博文
沸水堆断电后假想事件链
|||
福岛核电站一系列麻烦的开端在于柴油发电机停止工作。至此，所有的AC电源都没有了,唯一剩下的是DC电池。
下图（取自NUREG-1032）显示BWR 马克I型核壳电站断电后的事件发展图。资料来源: US NRC G.E. Technology Advanced Manual
t0 = 0, loss of off-plant power and failure of diesel generator
t1 = 6 hours, depletion of DC power; HPCI and RCIC inoperable.
t2 = 8 hours, primary coolant heatup, release of steam; depletion of primary coolant inventory, loss of makeup.
t3 = 10-11 hours, core temperature rises rapidly, resulting in core melt and vessel penetration.
t4 > 11 hours, containment failure occurs nearly coincident with vessel penetration, either by loss of electrical penetration integration or by containment overpressure after high pressure core melt ejection.
也就是说，根据反应堆安全分析，从柴油机失效开始，大概在11到13个小时内（视电池的工作时间定）如果一直得不到有效外部电源的话，堆芯熔化事件是很有可能的。不幸的是，在BWR的设计中，这类事故并非设计基准事故(Design Basis Accident, DBA)。原因？PRA分析认为，CCDP在十的负五次方以下。
在福岛，移动发电机在12个小时内送达事故现场，可是不知什么原因，花了很大的力气才续上。
Event Tree for 1989 Brunswick 2, loss of offsite power. Conditional Core Damage Frequency: 3.6E-5.
BWRs have such a large number of motor driven injection systems that a loss of electrical power implies loss of injection capability. This is why, station blackout is consistently identified by PRAs to be the dominant core melt precursor for BWRs. Operators have to be prepared to deal with the effects of a loss of and restoration of ac power to plant controls, instrumentation, and equipment.
Although loss of all ac power is a remote possibility, it is necessary to address the problem both in training of personnel and equipment design.
看来BWR的设计缺陷还是比较明显。
https://blog.sciencenet.cn/blog-103568-422896.html
上一篇：早泄的福岛核电站
下一篇：关于老蒋和BOBBY的争论
下图（取自NUREG-1032）显示BWR 马克I型核壳电站断电后的事件发展图。资料来源: US NRC G.E. Technology Advanced Manual
t0 = 0, loss of off-plant power and failure of diesel generator
t1 = 6 hours, depletion of DC power; HPCI and RCIC inoperable.
t2 = 8 hours, primary coolant heatup, release of steam; depletion of primary coolant inventory, loss of makeup.
t3 = 10-11 hours, core temperature rises rapidly, resulting in core melt and vessel penetration.
t4 > 11 hours, containment failure occurs nearly coincident with vessel penetration, either by loss of electrical penetration integration or by containment overpressure after high pressure core melt ejection.
也就是说，根据反应堆安全分析，从柴油机失效开始，大概在11到13个小时内（视电池的工作时间定）如果一直得不到有效外部电源的话，堆芯熔化事件是很有可能的。不幸的是，在BWR的设计中，这类事故并非设计基准事故(Design Basis Accident, DBA)。原因？PRA分析认为，CCDP在十的负五次方以下。
在福岛，移动发电机在12个小时内送达事故现场，可是不知什么原因，花了很大的力气才续上。
Event Tree for 1989 Brunswick 2, loss of offsite power. Conditional Core Damage Frequency: 3.6E-5.
BWRs have such a large number of motor driven injection systems that a loss of electrical power implies loss of injection capability. This is why, station blackout is consistently identified by PRAs to be the dominant core melt precursor for BWRs. Operators have to be prepared to deal with the effects of a loss of and restoration of ac power to plant controls, instrumentation, and equipment.
Although loss of all ac power is a remote possibility, it is necessary to address the problem both in training of personnel and equipment design.
看来BWR的设计缺陷还是比较明显。
https://blog.sciencenet.cn/blog-103568-422896.html
上一篇：早泄的福岛核电站
下一篇：关于老蒋和BOBBY的争论
