Based on the current high-level radioactive waste management basic plan and the analysis results of spent nuclear fuel characteristics, such as dimensions and decay heat, an improved geological disposal concept for spent nuclear fuel from domestic nuclear power plants was proposed in this study. To this end, disposal container concepts for spent nuclear fuel from two types of reactors, pressurized water reactor (PWR) and Canada deuterium uranium (CANDU), considering the dimensions and interim storage method, were derived. In addition, considering the cooling time of the spent nuclear fuel at the time of disposal, according to the current basic plan-based scenarios, the amount of decay heat capacity for a disposal container was determined. Furthermore, improved disposal concepts for each disposal container were proposed, and analyses were conducted to determine whether the design requirements for the temperature limit were satisfied. Then, the disposal efficiencies of these disposal concepts were compared with those of the existing disposal concepts. The results indicated that the disposal area was reduced by approximately 20%, and the disposal density was increased by more than 20%.

1. Introduction
2. Existing Disposal Concepts of spentnuclear fuel
    2.1 Reference spent nuclear fuel for existingconcept
    2.2 Reference disposal system
3. Analyses of the Characteristics of SpentNuclear Fuel and the Disposal Scenario
    3.1 Specifications of spent nuclear fuel
    3.2 Amount of spent nuclear fuel and time ofdischarge
    3.3 Disposal scenario depending on the timeof discharge
4. Disposal System Design Requirements
5. Improvement of the Existing Deep GeologicalDisposal Concepts
    5.1 Improvement of the CANDU spent nuclearfuel disposal concept
    5.2 Improvement of the PWR spent nuclearfuel disposal concept
6. Efficiency Analyses of the ImprovedDisposal Concept
    6.1 Unit disposal area
    6.2 Disposal efficiency analysis
7. Concluding Remarks and Future Plan
REFERENCES

• Jongyoul Lee(Korea Atomic Energy Research Institute) Corresponding Author
• Inyoung Kim(Korea Atomic Energy Research Institute)
• HeeJae Ju(Korea Atomic Energy Research Institute)
• Heuijoo Choi(Korea Atomic Energy Research Institute)
• Dongkeun Cho(Korea Atomic Energy Research Institute)