Publications related to Long-lived fission product

Atomic level insight into irradiation effects in nuclear fuel materials

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-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

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

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

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

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

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

Interface Tracking Investigation of the Sliding Bubbles Effects on Heat Transfer in the Laminar Regime

Konstantin Mikityuk, Lubomír Bures

Helium gases are utilized to remove fission products from the molten salt fast reactor (MSFR) core during operation. Helium gases and other volatile fission products may be introduced into the intermediate heat exchanger channels. The effect of these gases ...

2022

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

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

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

Data assimilation of post irradiation examination experiments to adjust fission yields

Andreas Pautz, Daniel Jerôme Siefman, Mathieu Hursin

Nuclear data, especially fission yields, create uncertainties in the predicted concentrations of fission products in spent fuel. Herein, we present a new framework that extends data assimilation methods to burnup simulations by using data from post-irradia ...

E D P SCIENCES2020

Artificial Neural Networks as Surrogate Models for Uncertainty Quantification and Data Assimilation in 2-D/3-D Fuel Performance Studies

Andreas Pautz, Mathieu Hursin, Carlo Fiorina, Alessandro Scolaro, Daniel Jerôme Siefman

This paper preliminarily investigates the use of data-driven surrogates for fuel performance codes. The objective is to develop fast-running models that can be used in the frame of uncertainty quantification and data assimilation studies. In particular, da ...

2020

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

Experimental and numerical study of stochastic branching noise in nuclear reactors

Oskari Ville Pakari

Noise analysis applied to nuclear reactor physics is a powerful tool to investigate a reactor's kinetic parameters, and more generally underlying physical processes determining core behavior. The kinetic parameters are the coefficients of simplified time-d ...

EPFL2020

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

Efficient Kr/Xe separation from triangular g-C(3)N(4)nanopores, a simulation study

Nicola Marzari, Kumar Varoon Agrawal, Nicola Colonna, Davide Campi, Luis Francisco Villalobos Vazquez de la Parra

Poly(triazine imide) or PTI is a promising material for molecular sieving membranes, thanks to its atom-thick ordered lattice with an extremely high density (1.6 x 10(14)pores per cm(2)) of triangular-shaped nanopores of similar to 0.34 nm diameter. Here, ...

Royal Society of Chemistry2020

Crosstalk between Drp1 phosphorylation sites during mitochondrial dynamics and metabolic adaptation

Miriam Valera Alberni

Mitochondria are highly dynamics organelles that undergo coordinated cycles of fission and fusion, referred to as mitochondrial dynamics. Mitochondrial dynamics regulate mitochondrial bioenergetics and allow cells to adapt to changing cellular stresses and ...

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

Development and Application of Data Assimilation Methods in Reactor Physics

Daniel Jerôme Siefman

Simulations of nuclear reactor physics can disagree significantly from experimental evidence, even when the most accurate models are used. An important part of this bias from experiment is caused by nuclear data. The nuclear data have inherent uncertaintie ...

EPFL2019

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

Sensitive THM coupled analysis of buffer-rock barriers for nuclear waste storage

Lyesse Laloui, Alessio Ferrari, Yafei Qiao

The buffer-rock barriers system is widely proved to be one of the most promising options for isolating high-level radioactive waste from the human environment. To certify the efficiency and provide the additional development regarding design and assessment ...

Crc Press-Taylor & Francis Group2015

Embrittlement induced by the synergistic effects of radiation damage and helium in structural steels

Kun Wang

Ferritic/martensitic steels are candidate materials for fusion reactor structural components, liquid metal containers of spallation neutron sources, and accelerator driven systems, with good radiation resistance and thermo-mechanical properties. However, e ...

EPFL2015

What Are the Best Materials To Separate a Xenon/Krypton Mixture?

Berend Smit, Cory Matthew Simon, Rocio Mercado, Sondre Kvalvag Schnell

Accelerating progress in the discovery and deployment of advanced nanoporous materials relies on chemical insight and structure-property relationships for rational design. Because of the complexity of this problem, trial-and-error is heavily involved in th ...

American Chemical Society2015

Ultrafast photoinduced processes in metal - containing molecular complexes and in proteins

Roberto Monni

The aim of this thesis is to investigate the ultrafast inter¿ and intra¿molecular processes, occurring in both metal¿containing molecular complexes and in proteins, by means of ultrafast Transient Absorption (TA) spectroscopy. The first part of the thesis ...

EPFL2015