Publications associées à Nuclear renaissance

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

Comparison of reduced model predictions for divertor detachment onset and reattachment timescales in ASDEX Upgrade and JET experiments

Holger Reimerdes, Haomin Sun

Building on prior analysis of ASDEX Upgrade (AUG) experiments (Henderson et al 2023 Nucl. Fusion 63 086024), this study compares simple analytical formula predictions for divertor detachment onset and reattachment timescales in JET experiments. Detachment ...

IOP Publishing Ltd2024

Analysis of the preliminary campaign for the PETALE program

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

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

Multi-physics modeling of VVERs with high fidelity high-resolution codes

Marianna Papadionysiou

The calculations performed for the design and operation of a Nuclear Power Plant (NPP) are a key factor for their safety analyses. The standard for the computational analysis of NPPs is the so called conventional approach, which relies on coarse mesh diffu ...

EPFL2022

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

Andreas Pautz, Dimitri Rochman, Stefano Caruso

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

A Hybrid Approach to Neutron Transport with Thermal-hydraulic Feedback for Reactor Transient Analysis

Alexander Aures

Understanding the time-dependent behaviour of a nuclear reactor following an intended or unintended change of the reactor conditions is of crucial importance to the safe operation of nuclear reactors. Safety evaluations of nuclear reactors involve the anal ...

EPFL2021

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

Andreas Pautz, Winfried Zwermann, 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

On data assimilation with Monte-Carlo-calculated and statistically uncertain sensitivity coefficients

Andreas Pautz, Mathieu Hursin, Daniel Jerôme Siefman

Sensitivity coefficients from Monte Carlo neutron transport codes have uncertainties that can affect nuclear data adjustments with integral experiments. This paper presents an extended version of Generalized Linear Least Squares (GLLS), called xGLLS, that ...

PERGAMON-ELSEVIER SCIENCE LTD2020

Nuclear data uncertainties for Swiss BWR spent nuclear fuel characteristics

Mathieu Hursin, Hakim Ferroukhi, Dimitri Rochman, Abdelhamid Dokhane, Alexander Vasiliev

The effect of nuclear data (fission yields, cross sections and emitted spectra) is quantified for spent nuclear fuel assemblies from a realistic boiling water reactor operated over 25 cycles. Nominal calculations are performed with the CASMO5, SIMULATE-3 a ...

2020

Development and verification of pin-by-pin homogenized simplified transport solver Tortin for PWR core analysis

Andreas Pautz, Petra Mala

Currently, the pin-by-pin homogenized solvers are a very active research field as they can, unlike the nodal codes, directly predict the local power, while requiring significantly less computational resources than the heterogeneous transport codes. This pa ...

2020

Systematic Sensitivity and Uncertainty Analysis of Sodium-Cooled Fast Reactor Systems

Friederike Bostelmann

Sodium-cooled fast reactor (SFR) technologies have the potential to guarantee energy supply and to reduce the burden of nuclear waste for future generations. For an adequate simulation of these reactor systems, well-established tools that have so far been ...

EPFL2020

Determination of the activity inventory and associated uncertainty quantification for the CROCUS zero power research reactor

Andreas Pautz, Vincent Pierre Lamirand, Mathieu Hursin, DongHyuk Lee, Pavel Frajtag

The paper describes the source term estimation of CROCUS, the zero power research reactor of EPFL, to be used for dispersion analysis under accidental conditions. To fulfil regulatory requirements, the source term of the CROCUS fuel is estimated through Mo ...

2019

Reactor simulations with nuclear data uncertainties

Andreas Pautz, Winfried Zwermann, Friederike Bostelmann, Alexander Aures

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

Analysis of reactivity worths of burnt PWR fuel samples measured in LWR-PROTEUS Phase II using a CASMO-5 reflected-assembly model

Mathieu Hursin, Hakim Ferroukhi, Daniel Jerôme Siefman

The reactivity loss of PWR fuel with burnup has been investigated experimentally by measuring the reactivity worths of highly-burnt fuel samples in a PWR test lattice in the framework of the LWR-PROTEUS Phase II program. Seven UO2 samples cut from fuel rod ...

2017

Sampling-Based Nuclear Data Uncertainty Quantification for Continuous Energy Monte Carlo Codes

Ting Zhu

The goal of the present PhD research is to establish a methodology of nuclear data uncertainty quantification (NDUQ) for MCNPX, the continuous-energy Monte-Carlo (M-C) code. The high fidelity (continuous-energy treatment and flexible geometry modelling) of ...

EPFL2015

Application of the PSI-NUSS Tool for the Estimation of Nuclear Data Related k(eff) Uncertainties for the OECD/NEA WPNCS UACSA Phase I Benchmark

Andreas Pautz, Hakim Ferroukhi, Tiankai Zhu, Alexander Vasiliev

At the Paul Scherrer Institute (PSI), a methodology titled PSI-NUSS is under development for the propagation of nuclear data uncertainties into Criticality Safety Evaluation (CSE) with the Monte Carlo code MCNPX. The primary purpose is to provide a complem ...

Academic Press Inc Elsevier Science2014

Study of Nuclear Decay Data Contribution to Uncertainties in Heat Load Estimations for Spent Fuel Pools

Andreas Pautz, Mathieu Hursin, Hakim Ferroukhi, Alexander Vasiliev

At the Paul Scherrer Institut (PSI), a methodology for nuclear data uncertainty propagation in CASMO-5M (C5M) assembly calculations is under development. This paper presents a preliminary application of this methodology to C5M decay heat calculations. Appl ...

Academic Press Inc Elsevier Science2014

Fission Rates Measured Using High-Energy Gamma-Rays from Short Half-Life Fission Products in Fresh and Spent Nuclear Fuel

Hanna Kröhnert

In recent years, higher discharge burn-ups and initial fuel enrichments have led to more and more heterogeneous core configurations in light water reactors (LWRs), especially at the beginning of cycle when fresh fuel assemblies are loaded next to highly bu ...

EPFL2011

Ion implantation in Ni-Ti shape memory alloy thin films

Thomas La Grange

The present thesis focuses on the effect of 5 MeV Ni ion irradiation on the microstructure and the thermomechanical behavior in prestrained (ε∼4%) martensitic Ti-rich NiTi thin films. At this ion energy, damage is limited to a depth of approximately 2 µm ( ...

EPFL2005