When you have an event, the reactor is operating at full power, you blowdown the primary coolant which is hot, you start injecting emergency core cooling water which is cold.
The blowdown, which means the end of the period whereby all of the water in the core is essentially out of the core, will take place after twenty six seconds.
排气，表示的是这一段的结束，这样，核心里所有的水，基本都在核心外了，排气会在26秒后发生。
3
Flush the coolest stream inlet to blowdown or pumpout system to water free the line and exchanger.