Showing papers by "Westinghouse Electric published in 2019"

110th Anniversary: Solvent Exchangein the Processing of Biopolymer Aerogels: Current Status and OpenQuestions

Abstract: In the past decade, the uses and applications of aerogels have garnered significant scientific curiosity in the aerogel community. Furthermore, renewed focus on the supercritical CO2 drying methodo...

Effect of cooling rate on the microstructure and hydrogen storage properties of TiFe with 4 wt% Zr as an additive

Abstract: In this paper, we report the effect of cooling rate on the microstructure and hydrogenation behaviour of TiFe alloy with 4 wt% Zr as an additive. An ingot of TiFe +4 wt% Zr was synthesized by induction melting, using industrial grade Fe and Ti. Step mold with a thickness of 25, 13, 6 and 3 mm were used to obtain different cooling rates. It was found that higher cooling rate leads to a rapid solidification and finer distribution of the secondary phase. There was no effect of cooling rate on the chemical composition of the different phases present in all thicknesses. However, faster cooling rate leads to faster first hydrogenation kinetics. The reason is that the scale of the secondary phase decreases with increasing cooling rates. The decrease in the scale of the secondary phase was evidenced by the measure of its perimeter. During activation, the hydrogenation rate limiting step for all alloys was found to be 3D growth, diffusion controlled with decreasing interface velocity. The gateway mechanism for the enhanced first hydrogenation kinetics has been confirmed.

Supercritical Extraction of Lanthanide Tributyl Phosphate Complexes: Current Status and Future Directions

Abstract: Many researchers have studied the extraction of lanthanides with tributyl phosphate in supercritical carbon dioxide. Potential applications include the enhanced extraction or separation of lanthanides from ores and recycled materials by making use of the unique solvation properties of supercritical CO2. In some cases, tributyl phosphate has been used to extract lanthanides from their solid nitrate salt form or from nitrate solutions. In other cases, tributyl phosphate/nitric acid adducts have been used to extract lanthanides from oxides, hydroxides, ores, phosphors, magnets, and waste batteries. Flow-through-type experiments have been useful for measuring extraction kinetics for various lanthanide-containing materials. Equilibrium -type experiments have helped to show the effect of different parameters on phase equilibria, often making use of spectroscopy to measure supercritical lanthanide concentrations in situ. Several studies have noted that extraction decreases when more water is added to the system;...

Zirconium Alloys for LWR Fuel Cladding and Core Internals

Abstract: This chapter reviews zirconium alloys (Zr-alloys) that are used as fuel cladding and other core components in light water reactors (LWRs). It emphasizes key factors pertaining to fabrication and microstructure, corrosion and crud buildup, concurrent hydriding and mechanical integrity, as well as effects of irradiation on the alloy. Considering the need to prevent fuel failures during reactor cycles, the chapter discusses various failure mechanisms. The chapter concludes with a historic timeline for application of Zr-alloys in the LWR fuel industry.

DFT + U Study of the Adsorption and Dissociation of Water on Clean, Defective, and Oxygen-Covered U3Si2{001}, {110}, and {111} Surfaces.

Abstract: The interfacial interaction of U3Si2 with water leads to corrosion of nuclear fuels, which affects various processes in the nuclear fuel cycle. However, the mechanism and molecular-level insights into the early oxidation process of U3Si2 surfaces in the presence of water and oxygen are not fully understood. In this work, we present Hubbard-corrected density functional theory (DFT + U) calculations of the adsorption behavior of water on the low Miller indices of the pristine and defective surfaces as well as water dissociation and accompanied H2 formation mechanisms. The adsorption strength decreases in the order U3Si2{001} > U3Si2{110} > U3Si2{111} for both molecular and dissociative H2O adsorption. Consistent with the superior reactivity, dissociative water adsorption is most stable. We also explored the adsorption of H2O on the oxygen-covered U3Si2 surface and showed that the preadsorbed oxygen could activate the OH bond and speed up the dissociation of H2O. Generally, we found that during adsorption on the oxygen-covered, defective surface, multiple water molecules are thermodynamically more stable on the surface than the water monomer on the pristine surface. Mixed molecular and dissociative water adsorption modes are also noted to be stable on the {111} surface, whereas fully dissociative water adsorption is most stable on the {110} and {001} surfaces.

