Given the domestic situation, all nuclear power plants are located at the seaside, where interim storage sites are also likely to be located and maritime transportation is considered inevitable. Currently, Korea does not have an independently developed maritime transportation risk assessment code, and no research has been conducted to evaluate the release rate of radioactive waste from a submerged transportation cask in the sea. Therefore, secure technology is necessary to assess the impact of immersion accidents and establish a regulatory framework to assess, mitigate, and prevent maritime transportation accidents causing serious radiological consequences. The flow rate through a gap in a containment boundary should be calculated to determine the accurate release rate of radionuclides. The fluid flow through the micro-scale gap can be evaluated by combining the flow inside and outside the transportation cask. In this study, detailed computational fluid dynamic and simplified models are constructed to evaluate the internal flow in a transportation cask and to capture the flow and heat transfer around the transportation cask in the sea, respectively. In the future, fluid flow through the gap will be evaluated by coupling the models developed in this study.

1. Introduction
2. CRIEPI’s Barrier Effect Model
    2.1 CRIEPI’s Scenario of RadioactiveMaterial Release
    2.2 Release Rate Calculation
    2.3 Modified Scenarios of Nuclide ReleaseFrom a Submerged Cask
3. Analysis of Internal Flow of SNF TransportationCask
    3.1 SNF Model Selection
    3.2 Development of a Simplified Model ofSpent Fuel Assembly
    3.3 CFD Model of Flow Inside the Spent FuelCask
4. Analysis of External Flow Around TransportationCask
    4.1 Simplification of Spent Nuclear FuelTransportation Cask
    4.2 Setting of Analysis Area for Flow EvaluationAround Transportation Cask
    4.3 External Flow Model of the SNF TransportationCask
5. Results
    5.1 Analysis Result of Internal Flow Model ofSNF Transportation Cask
    5.2 Appropriate Size of Analysis Area for theExternal Flow Simulation
    5.3 Analysis Result of External Flow Model ofSNF Transportation Cask
6. Discussion and Conclusions
Acknowledgements
Nomenclatur
REFERENCES

• Guhyeon Jeong(Keimyung University)
• Sungyeon Kim(Keimyung University)
• Sanghoon Lee(Keimyung University) Corresponding Author