Some of the highest grade uranium ores in the world were found in the Shinkolobwe mine in the Democratic Republic of the Congo ( the initial source for the Manhattan Project ) and in the Athabasca Basin in northern Saskatchewan , Canada .
Some of the highest grade uranium ores in the world were found in the Shinkolobwe mine in the Democratic Republic of the Congo ( the initial source for the Manhattan Project ) and in the Athabasca Basin in northern Canada .