The Supervisory Control System (SCS) provides overall coordination of the plant actuators that includes automatically regulating process variables so that performance goals are safely met for all operating modes. The system during normal electric power production operates through a hierarchical structure with steam demand supplied as an input at the top level, and based on this value, coordinated set points are issued to lower level sub-system controllers. Through the use of the Supervisory Control System, hot-side temperatures can be maintained near-constant during transients so that thermal fatigue is significantly reduced from otherwise. The design strategy for the control system regards the plant response to a change in electric generator load as consisting of two components: steady-state and transient. There is the equilibrium state the plant will reach in asymptotic time (steady-state) in response to the changed condition. The steady-state control algorithm, or Load Schedule as it is known, manages steady-state temperatures. There is the dynamic component of the response (transient) which can be regarded as superimposed on the asymptotic state. The Single-Input Single-Output (SISO) Controllers manage the dynamic response component. In this work, the Supervisory Control System is designed for electric power operation of a pool-type metallic-fueled Sodium-cooled Fast Reactor (SFR). 10% step and 5%/min ramp load change cases were simulated with a one-dimensional system analysis code to assess the performance of the SISO controllers.