The mechanism of irradiation creep and its effect on the internal stresses of reactor core graphite components are not well understood. Historical studies on Materials Test Reactor creep specimens have shown that thermal annealing can lead to recovery of creep strain. By selecting appropriate sets of trepanned graphite specimens for the AGR cores, the thermal annealing programme in this work uses the findings of these historical studies in order to investigate irradiation creep and importantly, the stress state of AGR core bricks. Changes in dimensions, Coefficient of Thermal Expansion and Young’s modulus after each annealing step are reported. Laser Raman spectroscopy is used to investigate the effect of thermal annealing on irradiated graphite. The results are combined with core inspection data and demonstrate the complexity of estimating irradiation creep in different parts of reactor graphite components.

辐照蠕变的机理及其对反应堆堆芯石墨组件内部应力的影响尚不清楚。材料测试反应堆蠕变样品的历史研究表明，热退火可导致蠕变应变的恢复。通过为AGR岩心选择合适的碳素化石墨样品集，这项工作中的热退火程序利用了这些历史研究的结果，以便研究辐照蠕变以及重要的是AGR岩心砖的应力状态。报告了每个退火步骤后尺寸，热膨胀系数和杨氏模量的变化。激光拉曼光谱用于研究热退火对辐照石墨的影响。