方家山核电站延伸运行期间氙振荡控制

Xenon Oscillations Control in Fangjiashan NPP During Stretch-Out Operation

对于大型商用反应堆,运行过程中出现一定扰动后,容易产生氙振荡。小幅度的氙振荡不会影响堆芯安全。大幅度的氙振荡会使堆芯局部区域的温度持续升高,可能会突破燃料设计限值,使燃料元件熔化。方家山核电站2号机组延伸运行期间出现了轴向氙振荡加剧的情况,通过适时移动控制棒组、降低单次降功率变化量、选择氙振荡负周期前3/4时段降功率的方式,有效地抑制了氙振荡,在保证堆芯安全的前提下顺利实施了延伸运行。

For a large commercial reactor,it is easy to cause xenon oscillations after a disturbance occurred during power operation.If the amplitude of xenon oscillations is small and stable,the core can stay safe.If the amplitude of xenon oscillations is large or unstable,the temperature of the local area in the reactor will continue to increase,the fuel design limit may be broken,and the fuel element can be melted down.The amplitude xenon oscillations expanded in Fangjiashan Unit 2 during stretch-out operation,which was effectively controlled by moving control rods appropriately,reducing the amount of once power reduction,choosing the power reduction in the first 3/4 period of the negative cycle of the xenon oscillations.The stretch-out operation was carried out smoothly under the premise of ensuring the safety of the core.