The electrical windings in the generator casing create heat which is removed using hydrogen gas which absorbs the heat and dissipates it by passing around water filled coolers. To prevent the hydrogen gas from leaking out and oxygen from leaking in along the rotating element shaft the seal oil system pumps oil around the rotating shaft to help create a seal. While flowing around the shaft the oil absorbs some hydrogen gas and oxygen and returns to the seal oil system where the oxygen and hydrogen is vented off and the oil is circulated back to the rotating shaft creating a continuous seal.