Showing papers in "Nuclear Engineering and Design in 1997"

TL;DR: In this article, the efficacy of external flooding of a reactor vessel as a severe accident management strategy is assessed for an AP600-like reactor design, and the assessment includes consideration of bounding scenarios and sensitivity studies, as well as arbitrary parametric evaluations that allow for the delineation of the failure boundaries.

TL;DR: The RERTR program has recently begun an aggressive effort to develop dispersion fuels for research and test reactors with uranium densities of 8 to 9 g U/cm{sup 3], based on the use of {gamma}-stabilized uranium alloys as discussed by the authors.

TL;DR: In this article, the key results of developments for use of a lead-bismuth coolant in nuclear reactors and accelerator-driven system, are presented, along with the salient points of the concept providing the safety of reactor facilities cooled by a lead bismuth eutectic are covered.

TL;DR: In-vessel retention of corium has been approved to be part of the severe accident management strategy for IVO's Loviisa plant as discussed by the authors, taking advantage of the unique features of the plant such as a low power density, a reactor pressure vessel (RPV) without penetrations at the bottom, and ice-condenser containment which ensures a flooded cavity in all risk significant sequences.

TL;DR: In this article, the authors investigated experimentally local heat transfer from condensation in the presence of non-condensable gases inside a vertical tube using a novel experimental apparatus for accurately measuring local heat fluxes, an extensive data base has been obtained for the condensation of pure steam, steam-air mixtures and steam-helium mixtures.

TL;DR: In this article, the ACOPO experiment simulates natural convection heat transfer from volumetrically heated pools, at a half-scale reactor lower head geometry (hemispherical).

TL;DR: In this paper, artificial neural networks were used to predict uniaxial behavior of concrete at high temperature using a feed-forward network and back-propagation algorithm to predict the stress-strain relationship of the material.

TL;DR: The ULPU experimental facility as discussed by the authors provides full-scale simulations of the boiling crisis phenomenon on the hemispherical lower head of a reactor pressure vessel submerged in water, and heated internally.

TL;DR: In this article, the SULTAN facility was designed to study large-scale structure coolability by water in boiling natural convection and the main characteristics of two-dimensional, two-phase flow, in order to evaluate the recirculation mass flow in large systems, and the limits of the critical heat flux (CHF) for a wide range of thermodynamic parameters.

TL;DR: In this paper, the effects of spacers on flow and phase distribution between, and pressure drop along, fuel elements in BWR fuel bundles have been modeled using a two-fluid model in which lateral interfacial effects are accounted for.

TL;DR: In this article, the authors used the PLEDGE (Plant Life Extension Diagnosis by GE) model to support the hypotheses that tie together the role of different contributing elements: residual stress, core water chemistry and microstructural features.

TL;DR: The GT-MHR facility is designed for burning weapons-grade plutonium and utilization of the heat produced in the direct gas-turbine cycle with electricity production efficiency of about 50%.

TL;DR: In this article, a photochromic dye activation method was used to obtain two-dimensional liquid velocity profiles around a Taylor Bubble rising in stagnant kerosene in a vertical 25.6 mm I.D. pipe.

TL;DR: In this article, the authors investigated the relation between the liquid-vapor behavior and the heat transfer characteristics in the boiling phenomena and developed a transparent heaters for both flow boiling and pool boiling experiments and were applied to the microgravity environment realized by the parabolic flight of aircraft.

TL;DR: In this article, the authors present a review of the available turbulence modelling techniques, with particular emphasis on selecting models capable of treating the mechanisms of turbulence that are relevant to high Rayleigh number natural convection.

TL;DR: In this article, the effects of the Prandtl number on heat transfer in volumetrically heated liquid pools with Rayleigh numbers up to 1012 have been investigated, with particular emphasis on the analysis of Pr number effects.

TL;DR: In this paper, a simple mathematical model is developed to describe the dynamics of the nuclear-coupled thermal-hydraulics in a boiling water reactor (BWR) core, which leads to a simple dynamical system comprised of a set of nonlinear ordinary differential equations (ODEs).

TL;DR: In this paper, an analytical study has been conducted on a large-scale steam injector for a next-generation reactor, in order to check the feasibility of a large scale steam injectors for which a demonstration test was not able to be conducted at present.

TL;DR: In this paper, the authors investigated the fracture behavior of CF8M duplex stainless steel after aging at 300-450°C for 300-10,000 h with a temper parameter P = log (t)+0.4343 Q/R 1/673.

TL;DR: In this paper, an air-water experiment has been performed to measure the entrainment rate in a small pipe and a mechanistic model was obtained based on Kelvin-Helmholtz' instability theory, including the Weber number of the gas and the liquid film Reynolds number.

TL;DR: In this paper, a large eddy simulation technique is used to predict turbulence in non-staggered and staggered tube bundles using the GUST simulation method, and the results indicate that the technique is capable of turbulence prediction in complex geometries.

TL;DR: In this article, a two-way particle tracking method was proposed to solve a three-dimensional bubble-induced liquid velocity field, provided that the bubble size is greater than the size of the computational cell for calculating the liquid phase.

TL;DR: In this paper, the effect of reinforcement ratio on perforation resistance of reinforced concrete elements is discussed and a way to evaluate it quantitatively is proposed, where the reinforcement ratio is used as a variable.

TL;DR: In this paper, a cast duplex stainless steel containing about 20% ferrite and embrittled at 400°C was studied and the main damage mechanism is nucleation of cleavage cracks in the ferritic phase.

TL;DR: The present level of knowledge and state of the art have to be evaluated so that the possibilities and limitations of the individual methods are recognized and the detection potential improved by the combined utilization of several techniques.

TL;DR: In this paper, the authors used a nonlinear κ−ϵ model with inequality of the Reynolds normal stresses, a necessary condition for calculating turbulence-driven secondary flows in non-circular ducts.

TL;DR: In this article, a Nusselt-type algebraic equation is derived for the film thickness as a function of flow and geometry parameters, and heat and mass transfer analogy relations are invoked to deduce the condensation rate of steam onto the tube wall.

TL;DR: In this article, the authors proposed a probabilistic safety assessment (PSA) for nuclear power plants using the GO-FLOW methodology, where CCF analysis together with uncertainty analysis has been provided.

TL;DR: In this paper, a concavo-convex plate type compact heat exchanger (CPCHX) is proposed to transfer high temperature heat to a process heat application for a next generation high temperature gas-cooled reactor (HTGR).

TL;DR: In this article, the effects of rotatory inertia and shear deformation for practical pipe geometries and loading conditions are investigated using computer code flustrin, developed by delft hydraulics and which enables the user to determine dynamic fluid pressures, structural stresses and displacements in a liquid filled pipeline system under transient conditions.