Question

The uranium used as nuclear fuel and in bombs has to be enriched before use. Explain what enrichment means and describe a method used to enrich uranium.

2. Describe why the mining or uranium ore often pollutes the local environment.

3. What is a breeder reactor and why is it useful to breed fissionable fuel?

Answer 1

1. Enrichment means to increase the percent composition of a particular element through various processes. In case of uranium, the enriched uranium is done by a process called isotopic separation. In this method, a particular isotope of an element is concentrated and other undesired isotopes are removed.

2. The mining of uranium ore often pollutes the local environment as it is itself radioactive. Uranium ore emits radon gas. The health effects of high exposure to radon are a particular problem in the mining of uranium; significant excess lung cancer deaths have been identified in epidemiological studies of uranium miners employed in the 1940s and 1950s.

3. A breeder reactor is a nuclear reactor capable of generating more fissile material than it consumes. It requires an initial charge of fissile material, such as highly enriched uranium or plutonium, and a supply of fertile material, such as natural uranium, depleted uranium or thorium. Excess neutrons generated in the fission reaction are absorbed by the fertile isotope, which is transmuted to a fissile isotope. These devices are able to achieve this because their neutron economy is high enough to breed more fissile fuel than they use from fertile material such as uranium-238 or thorium-232.