Publications related to BWR stability and bifurcation analysis using reduced order models and system codes: Identification of a subcritical Hopf bifurcation using RAMONA

Related publications (40)

Assessment of JEFF Nuclear Data Libraries for Reactor Physics and Spent Fuel Composition Applications

Informa UK Limited2025

Advancing Multi-Dimensional Simulation of Nuclear Fuel Behavior: from LOCA Analysis to Fast Reactor Applications

Current research on nuclear fuel focuses on two primary objectives. The first is to optimize the fuel used in the current generation of nuclear reactors in terms of safety, efficiency, and economics. This has driven efforts to increase discharge burnup and ...

EPFL2025

Deflation-based certified greedy algorithm and adaptivity for bifurcating nonlinear PDEs

Federico Pichi

This work deals with tailored reduced order models for bifurcating nonlinear parametric partial differential equations, where multiple coexisting solutions arise for a given parametric instance. Approaches based on proper orthogonal decomposition have been ...

2025

Investigation of Hydrogen Behaviour in Irradiated Zirconium-Based Fuel Claddings by Neutron Imaging and Complementary Techniques

Okan Yetik

Zirconium-based cladding tubes, mainly used as fuel cladding materials in light water reactors, serve as the primary barrier insulating the radioactive fission products from the environment. During operation, the cladding interacts with the coolant water, ...

EPFL2024

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

Multi-physics Sub-pin Resolution Analysis of a PWR core with nTRACER/CTF for the OECD/NEA TVA Watts Bar 1 Benchmark

Andreas Pautz, Marianna Papadionysiou

The systematic use of high-fidelity high-resolution codes which allow the prediction of safety parameters on a local scale, can result in more efficient use of the nuclear fuel and of the nuclear reactor.The Laboratory of Reactor Physics and Thermal-Hydrau ...

American Nuclear Society2024

Validation of Intrapin Reaction Rate Distributions from Deterministic Transport Codes

Tom Mager

Efforts are underway worldwide to develop advanced simulation methods of nuclear power plants, with an improved resolution in space, angle and energy. These tools aim to enhance operational efficiency through the predictions of local phenomena critical for ...

EPFL2024

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

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

Experimental study and interpretative modelling of the Power Exhaust in Configurations with Multiple X-Points in TCV

Sophie Danielle Angelica Gorno

Nuclear fusion presents a promising clean energy source to mitigate future energy crises, with magnetic confinement fusion well-positioned to provide a baseload scenario to power future reactors. The unmitigated power exhaust of such reactors threatens its ...

EPFL2024

Investigation of scrape-off layer and divertor transport using infrared thermography and SOLPS-ITER simulations

Claudia Colandrea

Nuclear fusion, with its potential to provide a nearly unlimited energy source, has inspired scientists to work on the development of fusion power plants. Among the various devices designed to harness nuclear fusion, the tokamak confines the fusion fuel, w ...

EPFL2024

Neutron-Gamma Noise Measurements in a Zero-Power Reactor Using Organic Scintillators

Andreas Pautz, Vincent Pierre Lamirand, Oskari Ville Pakari

Noise measurements in light water reactor systems aid in generating validation data for integral point kinetic parameter predictions and generating monitoring parameters for reactor safety and safeguards. The CROCUS zero-power reactor has been used to supp ...

Ieee-Inst Electrical Electronics Engineers Inc2024

Data-Driven Predictive Models: Calculational Bias in Characterization of Spent Nuclear Fuel

Ahmed Salaheldin Ahmed Shama

Characteristics of the spent nuclear fuel (SNF) are typically calculated, requiring validation a priori. The validation process relies on the difference between calculations and measurements, namely the bias. Usually, predicting the bias based on benchmark ...

EPFL2022

From thin plates to Ahmed bodies: linear and weakly nonlinear stability of rectangular prisms

Edouard Boujo, Giuseppe Antonio Zampogna

We study the stability of laminar wakes past three-dimensional rectangular prisms. The width-to-height ratio is set to W/H = 1.2, while the length-to-height ratio 1/6 < L/H < 3 covers a wide range of geometries from thin plates to elongated Ahmed bodies. F ...

Cambridge University Press2023

Postbuckling behavior and imperfection sensitivity of elastic-plastic periodic plate-lattice materials

Fani Derveni

Advances in additive manufacturing have enabled a new generation of materials with advantageous properties inherent to their architecture. Recently, architected materials with periodic arrangements of plates, called plate-lattice materials, have been devel ...

ELSEVIER2022

Analysis of transient measurements with thermal feedback and coupled TRACE/PARCS calculations performed on the BME Training Reactor

Mathieu Hursin

This paper presents nuclear reactor transient measurements with thermal feedback and corresponding coupled neutronic-thermohydraulic simulations performed for the natural circulation cooled Training Reactor of Budapest University of Technology and Economic ...

2023

The effects of Prandtl number on the nonlinear dynamics of Kelvin-Helmholtz instability in two dimensions

Jeremy Peter Parker

It is known that the pitchfork bifurcation of Kelvin-Helmholtz instability occurring at minimum gradient Richardson number Ri(m) similar or equal to 1/4 in viscous stratified shear flows can be subcritical or supercritical depending on the value of the Pra ...

Cambridge University Press2021

Monte Carlo analysis of BWR geometries using a cycle check-up methodology

Mathieu Hursin, Hakim Ferroukhi, Dimitri Rochman, Abdelhamid Dokhane

Recent fuel anomalies at a Swiss power plant have motivated the development at PSI of the "Cycle Check-Up" (CHUP) methodology which consists in performing Monte Carlo transport calculations using nuclide compositions and thermal-hydraulic boundary conditio ...

Pergamon-Elsevier Science Ltd2023

Global bifurcation at isolated singular points of the Hadamard derivative

Charles Stuart

Consider F is an element of C(RxX,Y) such that F(lambda, 0) = 0 for all lambda is an element of R, where X and Y are Banach spaces. Bifurcation from the line Rx{0} of trivial solutions is investigated in cases where F(lambda, center dot ) need not be Frech ...

2021

Extension of the OFFBEAT fuel performance code to finite strains and validation against LOCA experiments

Andreas Pautz, Alessandro Scolaro, Carlo Fiorina, Edoardo Luciano Brunetto

The mechanical analysis of nuclear fuel behavior under base-irradiation conditions has traditionally been performed adopting the small-strain approximation. However, many cases of interest for fuel behavior involve the occurrence of large rod deformations ...

ELSEVIER SCIENCE SA2023