ارزیابی ایمنی کسک سربی انتقال سوخت و مواد ساختاری تابش‌دیده در شرایط حادثه سقوط با شبیه‌سازی ANSYS

The assessment of the irradiation behavior of nuclear fuel and structural materials is carried out by conducting post-irradiation examination at the hot cell facility. One of the challenges in performing this examination is the safe transfer of cask containing irradiated nuclear fuel and structural materials from the reactor to the hot cell. Therefore, in this study, the safety assessment of the lead cask transfer of a fuel plate, a zirconium fuel cladding, and oxide fuel pellets (UO₂) against the drop accident was conducted using finite element analysis with ANSYS software. The drop of the cask from a height of 9 meters in vertical, horizontal, and inclined directions is one of the most common accidents defined in IAEA Safety Standards No. 6 (SSR-6). In this study, the yield stress of the materials inside the cask was extracted from the references and compared with the maximum stress resulting from the finite element simulation results. Therefore, the safety acceptance limit after an accident was presented as determining the safety factor for each component inside the cask. The simulation results showed that the cask contents are particularly susceptible to serious damage in the drop accident of a 9-meter, especially vertical and horizontal drop. Therefore, a corrective action was taken by incorporating a shock absorber made of polyurethane foam under and around the cask. Finally, a re-simulation with the presence of the shock absorber demonstrated the safety acceptance of the cask against the drop accident.