the earth's supply of uranium is nearly limitless.
Actually according to the article: The readily available uranium fuel wont last much more than 50 years.
Though it refers to it as the readily available so I guess your right. Ilike the Idea of using plants as a type of solar panel. Its funny but if you look at it its like all the renewable enery sources comes from the sun. Even wind is genertated by heat from the sun.