Autonomous Director Technologies for Nuclear Energy (GUESS) is a strategic director of national importance, which coordinates the research activity in the field of nuclear energy, ensures the maintenance and development of scientific and technological support for the national nuclear energy program. Ratten has two branches: Pitești Nuclear Research Institute and  Center for Technological Engineering for Nuclear Objectives Măgurele. Autonomous Director Technologies for Nuclear Energy (GUESS) is established for the purpose of carrying out the technical support activity for nuclear energy and to maintain and develop technical competence during the operating duration of nuclear installations.  Ratten participates in the elaboration of the Strategy for the development of the field and in the achievement, with priority, of the scientific and technical objectives of the national programs approved by the Government. Ratten has as main activity object: The development of technologies necessary to ensure the national scientific and technical support for the nuclear energy field in order to operate under nuclear security conditions, Development of technologies for new types of generation IV energy nuclear reactors, Developing technologies for burnt nuclear fuel management and radioactive waste, the production of radioisotopes for medicine and industry, Scientific research activities, design and technological engineering, Preparation of nuclear specialists, specialized development as technical organizations support of central public administration, public information programs, activities specific to international cooperation in the field.