Radiation shielding requirements for the full power operation of the linear IFMIF prototype accelerator (LIPAc) at Rokkasho

•Detailed shielding analysis was conducted for the full power operation of LIPAc.•Final design of the beam dump constructed was fully taken into consideration.•Optimization of local additional shieldings was conducted.•Duct shield design creating labyrinth is effective to reduce neutron streaming.•Legal criteria at the controlled area boundary are met with the additional shields.