Further improvements in the structural analysis of DEMO Divertor Cassette body and design assessment according to RCC-MRx.

Highlights • An improved geometrical conception of the DEMO Divertor Cassette has been considered and a suitable finite element mesh has been adopted. • The loads really acting on this component have been evaluated detailly and applied overcoming the early hypothesis of uniform distribution: so the load spatial gradients have been reprioduced with more precision. • The obtained results confirm the previous deductions: the main role has been carried out by the thermal loads, and moreover the electric-magnetic loads determine a state of stress far lower than that caused by the thermal loads. • These thermal loads are the results of a dedicated thermal-fluid–dynamic numerical code properly developed for this aim. • Also in this case, an early application of RCC-MRx design rule have been applied: the Divertor Cassette results to be safe in nominal conditions while the same assessment states that the knuckle stress state is above faliure. Abstract This paper presents the enhancements related to the structural analyses of DEMO Divertor in the framework of the EUROfusion Power Plant Physics & Technology (PPPT) program. This activity started two years ago and its preliminary results were published in previous papers. It has been divided in some areas defined by the similarity of the matters they contain: the structural analysis, of utmost importance, has been preceded by a preliminary phase, like the geometry definition or the thermal and the electric-magnetic analysis for loads evaluation; then the structural analysis has been finally confirmed with further evaluations related to excessive deformation or plastic instability. This paper discusses the improvements adopted either in the preliminary analysis or in the main structural analysis. Specifically it highlights the introduction of the thermal and electro-magnetic loads application in terms of a detailed spatial distribution that is now available. More the supports have been introduced in the model and their structural behavior has been investigated considering their interaction with the cassette. The structural assessment, according to the Design and Construction Rules for Mechanical Components of Nuclear Installation (RCC-MRx), has been performed either for the cassette or for the attachments: for the former it is positive while for the latter case serious limitations have been found. [ABSTRACT FROM AUTHOR]