1. Senior Researcher, Korea Radioactive Waste Agency, Decommissioning Waste R&D Team, 168, Gajeong-Ro, Yuseong-Gu, Daejeon 34129, Republic of Korea.
2. Professor, Dept. of Civil and Architectural Engineering, Sungkyunkwan Univ., Chunchun-Dong, Jangan-Gu, Suwon 440-749, Republic of Korea (corresponding author).