Speaker
Description
The Helium Cooled Pebble Bed (HCPB) is one of the breeding blanket concepts under investigation by EUROfusion for the EU DEMO fusion reactor. The DEMO Design Criteria for In-Vessel Components (DDC-IC), currently being developed within EUROfusion, aims to reduce over-conservatism and enhance performance by employing an in-elastic design-by-analysis approach based on advanced non-linear finite element analysis.
In this study, we performed the structural integrity assessment of the HCPB breeding blanket conceptual design based on the newly developed design rules within the DDC-IC, particularly against the exhaustion of ductility failure mode, aiming to form a basis for future component-level assessments employing inelastic analysis. The assessment results revealed several critical locations where the finite element strain prediction exceeds the allowable limits, specifically at the joints between the pressure tubes and the first wall as well as the breeder pin assembly. Additionally, a sub-modelling approach was developed to perform high-fidelity analyses of the region-of-interests containing joints, with advanced materials constitutive models more efficiently. All these results will support the breeding blanket design optimisation by mitigating mechanical failures and improving its lifetime. Another observation from the analysis is that the failure surface depends on both triaxiality and the Lode parameter, and their ranges observed in the components are often quite wide. These results will feed into the development of the DDC-IC to establish a more representative testing matrix for experimental validation of design criteria.
| Speaker affiliation | United Kingdom Atomic Energy Authority, Culham Campus, Abingdon, OX143DB, UK |
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