Once uranium is mined, it has to be transported and refined for use in nuclear weapons or reactors. As with mining, there are major problems involved in such activities.
Once uranium is leached from crushed ore, it is precipitated from solution and washed to produce a coarse powder which is around 80% uranium oxide. The powder has a strong order and cannot be dissolved in water. Although this powder is referred to as ‘yellow cake’ because of early ore extraction techniques, today most of the ‘yellow cake’ is brown or black.
The yellow cake is transported in sealed containers via rail or truck to plants where uranium fuel rods are manufactured. If the seal is maintained, the main dangers are from dust escaping from loading and unloading the containers. However, if there is a train derailment or a truck accident, a container could be broken open, spilling yellow cake out into the environment where wind and water could carry it away from the location of the accident.
When the yellow cake reaches the purification facility, it is smelted into uranium metal which is then combined with fluorine and subjected to isotopic separation where the level of highly radioactive U-235 is increased. Twenty percent U-235 is use to create uranium pellets for nuclear reactor fuel rods while highly enriched uranium with more than ninety percent U-235 is use to create nuclear weapons.
As with any complex industrial process, there is the potential for a number of problems. If the staff is not well trained and conscientious, such incompetence may lead to exposure of workers to radioactive materials or release of such materials into the environment. The company operating the facility may not be conscientious in providing properly functioning equipment and enforcing rigorous safety standards. And, finally, the government agencies tasked with overseeing uranium enrichment may fail to inspect and hold enrichment facilities responsible for breaches in following regulatory guidelines..
If the dangerous materials such as yellow cake or any of the products of intermediate stages of uranium enrichment as well as the finished fuel pellets and rods are not properly handled because of any of the problems mentioned above, workers can be exposed to radiation and radioactive materials may escape into the environment.
Highly toxic chemicals are used in enrichment such as fluorine gas. Fluorine bursts into flame when it comes into contact with ammonia, ceramics, copper wire and many organic and inorganic compounds. It changes to hydrofluoric acid when it comes in contact with moisture. It is highly damaging to the tissue of the respiratory tract. The gas formed when uranium interacts with fluorine is even more dangerous because it contains a heavy metal and is radioactive. Fluorine and uranium hexafluoride gas would be a serious health hazard if released into the environment.
Individual enrichment facilities around the world have been criticized for one or more of the above problems prompting protests aimed and redressing the problem and/or closing the facility.
