Recherche

Afficher tous les résultats pour

Accueil

Personne

Vincent Pierre Lamirand

À propos
Confidentialité
Mentions légales

Graph Chatbot

Publications associées (62)

Page 3 sur 4

Dosimetry modeling and experimental validation for the PETALE program in the CROCUS reactor

Andreas Pautz, Vincent Pierre Lamirand, Pavel Frajtag, Axel Guy Marie Laureau

The PETALE experimental program in the CROCUS reactor intends to provide integral measurements on reactivity worth and dosimetry measurement to constrain nuclear data relative to stainless steel heavy reflectors. The experimental setup consists in eight su ...

2021

Revisiting the reactor period capabilities in TRIPOLI-4®

Vincent Pierre Lamirand

This paper presents a novel approach in the Monte Carlo code TRIPOLI-4® for estimating the asymptotic reactor period by solving the α-eigenvalue equation, accounting for contributions from both neutrons and precursors. The proposed method incorporates a ta ...

American Nuclear Society2025

Highly localized azimuthal measurements in the CROCUS reactor towards the validaiton of high-fidelity neutronics codes

Andreas Pautz, Vincent Pierre Lamirand, Pavel Frajtag, Fanny Vitullo

Highly localized in-core measurements are necessary for the validation of neutron transport calculations with high spatial resolution. In the present work, a miniature neutron detector developed at EPFL in collaboration with PSI was used to carry out a set ...

2021

Analysis of the preliminary campaign for the PETALE program

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

The PETALE program aims to provide new experimental data to constrain the stainless steel nuclear data. In this frame, a preliminary measurement campaign has been performed to characterize the neutron flux in key positions of the CROCUS reactor and to deve ...

EDP SCIENCES S A2023

CORTEX experiments, Part III: Experimental determination of the zero power transfer function of AKR-2 with reliable uncertainties

Vincent Pierre Lamirand

The transfer function is an important characteristic quantity of a nuclear reactor, since it contains the kinetic parameters. It expresses the response of a nuclear reactor to a disturbance of a certain frequency. If it is determined experimentally, it can ...

2024

Review of kinetic modulation experiments in low power nuclear reactors

Vincent Pierre Lamirand

The safety improvement of nuclear reactors requires continuous efforts in understanding the fundamental physical quantities related to the fission process. In neutronic models, the reactor dynamics is covered by the kinetic parameters to characterize the t ...

2020

Gamma-ray Spectroscopy in Low-Power Nuclear Research Reactors

Andreas Pautz, Vincent Pierre Lamirand, Oskari Ville Pakari

Gamma-ray spectroscopy is an effective technique for radioactive material characterization, routine inventory verification, nuclear safeguards, health physics, and source search scenarios. Gamma-ray spectrometers typically cannot be operated in the immedia ...

MDPI2024

Welch Method and Bootstrapping Applied to Subcritical Gamma Noise

Andreas Pautz, Vincent Pierre Lamirand, Oskari Ville Pakari

We measured the prompt neutron decay constant

\alpha

alpha of the CROCUS zero-power reactor at the Swiss Federal Institute of Technology Lausanne using cross-power spectral density (CPSD) analysis of gamma-gamma correlations from two trans-stilbene org ...

TAYLOR & FRANCIS INC2025

CORE SIM+ simulations of COLIBRI fuel rods oscillation experiments and comparison with measurements

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

At EPFL, the CROCUS reactor has been used to carry out experiments with vibrating fuel rods. The paper presents a first attempt to employ the measured data to validate CORE SIM+, a neutron noise solver developed at Chalmers University of Technology. For th ...

2021

Intercomparison of neutron noise measurement systems in the CROCUS reactor

Andreas Pautz, Mathieu Hursin, Vincent Pierre Lamirand, Oskari Ville Pakari

In the framework of an international collaboration, the critical decay constant (α0 = β/Λ), and delayed neutron fraction (β) of the CROCUS reactor were measured by teams of EPFL/PSI, CEA and SCK•CEN research institutes using the Rossi-α and Power Spectral ...

