the United States entitlement to a portion of the output of power and energy from the Navajo Generating Station, Page, Arizona, pursuant to United States participation in that generating station;

in the event that said United States entitlement is integrated with other generating facilities, then Navajo Generating Station means that amount of power and energy from the integrated system which is attributable to the United States Navajo entitlement;

when the Navajo Generating Station is replaced at the end of its useful life or an alternative resource is established, then Navajo Generating Station means an amount of power and energy equivalent to the present United States entitlement from Navajo, from the replacement resource.