Publications associées à Steady-state neutronic measurements and comprehensive numerical analysis for the BME training reactor

Intra-pin Reaction Rate Measurements in the CROCUS Experimental Reactor

Andreas Pautz, Oskari Ville Pakari, Vincent Pierre Lamirand, Mathieu Hursin, Thomas Jean-François Ligonnet, Tom Mager

In response to the need for validating high-fidelity deterministic neutronics solvers capable of providing pin-resolved neutron flux distributions, intra-pin reaction rates measurements were performed in the CROCUS experimental reactor. A specially designe ...

2024

Design of an Open-Loop Pile-Oscillation Program in the CROCUS Reactor

Andreas Pautz, Vincent Pierre Lamirand, Thomas Jean-François Ligonnet, Axel Guy Marie Laureau

As a follow-up to the CEA-EPFL PETALE experimental program on stainless steel nuclear data, the EPFL initiated an open-loop pile-oscillation experimental program in the CROCUS reactor: BLOOM. A reproduction of the critical experiments of PETALE, the progra ...

2024

Gamma noise to non-invasively monitor nuclear research reactors

Pavel Frajtag, Andreas Pautz, Oskari Ville Pakari, Vincent Pierre Lamirand, Tom Mager

Autonomous nuclear reactor monitoring is a key aspect of the International Atomic Energy Agency’s strategy to ensure nonproliferation treaty compliance. From the rise of small modular reactor technology, decentralized nuclear reactor fleets may strain the ...

Nature Research2024

Atomic level insight into irradiation effects in nuclear fuel materials

Shaileyee Bhattacharya

Microstructural evolution during in-pile irradiation, radiation damage effects and fission products behavior in UO2 nuclear fuel are key issues in understanding and for the modeling of the performance as well as safety characteristics of nuclear fuels in t ...

EPFL2024

High-Resolution Modeling Without Computation Slowdown for PETALE in CROCUS

Andreas Pautz, Vincent Pierre Lamirand, Thomas Jean-François Ligonnet, Axel Guy Marie Laureau

In a collaboration between Ecole Polytechnique Fédérale de Lausanne (EPFL) and CEA, in the fall of 2020, the experimental Programme d’Étude en Transmission de l’Acier Lourd et ses Eléments (PETALE) was successfully carried out in the CROCUS reactor of EPFL ...

2024

Design and operational guidelines of solar-driven catalytic conversion of CO2 and H2 to fuels

Sophia Haussener, Sha Li

Sunlight-powered catalytic conversion of CO2 and (green) H2 into fuels and chemicals via Sabatier and reverse water gas shift (RWGS) processes offers a promising solution to reduce greenhouse gas emissions and increase renewable energy utilization. The suc ...

ELSEVIER SCI LTD2023

Metal Catalysts for the Electrochemical Reduction of CO2

Cedric David Koolen

The world by and large has adopted the The Paris Agreement, which commits any signing party to cut greenhouse emissions drastically and prevent global heating above 2 °C beyond pre-industrial levels. For this ambitious goal to be met, ratifying states need ...

EPFL2023

A holistic investigation of photocatalytic hydrogen generation

Sangram Ashok Savant

Photocatalytic (PC) solar hydrogen production is a promising way to provide green hydrogen using only sunlight and abundant reactants such as water. PC approaches use catalytically active semiconductor particles suspended in liquid electrolytes. The partic ...

EPFL2023

Design of an Instrumented Fuel Rod for Intra-pin Neutron Flux Measurements in the CROCUS Experimental Reactor

Andreas Pautz, Vincent Pierre Lamirand, Mathieu Hursin, Thomas Jean-François Ligonnet, Won Dong Shin, Tom Mager

In response to the need for validating high-fidelity deterministic neutronics solvers capable of pin-resolved neutron flux distributions, an instrumented fuel rod was designed for the experimental reactor CROCUS, operated by EPFL’s Laboratory for Reactor P ...

2023

How Words Move Hearts: Interpretable Machine Learning Models of Bias, Engagement, and Influence in Socio-Political Systems

Aswin Suresh

We study socio-political systems in representative democracies. Motivated by problems that affect the proper functioning of the system, we build computational methods to answer research questions regarding the phenomena occurring in them. For each phenomen ...

