Characterization of an underground site in Northern Italy in view of low radioactivity measurements

A low background station for the measurement of low level radioactivity is under development in Northern Italy. The rock cover is about 300 m water equivalent. We report and discuss measurements of radon concentration in air and of gamma, muon and neutron fluxes performed in the neighborhood of the station site. We present and apply a simple analytical model capable to disentangle the contribution to the measured gamma activities due to 222Rn in air from the one due to 238U and its daughters in the rocks.