核级石墨辐照变形对辐照应力和寿命的影响

Impact of Irradiation-Induced Deformation for Nuclear Graphite on Irradiation-induced Stress and Life

石墨是高温气冷堆的堆芯关键结构材料,其机械性能,尤其是辐照后特性,对反应堆的运行安全至关重要。不同牌号的石墨在制备工艺上有较大差异,导致内部微观结构的不同,从而影响石墨的辐照变形。本工作通过对高温气冷堆堆芯侧反射层石墨砖的辐照行为进行数值仿真,分析不同石墨材料的辐照变形对石墨结构的辐照应力和辐照寿命的影响。结果表明,石墨结构的辐照应力和辐照寿命对石墨材料的辐照变形高度敏感。相关结论将为高温气冷堆堆芯石墨砖的结构设计提供重要的数值依据。

Graphite serves as the principal structures in cores of high-temperature gas-cooled reactors(HTRs),and the irradiation-induced properties as well as mechanical properties are essential to the safe operation of reactors.There are large discrepancies in various graphite grades,resulting in the variations in microstructures and therefore having impact on the irradiation-induced deformation.In this paper,the irradiated behaviors of graphite side reflectors in HTRs were simulated,and the impacts of irradiation-induced deformation of various graphite grades on the irradiation-induced stresses and lives were analyzed.The result shows both the irradiated stresses and lives of graphite structures are strongly dependent on the irradiation-induced deformation.The conclusion could offer an important numerical basis for the structural design of graphite blocks in HTRs.