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101
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September 2005 - August 2006
September 2005 - August 2006
October 2006 - present
Publications
Publications (101)
Sensitivity computation in Monte Carlo-based codes is widely used and has been enhanced significantly. Although sensitivity converges in most reactor configurations, it encounters difficulties in large core designs. We suspect that this issue might be linked to the dominance ratio. To test this hypothesis, we develop a simple benchmark to validate...
The utilization of the Monte Carlo method in reactor physics has expanded notably, and its use for sensitivity calculations has expanded with the integration of perturbation theory in numerous Monte Carlo-based codes, enhancing the sensitivity calculations significantly. Despite the method's growing application, research on the statistical converge...
This paper depicts the power system adequacy with respect to nuclear strategies by coupling investment with dispatching. The long-term energy model POLES simulates the Paris Agreement worldwide and is soft-linked with a power market model applied to France, EcoNUK. The nuclear flexibility is described by cycling frequency and amplitude, constrained...
The operator needs to qualify the industrial core calcula-
tion line for situations where experimental data is not available.
The aim of this paper is to study the application of trans-
position, i.e. the incorporation of experimental information
acquired during the reactor start-ups tests to a configuration
where it is not possible to perform meas...
Global steel demand and production processes projections to 2070 using the energy system model POLES, with abatement options (electrification/recycling, direct reduction/hydrogen, carbon capture and sequestration), mitigation feedbacks on materials demand and senstivity studies
Numerous safety authorities require Uncertainty Analyses to support safety demonstrations. UAM-OECD Benchmark have been very successful in gathering the community, triggering many activities in the field, and contributed to the development and spread of many methodologies. Concerning power distributions (PD) uncertainty of LWR GEN-III UOx, we have...
Sensitivity analysis studies the effect of a change in a given parameter to a response function of the system under investigation. In reactor physics, this usually translates into the study of how cross sections and fission spectrum modifications affect the value of the multiplication factor, the delayed neutron fraction or the void coefficient for...
In the frame of the French nuclear industry, important safety parameters from the reload patterns are evaluated by the core calculation line. A few of these parameters are measured in the physical start-up tests and also during the cycle. Some of these measurements have to be below an established threshold and the difference between calculated (C)...
The study explores future development of biomass uses across different climate policy scenarios and under different assumptions of biomass supply availability and technology performances. Broad bioenergy technology portfolios and generations provide flexibility to allocate bioenergy to supply a specific final energy mix and to remove carbon dioxide...
This work presents some applications of classical criticality study tools, such as uncertainty studies and representativity to reactor physics' calculations, Representativity quantifies the similarity between two cases in terms of uncertainties. It is determined through the calculation of the sensitivities of a parameter to nuclear data for the two...
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 accounts for these uncertainties. With very large sensitivity uncertainties , xGLLS constrains...
The GLLS equations have been expanded in order to include the uncertainty of sensitivities generated by continous-energy Monte Carlo codes. We present these new equations which we call xGLLS and the results from applying them to a data assimilation benchmark. The results show that the sensitivty uncertainties have a small to negligible effect on th...
Sensitivity coefficients calculated with Monte Carlo neutron transport codes are subject to statistical fluctuations. The fluctuations affect parameters that are calculated with the sensitivity coefficients. The convergence study presented here describes the effects that statistically uncertain sensitivities have on first-order perturbation theory,...
An effort is being carried to create a reactor physics benchmark based on the Molten Salt Reactor Experiment (MSRE). In this framework, detailed benchmark specifications were compiled and a corresponding model was created using the Monte Carlo code Serpent. The model was used to analyze the first zero-power critical experiment at MSRE when 235 U wa...
Fuel cycle simulators are used worldwide to provide scientific assessment to fuel cycle future strategies. Those tools help understanding the fuel cycle physics and determining the most impacting drivers at the cycle scale. A standard scenario calculation is usually based on a set of operational assumptions, such as reactor Burn-Up, deployment hist...
This paper present basic nuclear reactor physics that may help to understand next challenges that nuclear industry have to face in the future. The ones considered in this work are waste production and natural resources consumption. This paper shows that waste and resources are linked by the plutonium status that could be considered as the principal...
