Comprehensive integrity assessment of spent nuclear fuel cladding during normal and postulated conditions of transportation

• Published in: Nuclear engineering and design 2024-05, Vol.421, p.113125, Article 113125
• Main Authors: Park, Min Jeong, Shin, Yong Gyun, Almomani, Belal, Chang, Yoon-Suk
• Format: Article
• Language: English
• Subjects: Finite element analysis; Hydrogen embrittlement; Machine learning; Spent nuclear fuel; Zirconium alloy
• ISSN: 0029-5493; 1872-759X
• DOI: 10.1016/j.nucengdes.2024.113125

•Employed machine learning and mechanical model to predict two zirconium alloys' tensile properties for integrity assessment.•Integrated test data, mechanical modeling, and machine learning to establish strain-based failure criteria, considering spent fuel characteristics.•Analyzed road, sea, and postulated conditions' shock and vibration loads, confirming cladding's elastic resilience during transportation.•Applied fracture mechanics analysis to ensure cladding structural integrity, confirming resistance to crack propagation under transportation-induced shock loads. As a part of Spent Nuclear Fuel (SNF) management, it is important to maintain the cladding integrity to prevent the potential release of hazardous radioactive materials. Accordingly, assessing the integrity of SNF under the generated shock and vibration loads during normal conditions is essential for safe transportation. In this study, failure criteria for two zirconium alloys were derived by utilizing data from tensile property tests, mechanical model calculations, and machine learning estimations. Integrity assessment under normal and postulated transportation conditions was also performed via finite element analyses. Loading conditions were generated by real time-acceleration data collected during transportation tests in the Republic of Korea. Shock and vibration loads were applied to a simplified light-water reactor assembly. Furthermore, postulated transportation conditions and pre-cracked cladding were assumed for more challenging conditions. Consequently, a comprehensive integrity assessment of SNF cladding under shock and vibration loads for both free-defect and defective (pre-cracked) cladding was conducted. In each case, the resultant maximum principal strains, stress intensity amplitudes, and stress intensity factors were significantly smaller than the strain-based failure criteria, S-N curve, and fracture toughness, respectively. Therefore, the integrity of SNF cladding under transportation conditions remained intact even when assuming further challenging postulated transportation load conditions.