Uranium is the principle fuel for nuclear reactors and the main raw material for fission nuclear weapons. Uranium is already radioactive when it is dug out of the ground, although weakly. Uranium ore needs to go through several processes - conversion and enrichment - in order to concentrate the radioactivity by 2-3% to become nuclear reactor grade fuel, and by 80% to become weapons grade, although lower levels of enrichment will suffice.

Over half of the world’s uranium is in Canada and Australia. Uranium is mined in 18 countries: Canada, Australia, Kazakhstan, Russia, Namibia, Niger, Uzbekistan, USA, Ukraine, China, South Africa, Czech Republic, India, Romania, Germany, Pakistan, France, Brazil.

In 2005, eight mining companies comprised 78% of uranium production: Cameco, Rio Tinto, Areva, KazAtomProm, BHP Billiton, TVEL and Navoi.

Uranium mining is a very ecologically damaging link in the nuclear chain. For every tonne of uranium oxide produced, hundreds of thousands of tonnes of wastes, or tailings, are left behind. Often the tailings are simply dumped on the land near the mine and left to the effects of the elements. Mine tailings (waste) contain around 80% of the radioactivity of the original ore. One of the major isotopes produced from uranium mine tailings is thorium-230 whose half-life is 75,000 years.

Uranium-238, the most prevalent isotope in uranium ore, has a half-life of about 4.5 billion years; that is, only half the atoms will decay in that amount of time.

Wind carries radon gas and radioactive dust from these tailings for many miles. Uranium miners are exposed to radioactive radon gas, and consistently suffer increased rates of lung cancer.

Uranium mining requires a great deal of water. BHP Billiton's Olympic Dam mine in South Australia, Australia's driest state, uses 33 million litres of water per day. A proposed expansion of the mine would increase this to up to 162 million litres per day (Olympic Dam eis.com). This water becomes radioactive waste, which is placed into evaporation ponds that are not always adequately secured from leaking and flooding. Contaminated rainwater can and does enter the soil and, eventually, the food chain, endangering health.

In addition, Indigenous peoples' lands have been used to mine uranium, dump radioactive wastes and to test (explode) nuclear bombs, both above-ground and below-ground, resulting in massive radioactive contamination.