Actinides, accidental release

Actinides in the environment can be classified into two groups (i) the uranium and thorium series of radionuclides in the natural environment and (ii) neptunium, plutonium, americium and curium which are formed in a nuclear reactor during the neutron bombardment of uranium through a series of neutron capture and radioactive decay reactions. Transuranics thus produced have been spread widely in the atmosphere, geosphere and aquatic environment on the earth, as a result of nuclear bomb tests in the atmosphere, and accidental release from nuclear facilities (Sakanoue, 1987). Most of these radionuclide inventories have deposited in the northern hemisphere following the tests conducted by the United States and the Soviet Union. 

Nuclear weapons testing was deliberate however many other releases of radionuclides are accidental. These have included fires and spillages at nuclear reprocessing plants resulting in releases of an assortment of nuclides to the atmosphere and the oceans, including super-heavy elements from the actinide group of the Periodic Table (Fig. 2.2) such as plutonium (Pu). Similarly, accidental sinking of nuclear submarines has released radionuclides to the bottom waters of the... 

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