NOVELTY - A fuel cell power plant includes an evaporator, an expansion valve for reducing the pressure of the secondary coolant stream so that it changes to steam in the evaporator, and a compressor for increasing the pressure of the steam exiting the evaporator.    USE - For supplying electricity.    ADVANTAGE - The invention provides a co-generated source of steam without adding auxiliary equipment, e.g. boiler. The amount of steam generated is greater than the steam required by the fuel processor, which allows the power plant to use additional steam for other co-generation requirements.    DETAILED DESCRIPTION - The fuel cell power plant (10) comprises a cell stack assembly of fuel cells (30) comprising a proton exchange membrane (PEM) (34) disposed between the cathode (36) and the anode (32). A cooler (38) circulates a coolant stream through the cell stack including a pump (64). A heat exchanger (70) removes heat from the coolant stream, and a temperature sensor (68) controls the temperature of the coolant stream, thus cooling the cell stack assembly. A flash evaporator (42), an expansion valve (40) for reducing the pressure of the secondary coolant stream so that the secondary coolant stream changes to steam in the evaporator, and a compressor (44) for increasing the pressure of the steam exiting the evaporator, are provided. An auto-thermal reformer (20) receives the hydrocarbon fuel and the steam, and produces a fuel reactant gas comprising hydrogen and carbon monoxide (CO). A shift converter (24) receives the fuel reactant gas from the reformer and converts a portion of the CO in the fuel reactant gas to carbon dioxide (CO2). A selective oxidizer (25) receives the fuel reactant gas from the shift converter and converts a further portion of the CO in the fuel reactant gas to CO2. A water transfer device (54) provides an oxidant reactant gas to the cathode.    An INDEPENDENT CLAIM is also included for a method for operating a fuel cell power plant comprising providing an oxidant reactant gas to the cathode; supplying a stream of coolant fluid to the cell stack assembly; creating a secondary stream of coolant fluid from the stream of coolant fluid exiting the cell stack assembly; reducing the pressure of the secondary stream of coolant fluid; supplying the steam and a hydrocarbon fuel to a reformer for producing a fuel reactant gas comprising hydrogen and CO; supplying fuel reactant gas exiting the reformer to a shift converter for converting a portion of the carbon monoxide in the fuel reactant gas to CO2; supplying the fuel reactant gas exiting the shift converter to a selective oxidizer for further converting the CO in the fuel reactant gas to CO2; and conveying the fuel reactant gas from the selective oxidizer to the anode.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic diagram of the fuel cell power plant.    Fuel cell power plant (10)    Autothermal reformer (20)    Shift converter (24)    Selective oxidizer (25)    Oxidizer stages (26, 28)    Fuel cells (30)    Anode (32)    PEM (34)    Cathode (36)    Cooler (38)    Expansion valve (40)    Flash evaporator (42)    Compressor (44)    Second compressor (48)    Heat exchangers (50, 52)    Water transfer device (54)    Pump (64)    Temperature sensor (68)    Heat exchanger (70)    Reformer burner (106)