On the thermal and thermomechanical assessment of the “Optimized Conservative” helium-cooled lithium lead breeding blanket concept for DEMO
Introduction
Within the framework of EUROfusion activities, CEA Saclay is in charge of developing the design of the Helium-Cooled Lithium Lead breeding blanket (HCLL) of DEMO nuclear fusion reactor.
In this context a fruitful collaboration has taken place with University of Palermo, as this latter has been involved, long time now, in the studies regarding the ITER Test Blanket Module (TBM) based on HCCL concept [1].
The work described in this paper, developed within the above said collaboration, has been aimed at the investigation of the thermal and thermomechanical performances of the HCLL Outboard Equatorial Module (OEM) under the envisaged nominal steady state loading conditions, paying also attention to the automation of the analysis procedure. In particular, the study has been aimed at the verification of the fulfilling of the set of thermomechanical requirements, in accordance with RCC-MRx code [2], prescribed for HCLL design.
A theoretical-numerical approach, based on the Finite Element Method (FEM), has been followed and the qualified Cast3 M 2015 and Siemens NX v. 10.0 FEM codes [3], [4] have been adopted in the study.
Section snippets
HCLL “Optimized Conservative” concept
Within the framework of HCLL design activities [5], 3 different concepts (Optimized Conservative, Advanced [6], [7], Advanced-Plus [8]) have been assessed. All the concepts use Eurofer steel as structural material, Helium at the pressure of 8 MPa as coolant and the eutectic alloy Pb-15.7Li enriched at 90% in 6Li as breeder, neutron multiplier and tritium carrier.
In this paper, attention has been focused on the “Optimized Conservative” concept, which is consistent with the TBM approach [9] and
The FEM models
In order to investigate thermal and thermomechanical performances of the “Optimized Conservative” DEMO HCLL OEM, paying also attention to analysis procedure automation, three successive FEM models (Model 1, Model 2 and Model 3) have been set-up. For all of them, cooling helium has been properly modelled, as well as the breeder.
As to material properties, they have been considered to depend uniquely by temperature [10].
Analysis and results
Un-coupled thermal and thermomechanical steady state analyses have been performed adopting the described FEM models. The most representative results are reported and critically discussed in the following.
Conclusion
The research campaign, carried out within the framework of a close collaboration between CEA Saclay and University of Palermo, has allowed of minimizing the number of user-defined variables in the analysis procedure. Moreover, obtained results show good thermal and mechanical behaviour of the “Optimized Conservative” DEMO HCLL concept. However high temperature on the FW-Cap connection occurs and high stress is calculated near to the bend region of the FW-SW, where only RCC-MRx criterion against
Acknowledgements
This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014–2018 under grant agreement No 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission.
References (13)
Thermal-mechanical and thermal-hydraulic integrated study of the helium-cooled lithium lead test blanket module
Fus. Eng. Des.
(2010)Thermo-mechanical analyses and ways of optimization of the helium cooled DEMO First Wall under RCC-MRx rules
Fusion Eng. Des.
(2017)Thermal optimization of the Helium-Cooled Lithium Lead breeding zone layout design regarding TBR enhancement
Fusion Eng. Des.
(2017)HCLL TBM design status and development
Fus. Eng. Des.
(2011)Design and Construction Rules for Mechanical Components of Nuclear Installations
(2018)- Cast3 M 2015....
Cited by (1)
Concept selection of the automated inspection and maintenance test unit for the EU DEMO using a novel fuzzy-based decision support tool
2019, Fusion Engineering and DesignCitation Excerpt :A broad application of SE principles integrated with MCDM methods could have a great impact in supporting R&D teams working in complex scenarios such as nuclear fusion technology. For example, these methods could efficiently be used to select the design concepts of key systems in fusion research, such as the breeding blanket [11–14]. However, implementing decision making sessions can be time-consuming, especially when a large number of alternatives and criteria are under consideration, or when information is scarce, and the range of uncertainty is wide at such early design stage.