Uranium mining takes uranium ore from the ground for processing. Kazakhstan, Canada, and Australia are the top three producers and together account for 64% of world uranium production. Uranium from mining is mostly used as fuel for nuclear power plants. Health and environmental studies show that radiation exposure poses a risk for uranium miners. In 1990, Congress passed legislation to help those affected by mining. As of July 2014, the price of uranium concentrate remained near a five-year low, the uranium price having fallen more than 50% from the peak price in January 2011, and reflecting loss of demand following the 2011 Fukushima nuclear disaster. Some plans for new mines and mine expansion have been deferred.