3-dimensional shielding design for a spallation neutron source facility in the high-intensity proton accelerator project

Tamura, Masaya; Maekawa, Fujio

JAERI-Tech 2003-010, 54 Pages, 2003/03

JAERI-Tech-2003-010.pdf:7.97MB

Evaluation of shielding performance for a spallation neutron source facility in the J-PARC Project is important from a viewpoint of radiation safety and optimization of arrangement of components. This report describes evaluated results for the shielding performance with modeling three-dimensionally whole structural components including gaps between them in detail. A Monte Carlo calculation method with MCNPX2.2.6 code and LA-150 library was adopted. Streaming and void effects, optimization of shield for cost reduction and optimization of arrangement of structures such as shutters were investigated. Horizontal required shield thicknesses were ranged from about 6.5m to 7.5m as a function of neutron beam line angles. A shutter mechanism for a horizontal neutron reflectometer that was directed downward was devised, and it was shown that the shielding performance of the shutter was acceptable. An optimal biological shield configuration was finally determined according to the calculated results.