A process for shutting down a fuel cell power plant (5) shuts off (40) process air, recycles (44-46) air exhaust 42 to air inlets 34, and connects an auxiliary load to the stack (6). Coulombs are counted by integrating (17) current (73) or voltage (75) to the load to determine when all oxygen in the air side (10, 27, 30, 34, 42, 44-47) of the power plant is consumed and a desired concentration of hydrogen is transferred to the air side of the power plant. The speed of the shutdown processes may be increased by increasing fuel pressure (15) or adding a battery (78) in series with the auxiliary load.