EPFL2023

High accuracy measurement of the prompt neutron decay constant in CROCUS using Gamma Noise and bootstrapped uncertainties

Pavel Frajtag, Andreas Pautz, Oskari Ville Pakari, Vincent Pierre Lamirand, Tom Mager

We experimentally demonstrate the advantages of gamma detection for noise measurements to deter-mine the prompt neutron decay constant a of a nuclear reactor using the power spectral density (PSD) method, coupled to a new uncertainty estimation scheme base ...

PERGAMON-ELSEVIER SCIENCE LTD2022

Combining hypothesis- and data-driven neuroscience modeling in FAIR workflows

Daniel Keller

Modeling in neuroscience occurs at the intersection of different points of view and approaches. Typically, hypothesis-driven modeling brings a question into focus so that a model is constructed to investigate a specific hypothesis about how the system work ...

2022

Advanced methodologies for modeling and assessment of SFR safety functions

Janos Bodi

The present doctoral work was performed to contribute to the conceptual design development and safety assessment of a Generation IV Sodium Fast Reactor (SFR) in the frame of the European Sodium Fast Reactor Safety Measures Assessment and Research Tools (ES ...

EPFL2022

Single photon detection with amorphous silicon-based microchannel plates: A Monte Carlo model

Christophe Ballif, Nicolas Würsch, Jonathan Emanuel Thomet, Janina Christine Isabelle Löffler, Samira Alexandra Frey

Microchannel plates based on amorphous silicon have the inherent capability to overcome the existing spatial and temporal resolution limitations of single photon detectors. A Monte Carlo model-based study is presented here that serves to exploit their full ...

2022

Cross verified independent measurements of correlated bubble property distributions as part of the scale-up of a catalytic bubbling fluidized bed reactor

Philipp Fedor Riechmann

Methanation can be applied as part of a Power-to-Gas (PtG) concept to store renewable electricity. Using a catalytic bubbling fluidized bed (BFB) methanation reactor allows a flexible and economic operation. Properties of bubbles rising through the fluidiz ...

EPFL2022

Incremental financial analysis of black liquor upgraded gasification in integrated kraft pulp and ammonia production plants under uncertainty of feedstock costs and carbon taxes

François Maréchal, Meire Ellen Gorete Ribeiro Domingos

In this work, the conventional scenario of the black liquor (BL) concentration and combustion is compared with the BL upgrading gasification process for ammonia production. The chemical processes synthesis, modeling and simulation are performed by using As ...

Elsevier2022

Unmoderated molten salt reactors design optimisation for power stability

Andreas Pautz, Axel Guy Marie Laureau, Andrea Bellè

The critical region of unmoderated molten salt reactors consists in a cavity filled with a liquid fuel. The lack of internal structure implies a complex flow structure of the circulating fuel salt. A preliminary core shape optimization has been performed d ...

PERGAMON-ELSEVIER SCIENCE LTD2022

Development of a Novel Finite Volume Methodology for Multi-Dimensional Fuel Performance Applications

Alessandro Scolaro

Fuel performance codes are an essential tool for ensuring the safe and economic opera-tion of nuclear reactors. Traditionally, these codes have been developed following a simple 1.5-D modelling approach, where the fuel behavior is simplified by assuming ax ...

EPFL2021

Analysis of the first COLIBRI fuel rods oscillation campaign in the CROCUS reactor for the European project CORTEX

Daniel Godat, Pavel Frajtag, Andreas Pautz, Adolfo Rais, Oskari Ville Pakari, Vincent Pierre Lamirand, Mathieu Hursin, Carlo Fiorina, Axel Guy Marie Laureau

The Horizon2020 European project CORTEX aims at developing an innovative core monitoring technique that allows detecting anomalies in nuclear reactors, such as excessive vibrations of core internals, flow blockage, or coolant inlet perturbations. The techn ...

2021

Delayed gamma fraction determination in the zero power reactor CROCUS

Pavel Frajtag, Andreas Pautz, Oskari Ville Pakari, Vincent Pierre Lamirand, Tom Mager

Gamma rays are an inextricable part of a nuclear reactor's radiation field, and as such require characterization for dose rate estimations required for the radiation protection of personnel, material choices, and the design of nuclear facilities. Most comm ...

EDP SCIENCES S A2021