Research on inner coupling shutdown dose rate calculation method based on CAD

With the increase of neutron source strength in nuclear installations, especially for fusion facilities, the activation analysis on structural material have had a major impact on radiation safety. shutdown Dose Rate (SDR) calculation is one of the key problem of activation calculation, correspondingly, render important reference for fusion reactor design. In this paper, based on the advanced neutron/photon transport calculation and activation calculation of SuperMC, research on R2S method was conducted and an inner coupling SDR calculation program was developed. Besides, a more effective material homogenization treatment method for activation mesh compared to that in conventional external coupling SDR calculation was implemented and a new approach based on CAD model were proposed, moreover, sector cylinder activation source was available. These novel capability makes SDR calculation more flexible and reliable compared to those earlier software in sector cylinder activation calculation and sophisticated geometry treatment. Finally, the ITER port plug SDR benchmark was performed and the good agreement of the results demonstrated the accuracy and reliability of this method. (authors)