反应堆物理启动提棒外推临界时考虑空间效应的修正方法

Correction Method for Critical Extrapolation of ControlRods-Rising during Physical Start-Up of Reactor with Spatial Effect

分析了反应堆物理启动提棒外推临界时,外推临界曲线经常出现外凸现象的原因。在消除中子源项方法的基础上,引入空间通量畸变因子的理论,提出了进一步消除反应堆空间效应影响的新的修正方法。利用该方法进行了实例计算,并将计算结果与反应堆物理启动的实际数据和采用消除中子源项修正方法的结果进行了比较。结果表明:新方法能更好地改善曲线外凸现象,用修正后的曲线进行临界外推,可以更加快速准确地确定临界棒位。

Reasons why the extrapolated critical curve obtained by lifting control rods is cambered during the physical start-up of a reactor are analyzed. Spatial flux deformation factor is introduced, and a new method, by which influences of spatial effect in the reactor are avoided additionally, is proposed based on what is achieved by removing source neutrons. The new method is employed to a real example. Comparing the new results with those of real physical start-up and achieved only by removing source neutrons, it is shown that the new method avoids cambering phenomenon of the extrapolated curve much better, and obtains more precise critical position of control rods, so the reactor will reach the criticality more safely.