论文部分内容阅读
加深燃耗和延长换料周期是提高核电站经济效益的手段之一。但燃耗加深后，偏离泡核沸腾比ＤＮＢＲ限制值将增大；长燃耗的堆芯装载布置使径向功率峰因子Ｆｘｙ上升、额定工况和事故工况下的最小ＤＮＢＲ大幅度下降。在大亚湾核电站改进燃料管理初步可行性研究中分析那些ＤＮＢＲ裕量较小的事故时，如沿用《广东核电站最终安全分析报告》ＦＳＡＲ中给出的超温和超功率保护定值进行计算，其计算结果不能满足ＤＮＢＲ安全限制准则。分析其原因，是由于ＤＮＢＲ准则值和Ｆｘｙ的改变，超温和超功率保护图也将随之变化，使原整定值不能满足安全要求。因此，需重新确定超温和超功率ΔＴ保护整定值。采用ＦＬＩＣＡⅢ程序和ＤＥＬＴＡＴ程序，对长燃耗条件下的超温和超功率ΔＴ整定值进行了初步研究，并将其结果应用于提棒事故分析，使该事故满足了ＤＮＢＲ安全准则。
One of the ways to improve the economic efficiency of nuclear power plants is to deepen fuel consumption and extend the life of the refueling cycle. However, when the fuel consumption is deepened, the deviation from nucleate boiling ratio (DNBR) will increase. The long-fuel load core loading arrangement will increase the radial power peak factor Fxy, and the minimum DNBR under rated conditions and accident conditions will decrease drastically. In the analysis of the preliminary feasibility study for improving fuel management in Daya Bay Nuclear Power Plant, those incidents with small DNBR margin are calculated using the set value of over-mild over-power protection given in the FSAR of “Final Analysis of Guangdong Nuclear Power Station Safety” DNBR security restrictions can not be met. Analysis of the reason is due to the change of DNBR guideline value and Fxy, over-temperature and over-power protection diagram will also change, so that the original setting value can not meet the safety requirements. Therefore, it is necessary to redetermine over-temperature and over-power ΔT protection settings. The FLACⅢ program and DELTAT program were used to study the ΔT setting value of ultra-mild super power under long-burn condition, and the results were applied to the analysis of lifting rod accident, which made the accident meet the DNBR safety criterion.