Showing papers in "Nuclear Engineering and Design in 1992"

TL;DR: In this article, the authors summarized the methods utilized by the staff of Sandia National Laboratories in performing four probabilistic risk assessments (PRAs) in support of NUREG-1150.

TL;DR: In this article, the authors preliminarily examined a new test method for acceleration of aging of mortar specimens by application of electrical potential gradients and observed whether the method could throw light on the deterioration process of cementitious materials under repository conditions.

TL;DR: In this article, a model for brittle material such as concrete based on continuum damage theory is presented, where elastic anisotropy induced by damage, the evolution of permanent strains, which are considered to be related to damage and a directional effect such as the closure of cracks are all clearly illustrated by different experiments.

TL;DR: In this paper, a Lagrangian method called G ( Θ ) method was proposed for calculating the energy release rate of 3-noded DKT shell elements and 20-nodes isoparametric 3-D elements.

TL;DR: In this article, an adaptive observer-based controller is proposed to estimate the water level contributions from the mass capacity, reverse dynamics, and mechanical oscillations by applying an adaptive observers.

TL;DR: In this paper, a parametric study using the Tate model is used to show that the total depth of penetration is sensitive to the value of R 1, time-resolved depth-of-penetration experiments and numerical simulations are used to examine R t as a function of penetration depth for long-rod tungsten-alloy projectiles impacting semi-infinite targets of S-7 steel and a titanium alloy.

TL;DR: In this paper, a new flooding correlation is presented, based on the classic flooding equation where the effects of gravity, interphase momentum exchange, and instability of the gas/liquid interface are considered.

TL;DR: In this paper, the importance of nuclear district heating is discussed and the development program of district nuclear heating in China is given in the report, where the main characteristics of these reactors are given.

TL;DR: In this paper, the authors present the findings of the probabilistic risk assessment for Unit 1 of the Surry Power Station performed in support of NUREG-1150, and show that the risk from internal initiators is well below the safety goals and is somewhat lower than estimated by Reactor Safety Study (RSS) over a decade ago.

TL;DR: In this paper, the influence of several parameters is explained through an analytical model: on one hand, the oxydo-reduction equilibrium is fixed by the ferrous iron ion concentration; on the other hand, convective diffusion moves soluble products to the flow.

TL;DR: In this article, the gas leakage rate through cracks in concrete walls was formulated by an isothermal compressible-flow equation for each identified crack and the two-dimensional Poiseuille flow equation was also applied successfully for a small leakage rate.

TL;DR: In this paper, a review was made of fatigue failures of nuclear power plant components in Japan, which were experienced in service and during periodical inspection, and the causes of service fatigue failures can be divided into two categories: mechanical-vibration-induced fatigue and thermal-fluctuation-induced fatigue.

TL;DR: In this paper, the authors applied the distinct element method (DEM) to simulate local damage of concrete structures and compared the numerical results with empirical formulas and experimental results, and found that the results were comparable to empirical formulas.

TL;DR: In this article, the conjugate phenomenon of the transient molecular diffusion and natural convection of a two-component gas mixture in two test sections, a reverse-U-shaped tube and a test model simulating simply the reactor, was investigated to investigate the process of air ingress during the early stage of the primary-pipe rupture accident.

TL;DR: In this article, it was shown that the radiation dose of the worst, still plausible hypothetical accident will not exceed the natural radiation dose accumulated over 50 years by more than an order of magnitude.

TL;DR: In this article, the authors summarized the findings of the probabilistic risk assessment (PRA) for Unit 2 of the Peach Bottom Power Station performed in support of NUREG-1150 and showed that the annual risk from internal initiators is much lower than estimated by the Reactor Safety Study (RSS) over a decade ago.

TL;DR: In this paper, the outer rod of a 37-rod bundle model was measured around its perimeter, and the measurements showed that the heat transfer coefficient was minimum near narrow gaps and maximum in open-flow regions but its variation became substantial only when the gap diminished below a certain value.

TL;DR: In this article, a phenomenological model of the thermal hydraulics of convective boiling in the post-critical heat-flux (post-CHF) regime is developed and discussed.

TL;DR: The U.S. Advanced Liquid Metal Reactor (ALMR) program has focused on PRISM (Power Reactor Inherently Safe Module) as mentioned in this paper, which utilizes inherent safety characteristics to simplify and improve operability and standardization.

TL;DR: In this paper, the authors summarized the findings of the probabilistic risk assessment (PRA) for Unit 1 of the Grand Gulf Nuclear Station performed in support of NUREG-1150.

TL;DR: In this paper, the stability of natural circulation with throughflow in a figure-of-eight loop was investigated and good agreement was found between theory and experiment, both experimental and theoretical.

TL;DR: In this article, a probabilistic risk assessment (PRA) for Unit 1 of the Sequoyah Nuclear Plant performed in support of NUREG-1150 is presented.

TL;DR: In this article, the experimental results of neutron transport and shielding properties of heavy concretes made from locally available ilmenite and magnetite sand are reported, with a BF 3 detector as a long counter.

TL;DR: In this paper, the first-order reliability method combined with a finite element method was used for fatigue reliability in two-dimensional finite element models of components with cracks in mode I with crack growth treated by the Paris law.

TL;DR: In this article, the relative statistical error in void fraction was the least when using beta particles, neutrons, and gamma rays consecutively, and X-rays exhibited a behavior between gamma and beta.

TL;DR: A design study of a standard Molten Salt Reactor: FUJI-II (350 MWth, 155-161 MWe) ensuring fuel self-sustaining nature (conversion-ratio ≈ 1.0) in spite of small-size, and pilot-plant miniFUJI II has been proceeded as mentioned in this paper.

TL;DR: In this paper, a method of measuring three-dimensional wave forms in a thin liquid film is presented, with experimental data, using a newly developed multi-conductance probe, along nearly horizontal (4.1°) and near vertical (87.0°) flat plates with air -water concurrent stratified flow.

TL;DR: In this article, a statistical uncertainty quantification methodology for evaluation of the emergency core cooling system (ECCS) performance is proposed and applied in assessing the best-estimate peak cladding temperature (PCT).

TL;DR: In this paper, a helium-cooled Modular High Temperature Reactor (MHT Reactor) was developed, where the temperature mixing of the simulated coolant flow as well as the leakage flows was larger than 95%.

TL;DR: In this article, the small-strain, isotropic viscoplasticity theory based on overstress (VBO) is used to model the rate dependence of stainless steel.