Showing papers in "Nuclear Engineering and Design in 1998"

TL;DR: In the 1960s and 70s, great interest developed in the thorium fuel cycle as a supplement to limited uranium reserves as mentioned in this paper, and a great amount of work was carried out and many interesting developments resulted, among which were prototype high temperature reactors.

TL;DR: The phenomena identification and ranking table (PIRT) process as discussed by the authors was originally formulated to support the best estimate plus uncertainty licensing option for light-water nuclear power plants, and has shown additional utility as a robust means to establish safety analysis computer code phenomenological requirements in their order of importance.

TL;DR: In this article, an Eulerian multidimensional two-fluid model for a cylindrical two-phase dispersed particle jet is proposed and compared with experimental data, where the averaged conservation equations of mass and momentum are solved for each phase and the turbulent kinetic energy equation is solved for the continuous phase.

TL;DR: An advanced non-intrusive impedance void-meter provides input signals to neural networks which are used to identify flow regimes, and the methodology presented holds considerable promise for multiphase flow diagnostic and measurement applications.

TL;DR: In this article, the authors performed a 2-year long-term study of water-penetrated separation cracks in reinforced concrete by the University of Kaiserslautern supported by the Deutsche Forschungsgemeinschaft (DFG).

TL;DR: In this paper, double sensor probe and hotfilm anemometry methods were developed for measuring local flow characteristics in bubbly flow and the formulation for the interfacial area concentration measurement was obtained by improving the formulation derived by Kataoka and Ishii.

TL;DR: In this paper, a review of the recent findings in the area of flow-induced vibration and some of the remaining questions are discussed, with particular emphasis on fluidelastic instability and damping in two-phase flows.

TL;DR: In this paper, a central channel of heated 37-rod bundles with triangular array at two different pitch-to-diameter ratios (P/D=1.12 and P/D =1.06) was investigated.

TL;DR: The Integrated Structure for Technical Issue Resolution (ISTIR) has been used for severe accident scaling issues as mentioned in this paper, which is a component II of the SASM, and has been tested and demonstrated in a postulated direct containment heating scenario.

TL;DR: In this paper, a scaling method consisting of the integral system scaling, whose components comprise the first two levels, and the phenomenological scaling constitutes the third level of scaling was developed for the scientific design of an integral test facility.

TL;DR: In this paper, the authors investigated the effect of steam condensation on the internal surfaces of the AP600 containment walls in two scaled vessels with similar aspect ratios to the actual AP600 and found that the heat transfer coefficients ranged from 50 to 800 J s −1 K −1 m −2 with the highest for high wall temperatures at high pressure and low noncondensable molar fractions.

TL;DR: In this paper, the analysis of the stress distribution at notch tip shows a pseudo-stress singularity characterised by the notch stress intensity factor (NSIF) Kρ, which is used to determine the fracture toughness of very brittle materials from notched specimens.

TL;DR: In this paper, a model of steam condensation on containment surfaces under anticipated accident conditions is presented and validated against an extensive and sound database, based on the diffusion layer theory and on the use of the heat/mass transfer analogy.

TL;DR: In this paper, the authors summarize the key aspects of a state-of-the-art scaling analysis performed to establish the facility design and test conditions for the Advanced Plant Experiment (APEX) at Oregon State University (OSU).

TL;DR: In this paper, the authors describe the Canadian algorithm for thermal hydraulic network analysis (CATHENA) transient, thermalhydraulics code developed for the analysis of postulated upset conditions in CANDU® 1 reactors.

TL;DR: In this paper, the feasibility of a new structural system for nuclear power plant buildings utilizing concrete filled steel structures, termed ''SC structural system'' was studied, and compressive loading tests were carried out to determine how to prevent buckling.

TL;DR: In this article, a new analytical approach for assessing local damage to reinforced concrete structures subjected to impact load, by applying the discrete element method (DEM), is proposed and validated through simulation analyses of various types of impact tests.

TL;DR: In this article, the authors examined the ductility of Zircaloy 4 cladding tubes under conditions of near plane-strain deformation in the hoop direction (transverse to the tube axis) at temperatures of 25 and 300°C and at strain rates of 10 3 and 10 2 s 1.

TL;DR: In this paper, a constant electric current method (CECM) is proposed for conductance measurement. But the performance of the CECM is limited due to the fact that the output from the sensor electrode is independent of the location of gas phase, and the sensitivity of detecting the change in the hold-up is higher in the case of thinner film thickness.

TL;DR: In this article, the effects of truncation error on the stability of natural circulation in a single-phase loop as predicted by finite difference numerical methods are discussed, and a short description of the characteristics of the selected problem is firstly given, also showing results obtained by a modal solution.

TL;DR: In this article, the application of a discrete element representation of solids to the analysis of reinforced concrete plates and shells is discussed, by means of constitutive criteria that quantifies coupling between both effects.

TL;DR: In this paper, a real-time signal processing system for phase detection as well as velocity measurements is described. But the sensitivity of the system to the operator inputs is less than the reproducibility of measurements, it is a fairly objective tool.

TL;DR: In this paper, the authors investigated the fluctuating velocity field in an air-water bubble column (i.e., 15.2 cm) at a gas fraction of 25% using backscatter LDA.

TL;DR: In this article, a method called Code Scaling, Applicability and Uncertainty (CSAU) was developed to apply realistic methods, while properly taking into account data uncertainty, uncertainty in physical modeling and plant variability.

TL;DR: In this article, an improved multi-channel conductance void meter (CVM) was developed to measure a void fraction based on the differences in electrical conductance of a two-phase mixture due to the variation of void fraction around a sensor.

TL;DR: In this article, the authors used a rotating reflector to measure time-dependent spatial distribution of liquid film thickness around a simulated nuclear fuel rod, which was used for analysis of the CHF under postulated loss-of-coolant-accidents in boiling water reactors.

TL;DR: In this article, an improved analytic equation-of-state (EOS) model using flexible thermodynamic functions is newly developed for a multiphase, multicomponent fluid-dynamics code for LMFR safety analysis.

TL;DR: In this paper, the authors reviewed the present status on the development of high-frame-rate neutron radiography with a steady thermal neutron beam and its application to multiphase flow researches.

TL;DR: In this paper, two models developed for several years at the French Atomic Energy Commission (CEA) for quantitative ultrasonic non-destructive testing (subsequently denoted by NDT) require simulation tools for cost-effective research and engineering works.

TL;DR: In this article, the effect of flow-induced vibration on flow structure in two-phase flow was investigated experimentally in order to investigate the impact of flow induced vibration on the flow structure.