Power Plants

Cs-137 is considered to be the most significant anthropogenic contributor to human dose and presents a particularly difficult remediation challenge after a dispersal following nuclear incident. The Chernobyl Nuclear Power Plant meltdown in April 1986 represents the largest nuclear accident in history and released over 80 PBq of Cs into the environment. As a result, much of the land in close proximity to Chernobyl, which includes the Polessie State Radioecology Reserve in Belarus, remains highly contaminated with Cs to such an extent they remain uninhabitable. Whilst there is a broad scale understanding of the depositional patterns within and beyond the exclusion zone, detailed mapping of the distribution is often limited. New developments in mobile gamma spectrometry provide the opportunity to map the fallout of Cs and begin to reconstruct the depositional environment and the long-term behaviour of Cs in the environment. Here, full gamma spectrum analysis using algorithms based on t...

... countries since many years ago and it is considered as one of the development indexes [1]. TheBOT contract is a contract in which the client, which usually is from government sector, assigns a private firm with the credit of executing a project or plan within a certain time. ...

Vertical cylindrical vessel-chambers as a part of coal — drying plants, whose purpose is to collect wastewater, are supported at 3 points in upper dish head area and are made of fine-grained Mn steel plates, joined by welding. Significant thinning and leaking in upper dish head area of the vessel occurred due to original design provoking an intensive abrasion, cracking and rupture. After reconstruction, in the upper zone of cylindrical shell, two new joints were made in sity by manual arc welding, with subsequent, local post-weld heat treatment. However, cracks appeared firstly in new welded zones in radial and axial joints, and then in zones of openings. Later, the similar failure features began to appear in the area of original welded joints. All of these cracks were repaired by properly specified technology. Unfortunately, after some period of exploitation the initiation of new cracks was observed, at first by the visual inspection. This problem was detected in the repaired areas...

The disposal of fly ash as a byproduct of thermic power stations, results in significant environmental problems. The leaching of coal fly ash during disposal is of concern for possible contamination, especially for the aquatic environment when ash is in contact with water. The aim of this study was to investigate the leaching behaviour of fly ashes currently disposed in Kemerkoy Power Plant (Turkey) fly-ash-holding pond. The studies were conducted with fly ashes from the electrostatic precipitators (fresh fly ash) and from the fly ash pond (pre-leached fly ash). The fly ashes has alkaline in nature and pH ranges between 11.9 to 12.2. The pre-leached fly ash exhibited lower EC values (7,400 µS) than the fresh fly ash (10,300 µS). In contrast to Fe and Pb, the elements such as Cr, Cd, Cu and Co did not leach from the fly ash. The Ca and Mn concentrations decreased with increasing temperature whereas, Na and K concentrations increased. The results showed that the most important effects of fly ash leaching were pH, Na, Ca, K, Fe, Mg, Mn and Pb.

