NOVELTY - A decontamination procedure involves operating fuel cell power plant (10) to produce electrical power, directing a flow of oxidant through cathode flow field (40), directing a flow of the hydrogen fuel through the anode flow field (22), terminating operation of fuel cell (12) of plant for decontamination period, decontaminating fuel cell during decontamination period, and directing flow of oxygen containing oxidant stream through the anode flow.    USE - The method is useful for decontamination method used for a fuel cell power plant for usage in transportation vehicles, portable power plants, or stationary power plants.    ADVANTAGE - The method removes contaminants from fuel cell electrodes of power plant without requiring extensive interruption of operation of fuel cell power plant and does not require costly, complex valve, and flow path apparatus. The method can be performed at normal operating temperature. The method eliminates virtually all contaminants from fuel cell electrodes of plant, resulting in no significant performance decay of plant for very protracted operation.    DETAILED DESCRIPTION - A decontamination procedure comprises operating the fuel cell power plant to produce electrical power for an operating period by connecting the primary electrical load (82) to the fuel cell, directing a flow of the oxidant through the cathode flow field, and directing a flow of the hydrogen fuel through the anode flow field, terminating operation of fuel cell of plant for decontamination period by disconnecting the electrical load from fuel cell whenever optimal electrical power production of fuel cell is reduced, decontaminating fuel cell during decontamination period by terminating flow of hydrogen fuel through the anode flow field, and directing flow of oxygen containing oxidant stream through the anode flow so that a potential of electrodes rises at 1-1.25 volts compared to the standard hydrogen reference electrode to oxidize contaminants adsorbed on anode and/or cathode electrode during operating period. The method includes cycling the potential of the electrodes by alternating the flow through the anode flow field between the oxygen containing oxidant stream and hydrogen containing fuel stream until the fuel cell is returned to optimal electrical power production during the decontaminating the fuel cell step and after the step of directing a flow of an oxidant containing oxidant stream through the anode flow field; cycling flow through the anode flow field between the oxidant and hydrogen reactant streams greater than or equal to2 cycles. 4. The optimal electrical power production of the fuel cell is reduced by greater than or equal to5% by contamination of anode and/or cathode electrodes. The plant includes fuel cell(s) for generating electrical power from hydrogen containing reducing fluid fuel and oxygen containing oxidant reactant streams, a power circuit (80) for directing the electrical power from the fuel cell to a primary electrical load, anode flow field in fluid communication with the anode electrode for directing hydrogen fuel to flow through the fuel cell and adjacent the anode electrode, and cathode flow field (40) in fluid communication with the cathode electrode (42) for directing the oxidant stream to flow through the fuel cell and adjacent the cathode electrode (42). The fuel cell includes anode and cathode electrodes. The cathode electrode is on opposed sides of an electrolyte (48).    DESCRIPTION OF DRAWING(S) - The figure shows simplified schematic representation of fuel cell power plant for implementing decontamination procedure for fuel cell power plant.    Fuel cell power plant (10)    Fuel cell (12)    Anode flow field (22)    Cathode flow field (40)    Cathode flow field (40)    Cathode electrode (42)    Power circuit (80)    Primary electrical load (82)