Showing papers in "Nuclear Engineering and Design in 2000"

TL;DR: In this paper, the basic concept of two-group interfacial area transport equations has been demonstrated, and the analysis of bubble interactions between spherical/distorted bubbles and cap/slug bubbles has been carried out.

TL;DR: In this paper, a set of condensation experiments in the presence of noncondensables (e.g. air, helium) was conducted to evaluate the heat removal capacity of a passive cooling unit in a post-accident containment.

TL;DR: Toumi et al. as discussed by the authors developed a finite volume numerical method for 3D two-phase flow calculations based on an extension of Roe's approximate Riemann solver to define convective fluxes versus mean cell quantities.

TL;DR: A number of IAEA activities have led to the conclusion that the use of passive safety features can be a desirable method of achieving simplification and increasing the reliability of the performance of essential safety functions, and care should be taken to evaluate possible new failure mechanisms, and both passive and active systems should be assessed from the standpoint of reliability and economics.

TL;DR: The 3D-field code, GASFLOW as mentioned in this paper, is a joint development of Forschungszentrum Karlsruhe and Los Alamos National Laboratory for the simulation of steam/hydrogen distribution and combustion in complex nuclear reactor containment geometries.

TL;DR: In this paper, a data base of 1036 fatigue tests was used to train an artificial neural network (ANN) to predict fatigue life for specified sets of loading and environmental conditions.

TL;DR: In this article, a method for preventive maintenance scheduling optimization of standby systems, based on genetic algorithm and probabilistic safety analysis, is described, which aims to improve the average availability of the system through the optimization of the preventive maintenance policy.

TL;DR: In this paper, the authors studied the oxidation rate of Nb-1Zr based on the calculations of thickness loss resulting from oxidation and suggested three candidate containment materials for the liquid lead eutectic target, based on a literature survey of the materials' compatibility and proton irradiation tests.

TL;DR: In this paper, a new correction method is developed for the effect of the length-to-diameter (L/D) ratio on critical heat flux (CHF) by applying artificial neural networks and conventional regression techniques to the KAIST CHF data base for water flow in uniformly-heated, vertical round tubes.

TL;DR: In this article, the transition from non-boiling to film boiling at CHF highly subcooled liquids at high pressure measured was not explained by the mechanism of heat transfer crisis based on the hydrodynamic instability (HI) model.

TL;DR: The management of high-active liquid waste includes the solidification and the subsequent isolation in a deep geological formation as discussed by the authors, which is the best-demonstrated available technology for its immobilization.

TL;DR: In this paper, an analytical study on the thermo-hydraulic stability of a boiling natural circulation loop with a chimney at low pressure start-up is presented, where the effect of flashing induced by the pressure drop in the channel and the chimney due to gravity head on the instability is considered.

TL;DR: In this paper, the effect of truncation error on stability of single-phase natural circulation loops is investigated for thermal-hydraulic system code applications, with the aim to point out the effects of truncations on stability prediction.

TL;DR: In this paper, the experimental study on critical heat flux (CHF) has been performed for water flow in vertical round tubes under low pressure and low flow (LPLF) conditions to provide a systematic data base and investigate parametric trends.

TL;DR: In this article, a step-by-step procedure for the deterministic analysis of hydrogen behavior and mitigation in severe accidents is presented, which can be subdivided into four main parts: (1) modeling of the H 2 -air-steam mixture generation in the containment, (2) prediction of the risk potential of this mixture with respect to flammability, flame acceleration and detonation on-set, using newly developed criteria, (3) numerical simulation of the appropriate combustion regime with verified 3D-computational fluid dynamics (CFD) tools, and (4

TL;DR: In this paper, an innovative advanced marine reactor with a passive safety system, MRX (Marine Reactor X) has been established for the primary application to ship propulsion, and the design goals of the reactor system, to be lightweight and compact, and to be enhanced in safety and reliability, are achieved with adoption of new technologies.

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, the feasibility of large-scale steam injectors for a next-generation BWR was evaluated using separate two-phase flow models installed in the PHOENICS Code, and scale-model tests were conducted for both SI-PCIS and SI-PLR.

TL;DR: An analytical model has been developed to study the nuclear-coupled density-wave instability in the Indian advanced heavy water reactor (AHWR) which is a natural circulation pressure tube type boiling water reactor.

TL;DR: In this paper, the effects of specimen thickness on crack tip deformation and fatigue crack growth rate (FCGR) were investigated on the compact tension (CT) specimens of Type 304 stainless steel and Inconel 718.

TL;DR: In this paper, an experimental and analytical study on the condensation-induced water hammer (CIWH) for steam-water countercurrent flow in a nearly horizontal circular pipe have been performed.

TL;DR: In this article, a three-dimensional boundary element-finite element method is presented for the analysis of the fluid-structure-isolator systems in time domain, where the base isolators are the high damping rubber-bearing type and are modeled using a bilinear analysis model.

TL;DR: The behavior of vapor bubbles and vapor film during the transition from non-boiling regime such as natural convection or transient conduction regime to film boiling regime on a 1.2mm diameter platinum horizontal cylinder in liquid nitrogen and in water due to exponentially increasing heat inputs, ranging from a quasi-steady state heat input to a very rapidly increasing one, were examined by photographs taken by a high-speed video camera as discussed by the authors.

TL;DR: In this paper, a comparative investigation was conducted on the mechanistic numerical simulation of mixing of non-isothermal, quasi-planar jets incorporating low Reynolds number turbulent stress and heat flux equation models (LRSFM) and an experiment.

TL;DR: In this paper, the authors present some validation efforts recently undertaken to determine the inherent margins in the design stress equation approach compared with the applied safety factors in the axial and circumferential flaw limit-load solutions in: (i) the gas and oil pipeline industries; (ii) the proposed criteria in Belgium for the nuclear industry and other criteria, and (iii) the preliminary criteria from a recently proposed ASME Code Case on erosion/corrosion acceptance criteria and the ASME Appendix H criteria for flawed ferritic nuclear pipe.

TL;DR: SMART (Systemintegrated Modular Advanced ReacTor) as discussed by the authors is an integral reactor of 330 MW capacity with passive safety features under development in Korea, which is developed by combining the firmly-established commercial reactor technologies with new and advanced technologies such as industry proven KOFA (Korea Optimized Fuel Assembly) based nuclear fuels, self-pressurizing pressurizer, helically coiled once-through steam generators, and new control concepts.

TL;DR: In this article, the authors developed a new high damping Fe-17%Mn alloy, which has good mechanical properties and is more economical than other known damping alloys (a quarter the cost of non-ferrous damping alloy).

TL;DR: In this paper, an axisymmetric solid element model was used to characterize the detailed evolution of residual stresses in a girth weld (H4) of a BWR core shroud.

TL;DR: In this article, an internal evaporator-only (IEO) concept was developed as a semi-passive containment cooling system for a large dry concrete containment, where the function of this system is to keep the containment integrity by maintaining the internal pressure not to exceed the ultimate design pressure.

TL;DR: The hydrodynamic characteristics of falling liquid films inside a vertical tube (50.8 mm ID and 244 cm high) with counter-current interfacial shear at the onset of flooding have been investigated experimentally.