This doctoral thesis represents a set of new ideas, methods and research re-sults related to improving the efficiency of functioning of ship power plants (SPP) of combined propulsion complexes (CPC). The main motivation for these studies is the existing current practice requests for the operation of the SPP CPC, such as: ensuring minimization of irreversible losses in the transmission of capac-ities from the SPP to the engines of the CPC; the need to improve the monitoring of the transfer of capacities in the SPP CPC with dynamic principles of retaining the vessel; increasing the operational reliability and strength of the SPP CPC; creation of new and improvement of existing decision support systems (DSS) during operation, research and design of the SPP CPC.
Based on the analysis of the existing state of the development of the SPP CPC, the following unresolved problems were found on the lines of propellers, in power systems of motors for thrusters and power distribution systems, which can be characterized as follows: reduction of propeller thrust and torque due to water flow perpendicular to the axis of the propeller caused by the flow from the vessel speed or flows from other engines with force in the direction of inflow due to the deflection of the propeller flow. This is often called a cross-combination of resistances; the presence of cavitation for heavy loads on the propellers leads to a reduction in pressure on the blade of the propeller and can occur during a small immersion of the propeller due to the movement of the ship across the waves; sudden drops of thrust and torque with the effect of hysteresis due to the large amplitude of the ship's motion perpendicular to the surface of the water; simulta-neous reduction of thrust and change of thrust direction due to interaction of the flow from the thruster to the hull (Coanda effect); loss of the thrust and reduction of thrust caused by the action of the propellant flow from one motor to adjacent motors; limitation of the increase in torque by the inductance of the motor with the prevention of damage to the mechanical part of the electric drive; limitation of the maximum power of the thruster, is taken into account when determining the overload capacity of the electric motor and frequency converter (FC); the absence of a control strategy for the thruster FC based on  variable speed governors which provide the transition of consumers, working on a constant power hyper-bola, to the torque or speed of rotation control mode; the need for Dynamic Posi-tioning (DP) systems to meet the quality management requirements encountered during the operational phase; unification of Power Management System (PMS) in a combination of functions in relation to others similar; the independence of PMS systems components from each other to the level of sensors; not only the reduc-tion in capacity based on the total design load, but also the load of an individual medium speed diesel generator (MSDG); compliance of the system with condi-tions increasing the load in terms of sufficiency to ensure normal operation in re-lation to any abnormal mode and non-overloading the ship electric power system (SEPS) in general.
The above problems directly led to the formulation of the main complex re-search task: the development of a DSS for the design, research and improvement of SPP CPC, consisting of three main tasks: the development of a monitoring system for degradation effects on the lines of propulsion flows of motors with the identification of relevant markers, the development of the strategy for all-mode power controllers, torque controllers and variable speed governors by the electric motors of the CPC thrusters and the development of the methodology for con-structing multi-criteria control strategies over power distribution of the SPP CPC.
As a result of solving the main and auxiliary tasks, the following scientific positions were obtained: improvement of the method of computational hydrody-namics is provided by using the distribution of the sought-for intensities of the degradation effects from the interaction of the propeller flows among themselves and the CPC body due to the use of piezoelectric sensors on the shaft lines of az-imuth thruster. Compensation of degradation effects is achieved by calculation of power flows from azimuth thrusters in the form of a power drive disc, which al-lows identifying turbulent regions with relative vortex viscosity coefficients μt/μw. Calculation of the components of the x-velocities at the intersection of the propel-ler flow along the axis of rotation with dimensions in units of the diameter of the DP propeller makes it possible to realize the method of surface-oriented averag-ing of the Reynolds-Navier-Stokes equation for mass transfer at the interface; limitations on power and torque on the shaft lines of the SPP CPC thruster of dynamically positioning vessels are provided by redistribution of the thrusts be-tween the thrusters or the reduction of the maximum load as part of the algo-rithm for distributing the thrust of the DP system due to the application of the strategy of full range speed governors in relation to operating conditions; for the first time, a three-level multi-criteria strategy for managing the distribution of en-ergy in the hybrid SPP CPC was developed by integrating the classical strategy of power distribution management with a strategy of control over the state of the MSDG and the degree of charge of the energy storage system alternative generat-ing element. The developed strategy differs from existing by higher speed detec-tion of risk of de-energization of ship electric power system, greater reliability and accuracy in determining the need for load reduction and the thruster speed of rotation fully integrated with variable speed governors and power supply system; for the first time, the DSS was created to study the ways of automating and com-puterizing the design and operation processes of the SPP CPC, which being based on theoretical, design and experimental methods, has enabled the introduction of a comprehensive substantiation, verification and self-testing of the developed components of the methodological and mathematical apparatus; for the first time, a physical model of a multifunctional CPC with a variable structure was created, which, in synergy with the solution of the problem of DSS development, allows iterative analysis of the structures of the SPP CPC with minimal initial data; the law of pulsations of thrusts on the lines of propeller shafts is established, which occur under conditions of interaction of several thrusters with each other and with the CPC body. In the process of studying the version of the configuration of a CPC with contra-rotating propellers (CRP) it was established that: 1) the rota-tion of the thruster body leads to the appearance of characteristic recirculation zones and changes in the velocity fields in its disk and differs by an increased de-gree of flow heterogeneity; 2) the characteristics of the thrust and the torque of the thruster differ significantly depending on the direction of rotation; 3) the pul-sation of the propeller thrust  of the azimuth thruster sharply increases with its rotation, and the most significant growth in pulsations occurs at the resonant fre-quencies of the interaction of the propeller flow of the azimuth thruster and the stationary one; the theory of non-stationary interaction of several propellers with each other has been developed, which made it possible to establish for the first time the following facts: 1) rotation of the thruster  leads to an increase in the ax-ial and tangential components of the thrusts and torques; 2) the operation of the azimuth thruster at large angles with respect to the stationary propeller results in the appearance of significant loads on the  thruster stock, which can be determi-native in terms of the strength of the structural components of the thruster, the presence of deformations of which has been experimentally established and con-firmed by calculation. Also, for the first time, the dependencies of the thrusts and torques of the azimuth thruster were determined as a result of the interaction of the propeller flow with the hull and the stock due to the occurrence of degrada-tion effects; for the first time, a simplified semi-empirical method for iterative progressively regressive parameterization of the SPP CPC was developed in off-design operation modes, which generalizes the previously relationship, which have been derived for thrusts and torques of co-axial CPP s in a homogeneous flow with ratios known from the theory of turbomachines for the case of interac-tion between the stationary propeller and the azimuth thruster. On the basis of this technique, a calculation method has been developed that makes it possible to accurately estimate the value of thrusts and torques of motors for azimuth thrust-ers in a wide range of operating conditions and the angles of flow deflection due to the influence of degradation effects that are substantially different from the de-sign ones. The necessity to take into account the influence of degradation effects on the lines of propeller shafts in the CRP Azipod® concept has been proved

The study area includes the Municipalities of Gela, Niscemi and Butera located in the South of Sicily, Italy. In 1990 it was declared Area at High Risk of Environmental Crisis. In 2000 part of it was designated as Gela Reclamation Site of National Interest, RSNI. The site includes a private industrial area, public and marine areas, for a total of 51 km(2). Gela populationin 2008 was 77,145 (54,774 in 1961). Sea level:46 m. Total area: 276 km(2). Grid reference: 37 degrees 4' 0" N, 14 degrees 15' 0" E. Niscemi and Butera are located border to Gela. Populations are respectively 26,541 and 5,063. Sea level respectively: 332 m and 402 m. Close to the city of Gela, the industrial area, operating since 1962, includes chemical production plants, a power station and an oil refinery plant, one of the larger in Europe, refining 5 millions tons of crude per year. From the beginning the workforces decreased from 7,000 to the current 3,000 units. Over the years, these industria...

