Publications associées à Welch Method and Bootstrapping Applied to Subcritical Gamma Noise

Publications associées (20)

Integrated modelling of neon impact on JET H-mode core plasmas

Nuclear fusion reactor plasmas will need to exhaust a significant proportion of energy flux through radiative processes, to enable acceptable divertor loads. This can be obtained by line radiation from impurities, injected from the plasma edge. There are h ...

IOP Publishing Ltd2023

Real-Time Optimization of Wastewater Treatment Plants via Constraint Adaptation

Dominique Bonvin

An important requirement of wastewater treatment plants (WWTPs) is compliance with the local regulations on effluent discharge, which are going to become more stringent in the future. The operation of WWTPs exhibits a trade-off between operational cost and ...

MDPI2022

Iterative Bayesian Monte Carlo for nuclear data evaluation

Mathieu Hursin

In this work, we explore the use of an iterative Bayesian Monte Carlo (iBMC) method for nuclear data evaluation within a TALYS Evaluated Nuclear Data Library (TENDL) framework. The goal is to probe the model and parameter space of the TALYS code system to ...

2022

Investigation and Validation of Unstructured Mesh Methodologies for Modeling Experimental Reactors

Andreas Pautz, Mathieu Hursin, Carlo Fiorina, Tom Mager

This paper summarizes a methodology developed at Ecole Polytechnique Federale de Lausanne for the neutronic modeling of the CROCUS experimental reactor and proposes solutions to the challenges one may face while modeling a research reactor with a complex g ...

MDPI2022

High resolution measurements with miniature neutron scintillators in the SUR-100 zero power reactor

Andreas Pautz, Vincent Pierre Lamirand, Fanny Vitullo

Three 1-mm(3) miniature fiber-coupled scintillators have been used to perform cm-wise resolution measurements of the thermal neutron flux within experimental channels of the SUR-100 facility, a zero power thermal reactor operated by the Institute of Nuclea ...

E D P SCIENCES2021

Uncertainty analyses of spent nuclear fuel decay heat calculations using SCALE modules

Andreas Pautz, Dimitri Rochman, Stefano Caruso, Ahmed Salaheldin Ahmed Shama

Decay heat residuals of spent nuclear fuel (SNF), i.e., the differences between calculations and measurements, were obtained previously for various spent fuel assemblies (SFA) using the Polaris module of the SCALE code system. In this paper, we compare dec ...

2021

Power calibration methodology at the CROCUS reactor

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

In the present article, we detail the method used to experimentally determine the power of the CROCUS zero-power reactor, and to subsequently calibrate its ex-core monitor fission chambers. Knowledge of the reactor power is a mandatory quantity for a safe ...

E D P SCIENCES2020

Development of Advanced Methodologies for Monitoring and Modelling of Neutron Noise in Modern LWR Cores

Dionysios Chionis

Nuclear reactors are inherently stochastic systems, in which neutronic and thermal-hydraulic parameters fluctuate continuously even during steady-state conditions. In addition, structural components vibrate due to the coolant hydraulic forces. This stochas ...

EPFL2020

Uncertainty and sensitivity analysis of PWR mini-core transients in the presence of nuclear data uncertainty using non-parametric tolerance limits

Andreas Pautz, Alexander Aures

The impact of nuclear data uncertainties is studied for the reactor power and the reactivity during control rod withdrawal transients with reactivity insertions of 0.5

and 0.97

, respectively, for a PWR mini-core model. Multi-group cross sections, the mul ...

PERGAMON-ELSEVIER SCIENCE LTD2020

Data assimilation of post-irradiation examination data for fission yields from GEF

Andreas Pautz, Mathieu Hursin, Dimitri Rochman, Daniel Jerôme Siefman

Nuclear data, especially fission yields, create uncertainties in the predicted concentrations of fission products in spent fuel which can exceed engineering target accuracies. Herein, we present a new framework that extends data assimilation methods to bur ...

