燃料通道定位端互换后缺失Z向位置的补算方法

Complementary Calculation Method for Missing Z-Direction Position after Interchange of Fuel Channel Positioning End

燃料通道是重水堆机组的重要设备,其内部包含的压力管是一回路压力边界的一部分。监督燃料通道的轴向伸长量是压力管的老化状态评价的基础。利用燃料通道轴向伸长记录中A、C侧读数与换料历史记录中上、下游Z向位置的内在关系,并结合通道轴向伸长量与运行时间的变化规律,开发了Z向位置补算模型。该模型计算的Z向位置估算值与通道的测量值之间吻合度良好,在此基础上,将电厂燃料通道轴向伸长监督系统进行升级,以监督新自由端轴向伸长量,为压力管的寿命评估和维修决策提供技术支持。

Fuel channels are important equipment of heavy water reactor unit,and the pressure tube contained in any channel is a part of primary loop pressure boundary.Supervising axial elongation of fuel channels is the basis for aging state assessment of pressure tubes.By utilizing the intrinsic relationship between A and C side readings in axial elongation records and upstream and downstream Z -direction positions in the refueling history records and in combination with change rule between axial elongation and operation time,the Z -direction position complementary calculation model was developed.Measured values of related channels were in good agreement with estimated values of Z -direction positions calculated by this model.On this basis,the axial elongation monitoring system of fuel channel of nuclear power plant was upgraded to supervise axial elongation of new free ends,and provide technical support for life assessment and maintenance decision of pressure tubes.