The Experimental Power Reactor (RDE) is designed based on High Temperature Gas Cooled Reactor (HTGR) technology which uses helium gas as a coolant. Helium gas is suitable as a coolant for heat transfer in reactors with very high temperatures considering the characteristics of helium gas as an ideal gas / inert gas, unchanged in physical or chemical properties at very high relative temperatures, unreacted with gases / other substances. The sustainability of the helium supply should be maintained so that the reactor primary coolant system pressure remains stable. Hence the design of Electrical for Helium Purification and Supply System - RDE (HPS-RDE) should be developed. The purpose of this study was to develop a detailed RDE design in terms of optimal primary cooling design. The research method is separated into 3 steps, that is designing electrical system at HPS-RDE with component simulation, electrical load distribution analysis and electrical component specification on HPS-RDE system using ETAP software. The final result of this research is the result of analysis and layout of electric load distribution and electrical component specification in HPS-RDE.