This open access book presents innovative strategies to address cross-cutting topics and foster transversal competences. The modernization of European legal education presents a compelling challenge ...that calls for enhanced interdisciplinary collaboration among academic disciplines and innovative teaching methods. The volume introduces venues towards education innovation and engages with complex and emerging topics such as datafication, climate change, gender, and the aftermath of the COVID-19 pandemic. The insights presented not only emphasize the importance of preserving traditional approaches to legal disciplines and passing them on to future generations, but also underscore the need to critically reassess and revolutionize existing structures. As our societies become more diverse and our understanding of legitimacy, justice, and values undergoes transformations, it is imperative to reconsider the role of traditional values while exploring promising alternative approaches.
A future nuclear fusion plant DEMO needs neutral beam injection (NBI) systems requiring a vacuum pumping system with a very high pumping speed, in the order of several 1000 m3/s. Large customized ...cryopumps are actually used to meet the requirements. A promising concept for future NBI systems is based on high capacity getter materials. The ZAO® alloy, developed by SAES Getters, Italy, provides a drastically improved performance for the pumping of hydrogen compared to conventional getter materials. This paper describes the experimental characterization of a large pump of scalable size with 15 kg of ZAO® and the achieved results, in particular the systematic investigation of sorption characteristics and regeneration behaviors. Major findings include a very good repeatability of the sorption performance, a reduced pumping speed at higher pressures only above the NBI relevant level, an improved performance (+20%) with elevated getter temperature and an isotope independent sticking coefficient for hydrogen. Furthermore, improved operation experience and regeneration prediction tools have been developed. Employing the experimental results, a simulation task was performed and the sticking factor of the getter cartridge was determined with 7%.
•A new vacuum pumping process for fusion power plants has been developed and is presented in this paper.•This process works continuously and non-cryogenic what leads to a strong reduction of the ...tritium inventory in the fuel cycle.•This pumping process is based on the use of a liquid metal (mercury) as working fluid and is called KALPUREX process.•The KALPUREX process is the technical realization of the DIR concept using a set of three vacuum pumps (metal foil pump/diffusion pump/liquid ring pump).•This paper discusses the arrangement of the pumps and also the required infrastructure for operation.
The Karlsruhe Institute of Technology (KIT) is developing a continuously working and non-cryogenic pumping solution for torus exhaust pumping of a demonstration power plant (DEMO) including Direct Internal Recycling (DIR).
This full pumping system consists of three pumps, namely a metal foil pump for gas separation, a linear diffusion pump as primary pump and a liquid ring pump as backing pump. The latter two pumps apply mercury as working fluid due to its perfect tritium compatibility. This asks for a baffle system on both sides of the pumping train to control working fluid vapour and to avoid any mercury propagation in the machine.
In this paper, the arrangement of all torus pumps required for a power plant reactor as well as the corresponding infrastructure and its effect on the DEMO machine design is presented and discussed. The full pumping process is called ‘Karlsruhe liquid metal based pumping process for fusion reactor exhaust gases’ (KALPUREX process, patent pending).
A new, continuous pumping train has been proposed for the European demonstration fusion power plant (DEMO). Mercury-driven linear diffusion pumps (LDPs) are suggested for use as high-vacuum pumps in ...this pumping train. In this work, we validate a 2-D simulation framework based on the direct simulation Monte Carlo (DSMC) method with experimental data of a two-stage mercury-driven LDP that was operated at the Lawrence Livermore National Laboratory (LLNL) in the 1950s. The simulation setup and assumed boundary conditions are described and their appropriateness discussed. Numerical results are compared to available experimental data for four different positions of the upper nozzle pipe. We find acceptable agreement between experimental and numerical results for the air pumping speed. This validation paves the way for using the simulation framework as a design and optimization tool in the further development process of the DEMO LDPs.
This volume contains essays and discussions from the Conference of the Association of German Constitutional Law Instructors held October 7 - 10, 2009 in Graz.
The requirement for a reduction of the tritium inventory of the European demonstration fusion reactor (EU-DEMO) has led to the active research and development of a continuously working pumping ...process termed "KALPUREX." This process foresees the direct recycling of a large fraction of the unburnt hydrogen isotopologues via superpermeation in metal foil pumps during the burn phase. The remaining exhaust gas mixture is pumped by continuously operating, mercury-driven linear diffusion pumps. Diffusion pumps are kinetic high vacuum pumps whose pumping principle is based on the momentum transfer from a supersonic mercury vapor jet to the pumped gas mixture. Like many high vacuum pumps, they feature species-dependent pumping speeds. In the present work, we develop a simplified hybrid model of the high vacuum pumping train in order to estimate the effective pumping speed of the integrated system. The results of this model and its implications on the further development of the vacuum system are discussed for the burn and dwell phases of EU-DEMO.
•The fusion fuel cycle is presented and its functions are discussed.•Tritium inventories are estimated for an early DEMO configuration.•The Direct Internal Recycling concept to reduce tritium ...inventories is described.•Concepts for its technical implementation are developed.
A new concept, the Direct Internal Recycling (DIR) concept, is proposed, which minimizes fuel cycle inventory by adding an additional short-cut between the pumped torus exhaust gas and the fuelling systems. The paper highlights quantitative modelling results derived from a simple fuel cycle spreadsheet which underline the potential benefits that can be achieved by implementation of the DIR concept into a fusion power plant.
DIR requires a novel set-up of the torus exhaust pumping system, which replaces the batch-wise and cyclic operated cryogenic pumps by a continuous pumping solution and which offers at the same time an additional integral gas separation function. By that, hydrogen can be removed close to the divertor from all other gases and the main load to the fuel clean-up systems is a smaller, helium-rich gas stream. Candidate DIR relevant pump technology based on liquid metals (vapour diffusion and liquid ring pumps) and metal foils is discussed.
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