The effect of cold work on the transformation kinetics and texture of a zirconium alloy during fast thermal cycling

Abstract: The effect of cold-work on the transformation kinetics and texture evolution after fast temperature cycling were studied in a dilute zirconium alloy. It was found that cold-work delays the onset of phase transformation and helps randomise the texture after the transformation. Samples of Zircaloy-4 in two conditions, cold-rolled to 70% reduction and fully recrystallised, were heated above the β-transus at a fast rate of 100 °C s−1 using resistive heating and without constraint. Electrical resistivity was used to measure the phase fraction during heating and electron back-scatter diffraction was used to measure the texture before and after the thermal cycle. Whereas previous work on titanium suggested that cold-work leads to texture strengthening after transformation, these new experiments show that, when the heating rate is fast enough, recrystallisation is incomplete on heating, which slows down the start of transformation, leading to a random α-texture after cooling. The texture in the recrystallised material after β heat-treatment is non-random but different from the start, a consequence of both a stronger β-texture after grain growth and stronger variant selection on cooling. This variant selection can be mostly explained by α-nucleation at special β-grain boundaries. These results demonstrate that prior deformation has a strong effect on the textures produced after β-heat treatment when heating rates are fast. This has implications for the anisotropy of nuclear cladding components after loss-of-coolant (LOCA) and reactivity-initiated accidents (RIA) but also more widely for the manufacturing of zirconium and titanium using welding or additive layer manufacturing where the heating rates are high.

Application of Fractional Scaling Analysis for Development and Design of Integral Effects Test Facility

Abstract: The aim of this paper is to present a fractional scaling analysis (FSA) application for a system with interacting components where multiple figures of merits need to be respected during complex transient accident scenario with several consecutive time sequences. This paper presents FSA application to the International Reactor Innovative and Secure (IRIS) reactor and Simulatore Pressurizzato per Esperienze di Sicurezza 3 (SPES3) integral effects test (IET) facility. The FSA was applied for the small break loss of coolant accident (SBLOCA) on the direct vessel injection (DVI) line as the most challenging transient scenario. The FSA methodologies were applied for two figures of merits: (1) reactor and containment vessels pressure responses, and (2) reactor vessel water collapsed level response. The space decomposition was performed first. The reactor vessel and containment vessel were divided in components so that important phenomena and their consequences can be evaluated in each of them. After that, the time decomposition in consecutive time sequences was performed for the considered transient (DVI SBLOCA) based on the starts, or ends, of the defining events. The configuration of the system in each time sequence might be different and dependent on the control system actions connecting, or disconnecting, various components of the system due to the valves openings, or closings. This way, the important phenomena and their consequences can be evaluated for each component and time sequence. Also, this paper presents and discusses options for deriving nondimensional groups and calculation of distortions between prototype and model responses for complex transients containing multiple consecutive time sequences. The input data for scaling analysis are based on the results of RELAP/GOTHIC analysis performed for IRIS and RELAP analysis performed for SPES3. The scaling analysis was applied iteratively several times for different IRIS and SPES3 configurations. Based on the intermediate results, some components in the IRIS and SPES3 were redesigned so that the distortions between IRIS and SPES3 responses are decreased.

Installing, Operating, and Maintaining dc Motors in a Paper Mill Environment: Using Proactive Measures that Promote Longevity

Abstract: To paraphrase the son of lady macduff in william Shakespeare's Macbeth, "DC is not dead, for all your saying!" When the paper industry was first electrified, the only type of machine capable of variable-speed operation was powered by dc. There were numerous manufacturers and users who knew how the machines worked and how to maintain them. Over time, the control of these machines has changed from relatively simple analog to complex digital systems. Those whose task it was to keep the machines healthy have since moved on to other things. The modern pulp, paper, and forest industries still have applications powered by dc equipment; however, the most recent installation trend is toward ac machines.

CFD Modeling Development for DNB Prediction of Rod Bundle with Mixing Vanes Under PWR Conditions

Abstract: Critical heat flux (CHF) is a primary parameter for nuclear fuel design and plant operation safety. CHF values are normally obtained from fuel bundle integral departure from nucleate boiling (DNB) or dryout experiments. These experiments are expensive, and detailed measurements (bubble dynamics, void fraction distribution, etc.) are difficult to obtain, particularly under typical pressurized water reactor (PWR) conditions of high pressure and temperature. Therefore, it is highly desirable that computational tools such as computational fluid dynamics (CFD) provide detailed flow and heat transfer information that will efficiently facilitate design improvements of PWR fuel designs.For the CFD studies described in this paper, an Eulerian-Eulerian two-phase modeling approach was adopted to predict DNB in a fuel assembly with mixing vane grids. Subcooled flow boiling was simulated using heat flux partition modeling and phase interactions. Direct addition of heat to the vapor was activated when the local...

