Review on Spent Nuclear Fuel Performance and Degradation Mechanisms under Long-term Dry Storage

Abstract

As the capacity of spent nuclear fuel storage pool at reactor sites becomes saturated in ten years, long term dry storage strategy has been recently discussed as an alternative option in Korea. In this study, we reviewed safetycriteria-related research results on spent nuclear fuel performance and integrity under long-term dry storage and proposed the direction and the scope of future domestic research and development. Creep and hydride effect in relation to the embrittlement are known to be the major degradation mechanisms of the spent fuels during the long term dry storage. However, recent research results showed that hydride reorientation and hydride embrittlement are one of the most critical factors to the spent fuel integrity. Accordingly safety criteria of US and Japan for the storage system are basically founded on those mechanisms. However, in Korea, not only in-pile but out-of-pile experimental data have not been generated to understand fuel cladding degradation and to determine the criteria to ensure the safety. In addition, the transient behavior of the spent fuel during transportation also needs to be thoroughly examined. Therefore, various experimental research and development will be required to establish our own safety criteria for future long-term dry storage of domestic spent fuels.

Influence of Gadolinium Addition on Mechanical and Corrosion Properties of 2205 Duplex Stainless Steel

“…최근 전 세계적으로 원자력 설비의 수요가 증가함에 따라 사용후핵연료 저장조의 개발이 대두되고 있다 [1]. 사용후핵연 료란 원자로에서 핵분열이 일어난 핵연료로서 반응 후에도 방사능이 계속 방출되기 때문에 고준위 방사성 폐기물로 분 류된다 [2].…”

Microstructure and Fracture Property of 1A Grade Duplex Stainless Steel with the Addition of Gadolinium

“…Gd의 중 성자 흡수 단면적은 255,500 barn (barn = 10 −24 cm 2 )으로서 B의 중성자 흡수단면적 3,840 barn에 비해 월등히 높다 [3][4][5][6][7][8][9][10][11]. 두 번째, B는 기존의 중성자 차폐 재료 주요합금원소인 크롬(Chromium, Cr)과 반응하여 크롬붕화물(Chromium borides)이란 화합물을 만들게 되며, 이는 핵연료 저장수조에서 내부식성과 열간 가공성 특성을 크게 떨어뜨리지만, Gd는…”