Design and Integration of the EU-DEMO Water-Cooled Lead Lithium Breeding Blanket

Abstract

The water-cooled lead lithium breeding blanket (WCLL BB) is one of two BB candidate concepts to be chosen as the driver blanket of the EU-DEMO fusion reactor. Research activities carried out in the past decade, under the umbrella of the EUROfusion consortium, have allowed a quite advanced reactor architecture to be achieved. Moreover, significant efforts have been made in order to develop the WCLL BB pre-conceptual design following a holistic approach, identifying interfaces between components and systems while respecting a system engineering approach. This paper reports a description of the current WCLL BB architecture, focusing on the latest modifications in the BB reference layout aimed at evolving the design from its pre-conceptual version into a robust conceptual layout. In particular, the main rationale behind design choices and the BB’s overall performances are highlighted. The present paper also gives an overview of the integration between the BB and the different in-vessel systems interacting with it. In particular, interfaces with the tritium extraction and removal (TER) system and the primary heat transfer system (PHTS) are described. Attention is also paid to auxiliary systems devoted to heat the plasma, such as electron cyclotron heating (ECH). Indeed, the integration of this system in the BB will strongly impact the segment design since it envisages the introduction of significant cut-outs in the BB layout. A preliminary CAD model of the central outboard blanket (COB) segment housing the ECH cut-out has been set up and is reported in this paper. The chosen modeling strategy, adopted loads and boundary conditions, as well as obtained results, are reported in the paper and critically discussed.

Thermomechanical and Thermofluid-Dynamic Coupled Analysis of the Top Cap Region of the Water-Cooled Lithium Lead Breeding Blanket for the EU DEMO Fusion Reactor

“…A detailed description of the DEMO WCLL BB and of its design evolution can be found in literature, for example, in [2,3].…”

“…Hence, an intense research work has been conducted since 2014 throughout EU, under the umbrella of EUROfusion consortium, to reach a sound WCLL BB design capable of matching all the design requirements [2,3] propagated from the plant level to the BB system's one. In particular, the WCLL BB must withstand the thermal and mechanical loads it undergoes under both nominal and accidental scenarios fulfilling the structural design criteria prescribed by the RCC-MRx code [4], currently the reference code for the DEMO BB structural design.…”

“…In particular, the proposed geometric layout has been changed in order to ensure the improvement of its structural performance leading to the fulfilment of the RCC-MRx criteria, allowing the design level to evolve from the preconceptual phase to a conceptual one [2]. At present, the aim of the WCLL BB thermomechanical activities is to make its conceptual design more robust in sight of the next DEMO BB concept down-selection and the further engineering design phase [3].…”

W-HYDRA: a new experimental platform for the Water-Cooled Lead Lithium Breeding Blanket

“…This phase will lead to the selection of a reference concept for the Breeding Blanket (BB). In this framework, ENEA is developing the Water-Cooled Lead Lithium (WCLL) BB concept [2,3]. The achievement of such a goal depends on the maturity demonstration of some technology characteristics of this blanket concept.…”

Geometric Optimization of Electrically Coupled Liquid Metal Manifolds for WCLL Blankets

“…I N THE frame of the European fusion research program, liquid metal blankets are being developed and experimentally tested in the International Thermonuclear Experimental Reactor (ITER), where lead lithium (PbLi) is used as breeder material and heat transfer medium. The present European reference concept is a water-cooled lead lithium (WCLL) blanket, where liquid metal velocities in the columnar arranged breeder units (BUs) are very small [1]. For purification and tritium extraction, the liquid metal is circulated toward external ancillary facilities.…”