Preliminary analysis of radiation characteristic at upper section of Accelerator Driven Subcritical System

•A detail 3-D neutronic model of 10MW ADS coupled 250MeV proton accelerator was built.•Both beam losses and leakage of particles through beam duct were considerated.•The main contributors for upper radiation were beam duct leakage and secondary radiation induced by beam losses.•The impact of beam losses on total dose was greater than that on total neutrons flux.