[en] Extensive neutron flux measurements were performed inside the drywell of Caorso (Italy) nuclear power plant, a 2600 MW/sub th/ BWR. The activation technique was used together with the fission track measurement in solid state detectors, with natural or depleted uranium as converter materials. The results were of utility to assess neutron dose rates and related quantities, such as the reliability functions of the exposed materials. Additional measurements are planned at the pressure vessel outer surface by means of the multiple foil activation technique, for an experimental validation of shielding and streaming calculations relating to the neutron environment between the pressure vessel and the sacrificial shield