Radiation Field due to Beam Losses and Back Streaming in the Proton Beam Handling Room of the MINERVA Full Power Facility

(MYRRHA) [1] is currently under design at SCK CEN, Belgium. The Accelerator-Driven System (ADS) concept (600 MeV, 4 mA) has been chosen as a basis for this irradiation facility. MINERVA (MYRRHA Isotopes productioN coupling the linEar acceleRator to the Versatile proton target fAcility), the first phase of the MYRRHA project focusing on the construction of the 100 MeV proton linac and two target facilities, is underway. The Full Power Facility (FPF) of MINERVA will have the functionality for the fusion material research (FMR) [2] and the full power beam dump (FPBD) in case FMR is not in operation. During the commissioning of the linac the FPF will operate with a beam dump rig. It allows to continuously stop the full power beam 400 kW (4 mA,100 MeV) on the Ta beam dump and test the reliability of the accelerator. Operational experience of the FPF as FPBD can be used to further develop the facility towards a versatile proton irradiation facility for FMR. Radiation shielding of the FPF is required to protect workers, public, environment and equipment against prompt and residual radiation. In this paper, only the radiation field in the proton beam handling room (PBHR) behind the shielding block that surrounds Ta beam dump is considered due to presence of multiple radiation sources needed to be tackled for a proper determination of radiation field.