Concept

Réacteur modéré au graphite

Publications associées (21)

Modelling of MSRE graphite temperature in porous-medium multi-physics simulations

MSRs stand out as prominent candidates among advanced reactor designs, addressing the global demand for safer and more sustainable nuclear energy. Accurate multi-physics modelling is essential for the advancement of MSR technology, particularly for understanding the thermos-hydraulic behaviour of graphite under irradiation. This study focuses on developing and implementing a high-fidelity methodology within the GeN-Foam code to model graphite temperature distribution within porous-medium multi-physics simul

2026

Predicting Neutron Noise Detector Responses for Zero-Power Molten Salt Reactor Experiments

We use Monte Carlo simulations to predict the responses of neutron noise experiments in zero-power Molten Salt Reactors (MSRs). As for conventional reactors, the initial testing of a newly constructed reactor often comprises zero-power tests and criticality experiments. In zero-power environments, neutron noise experiments can be part of the experimental portfolio to provide experimental data on integral kinetic parameters such as the prompt neutron decay constant or the effective delayed neutron fraction.

EDP Sciences2025

Nanoscale Band Gap Modulation and Dual Moiré Superlattices of Hexagonal Boron Nitride Weakly Coupled to Graphite

Klaus Kern

Van der Waals (vdW) materials, such as hexagonal boron nitride (h-BN), are highly promising for applications in optoelectronics and quantum technologies. When assembled into heterostructures, h-BN can form moiré superlattices, enabling the engineering of electronic and optical properties by varying the interlayer twist angle. However, understanding the nanoscale interplay between moiré patterns and electronic properties such as the band gap or work function, particularly in optically active h-BN structures,

American Chemical Society (ACS)2025

A methodology for microstructural evaluation of unsaturated flow phenomena by in‐situ UV‐flow freezing

Véronique Michaud

Microstructural analysis of resin flow in liquid composite molding is impeded by the absence of a characterization method that possesses both the required spatial and time resolution to capture the ongoing phenomena. An optimized UV‐flow freezing methodology is presented to rapidly capture dynamic flow behavior, followed by high‐resolution micro‐computed tomography (μCT) imaging to extract the flow front morphology. Optimisation of the resin strongly enhances the photopolymerisation kinetics, reducing the g

Wiley2024

Derivation and Implementation in OpenFOAM of a Point-Kinetics Model for Molten Salt Reactors

In the last couple of decades, the nuclear community has witnessed a renewed interest in Molten Salt Reactors (MSRs) [1]. MSRs are typically claimed to overcome the drawbacks of current LWR technology thanks to their ambient operating pressure, higher efficiency, as well as several positive features associated to a liquid fuel such as: avoiding by design core melting accidents; the possibility of extracting during operation the gaseous and volatile fission products, thus decoupling radioactive and power sou

American Nuclear Society2021

Effects of humid air on aerodynamic journal bearings

Jürg Alexander Schiffmann, Eliott Philippe Guenat

The development of aerodynamic bearings applications where ambient conditions cannot be controlled (e.g., for automotive fuel cell compressor) raises the question of the effects of condensation in the humid air on perfor-mance. A modified Reynolds equation ...

2018

Effect of Different Influent Compositions on Microbial Communities, Physical Characteristics and Nutrient Removal Performances of Aerobic Granular Sludge

Characterize the activity of granula and flocs in the 4 reactors with different inputs and their physical characteristics in order to deduce the contribution of each on the overall behaviour of the reactors.

2017

Deactivation Aspects of Methane Oxidation Catalysts Based on Palladium and ZSM-5

Davide Ferri

Catalytic methane oxidation is used in exhaust gas after treatment to reduce methane emissions in stationary combustion processes as well as in natural gas vehicles. Pd/zeolite catalysts provide higher activity than the commonly used Pd/Al2O3, but suffer f ...

Springer Verlag2017

Lamination of LTCC at low pressure and moderate temperature using screen-printed adhesives

Paul Muralt, Thomas Maeder, Peter Ryser

In this work, we investigate a new method of low-pressure lamination of low-temperature cofired ceramic (LTCC) tapes, by pre-coating with specially-formulated adhesive layers. This allows fabrication of intricate structures that would be destroyed by high lamination pressures, yet preserves compatibility with standard processing operations, such as blanking, laser cutting, punching, via filling and screen printing. Techniques proposed previously are application of adhesive tapes, solvents or glues. These me

IMAPS / ACerS2012

Multiscale Modelling of Irradiation Induced Effects on the Plasticity of Fe and Fe-Cr

Seyed Masood Hafez Haghighat

Degradation of mechanical properties due to nanometric irradiation induced defects is one of the challenging issues in designing ferritic materials for future nuclear fusion reactors. Various types of defects, namely dislocation loops, voids, He bubbles an ...

