Recently peaceful use of the nuclear energy and radioactive nuclides has increased the radiation pollution factor in the world and radiation safety problems have become actual ones. The development of the nuclear power engineering, protection and processing of radioactive wastes of nuclear reactors, the use of radioactive isotopes in national economy, nuclear explosion, industrial wastes and etc. may cause the radioactive pollution of the environment. In the case of such pollution the environment as well as living organisms are exposed to radioactive radiation (a-, b-, γ- etc.). Radioactive substances emit radioactive rays and as their decay time varies for natural and artificial radioactive substances the time of their environmental effect ranges from some years to million years.