<P> Radioactive ores were first extracted at Radium Hill in 1906 , and Mount Painter in South Australia in the 1930s , to recover radium for medical use . Several hundred kilograms of uranium were also produced . Of the world 's proven estimated uranium reserves ( 5,404,000 tonnes ) , 31 % are held in Australia ( 1,673,000 tonnes ) , ahead of the second largest , Kazakhstan ( 12.1 % or 651,800 tonnes ) . In terms of production , Canada is the largest supplier to export markets , followed by Kazakhstan and Australia . Uranium mined in Australia is mainly for export . Australia exported 50,235 tonnes of uranium oxide concentrate in the five years to 2008 , worth A $2.9 billion . </P>
<P> Radioactive ores were first extracted at Radium Hill in 1906 , and Mount Painter in South Australia in the 1930s , to recover radium for medical use . Several hundred kilograms of uranium were also produced . Of the world 's proven estimated uranium reserves ( 5,404,000 tonnes ) , 31 % are held in Australia ( 1,673,000 tonnes ) , ahead of the second largest , Kazakhstan ( 12.1 % or 651,800 tonnes ) . In terms of production , Canada is the largest supplier to export markets , followed by Kazakhstan and Australia . Uranium mined in Australia is mainly for export . Australia exported 50,235 tonnes of uranium oxide concentrate in the five years to 2008 , worth A $2.9 billion . </P>
how much of the world 's uranium does australia have
how much of the world 's uranium does australia have
31 %
31 %