In order to support the planning of efficient and effective decontamination activities formulated by the government and municipalities, we have developed the support system for decommissioning activities (Restoration Support System for the Environment: RESET). The system is being used for investigating the effective method and area for decontamination and predicting future radiation dose rates. Further, we are supporting the government for the strategic planning of technological development on volume reduction and reuse of decontaminated soil etc..