Investigation of flow and heat transfer in a large-scale spent nuclear fuel cooling pond

The recent focus on nuclear power has led to the need for more efficient and economical methods of operating the Spent Nuclear Fuel (SNF) cooling ponds as well as complying with the strict safety and environmental legislations imposed by the IAEA and the UK Government. Like many other industrial applications, the design and operation of the SNF cooling ponds have evolved from experience; trial and error. Since the stored materials in such ponds are radioactive, it is very difficult to perform experimental studies. As a result, a rigorous scientific study based on fundamental principles has to be performed. The present research explores analytically and numerically the main processes that take place across the pond installation. The body of the present study includes four main parts: the first part is involved in modelling the heat loss from the free water surface, mainly due to evaporation, using analytical and single-phase numerical approaches, which represents a critical factor in the modelling of the large-scale cooling ponds. The predicted results were in good agreement with experimental data available in open literature. In the second part, a thermal model using Microsoft Excel spreadsheet was developed for the cooling pond based on an analytical approach. The well-mixed hypothesis was adopted to describe the water zone as well as the humid air zone. Also, the ventilation system was considered within this model. The developed spreadsheet tool was validated against reliable data available for Maine Yankee pool as well as temperature measurements collected from the Sellafield site. This spreadsheet tool is able to describe the transient behaviour with low computational cost, allowing many "what-if" scenarios to be rapidly investigated. In the third part, Computational Fluid Dynamics (CFD) was used to model the cooling pond at both macro and micro levels. The macro level modelling involved in developing a CFD model for Sellafield’s cooling pond where the fuel regions were approximated to porous medium. The computational domain was produced for the water zone only, where the humid air zone was introduced to the model by coupling of the spreadsheet model with the CFD model. This model was validated and used to examine the distribution of water temperature to confirm the reliability of the adopted well-mixed approach in the analytical model. The outcomes from the CFD and spreadsheet models were used to provide some boundary conditions to the micro-level model of the fuel assemblies. The modelling methodology of the fuel assemblies was partially validated with experimental data for heat transfer around vertical cylinder. The maximum temperature of the water within the rack arrangement was determined under various conditions and a correlation was proposed. Finally, a sensitivity study was performed using Taguchi method and the statistical method of ANOVA to assess the influence of the cooling systems as well as the environmental conditions on the thermal performance of the cooling pond. The spreadsheet model was implemented to carry out the calculations. The outcomes from this study were presented in the form of recommendations that may be able to aid the organisation to manage their cooling pond more efficiently and safely during the normal operating conditions as well as recovery from an accident scenario

Data communication between Distributed Control System, Serial Device and Android App

Nowadays, the world is searching for new technologies or new methods to make the controlling process more automated or easier to access. This search has widely increased to reach such technology starting from HART technology and passing through Asset Management system (AMS). So developing such technology will open the field for another technologies to be introduced in the industry. One of those technologies is Android. Many of the machines in the plants have been purchased with its own control system , this system consider a remote system comparing with one in the control room which in most of the time the control system is Distributed Control System (DCS). This remote system is connected the control system through alarms and trips only. So Data communication between the remote system (Serial Device) and DCS was a must to reach any readings from the remote system. This data communication can be achievable through the Modbus. To reach more and more automated plants, the android technology has to take place in such industry which you can receive the real-time reading of any machine in the plant on your android platform (Mobile phone or Tablet). And the methodology of such technology can be achieved by many steps, starting with creating a database of readings of the DCS, this database has to be an online database to be able to retrieve data from it as long as you want, and the final part is to design an android application that responsible to retrieve the data from the online database. Such technology makes you to reach the readings of the plant from anywhere at any time. This technology is a step to create and fully automated plants, and you can supervise the plant from anywhere as long you an internet connectio

Planning Coastal Areas and Waterfronts for Adaptation to Climate Change in Developing Countries

AbstractMost of developing countries suffer from climate change impacts. Scenarios projected increase intensity and frequency of climate hazards especially sea level rise and storm surge. Coastal areas in developing countries already suffer coastal erosion in developing countries situation of coastal areas is the worst due to human-induced pressures on environmental and absence of sustainable development. The inevitability of climate change highlights the importance of adaptation. Climate change adaptation through land use planning strategies increase the resilience to risks, enhance economic and social conditions of community and safeguarding resources for next generations. Mainstreaming the UN millennium development goals in climate change adaptation process through sustainable planning of coastal areas will maximize the benefits of the adaptation process. Land use planning adapt with sea level rise risks through use some strategies ranging between official or local plans, zoning, land subdivision and development controls, design guidelines, environmental review of development projects

