Abstract: A power system can connect to a nuclear reactor through a standardized connection. The standardized connection is configured so that the nuclear reactor may be designed independently of the power system. Systems include a reactor core in fluid communication with a heat exchanger. A fluid loop passes through the heat exchanger. The system includes an output and inlet manifolds at the ends of the fluid loop, terminating in ports that include a standardized connection mechanism. When the secondary system is coupled to the connection mechanism, the fluid loop and the secondary system define a distal loop. A working fluid can then flow through the distal loop and transfer heat from the reactor core to the secondary system.