To meet the increasing demands for energy throughout the world, the use of nuclear power sources will increase in spite of their potential hazards.  The increased expense in using fossil fuels, the monopolistic control of the oil producing nations and the limited availability of other energy sources at the present time and in the foreseeable future will require the use of nuclear energy to assist in supplying the growing needs of countries throughout the world. 
Radioactive products, which are used in nuclear power plants and which are formed in nuclear reactors, represent a hazard to man and his environment, since some long-lived nuclides can contaminate areas for thousands of years.  They can become deadly to organisms into which they are ingested, even when the dosages are in trace quantities.  Moreover, on exposure to the environment the rays emitted by such nuclides can kill organisms very rapidly, even when the latter are exposed for only brief time periods. 
The production and transportation of radioactive products over wide areas, the proliferation of nuclear power plants, the presence of service stations for radioactive fuels and areas used for the storage of radioactive wastes all represent a relatively permanent menace to large land areas and populations thereof.  While such areas can be centralized to a certain extent so as to avoid heavily populated regions, other installations using radioactive nuclides, such as hospitals, medical and pharmaceutical laboratories, as well as many research facilities using radioactive isotopes in compound form, which may not be conveniently places in locations remote from population centers, also represent potential hazards, particularly where, as in most cases, such facilities do not have specialized personnel to safeguard the handling of the radioactive products in the event of accident. 
Accidents have taken place in even the most guarded installations which handle radioactive materials, such accidents being due, for example, to the leakage of stored radioactive liquid wastes from tanks placed above or below ground.  At least one chemical explosion, for example, has occurred in one of the shielded cells of a radiochemical processing pilot plant releasing quantities of plutonium-239, zirconium-95 and niobium. 
In summary, many sites exist where radiation hazards are present and where spills or leakages can occur, such as at uranium mines and refineries, at facilities for transporting radioactive products, at nuclear power plants utilizing reactors, fuel pools and radioactive waste storage tanks, at isotope purification sites, at laboratories preparing radioactive isotope containing compounds, and at installations using isotope compounds or other radioactive material, i.e., nuclear submarines and ships, nuclear power plants and storage sites for such materials.