Shielding design of the 200kW Pb-Bi spallation target for the transmutation experimental facility

Sasa, Toshinobu   ; Oigawa, Hiroyuki ; Tayama, Ryuichi*; Hayashi, Katsumi*

The construction of Transmutation Experimental Facility (TEF) is planned under the framework of Japan Proton Accelerator Research Complex (J-PARC) project. A liquid lead-bismuth (Pb-Bi) spallation target with beam power of 600MeV-200kW will be installed into the TEF. Analyses were performed to determine the effective thickness of biological shield for Pb-Bi target by using both MCNPX and ATRAS code system. Thickness of around 6m should be required to decrease the radiation level. The streaming analyses through the proton injection beam duct and the primary cooling circuit piping were also performed. The result of the beam duct streaming shows good agreement between the results of MCNPX and DUCT-III. The additional shield must be installed to suppress the activation of accelerator components. In the case of streaming through the primary cooling circuit piping, it is proved that the radiation level at the exit of the shield is allowable. The radiation level can be much more reduced by optimizing the bending position and length of the piping.