American Nuclear Society2018

Bayesian Monte Carlo assimilation for the PETALE experimental programme using inter-dosimeter correlation

Andreas Pautz, Vincent Pierre Lamirand, Dimitri Rochman, Axel Guy Marie Laureau

This article presents the methodology developed to generate and use dosimeter covariances and to estimate nuisance parameters for the PETALE experimental programme. In anticipation of the final experimental results, this work investigates the consideration ...

2020

CORTEX experiments – Part I: Modulation campaigns in AKR-2 & CROCUS for the validation of neutron noise codes

Andreas Pautz, Vincent Pierre Lamirand, Mathieu Hursin, Oskari Ville Pakari, Pavel Frajtag, Axel Guy Marie Laureau, Fanny Vitullo, Adolfo Rais, Thomas Jean-François Ligonnet, Nicolas Weiss, Daniel Godat, Klemen Ambrozic

We present the experimental campaigns – namely, three per facility – carried out between 2018 and 2021 in the AKR–2 and CROCUS zero power reactors within the framework of the Horizon 2020 European project CORTEX. Their purpose was to produce high-quality a ...

2025

Design of a 150-miniature detectors 3D core-mapping system for the CROCUS reactor

Andreas Pautz, Vincent Pierre Lamirand, Pavel Frajtag, Fanny Vitullo

The present article provides an overview of the design of a three-dimensional (3D) full-core mapping system for the CROCUS reactor, operated at the Ecole polytechnique federale de Lausanne (EPFL), Switzerland. The system is composed of 149 miniature neutro ...

E D P SCIENCES2021

PISTIL, a reactivity modulation device to probe the transfer function of the nuclear reactor CROCUS

Andreas Pautz, Vincent Pierre Lamirand, Pavel Frajtag

The present article summarizes the development and testing of a reactivity modulation device developed by the French Atomic and Alternative Energies Commission (CEA). It was installed in the CROCUS reactor of the Swiss Federal Institute of Technology in La ...

E D P SCIENCES2021

An Experimental Programme optimized with Uncertainty Propagation: PETALE in the CROCUS Reactor

Andreas Pautz, Vincent Pierre Lamirand, Dimitri Rochman, Axel Guy Marie Laureau

The PETALE experimental programme in the CROCUS reactor at EPFL intends to contribute to the validation and improvement of neutron nuclear data in the MeV energy range for stainless steel, particularly in the prospect of heavy reflector elements of pressur ...

EPJ Web of conference2019

Gamma noise to non-invasively monitor nuclear research reactors

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

Towards a highly efficient and unbiased population-control algorithm for kinetic Monte Carlo simulations

Vincent Pierre Lamirand

Population-control methods are key to non-stationary Monte Carlo simulations of multiplying systems: they prevent either the unbounded growth or the disappearance of neutrons, occurring respectively in supercritical and subcritical conditions; furthermore, ...

EDP Sciences2024

Assessment of representativity of the PETALE experiments for validation of Swiss LWRs ex-core dosimetry calculations

Andreas Pautz, Vincent Pierre Lamirand, Hakim Ferroukhi, Dimitri Rochman, Axel Guy Marie Laureau

The international experimental program PETALE will be carried out at the CROCUS research reactor of EPFL. The program aims at measuring neutron penetration in slabs made of materials composing typical LWR reactor pressure vessel. The measurements will be u ...

E D P SCIENCES2020

Uncertainty propagation based on correlated sampling technique for nuclear data applications

Andreas Pautz, Vincent Pierre Lamirand, Dimitri Rochman, Axel Guy Marie Laureau

A correlated sampling technique has been implemented to estimate the impact of cross section modifications on the neutron transport and in Monte Carlo simulations in one single calculation. This implementation has been coupled to a Total Monte Carlo approa ...

2020

Total Monte Carlo acceleration for the PETALE experimental programme in the CROCUS reactor

Andreas Pautz, Vincent Pierre Lamirand, Dimitri Rochman, Axel Guy Marie Laureau

The Bayesian Monte Carlo technics requires individual evaluations of random cross section files based on a Total Monte Carlo propagation. This article discusses the use of a Correlated Sampling acceleration applied to TMC calculations for experiments where ...

EPJ Web of conference2018