At the current usage rate of 69,000 tonnes of uranium—and assuming all of it would come from mining—there is an 80-year supply based on the Red Book recoverable resources at a cost less than $130 per kilogram but that increases to a 100-year supply at double the cost. But what would happen if the number of reactors increased from the current 443 nuclear reactors to 1,000 reactors? Could they be supplied with uranium fuel? The Red Book estimates that there are undis­covered uranium resources of about 10.4 million tonnes, more than doubling the available uranium resources. And that does not include several major producers with large identified uranium resources that do not report estimates of undiscov­ered resources. Uranium resources should be similar to other metals that have been mined historically, in which the predictions of the depletion of a resource have not been met in reality (45). The MIT study on the future of nuclear power used a model to predict a tenfold increase in resources at a doubling of price due to increased exploration and reclassifying resources as economically recoverable. The study concludes that “the world-wide supply of uranium ore is sufficient to fuel the deployment of 1,000 reactors over the next half century and to maintain this level of deployment over a 40 year lifetime of this fleet” (52, 53).

But that is not the end of the story. Most of the world’s—and all of the United States’—nuclear fleet operates in a once-through mode known as an open fuel cycle. In an open fuel cycle, uranium is mined, enriched, made into fuel, burned in a reactor, and the spent nuclear fuel has to be stored until it decays. But the spent nuclear fuel contains uranium and plutonium that can be used for new nuclear fuel. In a closed fuel cycle, the spent nuclear fuel is recycled to extract the plutonium and uranium, providing a new resource to fuel reactors and reducing the nuclear waste storage problem. This is not only feasible but is currently being done in France and a few other countries, as discussed in Chapter 9. Reactors can have a maximum of about 30% of their fuel supply provided by recycled MOX fuel. If both the plutonium and uranium were recycled into new fuel, that could increase the available fuel resources by about 25%.