Validation of RELAP-7 for Forced Convective and Natural Circulation Reactor Flows

Abstract: Nuclear reactor systems present a significant challenge to computational simulation due to the wide range of system conditions and associated physics. Furthermore, the regulatory demands to increase safety margin and justify safe operation and shutdown adds a daunting challenge for complete system understanding. Together these requirements result in the need for large amounts of validation data under varying conditions and configurations. The degree of reliance on computational tools for nuclear power plant regulation and design can only be justified by extensive code validation with experimental data. Therefore, this work aims to generate a large database for forced convective and natural circulation reactor flows. Through the synthesis of existing data from past experimental efforts and generation of new data from an existing wellscaled facility, a database providing a logical path to system code validation can be created. The experimental data will be used to validate the new RELAP-7 thermal-hydraulics code under conditions critical to analysis of current and future Light Water Reactor (LWR) systems. The experiments follow a sequential hierarchy validation path (pyramid), which starts with forced convective flows based on wellestablished benchmark data spanning prototypic LWR operational and accident conditions. The validation is then extended to the newly generated natural circulation data. Due to the coupling of pressure drop, flow rate and heat transfer through the void fraction, accident mitigation strategies relying on natural circulation present significant challenges for system codes. Such a path allows for a consistent delineating of phenomenological contributions and quantifying uncertainties of different physics phenomena. A key component of the proposed validation strategy is the development and implementation of state-ofthe-art uncertainty characterization (UC) algorithms in the form of a toolkit that can be readily accessible by the various models used to analyze the experiments proposed in this project. Despite the importance of uncertainties, nuclear simulation codes have always lacked an integrated framework for their characterization. This project will combine well-established techniques with recently developed UC algorithms to ensure a comprehensive treatment and understanding of all uncertainty sources that can be efficiently computed. These algorithms will provide a rigorous manner by which the credibility of the model can be established. Close collaboration between experimental, modeling, and computational experts will provide an expansive study of reactor flows from inception of data through validation and model uncertainty quantification. The outcomes of the work include: synthesis of existing experimental data for thermal-hydraulic system code validation spanning the full range of prototypic system pressures under forced convection two-phase flow; a new experimental database from an existing well-scaled facility under natural circulation conditions; validation and uncertainty quantification of RELAP-7 under forced convection and natural circulation reactor conditions.

Results of the ASTM Round Robin on Creep-Fatigue Crack Growth Testing of a P91 Steel

Abstract: This article summarizes the results of a round robin (RR) study begun in 2013 to evaluate ASTM E2760-10, Standard Method for Creep-Fatigue Crack Growth Testing (Superseded). Thirteen laboratories from around the world conducted testing and reported results. The test material was a creep-ductile, ASTM Grade P91 9Cr-1Mo steel. All testing was performed using nominally 50-mm-wide compact tension specimens at a test temperature of 625°C using trapezoidal waveforms with hold times of 0, 60, and 600 s. The 600-s hold time condition was the primary condition used for assessing interlaboratory variability among crack growth rates. Loading/unloading times were 2 s each. All laboratories tested duplicate specimens that were identical in all respects except for the force amplitude levels. Results from prior studies that included tensile, creep deformation and rupture, and low-cycle fatigue properties were available for the analysis of tests conducted as part of this RR testing. Crack growth rates at 600-s hold time reported by six laboratories fall within a 95 % confidence band (interlaboratory variability) separated by a factor of 6.16 when correlated with ΔK, 10.76 when correlated with measured vales of (Ct)avg, and 7.17 when correlated with calculated values of (Ct)avg.

System, Method, and Computer Program Product for Automatic Inspection of a Train

Abstract: Described are a system, method, and computer program product for automatic inspection of a train including one or more locomotives and/or railcars. The method includes activating, or causing the activation of, at least one scanning drone including at least one sensor configured to obtain primary inspection data of the train. The method also includes communicating at least one set of scanning drone operating instructions configured to cause the at least one scanning drone to obtain the primary inspection data along a travel path associated with the train. The method further includes receiving the primary inspection data from the at least one sensor. In further non-limiting embodiments or aspects, the method includes activating, or causing the activation of, at least one micro drone including at least one sensor configured to obtain secondary inspection data of the train.

