Showing papers in "Nuclear Engineering and Design in 2018"

TL;DR: In this article, the authors used Bayesian analysis to establish the inverse UQ formulation, with systematic and rigorously derived metamodels constructed by Gaussian Process (GP), and proposed an improved modular Bayesian approach that can avoid extrapolating the model discrepancy that is learnt from the inverse uncertainty quantification domain to the validation/prediction domain.

TL;DR: In this article, Chen et al. proposed an improved version of the Cheng and Todreas (detailed) correlation (CTD) for wire-wrapped rod bundle friction factor published in 1986 has been refined in three aspects and renamed the Upgraded CTD (UCTD) correlation.

TL;DR: A review of the application of conductivity based wire-mesh sensors for the measurement of void fraction, bubble size, and gas fraction velocity in multiphase flows and their associated uncertainties is presented in this paper.

TL;DR: A comprehensive review of sub-channel thermal hydraulic codes used for the analysis of nuclear reactor core is presented in this article, which covers various aspects of experimental, analytical and computational works related to rod bundles carried out in the past and brings out future directions derived from earlier research works.

TL;DR: This research addresses the “lack of input uncertainty information” issue for TRACE physical input parameters, which was usually ignored or described using expert opinion or user self-assessment in previous work.

TL;DR: In this paper, a multiphysics Object-Oriented Simulation Environment (MOOSE) using the OOP method has been developed for U3Si2-FeCrAl fuel performance analysis.

TL;DR: In this paper, the tangential fretting wear of alloy 690 tube mated with 405 stainless steel (SS) plate exposed to different temperature water was investigated and the worn surfaces were examined with optical microscope (OM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and 3D microscopy.

TL;DR: In this article, the authors proposed an improved particle swarm optimization (PSO) algorithm to solve the path-planning problems in the radioactive environment of nuclear facilities, and experimental simulation for three cases is carried out and the results are compared to those from traditional PSO method.

TL;DR: In this paper, a three-dimensional numerical study on steady state was designed for a safety relief valve using several openings and inlet pressures, and the ANSYS-CFX commercial code was used as a CFD tool to obtain several properties using dry saturated steam revised by IAPWS-IF97.

TL;DR: The aim of the present study has been to generate a high fidelity reference database for a wire-wrapped fuel assembly for application to LMFR fuel, which can serve as a reference to validate the low order turbulence modelling approaches, such as hybrid (URANS/LES) methods and RANS.

TL;DR: In this article, the conceptual design of a small lead-cooled nuclear reactor intended to replace diesel-power in off-grid applications is presented in a vessel of dimensions making it transportable.

TL;DR: In this paper, post-irradiation examination was completed on two asirradiated compacts from the US Advanced Gas Reactor Fuel Development and Qualification Program's second irradiation test.

TL;DR: The verification and validation work on the newly developed fast reactor code SARAX has good accuracy in modeling a sodium fast reactor regardless of the integration parameters, such as k eff , or the distributed parameters like the sub-assembly power/reaction rate.

TL;DR: In this article, a unified set of closures have been applied to simulating different configurations and fluids, i.e. pipe flow and bubble column, air/water and air/liquid metal.

TL;DR: In this paper, the main condensation regimes at sub-atmospheric pressure conditions were identified and a comparison was done between the condensation regime experimentally determined and those available in the literature, which were obtained at atmospheric pressure.

TL;DR: In this article, two ways for the thorium fuel cycle transition are proposed, and the transition performances for the two ways are analyzed based on a thermal TMSR configuration with negative coefficient and BR greater than 1.0.

TL;DR: In this article, the thermal-hydraulic effects of internal flow blockages in a heated rod bundle cooled by lead-bismuth eutectic (LBE) are investigated in prototypical experiments.

TL;DR: It is the first time to employ the Variational Nodal Method (VNM) as the neutron diffusion solver in PWR core calculation and can eliminate the large error in pin-power reconstruction due to the elimination of the technique in VNM.

TL;DR: This paper reviews the recent research progress of two-phase flow DNS related to reactor applications and describes the current areas of active research including modeling of subcooled boiling, bubble coalescence, as well as the advanced post-processing toolkit for bubbly flow simulations in reactor geometries.

TL;DR: In this paper, an up-to-date review of methods used to predict the effective thermal conductivity is presented and methods that specifically account for the near-wall region are identified.

TL;DR: The AGR-1 irradiation experiment was performed as the first test of tristructural isotropic (TRISO) fuel in the US Advanced Gas Reactor Fuel Development and Qualification Program as discussed by the authors.

TL;DR: In this paper, the instantaneous vortical flow structure is one of the typical flow structures inside the nuclear reactor coolant pump (RCP), which would cause the unsteady pressure pulsations, vibrations of the unit and fatigue of components.

TL;DR: In this paper, the curvature correction in the realizable k-e model reduces the initial angular momentum, but it does not affect the decay rate, which indicates that the curvatures correction is effective near the twist vanes where the flow curvature is strong.

TL;DR: In this article, the authors compared the surface wettability of FeCrAl samples oxidized under different simulated Light Water Reactor (LWR) water chemistry conditions to Zircaloy-4 (Zirc-4), the reference cladding material in LWRs, under the same conditions.

TL;DR: This paper reviewed current fast reactor neutronics analysis codes and provided an overview of SARAX developments and introduced the following three methods: a hybrid method for cross-section generation, a two-level coarse mesh method for transport calculation acceleration, and a combined sensitivity and uncertainty analysis method.

TL;DR: In this article, experiments on air-water two-phase swirling annular flows in a vertical pipe of 40mm diameter were carried out at atmospheric pressure and room temperature to investigate interfacial and wall friction factors, fi and fw.

TL;DR: In this paper, a new model for active nucleation site density in boiling systems has been developed and preliminarily applied in Computational Fluid Dynamics (CFD) simulations of subcooled boiling in a vertical heated tube.

TL;DR: In this article, the unsteady pressure pulsation characteristics in a reactor coolant pump with steam-generator simulator are investigated in various flow rates and various rotational speeds.

TL;DR: Nuclear Reactor Safety, Deterministic Safety Assessment (DSA), and Accident Analysis (AA) constitute the general framework for the topic of the present paper and a list of 116 T-HP is derived, based on the documents issued in the last three decades by the Committee on the Safety of Nuclear Installations of Nuclear Energy Agency and by the International Atomic Energy Agency.

TL;DR: In this article, the safety boundary of flow instability and critical heat flux for parallel channels was theoretically investigated in static and motion, and it was shown that the instability boundary consists of CHF lines and instability boundary, while the heating power of the parallel channels is limited by flow instability or CHF depending on the mass flux.