According to NSSC Notice No. 2021-10, safety analysis needs to be introduced in the decommissioning plan. Public and occupational dose analyses should be conducted, specifically for unexpected radiological accidents. Herein, based on the risk matrix and analytic hierarchy process, the method of selecting accident scenarios during the decommissioning of nuclear power plants has been proposed. During decommissioning, the generated spent resin exhibits relatively higher activity than other generated wastes. When accidents occur, the release fraction varies depending on the conditioning method of radioactive waste and type of radioactive nuclides or accidents. Occupational dose analyses for 2 (fire and drop) among 11 accident scenarios have been performed. The radiation doses of the additional exposures caused by the fire and drop accidents are 1.67 and 4.77 mSv, respectively.

1. Introduction
2. Safety Analysis
    2.1 Safety Analysis Procedure
    2.2 Scenario Selection
    2.3 Ranking of Scenarios
3. Occupational Dose Analysis Methodfor Workers
    3.1 General Analysis Approach&CalculationProcess
    3.2 Fraction of Release
    3.3 Assumption
4. Fire Accident Analysis
    4.1 Flammability Multiplier
    4.2 Calculation Result
5. Drop Accident Analysis
    5.1 Release Fraction&Operational DispersibilityFactor
    5.2 Calculation Result
6. Conclusion
Acknowledgements

• Sun-Kee Lee(KEPCO International Nuclear Graduate School, 658-91, Haemaji-ro, Seosaeng-myeon, Ulju-gun, Ulsan 45014, Republic of Korea)
• Sang-Rae Moon(KEPCO International Nuclear Graduate School, 658-91, Haemaji-ro, Seosaeng-myeon, Ulju-gun, Ulsan 45014, Republic of Korea)
• Chang-Lak Kim(KEPCO International Nuclear Graduate School, 658-91, Haemaji-ro, Seosaeng-myeon, Ulju-gun, Ulsan 45014, Republic of Korea) Corresponding Author
• Hyunjin Lee(KEPCO International Nuclear Graduate School, 658-91, Haemaji-ro, Seosaeng-myeon, Ulju-gun, Ulsan 45014, Republic of Korea)