Modelling and Experimental Characterization of Photovoltaic/Thermal Systems for Cooling and Heating of Buildings in different climate conditions

La integración de sistemas de fotovoltaicos/térmicos (PV/T) y un eficiente aire acondicionado en los edificios permite el suministro de calefacción, refrigeración y electricidad con una reducción de las emisiones de efecto invernadero. Las configuraciones de integración de: a) sistemas fotovoltaicos (PV) con enfriadores eléctricos refrigerados por aire y sistemas de bombas de calor aire-agua; b) sistemas fotovoltaicos/térmicos (PV/T) basados en aire con sistemas de bomba de calor aire-agua; y c) Los sistemas fotovoltaicos/térmicos de baja concentración (LCPV/T) con enfriadores de compresión y absorción tienen un gran potencial para aumentar la proporción de electricidad fotovoltaica in situ. La flexibilidad de incorporar energía LCPV/T para la red bidireccional de baja temperatura en distritos urbanos reduce las pérdidas térmicas y proporciona edificios de productores y consumidores (prosumidores). En comparación con la configuración típica del enfriador de compresión integrado fotovoltaico, la configuración propuesta de LCPV/T junto con los enfriadores de compresión y absorción reduce el período de recuperación en un 10-40% en el edificio de cajas en El Cairo. Sustituir la conexión a la red de agua del campus por el uso de bomba de calor reversible reduce en un 15-30% el coste operativo de refrigeración y calefacción en el edificio de cajas en España.The integration of photovoltaic/thermal (PV/T) and efficient air conditioning systems into buildings allows the provision of heating, cooling and electricity with a reduction in greenhouse emissions. The integration configurations of: a) photovoltaic (PV) systems with air-cooled electric chillers and air-to-water heat pump (HP) systems; b) air-based PV/T systems with air-to-water HP systems; c) Low concentrated photovoltaic/thermal systems (LCPV/T) with compression and absorption chillers; and d) LCPV/T coupled with water-to-water HP have a great potential in boosting the share of onsite PV-electricity. The flexibility of incorporating LCPV/T energy for the bidirectional low temperature network in urban districts reduces thermal losses and provides producer and consumer (prosumer) buildings. In comparison to the typical configuration of PV integrated compression chiller, the proposed configuration of LCPV/T coupled with the compression and absorption chillers reduces the payback period by 10-40% in the case building in Cairo. Substituting the connection to the campus water network with the use of reversibl

Ground Motion Spatial Incoherence, Its Modelling And Effects On Long Gravity Dams

Seismic design of concrete gravity dams is usually based on a two-dimensional analysis of one monolith, or slice. This analysis provides the basic information but neglects the interaction between adjacent dam monoliths and assumes uniformity of dam section, foundation properties and ground motions along the dam longitudinal axis. While the seismic response of gravity dams has been investigated in considerable detail, the effects of ground motion spatial incoherence on dam response have not been investigated to any great detail.;In this study, dam response to spatially variable seismic excitations is theoretically investigated. Deterministic and random representations of the space-time random field of the ground motion are included.;Available models for the spatial coherency function are critically reviewed and unified in a general model. This model agrees well with theoretical studies, coherency established for similar random fields, and data collected during recent earthquakes. Two novel simulation techniques for generating spatially multi-dimensional seismic motions are developed. These simulation techniques allow for the digital simulation of ground motions in the near and far fields of small and extended faults. They are computationally efficient and require the summation of cosine functions only.;For long dams, a simplified analytical model, complementary to the conventional two-dimensional analysis is formulated. Dam-reservoir-foundation interaction is accounted for including water viscosity and through-rock interaction of foundation elements. Both continuous and segmented dams are considered. An extensive parametric study is conducted and the relative importance of the main parameters is identified.;Responses of long structures to spatially incoherent ground motions are also derived in closed forms neglecting soil-structure interaction.;The results suggest that both spatial incoherence and wave passage effects can produce significant stresses on dams. The effects of spatial incoherence are qualitatively different and can be more important than those of fully correlated travelling waves. Dam response is considerably affected by the interaction with the foundation and the reservoir.;The formulations presented are quite general and may be equally applicable in response analysis of other structures subjected to similar random fields such as those of turbulent wind and sea waves

