Showing papers in "Nuclear Engineering and Design in 1995"
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TL;DR: In this article, the authors illustrate the relevant use of infrared thermography as a non destructive, real-time and non contact technique to observe the physical processes of damage, fatigue and failure on metallic specimens subjected to low-cycle rotating bending loadings, detect the occurrence of intrinsic dissipation and evaluate rapidly the fatigue strength of the tested materials.
251 citations
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TL;DR: In this article, the damage in a solid result from microscopic movements is included in the power of the internal forces in order to describe the unilateral phenomenon observed in concrete, and a model using two damage quantities is also presented.
93 citations
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TL;DR: In this paper, a simulation of the oscillatory behavior using the computer code athlet did not show instability with a coarse nodalization and with a fine nodalisation athlet was able to predict the instability behavior and to reproduce all the essential characteristics of the observed oscillatory behaviour.
90 citations
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TL;DR: In this paper, the safety of liquid-metal-cooled fast breeder reactors (LMFBRs) was studied with respect to fuel-coolant interactions in a jet contact mode and it was concluded that energetic jet-water interactions are only possible under relatively narrow initial thermal conditions.
85 citations
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TL;DR: An experimental simulation study on the start-up of a low temperature, natural circulation nuclear heating reactor (5 MW developed by the Institute of Nuclear Energy of Tsinghua University, Beijing) is presented in this paper.
74 citations
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TL;DR: A review of the current state of knowledge of the triggering stage of a steam explosion can be found in this paper, where a large body of empirical evidence available from which the experienced worker can decide how likely it is that triggering will occur in any given situation.
63 citations
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TL;DR: In this article, the authors present a model of the initial stages of the explosive eruption of magma from a volcanic conduit as occurs in Vulcanian style eruptions, assuming that there is a volatile rich (1 − 10 wt%) mixture of magmas, vaporised groundwater and exsolved volatiles, trapped at high pressure (1 -100 atm).
62 citations
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TL;DR: In this article, a comprehensive approach is described and sample results are provided on 2D explosions from the recently proposed microinteractions model (the esprose.m code) and on the chemical augmentation of steam explosions with highly reactive metals.
61 citations
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TL;DR: In this article, the mechanical properties of fiber-reinforced concrete with different ratios of polypropylene and steel were tested under repeated loading and the workability of mixes was measured by Vebe method and regulated by the plasticizing admixture Ligoplast Na.
61 citations
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TL;DR: In this paper, a detailed model of the Ikejet was developed at the IKE and strong differences between the Kelvin-Helmholtz (KH) description of the interface instabilities and the Jeffreys-Miles (JM) approach were analyzed in comparison with experimental results.
60 citations
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TL;DR: In this paper, first-of-a-kind experimental data on the quenching of large masses of corium melt of realistic composition when poured into pressurised water at reactor scale depths are presented and discussed.
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TL;DR: In this article, a simple one-dimensional three-fluid model is presented for the simulation and analyses of vertical annular and stratified horizontal or inclined two-phase flows, where emphasis has been laid upon several mass, momentum and energy interfacial transfer processes.
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TL;DR: In this article, a series of experiments to investigate melt-coolant interactions have been performed as part of the ALPHA program at JAERI, where melt simulating a molten core was dropped into a pool of water and volume fractions of the melt, water and steam in the mixing region prior to the occurrence of spontaneous steam explosions were quantified.
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TL;DR: In this paper, numerical modeling was applied using advanded tools of mathematical approximation theory, i.e. multiregression algorithms and neural networks, to characterize microstructural states superimposed by residual stresses in an unambiguous way.
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TL;DR: An experimental set-up for the generation of mixtures of silicate melt (remolten volcanic rocks) and water and the triggering of steam explosions was built at the Institut fur Kernenergetik (IKE) at Stuttgart as discussed by the authors.
