In this study, we employed a small-scale experiment to demonstrate the introduction of a thin copper heat dissipation plate into a bentonite buffer layer of an engineered barrier system. This experiment designed for spent nuclear fuel disposal can effectively reduce the maximum temperature of the bentonite buffer layer, and ultimately, make it possible to reduce the area of the disposal site. For the experiment, a small-scale engineered barrier system with a copper heat dissipation plate was designed and manufactured. the thickness of the cylindrical buffer was about 2 cm, which was about 1/20 of KAERI Repository System (KRS). At a power supply of 250 W, the maximum buffer temperature reduced to a mere 1.8°C when the thin copper plate was introduced. However, the maximum surface temperature reduced to a remarkable 9.1°C, when a U-collar copper plate was introduced, which had a good contact with the other barrier layers. Consequently, we conclude that the introduction of the thin copper plate into the engineered barrier system for spent nuclear fuel disposal can effectively reduce the maximum buffer temperature in high-level radioactive waste disposal repositories.

1. Introduction
2. Experiment
    2.1 Design & Manufacturing
    2.2 Operation of Small Module
3. Result and Discussions
    3.1 Temperature Measurement
    3.2 Temperature Gradient
    3.3 Degree of Heat Dissipation
    3.4 Comparison With Computational Analysis
4. Conclusions
Conflict of Interest
Acknowledgements
REFERENCES

• Minsoo Lee(Korea Atomic Energy Research Institute, 111, Daedeok-daero 989beon-gil, Yuseong-gu, Daejeon 34057, Republic of Korea) Corresponding author
• Jin-Seop Kim(Korea Atomic Energy Research Institute, 111, Daedeok-daero 989beon-gil, Yuseong-gu, Daejeon 34057, Republic of Korea)
• Min-Seop Kim(Korea Atomic Energy Research Institute, 111, Daedeok-daero 989beon-gil, Yuseong-gu, Daejeon 34057, Republic of Korea)
• Seok Yoon(Korea Atomic Energy Research Institute, 111, Daedeok-daero 989beon-gil, Yuseong-gu, Daejeon 34057, Republic of Korea)