Estimation of radioactivity produced in cooling water at high-intensity proton accelerator facility

Masukawa, Fumihiro  ; Nakane, Yoshihiro  ; Iwamoto, Yosuke   ; Nakashima, Hiroshi

The radioactivity produced in the accelerator cooling water was estimated to draw up the maintenance scenario of the J-PARC accelerators. Activation cross section sets from Nitrogen and Oxygen were evaluated from the available experimental data and theoretically calculated data by INC/GEM and LAHET for high-energy proton and neutron. The PHITS and MCNPX codes were used to calculate the proton and neutron fluxes in the water-cooled accelerator components. The radioactivity from the corrosion product was also estimated by scaling of the measurements at KEK-PS and LAMPF. Tritium are estimated 5.710 [Bq] in LINAC and 2.510 [Bq] in 3-GeV Synchrotron by annual operation. Dose in machinery rooms by short-lived nuclides are reasonably low at LINAC, whereas 10 times higher at 3-GeV Synchrotron. The estimation of tritium is acceptable level for the disposal to the environment, while short-lived nuclides at 3-GeV Synchrotron may make the facility maintenance difficult.