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TL;DR: In this paper, fracture and fatigue tests of steel-fibre-reinforced concrete (SFRC) structures were performed in order to investigate the fracture behavior of SFRC structures, and the relationship between loading, strain and midspan deflection of the beams was observed under the three-point loading system.
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TL;DR: In this paper, the authors used the KROTOS facility at JRC Ispra to study experimentally melt-coolant premixing and steam explosion phenomena in Al2O3/water mixtures with approximately 1.5 kg melt at 2300-2400 °C.
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TL;DR: The most appropriate conceptual model for performance assessment (PA) at the waste isolation pilot plant (WIPP) is believed to include gas generation resulting from corrosion and microbial action in the repository, and a dual-porosity (matrix and fracture porosity) representation for the solute transport in the Culebra dolomite member of the Rustler formation as mentioned in this paper.
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TL;DR: In this paper, the authors simulated the thermal-hydraulic phenomena in the hot leg of a pressurized water reactor during the small break loss of coolingant accident (SBLOCA) and found that the fluid flow exhibits strong multi-dimensional effects, i.e., an appreciable acceleration and deceleration along different regions of hot leg, and a four-vortex secondary flow structure in the cross-section of the bend region.
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TL;DR: In this paper, analytical models of systems of thin flat rectangular fuel element plates are developed which take into account the effects of the fluid reactive loadings, coolant flow velocity, plate aspect ratio and the channel height between the plates.
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TL;DR: In this paper, a simple and systematic method for carrying out inelastic evaluations of mechanical components and structures on the basis of two linear elastic finite element analyses is presented, where the degree of interaction between the local and remainder regions is characterized by studying the relaxation response on the generalized local stress strain (GLOSS) diagram.
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TL;DR: In this article, the authors measured the strain behavior of three advanced-gas-cooled-reactor-type nuclear reactor concretes during the first heat cycle and their relative thermal stability determined.
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TL;DR: In this paper, a mathematical formulation for the air leakage rate through cracks in concrete is given, which works well as a good approximation for crack widths up to 1.30 mm and overpressures up to 0.80 MPa.
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TL;DR: In this article, the authors proposed a sliding pressure venting process, combining a venturi scrubber in a water pool and a mesh filter, which is used in all five nuclear power plants of Switzerland.
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TL;DR: In this article, a theoretical model based on pore pressure gradients as the driving potentials is introduced and used to predict water migration in a concrete wall of 5 m thickness, heated at the inner face to 200 °C.
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TL;DR: In this article, the authors generalized the elastic follow-up model by introducing the following concepts: (1) an elastic followup model using a power law, for the purpose of the quantitative evaluation of material properties; (2) combined elastic follow up models, for consideration of stress redistributions; (3) an equivalent elastic follow -up model of Neuber's rule.
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TL;DR: In this paper, the results of these analyses are shown to provide quantitative interpretations of the data, and to suggest conditions/measurements in further experiments to enhance the insights obtained, and a quantitative radiography technique is described and applied to Magico for the measurement of chordal-averaged void fractions in the mixing zone.
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TL;DR: In this paper, the creep characteristics of a Zr1Nb-1Sn-0.2Fe alloy sheet were investigated at temperatures from 773 to 923 K and at stresses ranging from 9 to 150 MPa along both the rolling and transverse directions, with diffusional viscous creep at low stresses, viscous-glide-controlled microcreep in the intermediate stress regime and the climb of edge dislocations at high stresses.
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TL;DR: In Swedish BWRs, the lower drywell beneath the reactor vessel is flooded with water to mitigate against the effects of melt release into the drywell during a severe accident as discussed by the authors, and experiments have also been performed to investigate the benefits of adding surfactants to the water to reduce the likelihood of fine-scale debris formation from steam explosions.
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TL;DR: In this article, a higher-order hyperbolic scheme is proposed to describe a sharp interface of two fluids by one grid throughout computation, which is applicable simultaneously to compressible and incompressible fluids.