Fuel handling system, layout, and process for nuclear reactor

A sodium removal machine for cleaning a discharged core assembly, comprising:

• a receiver coupled to a fueling floor valve, the receiver having one or more process fluid couplings;
• a cleaning vessel configured to receive and retain a spent fuel assembly, the cleaning vessel having an open upper end configured to sealingly couple with the receiver and a closed lower end, wherein the cleaning vessel is configured to be at least partially submerged in a spent fuel pool during cleaning;
• and
• an elevator configured to convey the cleaning vessel containing the spent fuel assembly from an upper position in which the cleaning vessel is sealingly coupled to the receiver to form a substantially enclosed cleaning chamber having controlled fluid inlet and outlet paths, to a lower position in which the cleaning vessel is decoupled from the receiver, and the open upper end of the cleaning vessel is submerged within the pool to allow water from the pool to enter the cleaning vessel.