[en] Full text: The fields of fast neutrons are created at the RB reactor. They are: experimental fuel channel (EFC), coupled fast-thermal system in two configurations (CFT-a and CFT-2) and fast-thermal core HERBE. RB is an Unshielded, zero power nuclear facility with natural and enriched uranium fuel (2% and 80%) and D₂O as moderator. During operation of the RB reactor the doses of neutron and gamma radiation are continuously controlled and registered by measuring the dose rates in determined measuring points. The intermediate and fast neutron spectra in fast neutron fields are measured by improved version of activation technique. The mean neutron and gamma dose rates in measuring points are analyzed. The intermediate and fast neutron absorbed doses in fast neutron fields are computed on the basis of experimental results. The review of the stay of reactor staff in rooms of reactor building during various modes of reactor operation is given as the result of topography, as well as the dosimetry and other purposes of constructed fast neutron fields. (author)