EPFL2010

N-removal optimization by various aeration strategies

In order to improve the purification capacity of an aerobic granular sludge, two aeration strategies were designed and tested. The goal was to optimize the nitrogen removal performances via various oxygen patterns in the aeration phase of the reactor cycle. The main process driving theses patterns is that a difference between oxygen concentrations in the reactor will modify the size of the anoxic inner zone of a granule. The first aeration was based on a succession of oxygen peaks (50%DO) and semi anoxic va

2009

Optimization of reaction calorimetry for monitoring chemical reactions in supercritical fluids

The PhD thesis deals with the optimization of the reaction calorimetry technique to monitor chemical reactions in supercritical fluids. The aim is to develop this thermal analysis technique to monitor the heat released by a chemical reaction in a high pres ...

EPFL2008

High performance low-firing temperature thick-film pressure sensors on steel

Thomas Maeder, Peter Ryser, Giancarlo Corradini, Niklaus Johner

Performance of piezoresistive thick-film pressure sensors on steel substrates is hindered by the high required firing temperatures of the layers, which cause degradation of the substrate mechanical properties. Special steels or alloys that are relatively unaffected by these temperatures are available, but their cost is very high. A much more promising alternative is the reduction of the thick-film firing temperature, in order to allow application of the standard high-strength steels used in thin-film cells.

2007

Loop reactor staged with structured fibrous catalytic layers for liquid-phase hydrogenations

Albert Renken, Lioubov Kiwi, Eric Joannet

A novel concept of a recycle loop reactor is developed with structured filamentous catalysts integrated as trays in a staged bubble column. The reactor can be operated in batch or continuous mode. Woven fabrics of activated carbon fibers (ACF) were used as support for the Pd catalyst. The loop reactor was tested in the 2-butyne-1,4-diol hydrogenation showing selectivity up to 97% towards 2-butene-1,4-diol at conversions up to 80%. The reactor behavior was described quant. assuming an ideally mixed reactor a

Elsevier2004

Study of radio-frequency plasma deposition of amorphous silicon for the improvement of solar cell production

Juliette Ballutaud

Plasma enhanced chemical vapour deposition (PECVD) of thin films such as amorphous silicon has widespread applications especially in the field of photovoltaic solar cells and thin-film transistors for flat screen production. Industrial applications require high depositions rates over large areas with a good uniformity in layer thickness. In this thesis, some aspects of PECVD in large surface, industrial type, capacitive radio frequency reactor are investigated. The aim of this work is to study the plasma pr

EPFL2004

Interpretation of experimental results from moderate-power in-pile testing of a Pu-Er-Zr-oxide inert matrix fuel

Rakesh Chawla

Pu-Er-Zr oxide as an inert matrix fuel (IMF) could be an attractive option for a once-through LWR strategy aimed at reducing the currently growing plutonium stockpiles. A basic question related to the practical introduction of such an IMF into a current-day LWR, without affecting any significant change in fuel element design and core performance, is the irradiation behaviour of the proposed IMF. The present paper reports first results from a corresponding validation experiment which has been launched recent

Elsevier2003

Performance enhancement by unsteady-state reactor operation: Theoretical analysis for two-sites kinetic model

Albert Renken, Lioubov Kiwi

Theor. anal. of the reactor performance under unsteady-state conditions was carried out. The reactions are described by two kinetic models, which involve the participation in catalytic reaction of two types of active sites. The kinetic model I assumes the blocking of one of the active sites by a reactant, and the kinetic model II suggests a transformation of active sites of one type into another under the effect of the reaction temp. The unsteady-state conditions on the catalyst surface are supposed to be c

2003

Electron transfer kinetics on composite diamond (sp3)-graphite (sp2) electrodes

Christos Comninellis, Ilaria Duo

The concept of non-diamond sp2 impurity states as charge transfer mediators on boron-doped diamond (BDD) surface was suggested as an explanation for the electrochem. behavior of synthetic diamond-based electrodes. To verify this concept, graphite particles (sp2) were deposited on diamond electrodes (sp3) by mech. abrasion. The behavior of the so prepd. diamond-graphite composite electrodes were compared with those of as-grown (BDDag) and those after mild anodic polarization (BDDmild). Outer-sphere electron

Elsevier2003

Characterization of diamond-like carbon by Raman spectroscopy, XPS and optical constants

Crystalline diamond coatings and, increasingly, diamond-like amorphous carbon (DLC) films are used for tribological and protective layers for their hardness and chemical inertness. They are also under investigation for their electron emitting properties, with possible applications in field emission displays. In this study, hydrogen-free DLC films were deposited by laser ablation using a KrF excimer laser and fluences between 0.5 and 2 J/cm(2). Information about the disorder and short range order in the film

1998

FTIR spectroscopic studies in a loop reactor for the characterization of heterogeneously catalyzed reactions

Albert Renken

A modified DRIFTS cell is presented for diffuse reflectance FTIR of catalyzed reactions (temp. detn., gas-phase anal., etc.). The performance of the cell is exemplified by the catalytic methanation of CO2. [on SciFinder (R)]

1994

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Publications associées (21)

Effect of Different Influent Compositions on Microbial Communities, Physical Characteristics and Nutrient Removal Performances of Aerobic Granular Sludge

2017