Calculation and Application of Discontinuity Factors in Control Rod Region for High Temperature Gas-Cooled Reactor

For the strong absorber and void in the control rod region located in the reflector area of the High Temperature Gas-Cooled Reactor（HTGR）,this paper presents the method of diffusion equation cor-rected by discontinuity factor based on the homogenization on the local area.Facing the difficulties such as no fission source in the homogenous area and strong neutron current in the boundary,a special skill is required for the homogenization and calculation of discontinuity factor.Taking the fine mesh transport solution as the reference,the verification results demonstrates that the control rod region can be homogenized individually with approximate boundary condition,and the diffusion theory corrected by discontinuity factors can accu-rately model the control rod.Hence,applying the diffusion calculation with discontinuity factor correction to calculate the control rod in HTGR is excellent not only in accuracy but also in consumed calculation time.