Pumps are the driving forces in fluid systems for nuclear power plants. The pump in each system drives the fluid through the piping to provide transfer of energy from one component to another. A pump is used in the main reactor circulating system to create the fluid flow that transfers the heated water to the steam generator. A pump provides the coolant flow that serves the steam condenser. There are pumps in all the fluid systems that make up a nuclear power plant. Fluid systems have varying degrees of importance depending on their function. The reactor cooling system is critical to maintaining the temperature of the fuel charge and transferring energy to the steam generator. The reactor coolant pump provides flow in this system. The steam system transfers energy from the steam generator to the turbine and then to the condenser. Cooling water supplied by a pump that circulates water from a coolant source through the condenser and back to its source condenses the steam. In addition to these primary fluid systems there are many others that provide for operation of the plant. Some of these systems are related to the safe operation of the power plant. Others are non Code and not safety related and therefore are not covered by the requirements of the Code. This commentary will explain how the ASME Boiler and Pressure Vessel Code (BPVC) requirements are implemented for Code nuclear pumps.