Dynamic fuel cycle simulation codes model evolving nuclear fuel cycles, and calculate nuclides inventories and material flows in each unit of the cycle. In the nuclear fuel cycle simulation code CLASS (Core Library for Advanced Scenario Simulation), a Fuel Loading Model (FLM) builds a fresh fuel fulfilling the reactor criticality requirement, depen...
An economical module to calculate the financial aspect of nuclear industry was developed based on CLASS [1], a library used for performing dynamic fuel cycle simulations. The tool will be introduced and a simple case of a PWR reactor will be presented to validate the module looking forward to evaluate a symbiotic scenario in the full paper involvin...
This paper presents some of the recent and new advancements in the extension of Monte Carlo Perturbation Theory methodologies and applications. In particular, the discussed problems involve Brunup calculation, perturbation calculation based on continuous energy functions, and Monte Carlo Perturbation Theory in loosely coupled systems.
In contrast to the straight final disposal solution, countries like France have opted to reprocess their nuclear reactors spent fuel and defined another way to take care of sensitive elements such as the plutonium or minor actinides. Even in countries which have chosen to reprocess their spent fuel, americium is still considered as a final disposal...
Total Monte Carlo has become a standard approach for direct propagation of Nuclear Data uncertainty in reactor physics calculations. Coupled neutron and nuclide fields Generalized Perturbation Theory was developed many decades ago. The resolution of a lot of generalized adjoint neutron transport equations associated with the resolution of the adjoi...
Dynamic fuel cycle simulation tools model the entire fuel cycle, from fuel fabrication to spent fuel storage, and calculate nuclei inventories and material flows evolution in each unit. In the fuel cycle simulation tool CLASS, a fuel loading model builds a fresh fuel meeting the reactor requirements at each reactor loading and a cross-section predi...
Simulation of Pressurized (PWR) Brazilian Reprocessed uranium use in Argentinian Candu Heavy Water Reactor (PHWR)
Nuclear energy’s low variable cost makes it a base load technology, but variable renewable production has a higher priority on the grid, having a zero marginal cost. Therefore, variable renewable production will reduce load factors of dispatchable technologies. If not able to follow residual load, some more flexible technologies could be preferred...
The aim of this paper is to analyze and compare nuclear scenarios including the Argentinian and the Brazilian nuclear fleets working either in a collaborative scenario or separately.
Brazilian nuclear fleet is composed of PWRs (Pressurized Water Reactors). For decades, Argentina has been operating Pressurized Heavy Water Reactors (PHWR), in partic...
GPT allows calculating sensitivities of one observable (as k eff ) to all nuclear data in all energy groups
with only two neutron transport calculations: one direct and one adjoint. Deterministic transport calculations
were the preferred for decades despite the fact that only sensitivities to energy grouped stepwise functions were computable.
In...
Abstract In this work, the implementation of a collision history-based approach to sensitivity/perturbation calculations in the Monte Carlo code SERPENT is discussed. The proposed methods allow the calculation of the effects of nuclear data perturbation on several response functions: the effective multiplication factor, reaction rate ratios and bil...
A dynamic fuel cycle simulation code models all the ingoing and outgoing material flow in all facilities of a nuclear reactor’s fleet as well as their evolutions through the different nuclear processes (irradiation, decay, chemical separation, etc.). One of the main difficulties encountered when performing such calculation comes from the fuel fabri...
A dynamic simulation of coupled supply and demand of energy, resources and nuclear
reactors is done with the global model Prospective Outlook for Long Term Energy Supply
(POLES) over this century. In this model, both electricity demand and uranium supply are not
independent of the cost of all base load electricity suppliers. Uranium consuming Therm...
Subcritical reactors, also called Accelerator Driven Systems (ADS), are specifically studied for their capacity in transmuting Minor Actinides (MA). Nuclear fuel cycle scenarios involving MA transmutation in ADS are widely researched. The nuclear fuel cycle simulation tool code CLASS (Core Library for Advanced Scenarios Simulations) is dedicated to...
Dynamic fuel cycle simulation tools calculate nuclei inventories and mass flows evolution in an entire fuel cycle, from the mine to the final disposal. Usually, the fuel depletion in reactor is handled by a fuel loading model and a mean cross section predictor. In the case of a PWR–MOX, a fuel loading model provides from a plutonium stock the pluto...