ECP overlay system for W-type triple valve

Abstract: An ECP overlay system for a W-type triple valve includes a manifold body having a pipe bracket face configured to engage a face of a pipe bracket of a railway brake system, a valve face configured to engage a face of a W-type triple valve of a railway brake system, and an electric manifold face. The system also includes an electric manifold assembly engaged with the electric manifold face of the manifold body, with the electric manifold assembly having a pneumatic mode where the electric manifold assembly is configured to allow pneumatic-only control of a brake cylinder of railway brake system and an ECP mode where the electric manifold assembly is configured to allow electronic control of a brake cylinder of a railway brake system. 12 - 48 52 44 34 38 4 20 56 46 36

Ventilated brake disc

Abstract: A friction ring configured to be fixed to a hub at one or more fixation points is provided. The friction ring includes a ring shaped body; an outer surface configured to be contacted by a brake mechanism; an inner surface configured to contact a portion of a hub or axle to impart a braking force thereto; at least one through-hole for receiving a fastener for fixing the friction ring to the hub or axle; and at least two protrusions extending from the inner surface of the friction ring forming a channel. A cross-sectional area of an inflow portion of the channel is smaller than a cross-sectional area of an outflow portion of the channel. A brake assembly including a hub and the fixation ring is also provided.

Automatic brake control valve test unit for railway vehicle

Abstract: An automatic single-car test device for a distributor valve of a railway vehicle includes an air supply source, an adapter having a working chamber fitting, a valve chamber fitting, a reservoir fitting, a brake cylinder fitting, and a brake pipe fitting, an operating portion in fluid communication with the air supply source and the adapter, where the operating portion is configured to measure pressure within the working chamber fitting, the valve chamber fitting, the reservoir fitting, the brake cylinder fitting, and the brake pipe fitting and generate an electrical signal representing the respective pressure with the fittings. The test device further including a processing portion having a microprocessor, an input/output device, and a power supply. The processing portion configured to manipulate pressure within the working chamber passage, the valve chamber passage, the reservoir passage, the brake cylinder passage, and the brake pipe passage of the distributor valve via the adapter.

ECP overlay system for UIC-type distributor valve

Abstract: An ECP overlay system (10) for a UIC-type distributor valve (4) includes a manifold body (12) having a pipe bracket face (16) configured to engage a face of a pipe bracket (2) of a railway brake system, a valve face (20) configured to engage a face of a UIC-type distributor valve (4) of a railway brake system, and an electric manifold face (24). The system (10) further including an electric manifold assembly (14) engaged with the electric manifold face (24) of the manifold body (12), with the electric manifold assembly (14) having a pneumatic mode where the electric manifold assembly (14) is configured to allow pneumatic-only control of a brake cylinder (9) of railway brake system and an ECP mode where the electric manifold assembly (14) is configured to allow electronic control of a brake cylinder (9) of a railway brake system.

Phase module assembly of a multi-phase inverter

Abstract: A phase module assembly includes a first flat laminated busbar elongated along a first direction, including a positive layer, a negative layer, and a load layer that is configured to be conductively coupled with a load. The first flat laminated busbar is conductively coupled to a second flat laminated busbar extending in a plane that is orthogonal to the first direction. The second flat laminated busbar is conductively coupled with a power source of direct current. The phase module assembly also includes one or more switches conductively coupled with internal terminal connectors of the first flat laminated busbar and configured to convert the direct current into one phase of a multi-phase alternating current, and to output the phase to the load. The phase module assembly also includes one or more capacitors mechanically mounted on and conductively coupled with the second flat laminated busbar.

Drilling device for machining tubes in tube sheets in a radioactive environment

Abstract: The present disclosure relates to a drilling device for machining tubes in tube sheets of heat exchangers in a radioactive environment A retaining plate is clampable in the tubes with at least two retaining fingers on a first side and a first drive, which drives a tool shaft, is arranged on a second side A tool chuck on a first end side of the tool shaft is connected detachably to the latter, wherein a forward feed of the tool shaft is brought about by a feed device In addition, the tool chuck is unlockable from the tool shaft by way of an unlocking instrument and the unlocking instrument is controllable by a remote-control device

Mechanically activated cam extension cylinder

Abstract: A brake actuator for a brake rigging in a railway brake system includes a brake cylinder; a piston rod disposed on the brake cylinder and connected to a piston assembly in the brake cylinder, the piston rod being configured to be moved by the piston assembly in a reciprocal axial motion and including at least one lateral protrusion extending therefrom; and an extension cylinder disposed on the brake cylinder at least partially surrounding the piston rod, the extension cylinder including at least one cam surface engaged by the at least one lateral protrusion of the piston rod. The extension cylinder is configured to be connected to a hand brake mechanism and to be actuated by the hand brake mechanism to rotate such that the cam surface engages the lateral protrusion of the piston rod to cause the piston rod to move to the extended position.