Estimation of Radioactivity Produced in Cooling Water at High-Intensity Proton Accelerator Facility

The radioactivity produced in accelerator cooling water was estimated to determine the maintenance scenario of Japan Proton Accelerator Research Complex (J-PARC) accelerators. The PHITS and the MCNPX codes were used to calculate the proton and neutron fluxes in water-cooled accelerator components. The activation cross-section sets of oxygen for high-energy protons and neutrons were evaluated from the available experimental data and theoretically calculated data by the INC/GEM and the LAHET codes. The radioactivity from corrosion products was also estimated by scaling of the measurements at the High Energy Accelerator Research Organization 12 GeV Proton Synchrotron Experiment (KEK-PS) and Los Alamos Meson Physics Facility (LAMPF). The tritium estimation is an acceptable level for disposal to the environment, while short-lived nuclides at the 3-GeV synchrotron may raise the dose rate in the machine room.