowledge in Fukushima, it is necessary to pay attention to being information obtained under Japanese environmental conditions.
・Experience in Fukushima is the latest information, and future knowledge will be added as necessary.
・DF depends on environmental conditions, when the source of contamination is easy to move, sufficient effects may not be obtained.
〇Additional necessary information
・It is meaningless to show only the cost, and a calculation basis is necessary.
(Costs vary depending on the circumstances of each country.)
・Explanation of calculation method of DF described in existing information is necessary (Dose rate or surface contamination density).