Radioactive waste

Radioactive waste is waste material containing radioactive chemical elements that does not have a practical purpose. It is often the product of a nuclear process, such as nuclear fission. Waste can also be generated from the processing of fuel for nuclear reactors or nuclear weapons.

Related Topics:
Waste - Radioactive - Chemical element - Nuclear fission - Nuclear reactor - Nuclear weapon

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The radioactivity of all nuclear waste diminishes with time. All radioisotopes contained in the waste have a half-life - the time it takes for any radionuclide to lose half of its radioactivity. Eventually all waste decays into non-radioactive elements. After 40 years 99.9% of radiation in spent nuclear fuel disappears http://www.world-nuclear.org/education/ne/ne5.htm.

Related Topics:
Radioisotope - Half-life

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The faster a radioisotope is decaying, the more radioactive it will be. Another factor in deciding how dangerous a pure radioactive substance will be is the energy of the radiation. Some decays yield more energy than others. This is further complicated by the fact that few radioisotopes decay immediately to a stable state, but rather to a radioactive decay product leading to decay chains.

Related Topics:
Radioisotope - Decay product - Decay chains

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The main objective in managing and disposing of radioactive (or other) waste is to protect people and the environment. This means isolating or diluting the waste so that the rate or concentration of any radionuclides returned to the biosphere is harmless. To achieve this for the more dangerous wastes, the preferred technology to date has been deep and secure burial. Transmutation, long-term retrievable storage, and removal to space have also been suggested.

Related Topics:
Biosphere - Transmutation

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