Once built, each reactor must be provided with fuel in the form of enriched uranium oxide. As discussed earlier, the isotopic content of uranium 235 must be increased from the naturally occurring value of 0.7% to 3-5%. To do so requires a large quantity of raw uranium ore. It takes about 10 metric tons of raw uranium to produce one metric ton of enriched uranium. To fuel all of the 400+ reactors currently operating in the world requires about 65,000 metric tons of ore. The current estimate of proven reserves is 4.7 million tons. In addition it is estimated that about ten million tons have yet to be discovered. Total, this suggests that there is enough fuel to supply the existing reactors for over 200 years. In addition there are a number of non-traditional sources from which one could obtain uranium albeit at a higher cost. These include the extraction of uranium from the ocean as well as from areas of very low concentration such as Chattanooga shale, which contains about 66 ppm of uranium . Thus, it is likely that current reactors, even considering a major expansion of such reactors, will have sufficient fuel for the foreseeable future.
Other technologies are also available and are being considered for commercial exploitation. The current generation of light water reactors such as those discussed earlier mostly employ what is referred to as a once through fuel cycle. The fuel is manufactured, burned in the reactor for about 6 years and then is removed for ultimate disposal. Even when spent, the fuel still contains nearly half the energy it had when it was new. Techniques are available and in use in Europe and Japan to extract the unburned fuel and recycle it. This enables the fuel to be used again for at least two additional cycles. Because of proliferation concerns, the U.S. has not adopted this approach but this policy is now being reevaluated.
Was this article helpful?