Showing papers in "Annals of Nuclear Energy in 2011"

TL;DR: In this article, the total mass attenuation and linear attenuation coefficients, half-value thicknesses, effective atomic numbers, effective electron densities and atomic cross-sections at photons energies of 59.5 and 661 keV have been measured and calculated.

TL;DR: In this article, experimental measurements and Monte Carlo simulations were carried out for hematite-loaded concrete samples to obtain gamma and neutron attenuation characteristics, and the mechanical strength of samples was studied.

TL;DR: In this article, the radiation shielding and optical properties of xBi2O3, xPbO, xSiO2 and xBaO glass systems were investigated and the results indicated that photon is strongly attenuated in Bi2O 3 and PbO containing glasses, and but not in BaO containing glass.

TL;DR: In this paper, a fractional point-neutron kinetics model for the dynamic behavior in a nuclear reactor is derived and analyzed, which retains the main dynamic characteristics of the neutron motion in which the relaxation time associated with a rapid variation in the neutron flux contains fractional order.

TL;DR: Serpent is a recently developed 3D continuous-energy Monte Carlo (MC) reactor physics burnup calculation code as mentioned in this paper, which is specifically designed for lattice physics applications including generation of homogenized few-group constants for full-core core simulators.

TL;DR: The present version of the tool, which is based on two-group diffusion theory, is mostly suited to investigate thermal systems, and the definition of both the static and dynamic core configurations directly from the static macroscopic cross-sections and their fluctuations, respectively, makes the tool particularly well suited for research and education.

TL;DR: Five algorithms for solving the system of decay and transmutation equations with constant reaction rates encountered in burnup calculations were compared and Chebyshev rational approximation method (CRAM) was the clear winner of the comparison.

TL;DR: In this article, a reliability block diagram with general gates (RBDGG) was developed as an intuitive and easy-to-use method for system reliability analysis, which allows node connection relations of general gates such as the AND gate and the k-out-of-n gate other than the OR gate connection relation.

TL;DR: In this paper, the removal and attenuation coefficients of transmitted fast neutrons and γ-rays, respectively, through mixtures, composites, concretes and compounds are calculated.

TL;DR: The High Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory (ORNL) tested the potential of predictive or condition-based maintenance techniques to reduce maintenance costs, minimize the risk of catastrophic failures, and maximize system availability by attaching wireless-based sensors to selected rotating equipment at HFIR as discussed by the authors.

TL;DR: In this paper, the authors have made accurate measurements of concretes produced with barite, colemanite and normal aggregate by using beam transmission method for 0.663 MeV γ-rays energy of 137 Cs radioactive isotopes by using NaI(Tl) scintillation detector.

TL;DR: In this article, a multi-physics modeling approach is presented for the study of the dynamics of the Molten salt Reactor (MSR) core channel, taking into account the spatial effects of the most relevant physical quantities.

TL;DR: In this article, two methods of nuclear data uncertainty propagation are compared, using the same nuclear data uncertainties and criticality-safety benchmarks, and the consistency of the nuclear data used by both methods is checked and results for 33 criticality safety benchmarks are presented.

TL;DR: In this article, the results of using linear, rather than constant, extrapolation on the predictor and quadratic interpolation on the corrector were compared by using data from the previous step, and thus do not affect the stepwise running time.

TL;DR: Improvements implemented in a simulation tool for assessment of radiation dose exposition by nuclear plant’s personnel, using artificial intelligence and virtual reality technologies are described.

TL;DR: The results show that the performance of the ABCRK algorithm is better than or similar to that of other population-based algorithms, with the advantage of employing fewer control parameters.

TL;DR: A review of the related literature has made in order to present the most important studies about the phenomenon and to reach common general understanding of the different factors that govern CCFL as mentioned in this paper.

TL;DR: The depletion steps are divided to substeps that are solved sequentially, allowing finer discretization of the reaction rates without additional neutronics solutions and, at least when combined with Monte Carlo neutronics, causes only minor slowdown as neutronics dominates the total running time.

TL;DR: In this paper, an easy-to-implement global variance reduction procedure is demonstrated, which is capable of flattening the relative error distribution in a global mesh tally covering the geometry of a complex system.

TL;DR: Numerical results demonstrate that the modular ray tracing technique can significantly reduce the amount of ray tracing data, and the CMFD acceleration method is effective in shorting the computing time.

TL;DR: In this article, the stability of a simple heated channel containing fluids at supercritical pressure with an external imposed pressure drop was analyzed using three different analysis tools, including a system code and in-house linear and transient analysis programs, to evaluate stability thresholds at different channel throttling conditions and orientations.

TL;DR: In this paper, the effect of high density concretes on photoneutron productions in radiation therapy was studied using Monte Carlo simulations using the photon and neutron spectra of an 18-MeV photon beam of the Varian linac head.

TL;DR: These methods have been devised to reduce an effort to convert resonance integral table into subgroup data to be used in the physical subgroup method and computational results show that these iteration methods are quite promising in the practical transport lattice calculations.

TL;DR: Results obtained indicate that in the cases of datasets of large or very small sizes and/or complex decision boundaries, the bagging ensembles can improve classification accuracy.

TL;DR: In this paper, the point reactor kinetics equations of six groups of delayed neutrons with step, ramp, sinusoidal and temperature feedback reactivities are rewritten in the matrix form and the solution of this matrix form is introduced.

TL;DR: In this study, PSFs for advanced MCR HRA are derived, and a new qualitative evaluation framework for these PSFs is suggested, and PSFs from various HRA methods are collected and grouped into PSFs categories to be used in advanced M CR HRA.

TL;DR: In this paper, a dual-weighted residual approach is proposed to obtain both economical finite element meshes tailored to the solution of the target functional as well as providing reliable error estimates.

TL;DR: The results, convergence rate and reliability of the new method are quite promising and show that the ABC algorithm performs very well and is comparable to the canonical Genetic Algorithm and Particle Swarm Intelligence, hence demonstrating its potential for other optimization applications in nuclear engineering field.

TL;DR: A new adaptive algorithm for estimating the effective multiplication factor, keff, for the neutron transport equation is presented, based on a dual weighted residual approach where an appropriate adjoint problem is solved to obtain the importance of residual errors to the multiplication factor.

TL;DR: In this article, the elemental composition of amethyst using WDXRF spectroscopy technique was determined and linear attenuation coefficients have been calculated according to the simulation results, these values have been compared to a fine shielding concrete material.