What is a SCRAM and when is it typically initiated?

What is a SCRAM and when is it typically initiated?

• A. A SCRAM is a gradual reduction of reactor power.
• B. A SCRAM is an automatic venting of containment.
• C. A SCRAM is an immediate rapid insertion of control rods to stop fission; typically triggered automatically by safety systems or manually in emergencies.
• D. A SCRAM is a test of the cooling system.

Answer: (C)

A SCRAM is a rapid shutdown of a reactor achieved by inserting neutron-absorbing control rods all the way into the core to stop fission almost immediately. The goal is a quick drop in reactivity, so reactor power falls to a safe level within seconds. This action is driven by safety systems that automatically trip when unsafe conditions are detected (like unusual temperature, pressure, or flow) and can also be performed manually by an operator in an emergency. It’s not a normal power change, not an venting action, and not a test of the cooling system—it's an emergency shutdown to halt fission as fast as possible.

A SCRAM is a rapid shutdown of a reactor achieved by inserting neutron-absorbing control rods all the way into the core to stop fission almost immediately. The goal is a quick drop in reactivity, so reactor power falls to a safe level within seconds. This action is driven by safety systems that automatically trip when unsafe conditions are detected (like unusual temperature, pressure, or flow) and can also be performed manually by an operator in an emergency. It’s not a normal power change, not an venting action, and not a test of the cooling system—it's an emergency shutdown to halt fission as fast as possible.