Showing papers in "Annals of Nuclear Energy in 2003"

TL;DR: The Island Genetic Algorithm (IGA), a coarse-grained parallel GA model, is explored, comparing its performance to that obtained by the application of a traditional non-parallel GA, and it is observed that the IGA provided gains not only in terms of computational time, but also in the optimization outcome.

TL;DR: A new method using a radial basis function network is presented, which shows dramatic reduction of the training time, no tedious heuristic process for optimizing parameters, and no local minima problem during the training.

TL;DR: The search for an optimum fuel-loading pattern has been conducted by predicting several core parameters such as the power distribution by means of an artificial neural network, which reduces the calculation time and makes it possible to analyse more loading patterns in the same time interval.

TL;DR: In this article, the point reactor kinetics equations of reactor are solved analytically in the presence of delayed neutron with Newtonian feedback for different types of reactivity input using a straightforward recurrence relation of a power series.

TL;DR: In this paper, the effects of the particle size on the mechanical strength of epoxy resin filled with crushed ilmenite with different maximum particle sizes ranging from 32 to 500 μm.

TL;DR: In this paper, the authors presented an empirical mode decomposition method for the stability analysis of BWR, which decomposes the original time series data in intrinsic oscillation modes or IMFs and then compute for each IMF, its Hilbert amplitude spectrum and its Hilbert marginal spectrum.

TL;DR: In this paper, a Monte Carlo approach is employed to characterise the neutron fluxes and the fuel evolution inside the tiny 200-μm diameter fuel kernels with an exact and finite geometry description.

TL;DR: In this article, a modified two-fluid model is presented for the approach of the two-group interfacial area transport equation, where bubbles are categorized into two groups: spherical/distorted bubbles as Group 1 and cap/slug/churn-turbulent flows as Group 2.

TL;DR: An algorithm to optimise the fuel loading pattern (LP) in nuclear reactors was developed using an artificial neural network to generate arrangements for the fuel in the core, indicating the viability of the developed methodology.

TL;DR: The theory is extended to treat pulses having finite width by describing the source as a doubly stochastic Poisson point process and the results of the extended theory reduce to those of the earlier formulation (or to other published results) under appropriate conditions.

TL;DR: This paper designed an on-line intelligent core controller for load following operations, based on a heuristic control algorithm, using a valid and updatable recurrent neural network (RNN) and has used an accurate 3-dimensional core calculation code to represent the real plant and to train the RNN.

TL;DR: In this article, a three-dimensional reactor dynamics program for coupled neutron kinetics and thermohydraulics calculation of VVER type pressurized water reactor cores has been developed and benchmarked.

TL;DR: This article extends previous efforts on genetic algorithms applied to a nuclear power plant (NPP) auxiliary feedwater system (AFWS) surveillance tests policy optimization to introduce the application of a niching genetic algorithm (NGA) to this problem and compare its performance to previous results.

TL;DR: In this paper, a 60 cm thick flowing liquid wall coolant is investigated as energy carrier and fusile and fissile breeder medium in an inertial fusion energy (IFE) reactor.

TL;DR: In this paper, a characteristics solver is proposed for solving general 3D geometries in the case of isotropic boundary conditions. But the main advantage of this treatment is to get rid of collision probability matrices which have a dimensionality of the size of the square of the number of regions.

TL;DR: In this paper, enriched boric acid (40% enriched B10concentration) for the reactivity control is adopted for the simulation as the required chemical shim rather than natural Boric acid, and the COTRAN code used, which simulate the behavior of the CRUD based on double layer concept model and solubility difference.

TL;DR: The main contribution of this study is the development of a practical TDD optimization procedure for BWR fuel lattice design, using TS with a multiobjective function, and a strategy to economize computing time.

TL;DR: In this article, the authors present the results obtained in the analysis of stability of flow in single-phase natural circulation loops by a computer program incorporating two different numerical schemes for discretisation of the energy balance equation.

TL;DR: The nuclear data library ERALIB1 has been obtained by a consistent statistical adjustment based on 355 integral data from 71 different systems as discussed by the authors, which represents a significant improvement on previous schemes such as CARNAVAL-IV, PROPANE and VASCO, each of which were required to calculate one specific application.

TL;DR: This work analyze the evolution strategy followed by a GA in its search for the optimal solution with the aim of extracting information on the importance of the control (decision) variables of the optimization with respect to the sensitivity of the objective function.

TL;DR: In this article, the average chord length for a convex body in an isotropic flux is given by the body's volume divided by its average projection area, and it is shown that the chord length can be expressed in such an elegant way, and has to be calculated for each body (and orientation) separately.

TL;DR: In this article, the burning and/or transmutation of minor actinides (MAs) has been investigated for an operation period (OP) of up to 10 years in the FFHR by 75% plant factor (η) under a neutron wall load (P) of 1.5 MW/m2.

TL;DR: The Implicitly Restarted Arnoldi Method (IRAM) is applied to the computation of prompt time-eigenvalues of the neutron transport equation as mentioned in this paper, which is based on a least-squares functional combined with a spherical harmonics angular discretization and spatial finite elements.

TL;DR: In this paper, a finite element model is developed at the FZR using a numerical approach which avoids the use of a single creep law employing constants derived from the data for a limited stress and temperature range.

TL;DR: In this paper, a lumped-differential formulation based on Hermite integration is proposed for the porous matrix thus eliminating the dependence on the transverse direction, and the resulting coupled partial differential equations are then handled through the generalized integral transform technique (GITT), which yields analytical expressions for the space dependence and numerical estimates for the concentration fields as a function of time.

TL;DR: In this paper, a computational method is presented as an alternative to the Monte Carlo and transport theory models presently used for the criticality analysis of regular lattices for spent fuel storage, which is developed in the framework of nodal diffusion theory, with nodal parameters obtained from continuous energy Monte Carlo computations.

TL;DR: In this paper, a link between integral geometry (where chord length distribution and its properties come from) and its applications in reactor physics has been proposed and Monte Carlo simulations illustrate these points.

TL;DR: In this paper, the possibility of power flattening of the DT driven blanket in the Prometheus-H (heavy ion) breeder reactor cooled with helium and fueled with different mixed fuels and nuclear waste actinide is investigated.

TL;DR: Using data characteristic of the nature of the problem to be analyzed, a reduced number of rules can be establish to represent the actual problem to provide the engineer with the knowledge to work in the space of solution of rules to do the necessary inferences.