New pixelized Micromegas detector with low discharge rate for the COMPASS experiment

New Micromegas (Micro-mesh gaseous detectors) are being developed in view of the future physics projects planned by the COMPASS collaboration at CERN. Several major upgrades compared to present detectors are being studied: detectors standing five times higher luminosity with hadron beams, detection of beam particles (flux up to a few hundred of kHz/mm^{2}, 10 times larger than for the present Micromegas detectors) with pixelized read-out in the central part, light and integrated electronics, and improved robustness. Two solutions of reduction of discharge impact have been studied, with Micromegas detectors using resistive layers and using an additional GEM foil. Performance of such detectors has also been measured. A large size prototypes with nominal active area and pixelized read-out has been produced and installed at COMPASS in 2010. In 2011 prototypes featuring an additional GEM foil, as well as an resistive prototype, are installed at COMPASS and preliminary results from those detectors presented very good performance. We present here the project and report on its status, in particular the performance of large size prototypes with an additional GEM foil.Comment: 11 pages, 5 figures, proceedings to the Micro-Pattern Gaseous Detectors conference (MPGD2011), 29-31 August 2011, Kobe, Japa

Symbiotic equilibrium between Sodium Fast Reactors and Pressurized Water Reactors supplied with MOX fuel

International audienceThe symbiotic equilibrium between 1.51 GWe breeder SFR (Sodium Fast Reactors) and 1.6 GWe EPR$^{TM}$ (European Pressurized water Reactors) is studied. EPR$^{TM}$ are only supplied with MOX (Mixed OXide) fuel to avoid the use of natural uranium. The equilibrium is studied by considering the flows of plutonium. Its isotopic composition is here described by a single real number referred to as the Pu grade. Plutonium flows through both reactor types are characterized by using linear functions of the Pu grade in new fuels. These functions have been determined by fitting data from a former scenario study carried out with the COSI6 simulation software. Two different reprocessing strategies are considered. With joint reprocessing of all spent fuels, total and fissile plutonium flows balance for a unique fraction x of EPR$^{TM}$ in the fleet, equal to 0.2547. This x value is consistent with the results reported in the former scenario study mentioned above. When EPR$^{TM}$ spent fuels are used in priority to supply SFR (distinct reprocessing), x reaches 0.2582 at most. COSI6 simulations have been performed to further assess these results. The EPR$^{TM}$ fraction in the fleet at symbiotic equilibrium barely depends on the applied reprocessing strategy, so that the more flexible joint reprocessing constitutes the reference option in that case

Thermodynamic analysis of carbon dioxide storage in salt caverns to improve the Power-to-Gas process

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Fuel Cycle interfaces with the ASTRID core

International audienceSince 2010, CEA (French Alternative Energies and Atomic Energy Commission) and industrial partners have worked on ASTRID (Advanced Sodium Technological Reactor for Industrial Demonstration) project to design an innovative GEN IV Sodium Fast Reactor with a high level of requirements. At the start of the Basic Design phase, in 2016, different performance phases of the core have been defined on the life of ASTRID in particular to demonstrate the capability to recycle plutonium coming from the treatment of UOX and MOX fuels from PWRs and also the MOX coming from ASTRID itself. The objectives of these phases are to increase the burn up with using different fuel pin claddings from 90 to 150 displacements per atom (dpa). After a presentation of the innovative CFV core (low void sodium worth) and the different type of subassemblies, the paper presents some core performances and the fuel cycle needs (uranium, plutonium, B4C) on the different equilibrium phases of the core; we mention the phases to enhance performances, experimental programs for the envisaged claddings, the gradual introduction of Pu ex MOX-PWR, the experimental programs (transmutation, breeding ratio, plutonium burn up) in support to demonstrate these options for the commercial Sodium Fast Reactor. The paper shows the interfaces between the reactor and the different steps of the cycle from the front of the cycle (fabrication), the subassemblies management on ASTRID, to the back end (fuel treatment, wastes management)

Plutonium recycling capabilities of ASTRID reactor

International audienceAmong the ASTRID's main goals, one of them is to demonstrate the full fuel cycle closing at the industrial scale. In particular with the recycling of plutonium coming from the treatment of UOX and MOX fuels from PWRs and also the MOX coming from ASTRID itself. Associated with the fuel cycle facilities, fabrication and reprocessing, the lessons learned from this industrial demonstration will be transposable to commercial Sodium cooled- Fast Reactors (SFR) and their associated fuel cycle. The paper presents the capability of the ASTRID reactor with its innovative CFV core (low void sodium worth), to recycle Pu from the treatment of MOX fuels from PWR, during its operation. The safety and performances goals assigned to the CFV core by the ASTRID project are maintained. Physic impacts linked to various aspects initial content of Pu, decay heat, fuel subassemblies type (fresh and used) has been evaluated to identify the plutonium needs and the impacts on ASTRID fuel management (interim storage, handling) and in its associated fuel cycle (transport, facilities)

Development of a New Alpha Function for the Peng–Robinson Equation of State: Comparative Study of Alpha Function Models for Pure Gases (Natural Gas Components) and Water-Gas Systems

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