Rational Chebyshev functions with new collocation points in semi-infinite domains for solving higher-order linear ordinary differential equations

The purpose of this paper is to investigate the use of rational Chebyshev (RC) functions for solving higher-order linear ordinary differential equations with variable coefficients on a semi-infinite domain using new rational Chebyshev collocation points.  This method transforms the higher-order linear ordinary differential equations and the given conditions to matrix equations with unknown rational Chebyshev coefficients. These matrices together with the collocation method are utilized to reduce the solution of higher-order ordinary differential equations to the solution of a system of algebraic equations. The solution is obtained in terms of RC series. Numerical examples are given to demonstrate the validity and applicability of the method. The obtained numerical results are compared with others existing methods and the exact solution where it shown to be very attractive and maintains better accuracy

Assessment Of Knowledge, Attitudes, Perception And Barriers Towards Pharmacovigilance Activities Among Community Pharmacists And Final Year Pharmacy Students In Malaysia.

Tindak Balas Ubat Berbahaya (Adverse Drug Reactions, ADR) sering kali dikaitkan dengan kadar morbiditi dan mortaliti yang tinggi di serantau dunia. Adverse Drug Reactions (ADRs) are associated with a high rate of morbidity and mortality worldwide

An Overview on Evaluation of E-Learning/Training Response Time Considering Artificial Neural Networks Modeling

The objective of this piece of research is to interpret and investigate systematically an observed brain functional phenomenon which associated with proceeding of e-learning processes. More specifically, this work addresses an interesting and challenging educational issue concerned with dynamical evaluation of e-learning performance considering convergence (response) time. That's based on an interdisciplinary recent approach named as Artificial Neural Networks (ANNs) modeling. Which incorporate Nero-physiology, educational psychology, cognitive, and learning sciences. Herein, adopted application of neural modeling results in realistic dynamical measurements of e-learners' response time performance parameter. Initially, it considers time evolution of learners' experienced acquired intelligence level during proceeding of learning / training process. In the context of neurobiological details, the state of synaptic connectivity pattern (weight vector) inside e-learner's brain-at any time instant-supposed to be presented as timely varying dependent parameter. The varying modified synaptic state expected to lead to obtain stored experience spontaneously as learner's output (answer). Obviously, obtained responsive learner's output is a resulting action to any arbitrary external input stimulus (question). So, as the initial brain state of synaptic connectivity pattern (vector) considered as pre-intelligence level measured parameter. Actually, obtained e-learner’s answer is compatibly consistent with modified state of internal / stored experienced level of intelligence. In other words, dynamical changes of brain synaptic pattern (weight vector) modify adaptively convergence time of learning processes, so as to reach desired answer. Additionally, introduced research work is motivated by some obtained results for performance evaluation of some neural system models concerned with convergence time of learning process. Moreover, this paper considers interpretation of interrelations among some other interesting results obtained by a set of previously published educational models. The interpretational evaluation and analysis for introduced models results in some applicable studies at educational field as well as medically promising treatment of learning disabilities. Finally, an interesting comparative analogy between performances of ANNs modeling versus Ant Colony System (ACS) optimization presented at the end of this paper

Power Sharing Method Based on Droop Control for Three-Phase UPS Systems

The main objective of this paper is to improve the power sharing capability and to achieve synchronization between three-phase Uninterruptible power supply (UPS) units in the presence of load interruption. This paper presents a droop-controlled scheme in such a way that the computation of the instantaneous value of the active power and the reactive power are taken as feedback signals to the frequency and voltage restoration control system. The restored frequency and voltage are introduced to voltage controller circuit, which produces a suitable control signal to sinusoidal pulse width modulation circuit (SPWM). Thus producing a suitable trigger pulses to the inverter gate in order to guarantee synchronization between three-phase UPS units. Simulation of two UPS units with the same ratings (4 KW) are carried out using MATLAB. The results show the effectiveness of the proposed control system in achieving synchronization and improving the power sharing capability in the presence of load interruption. Keywords: Uninterruptible power supply; power sharing; parallel operation; droop control. DOI: 10.7176/JETP/9-4-02 Publication date: April 30th 201