In order to study the possibility of advanced management of plutonium in existing
reactors, 8 strategies for plutonium multi-recycling in PWRs are studied. Following
equilibrium studies, it was shown that, by using homogeneous assemblies, the use of
thorium cannot reduce the plutonium inventory of equilibrium cycle or production of
americium. By di...
Proceedings of Global 2009 - 2734-2743 Selected paper - RGN
The Lohengrin mass spectrometer is one of the 40 instruments built around the reactor of the Institute Laue-Langevin (France) which delivers a very intense thermal neutron flux. Usually, Lo-hengrin was combined with a high-resolution ionization chamber in order to obtain good nuclear charge discrimination within a mass line, yielding an accurate is...
Analysis and results of the measurements of the independent isotopic and mass fission yields for the 233 U(n th ,f) reaction are presented, which were performed at the Lohengrin recoil mass spectrometer in ILL. The spectrometer separates the fission products according to their mass to ion charge ratio and kinetic energy to ion charge ratio. Mass yi...
The development of tools for nuclear data uncertainty propagation in lattice calculations are presented. The Total Monte Carlo method and the Generalized Perturbation Theory method are used with the code DRAGON to allow propagation of nuclear data uncertainties in transport calculations. Both methods begin the propagation of uncertainties at the mo...
chromatographic separation and 249 Bk/ 248 Cm and 249 Cf/ 248 Cm elemental ratios determination by inductively coupled plasma quadrupole mass spectrometry. Talanta, Vol. 106, p. 39, 2013. 243 Am neutron-induced fission cross section in the fast neutron energy range. Phys. Rev. C.. Accurate determination of Curium and Californium isotopic ratios by...
The study of fission yields has a major impact on the characterization and understanding of the fission process and is mandatory for reactor applications. While the yields are known for the major actinides (U-235, Pu-239) in the thermal neutron-induced fission, only few measurements have been performed on Am-242. This paper presents the results of...
The study of fission yields has a major impact on the characterization
and understanding of the fission process and is mandatory for reactor
applications. While the yields are known for the major actinides
(235U, 239Pu) in the thermal neutron-induced
fission, only few measurements have been performed on 242Am.
The interest of 242Am concerns the red...
The existing evaluations of the 243Am neutron-induced fission cross section have been questioned by recent measurements performed at the GNEISS facility. In the neutron energy range from 1 to 6 MeV, the GNEISS data present deviations of more than 15% with respect to the evaluations. In order to solve this problem, we have measured this cross sectio...
An alternate method for the estimation of the global uncertainty on criticality, using the total cross section and its covariances, is proposed. Application of the method with currently available covariance data leads to an unrealistically large prediction of the global uncertainty on criticality. New covariances for total cross section and individ...
The sensitivities of the keff eigenvalue to neutron cross sections have become commonly used in similarity studies and as part of the validation algorithm for criticality safety assessments. To test calculations of the sensitivity coefficients, a benchmark study (Phase III) has been established by the OECD-NEA/WPNCS/EG UACSA (Expert Group on Uncert...
We study here the conversion performance of thorium-fueled standard or only slightly modified CANDU and PWR reactors with unchanged core envelope and equipments, to be eventually used as the third and last tier of symbiotic scenarios. For instance, plutonium extracted from the spent fuel of UOX PWRs could be converted in Th/Pu CANDUs to uranium (ma...
Over the last 10 years, a vast campaign of measurements has been initiated to improve the precision of neutron data for the involved key nuclei (232Th, 233Pa and 233U) of the innovative Th−233U cycle. This latter might indeed provide cleaner nuclear energy than the present U-Pu one. New measurements of charge and mass distributions of the fission p...
We present a review of the fission cross section measurements made by the CENBG collaboration over the last years using the surrogate reaction method. For example the neutron-induced fission cross sections of 233Pa(T1/2 = 27 d), 242Cm(T1/2 d) and 243Cm(T1/2 y) have been obtained by our group with this technique. The advantages and the difficulties...
CD Rom ISBN 9780894480690
The measurement of neutron-induced cross sections of short-lived nuclei is extremely difficult due to the radioactivity of the samples. The surrogate reaction method is an indirect way of determining cross sections for nuclear reactions that proceed through a compound nucleus. This method presents the advantage that the target material can be stabl...
EUR 23883 EN; ISBN 9789279117053; European Union (2010)
EUR 23883 EN; ISBN 9789279117053; European Union (2010)