Main instrument systems Introduction Instruments at nuclear plants monitor key systems to assist operators with running the plant safely and efficiently. This topic discusses the 3 major FPL nuclear plant instrumentation systems. If system components fail to keep normal operating parameters, the reactor protection system shuts down the unit. If the reactor approaches an abnormal operating condition cuts power to electromagnets that keep the reactor control rods out of the core and stops the fission process. Excore instrumentation monitors reactor power levels.
Incore instrumentation monitors coolant temperatures and reactor power levels.
Alternate shutdown panels exist in the event of fire or limited access.