The CANDU system employs a unique, on-power refueling system for optimum performance. Two identical fueling machines rise from a fueling duct under the reactor and latch onto opposite ends of a designated fuel channel. Each machine is operated remotely from the control room.

With both machines latched on and brought up to system pressure, the ends of the fuel channel are opened and new fuel is exchanged for used fuel – one machine discharging and the other accepting. The on-power refueling system allows Bruce Power the ability to refuel everyday to avoid refueling outages as is with other types of nuclear reactors.