【摘要】 对于自然循环低温核供热堆的压水运行工况,在发生丧失全部热阱ATWS事故时,由于功率下降滞后于流量下降,反应堆在事故过程中可能进入低干度两相流不稳定区,堆功率及流量出现较大幅度的振动。本文针对这一现象,分析了物理机制及参数影响,指出通过加大慢化剂负温度系数、或提高堆芯出口过冷度、或减小烟囱面积,可避免出现这种振荡。更多还原

【Abstract】 Under the loss of heat sinks ATWS (anticipated transients without scram) accident of the PWR operation of nuclear heating reactors with natural circulation, the reactor is probably to enter a low quality two-phase flow density wave instability region and an oscillation of the power and flow rate can be induced because the decrease of core power lags behind the flow rate. This article explains this phenomenon and analyses its physical mechanism and effects of relevant parameters. Finally* it is noted that the oscillation could be avoided if negative temperature coefficient of moderator or core outlet subcooling is increased?or cross-section area of the riser is reduced.更多还原