A reactor trip is not the end of control. It is a transition into another controlled state. After the chain reaction stops, decay heat remains, cooling continues, parameters are monitored and operators verify that the plant is moving toward a stable condition.
SCRAM is often imagined as a dramatic emergency action. In reality, it is a designed safety function: a rapid shutdown of the fission chain reaction by inserting negative reactivity into the reactor core. But shutting down fission is not the same as removing heat. After SCRAM, the system continues to require cooling, monitoring, procedures and control.
