Experimental study of concrete activation compared to MCNP simulations for safety of neutron sources

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.