Investigation of beam window structure for accelerator driven system with subcriticality adjustment rod

Sugawara, Takanori  ; Iwamoto, Hiroki   ; Tsujimoto, Kazufumi 

In this study, new beam window concept for accelerator-driven system (ADS) is investigated by changing the design condition. The most important factor for the beam window design is the proton beam current, and the design condition will be mitigated if the proton beam current will be reduced. To reduce the proton beam current, a subcriticality adjustment rod which was a BC control rod was employed and neutronics calculations were performed by ADS3D code. The results of the neutronics calculation indicated that the proton beam current was reduced from 20mA to 10mA by the installation of the subcriticality adjustment rods. Based on the mitigated calculation condition, the investigation of the beam window was performed by the particle transport analysis by PHITS code, the thermal hydraulics analysis by STAR-CCM+ code and the structural analysis by ANSYS code. Through these coupled analyses, more feasible beam window concept which was the hemispherical shape, the outer diameter = 470mm, the thickness at the top = 4.0mm and factor of safety =12, was presented.