EDP SCIENCES S A2020

Reactor simulations with nuclear data uncertainties

Andreas Pautz, Alexander Aures, Friederike Bostelmann

The paper demonstrates the influence of uncertainties in microscopic nuclear data on the results of reactor simulations, both for stationary and transient states. It gives an overview on the methods in use for uncertainty and sensitivity analyses with resp ...

ELSEVIER SCIENCE SA2019

Conceptual Design of a Sustainable Waste Burning Molten Salt Reactor

Boris Aviv Hombourger

For an energy source to qualify as sustainable, it must maximize the efficiency with which it uses natural resources while minimizing the amounts of waste it produces. Currently deployed nuclear power plants however use a very limited amount of the energy ...

EPFL2018

Pin-by-Pin Treatment of LWR Cores with Cross Section Equivalence Procedures and Higher-Order Transport Methods

Petra Mala

This thesis presents a systematic study on the merits and limitations on using pin-by-pin resolution and transport theory based approaches for nuclear core design calculations. Starting from the lattice codes and an optimal cross section generation scheme, ...

EPFL2018

Full Core modeling techniques for research reactors with irregular geometries using Serpent and PARCS applied to the CROCUS reactor

Andreas Pautz, Mathieu Hursin, Daniel Jerôme Siefman, Adolfo Rais, Gaëtan Girardin

This paper summarizes the results of modeling methodologies developed for the zero-power (100 W) teaching and research reactor CROCUS located in the Laboratory for Reactor Physics and Systems Behavior (LRS) at the Swiss Federal Institute of Technology in L ...

2015

Multi-Scale Modelling of a Solar Reactor for the High-Temperature Step of a Sulphur-Iodine-Based Water Splitting Cycle

Sophia Haussener

The 3-step sulphur-iodine-based thermochemical cycle for splitting water is considered. The high-temperature step consists of the evaporation, decomposition, and reduction of H2SO4 to SO2 using concentrated solar process heat. This step is followed by the ...

ASME2012

Comparative transient analysis of critical and subcritical 80-MW Pb-Bi eutectic-cooled reactor systems

Rakesh Chawla, Konstantin Mikityuk

A consistent analytical comparison has been made of the transient behavior of critical and subcritical fast-spectrum reactor systems, the basic core design assumed in each case being that of the 80-MW(thermal) mixed-oxide-fueled, Pb-Bi-cooled, experimental ...

American Nucl. Soc.2007

Optimised non-invasive method to determine 238U-captures-to-total-fissions in reactor fuel

Rakesh Chawla

High-resolution gamma spectroscopy was performed on individual fuel rods of a fresh, highly heterogeneous Boiling Water Reactor (BWR) fuel assembly, after irradiation at low power in the PROTEUS reactor at PSI, to determine the ratio of neutron captures in ...

Elsevier2006

Within-pin reaction rate distributions: CASMO-4 and HELIOS compared against tomographic measurements at the PROTEUS reactor

Rakesh Chawla

In the framework of the LWR-PROTEUS project - an extended validation program for advanced light water reactor core analysis tools conducted at the Paul Scherrer Institute - the radial, internal variations of the total fission rate (Ftot) and the capture ra ...

American Nuclear Society2005

Continuous high-temperature polymerisation of methyl methacrylate

Thierry Meyer, Philip Nising

As the need for lower mol. wt. acrylates for specialty and molding applications increases, industry is looking for substitute prodn. processes. An alternative to the increasing of initiator and chain transfer agent concn. is working at higher temps. Howeve ...

2005

Development of a drift-flux model for heavy liquid metal/gas flow

Rakesh Chawla, Konstantin Mikityuk

The gas lift pump concept based on the bubbling of an inert gas into the primary reactor coolant to enhance natural circulation is currently considered in a number of PbBi-cooled reactor concepts. Thus, the analysis of available void fraction data and the ...

Atomic Energy Society of Japan2005