Key conception of the remote maintenance for the target assembly of Advanced Fusion Neutron Source (A-FNS)

摘要

A key conception of the remote maintenance (RM) method is presented of the target assembly (TA) of Advanced Fusion Neutron Source (A-FNS), that is an accelerator-driven fusion neutron source utilizing the Li(d,xn) nuclear reactions. The RM method, newly proposed here, is aimed at (i) enhancing the modularity of the TA RM and (ii) keeping the compatibility with the materials irradiation tests, compared to the preceding TA RM design of International Fusion Material Irradiation Facility (IFMIF). A 3-dimensional kinematics simulation indicates that the large clearance of 52 mm between the TA and high flux WA module (HFTM) brings the independent removal from and the installation in the WA cell, regardless of the presence of the WA modules in the WA cell. A neutronics performance of the HFTM with the enlarged clearance is also studied. The gradient of the calculated neutron irradiation damage is found to be decreased and satisfies a users' requirement of the irradiation environment when the clearance is enlarged from 2 to 52 mm. (The former value was the IFMIF engineering design value.) These simulation results suggest that the proposed TA RM method will enhance not only the modularity of the TA, but also will improve the materials irradiation WA environment.