In this study, basic strategies for the decommissioning and site remediation of the Fukushima Daiichi Nuclear Power Station (FDNPS) were investigated. Six scenarios were formulated based on two of the three decommissioning strategies of nuclear power plants defined by the International Atomic Energy Agency (IAEA): immediate dismantling and deferred dismantling. A multicriteria decision analysis was performed to analyze the preferences of the options from the viewpoints of the timeframe to complete decommissioning, the resulting waste, the site usability, and the availability of the radioactive waste disposal route. The same six scenarios were applied to both the FDNPS and the nuclear power plants that ceased operation after a normal plant life cycle for comparison. For the FDNPS, the decommissioning project involved fuel debris retrieval, dismantling, and site remediation. The analysis results suggest that the balance between the amount of waste and the time to achieve the end state may be one of the most critical factors to consider when planning the decommissioning and site remediation of the FDNPS.

1. Introduction
2. Methods
    2.1 Decommissioning Scenarios
    2.2 Multi Criteria Decision Analysis
    2.3 Values of Attribute for Scoring
3. Results and Discussion
    3.1 Scores of NPP
    3.2 Scores of FDNPS
    3.3 Comparison of Attribute Scores
4. Conclusions
REFERENCES

• Naoko Watanabe(Hokkaido University) Corresponding Author
• Satoshi Yanagihara(University of Fukui)