Design and Structural Safety Evaluation of the High Burn-up PWR Spent Nuclear Fuel for Storage Cask

Taehyung Na¹, Youngoh Lee², Yeji Kim¹, Donghee Lee¹, Taehyeon Kim¹, Kiyoung Kim¹, Yongdeog Kim^1,*

¹Central Research Institute, Korea Hydro & Nuclear Power Co., Ltd., 70, Yuseong-daero 1312beon-gil, Yuseong-gu, Daejeon 34101, Republic of Korea
²Korea Nuclear Engineering & Service, 65, Myeongdal-ro, Seocho-gu, Seoul 06667, Republic of Korea

Received 2024-02-29 ; Revised 2024-03-20 ; Approved 2024-04-03

Abstract

Due to the majority of spent nuclear fuel storage casks being designed for low burnup fuel, developing a safety-significant high burnup dry storage cask capable of storing the increasing high burnup and damaged fuels for nuclear facilities in Korea is required. More than 20% of fuel generated by PWRs is composed of high burnup fuels. This study conducted a structural safety evaluation of the preliminary designs for a high burnup storage cask and evaluated feasible loading conditions under normal, off-normal, and accident conditions. Structural integrity is assessed by comparing load combinations and stress intensity limits under each condition. Evaluation results show that the storage cask has secured structural integrity as it satisfies the stress intensity limit under normal, off-normal, and accident conditions, which may also serve as baseline data for the detailed design of high burnup storage casks.

Key Words : Storage cask, High burnup spent nuclear fuel, Damaged fuel, Tip-over