Showing papers in "Nuclear Engineering and Design in 1978"

TL;DR: In this paper, the authors developed a thin plate theory in which transverse shear strains are accounted for, and the variables in the theory are all kinematic, namely, displacements and independent rotations.

TL;DR: In this article, a new discrete models and their application to seismic response analysis of structures is proposed. These models consist of finite number of small rigid bodies connected with springs distributed over the contact area of two neighbouring bodies.

TL;DR: In this article, the quenching of 19 and 25.4 mm spheres of steel, copper, and silver by water in natural and forced flow has been studied experimentally and theoretically.

TL;DR: In this paper, two-dimensional finite element models for the treatment of the nonlinear, transient response of fluids and structures are described, and procedures for treating the various aspects of subassemblies, such as the narrow fluid channels, the fuel bundles which are immersed in the coolant, and the axial flow, are developed.

TL;DR: In this paper, simplified rules to account for embedment and soil layering in the soil-structure interaction problem, to be used in dynamic analyses, are presented, and the relationship between the spring method, and a direct solution (in which both soil and structure are modeled with finite elements and linear members) is first presented.

TL;DR: In this paper, an extensive analytical investigation of annular two-phase flows has been conducted with a general mathematical formulation which is applicable to both adiabatic and boiling flows.

TL;DR: A thorough flow-induced vibration analysis of nuclear components such as heat exchangers and steam generators is essential at the design stage to ensure good performance and reliability as mentioned in this paper. But this analysis is limited to two-phase systems.

TL;DR: The results of these tests may be summarized in a homogeneous perforation formula in the case of a velocity lower than 200 m/sec: V 2 c = 1.7δρ 1 3 θe 2 M 4 3 where Vc is the minimum velocity for perfation, o diameter of the missile, M its mass, σ the ultimate compressive strength of the concrete, ϱ its density and ρ its thickness as discussed by the authors.

TL;DR: Future emphasis is needed to exploit the BIE method in conjunction with other techniques such as the finite element method through the creation of hybrid stress analysis methods.

TL;DR: In this article, an effective engineering solution for the type of cracks that have been discovered in boiling water Reactor (BWR) plants was first developed, based upon a simple net section flow stress criterion.

TL;DR: In this paper, an experimental investigation was performed to establish reliable information on the transport properties of turbulent flow through subchannels of rod bundles, and detailed data were measured of the distributions of the time-mean velocity, the turbulence intensities in all directions and hence, the kinetic energy of turbulence, of the shear stresses in the directions normal and parallel to the walls and of the wall shear stress for a wall subchannel of a rod bundle of four parallel rods.

TL;DR: In this paper, constitutive equations for representing the inelastic behavior (elastic-plastic and creep) of fast-reactor structural alloys are discussed with an emphasis on 2 1 4 Cr-1 Mo steel.

TL;DR: The URANUS code as discussed by the authors is a digital computer program for the thermal and mechanical analysis of integral fuel rods, which is built around a quasi-two-dimensional analysis of fuel and cladding.

TL;DR: In this article, the authors present a refinement of the endochronic theory of concrete which consists mainly in taking into account; (a) the inelastic strains due to hydrostatic compression; (b) improved descriptions of strain-softening behavior, (c) cyclic loading in strainsoftening range, and (d) volume change in strain-hardening range; (e) the differences between proportional and standard triaxial tests; (f) triaxeial failure envelopes; and (g) dependence of material parameters on strength.

TL;DR: In this article, the authors compared the results of the Riera model and of a lumped-mass model for rigid and deformable targets for aircraft impact and demonstrated the importance of adequate modelling of structures to enable the calculation of response spectra also in the high-frequency range.

TL;DR: In this paper, a detailed densification model is presented which describes the dependence of densification on time, burn-up, temperature, density, pore size distribution, and grain size.

TL;DR: In this article, a mathematical model for crossflow-induced vibration of tube banks is presented, and an analytical solution for the fluid inertia force, hydrodynamic damping force, and fluid elastic force is given for tube banks arranged in an arbitrary pattern.

TL;DR: In this article, an automated iterative procedure employing a combination of frequency and time-domain techniques in any desired sequence for the development of spectrum-compatible artificial time histories is presented.

TL;DR: The computational capabilities available in the current version of the computer program ADINA for stress analysis of structures and continua are described and the solution capabilities of the program are presented.

TL;DR: In this article, a nonlinear transient model for the calculation of the dynamic behavior of a vertical natural-circulation U-tube steam generator together with its steam removal system is presented.

TL;DR: In this article, an experimental and computational study was undertaken to determine the response of reinforced concrete walls to impacts from postulated tornado and other missiles, including laboratory-scale missile impacts, experiments to characterize concrete, computational model development, and two-dimensional simulations of missile impacts.

TL;DR: In this paper, the authors used successive approximation technique to obtain a solution to the non-linear freezing problem, where such effects or heat generation, viscous heat dissipation, temperature dependent thermophysical properties and a convective boundary condition at the solidification front have been incorporated into the present analytical formulation.

TL;DR: In this paper, the authors investigated the effect of warm prestress on the crack-tip stress intensity factor of a nuclear vessel during a loss of coolant accident (LOCA) followed by operation of the emergency core cooling system.

TL;DR: In this paper, a parametric analysis of the effect of lifting-off on the relative displacements of the base mat of the structure and the soil has been performed, and it is concluded that lifting off generally leads to a reduction of the total accelerations, of the stress resultants and of the relative displacement within the structure, while the total displacements, the vertical response and sometimes the response spectra in the higher frequency range are increased.

TL;DR: In this article, a stochastic theory of fracture of concrete and mortar is briefly presented and the strength and elastic modulus of concrete under impact load and under high rate of loading is discussed.

TL;DR: In this paper, full-scale poles, pipes, and rods, representing postulated tornado-borne missiles, were rocket-propelled into reinforced concrete panels with thicknesses typical of walls and roofs in the auxiliary buildings of nuclear power plants.

TL;DR: An analytical model of a prestressed concrete reactor vessel (PCRV) for LMFBR and the associated finite element computer code, involving an explicit time integration procedure, is described in this article.

TL;DR: In this article, the removal efficiency of methyl iodide for silver impregnated alumina and zeolite has been experimentally evaluated as functions of the relative humidity in the atmosphere and the amount of impregnATED silver.

TL;DR: In this paper, the effect of increasing cladding thickness on the acceleration of a cracked fuel pellet was examined using a Fourier series technique, and the implications of the results for the mechanism of stress corrosion cracking in Light Water Reactors were discussed.

TL;DR: In this article, a reliability analysis of a structural component, i.e., a reactor containment structure, is carried out, and the results are used for the quantification of the risk of nuclear power plants.