  The neutron activation of shielding materials and the generated decay gamma
radiation are well-known issues in terms of occupational exposure. Though the
trace elements of shielding concretes can be dominant sources of the produced
activity in such cases, their concentrations are often missing from the input
data of shielding-related Monte Carlo simulations. For this reason, three
concrete types were studied, that were considered in the European Spallation
Source (ESS) ERIC. Their composition - including the trace elements - were
determined via XRF, PGAA and NAA techniques. Realistic input data were
developed for these materials, containing the parent elements of all the
dominant radioisotopes, and were validated against measured data of neutron
irradiation experiments.
