含钆堆芯平衡循环优化技术研究  

Research of Optimization Technology for Equilibrium Cycle with Gadolinium

作　　者：马兹容 宿健 周胜 Ma Zirong;Su Jian;Zhou Sheng(Hualong Nuclear Power Technology Co.,Ltd.,Beijing,100036,China)

机构地区：[1]华龙国际核电技术有限公司,北京100036

出　　处：《核动力工程》2021年第3期1-5,共5页Nuclear Power Engineering

摘　　要：通过对平衡循环燃料管理技术进行分析,确定对钆棒采用两端装UO_(2)芯块的轴向分区设计并提高UO_(2)-Gd_(2)O_(3)芯块中^(235)U富集度的优化方法。根据钆棒两端不同长度UO_(2)芯块对堆芯轴向功率分布的影响初步确定了钆棒两端UO_(2)芯块的长度,根据UO_(2)-Gd_(2)O_(3)芯块中^(235)U富集度对燃料经济性和制造的影响初步确定了UO_(2)-Gd_(2)O_(3)芯块中的^(235)U富集度。分析了钆棒轴向分区和提高UO_(2)-Gd_(2)O_(3)芯块中^(235)U富集度各自及综合相对于比较基准方案对堆芯功率分布的影响,优化方案相对于比较基准方案在Ⅰ和Ⅱ类反应性事故工况下对安全性的影响,并对优化方案中的UO_(2)-Gd_(2)O_(3)芯块进行了安全验证。研究结果表明,通过在钆棒两端特定区域装载全富集的UO_(2)芯块,能改善堆芯的轴向功率分布,降低UO_(2)-Gd_(2)O_(3)芯块在Ⅱ类反应性事故工况下的最大线功率密度;优化方案UO_(2)-Gd_(2)O_(3)芯块未超熔化限值且能提高含钆堆芯安全裕量约5.6%;优化技术能为每个含钆堆芯每循环节省燃料费约2300万元。因此,本研究提出的钆棒优化方法能用于大量运行机组的燃料管理改进。The design optimization of gadolinium rods is determined by analyzing the fuel management technology used for equilibrium cycle,and the optimization methods are to raise the bearing enrichment of the UO_(2)-Gd_(2)O_(3) pellets and loading fully enriched UO_(2) pellets at both ends of the gadolinium rods.The length of fully enriched UO_(2) pellets at both ends of the gadolinium rods is determined by analyzing the effects of axial power distribution for different lengths.The bearing enrichment of the UO_(2)-Gd_(2)O_(3) pellets is also determined by analyzing the effects for fuel economy and fuel manufacture.The effects of core power distribution when raising the bearing enrichment of the UO_(2)-Gd_(2)O_(3) pellets and loading fully enriched UO_(2) pellets at both ends of the gadolinium rods are analyzed individually and systematically.The effects of safety in conditionⅠandⅡfor design optimization are analyzed.Safety for the UO_(2)-Gd_(2)O_(3) pellets in optimization case has been confirmed.It is found that the axial power distribution can be improved by loading fully enriched UO_(2) pellets at both ends of the gadolinium rods,and the maximum local linear power density of UO_(2)-Gd_(2)O_(3) pellets under reactivity accidents in conditionⅡcan be reduced.UO_(2)-Gd_(2)O_(3) pellets is within the melting limit and the safety margin can be improved by about 5.6%in safety analysis.The fuel cost can be saved by about 23 million yuan per cycle for each core with gadolinium.Thus,the optimization method of gadolinium rods design can be used to improve the fuel management for the operating units.

关 键 词：燃料管理 可燃毒物 轴向功率分布 

分 类 号：TL371[核科学技术—核技术及应用]