The reactor core is divided into a central region and a surrounding outer region in the radial direction. First fresh fuel unirradiated assemblies newly loaded onto the outer region contain a fissible material in amounts less than that of the fissible material of second fresh unirradiated fuel assemblies newly loaded onto the central region. If the amount of the fissible material in the upper region of the first fuel assembly is denoted by a, the amount of the fissible material in the lower region of the first fuel assembly by b, the amount of the fissible material in the upper region of the second fuel assembly by c, and the amount of the fissible material in the lower region of the second fuel assembly by d, then a relationship a/b c/d is satisfied. The reactor core provides sufficient thermal margin and improved cold shutdown margin.
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机译:电抗器芯在径向方向上被分为中心区域和周围的外部区域。新装到外部区域上的第一未辐照燃料组件的易裂变材料的数量少于新装到中心区域上的第二未辐照燃料组件的易裂变材料的数量。如果第一燃料组件上部区域中的易裂变材料的量由a表示,则第一燃料组件下部区域中的易裂变材料的量由b表示,第一燃料组件上部区域中的易裂变材料的量为b。如果第二燃料组件的可燃物质的量为c,则第二燃料组件的下部的易裂变材料的量为d,则满足a / b 展开▼