Current economic uranium resources will last for over 100 years at current consumption rates, while it is expected there is twice that amount awaiting discovery. With reprocessing and recycling, the reserves are good for thousands of years.[34]. It is estimated that 5.5 million tonnes of uranium ore reserves are economically viable[35] , while 35 million tonnes are classed as mineral resources (reasonable prospects for eventual economic extraction).[36] An additional 4.6 billion tonnes of uranium are estimated to be in sea water (Japanese scientists in the 1980s showed that extraction of uranium from sea water using ion exchangers was feasible
