改进型气冷反应堆 (advanced gas-cooled reactor, AGR)作为二代堆型,在英国大量装备,目前已经进入设计寿期末期,能否顺利延寿,很大程度上取决于作为堆芯支撑和慢化作用的石墨构件的结构完整性。针对 "全堆芯石墨构件原位多维度损伤探查"这一技术挑战,该文采用迭代图像重建算法(simultaneous algebraic reconstruction technique, SART)对直线计算机断层成像(computed tomography, CT)检测方案进行模拟计算。基于已知的堆内环境和石墨构件的几何参数建立模型,探究了堆内背景辐射场对直线CT成像检测的影响,模拟了对石墨构件内部裂纹以及质量损失缺陷的检测和重建。估算结果证明该方案具备一定可行性,能为延长AGR堆延寿提供重要的参考数据。
The advanced gas-cooled reactor (AGR) was developed in the UK and is now approaching the end of its design life.Extensions of the design life mainly depend on the structural integrity of the graphite components used for core support and moderation.This study used the simultaneous algebraic reconstruction technique (SART) to simulate the linear computed tomography (CT) imaging detection scheme.The model was used to explore the influence of the background radiation in the reactor on the linear CT imaging detection and to simulated the detection and reconstruction of internal cracks and quality loss defects in the graphite components based on the known internal environment and geometric parameters of the graphite components.The predictions show that the scheme can provide important reference data for extending the life of the AGR.
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