Structural assessment investigations of the DEMO Divertor shielding components with reference to RCC-MRx

Abstract

• This paper relates the activity on structural analysis (integrity assessment) carried on the DEMO divertor cassette shielding components. The first step has regarded the evaluation of electromagnetic, thermal and mechanical loads. The structural analysis has focused attention on the integrity assessment of the shielding components (Shielding Liner, inboard and outboard reflector Plates) and their attachment systems. The elastic design-by-analysis rules of the RCC-MRx design code have been adopted. The verification has been performed for monotonic and cyclic loads (primary and secondary damages) under both negligible and significant irradiation conditions. Even though the assessment is not complete, important findings have allowed to refine the geometry of the shielding components to improve the internal stress distribution. The procedures foreseen by the RCC-MRx design rules (elastic analysis) have been constructed to compare the calculated stress values against the allowable ones.. This work describes the structural integrity assessment performed on a part of the DEMO Divertor Cassette, starting from the evaluation of electromagnetic, thermal and mechanical loads. The study focused on the shielding components (Shielding Liner, Inboard and Outboard Reflector Plates) and their attachments on the cassette. The assessment is made applying the elastic design-by-analysis rules of the RCC-MRx design code. The verification has been made for monotonic and cyclic loads (primary and secondary damages) under both negligible and significant irradiation conditions. The assessment is not complete because the verification against the fatigue damage has not been considered, but the overall findings allow to plan some improvements related to the shielding components to decrease the internal stress distribution. The elastic analysis performed according to the RCC-MRx design rules allows to compare the calculated stress values with the allowables.