Safety issues related to use of nuclear energy and secure operation of nuclear installations are mail stones of great importance. Although none of technologies producing energy are absolutely safe it is obvious that technology “extracting” the electricity from nuclear fuel needs to apply relatively higher level safety and security. Risk of safety operation depends on many factors and varies country-bycountry as well as technology-by-technology. The main principle of obtaining energy from the nuclear fuel is same for all nuclear power plants. In spite of this, safety level in modern technologies much higher. Past accidents and catastrophes on nuclear power plants served as a basis for improvement of nuclear technologies. Level of knowledge is also raised. First nuclear power plants were constructed by general engineers. Subsequently nuclear engineering established as a separate part with experience and knowledge oriented mainly on nuclear installations. Decision of application of nuclear energy (as a source of electricity generation) should be based on routine investigation of risks, benefits and needs. It should be taken into consideration that nuclear energy technologies while decided to be applied may motivate the country to raise level of education, science, industry, state security. So nuclear energy may be considered as a locomotive for progress. But this needs to be applied right time and right place. Otherwise it may cause catastrophic consequences for economy and society.