In high pressure turbine the temperature of the steam will be in a range of 5400c – 5600c and the flow of the fluid flow will be subsonic and supersonic.  The pressure and temperature on the blade effects the surface of the blade, life cycle, deformation of the blade. In order to withstand blade at high pressure, temperatures, stresses and thermal loads the model of the blade is designed by introducing the cooling channels to the blade by supplying the cooling air through the rotor shaft which is extracted from the atmosphere and condenser to supply the coolant to the turbine blade. Using Grey cast iron material the blade profile can be able to withstand maximum pressure and temperatures and reduces the deformation levels. The aerodynamic profile, root notch and the shroud are designed using the CATIA v5 3D modeling software. The part is analysis with a material in ANSYS analysis software to observe the static structural, thermal and other required stresses at critical conditions in order to increase the life cycles and give better performance of the blade by using the Grey cast iron main high pressure steam turbine blade.

The study area includes the Municipalities of Gela, Niscemi and Butera located in the South of Sicily, Italy. In 1990 it was declared Area at High Risk of Environmental Crisis. In 2000 part of it was designated as Gela Reclamation Site of National Interest, RSNI. The site includes a private industrial area, public and marine areas, for a total of 51 km(2). Gela populationin 2008 was 77,145 (54,774 in 1961). Sea level:46 m. Total area: 276 km(2). Grid reference: 37 degrees 4' 0" N, 14 degrees 15' 0" E. Niscemi and Butera are located border to Gela. Populations are respectively 26,541 and 5,063. Sea level respectively: 332 m and 402 m. Close to the city of Gela, the industrial area, operating since 1962, includes chemical production plants, a power station and an oil refinery plant, one of the larger in Europe, refining 5 millions tons of crude per year. From the beginning the workforces decreased from 7,000 to the current 3,000 units. Over the years, these industrial activities have been a major source of environmental pollution. Extremely high levels of toxic, persistent and bio-accumulating chemical pollutants have been documented. Many relevant environmental and health data are available. Prior to the studies described in the present publication, their use in order to identify environmental pressures on health has been limited. Nevertheless, since several years different epidemiological studies have provided evidence of the occurrence of health outcomes significantly higher than in neighbouring areas and compared to regional data. In 2007 a Multidisciplinary Working Group has been established, to analyze the existing data on pollution-exposure-effect and to complete current knowledge on the cycle of pollutants, from migration in the environment to health impact. The present publication is a collection of contribution of this group of experts, supported by the following projects: Evaluation of environmental health impact and estimation of economic costs at of National Interest Remediation Sites coordinated by the Italian National Institute of Health on behalf of the Ministry for the Environment and Technical Assistance of WHO Health and Environment Centre to the Sicilian Region to develop plans for environmental remediation. Results describe the state of contamination of a variety of environmental matrices in the area. Other contributions are addressed to understanding action mechanisms of main pollutants and their environmental pathways, as well as to identifying crucial knowledge to be used for studying the environment-health relations. A specific attention has been paid to pollutants migration in the environment and to the potential exposure of the population. Appropriate markers of exposure and physiological changes are described and referred to the chemical substances identified in the environment in Gela. Details are given about the genotoxic and endocrine disrupting potential, and about the potential association between markers of exposure and diseases observed in excess in the same area. Indications to develop specific biomarkers for Index Substances and human biomonitoring surveys for populations exposed to environmental risk are presented and discussed. A specific multiple-exposure risk assessment procedure is proposed for Index Substances. Epidemiological studies useful to describe the health status of Gela population are summarized. One report deals with the occupational and residential analyses of male petrochemical workers, born in Sicily, employed from 1960 to the end of 1993, followed up for mortality from 1960 to 2002. Major findings were amarked healthy worker effect and an increased lung cancer risk for residence in Gela. The analyses of death certificates from 1995 to 2002 and of hospital discharge records from 2001 to 2007 confirm the potentialities of these current statistics for ecological studies: they depict the poor health conditions of Gela residents compared to other neighbouring municipalities in a 40-km range. Infact, the overall mortality rate for tumor and non-tumor causes in Gela is significantly higher for both sexes, and this is shown also in the Municipality of Niscemi, especially among the male population. Hospital discharge records for tumor causes, but especially for non-tumor ones, exceeded expectations in both genders and must be analysed taking into consideration the attraction exerted on the surrounding areas by the Gela hospital. Data analysis according to 5 ten-year birth cohorts, from 1915 to 1964, shows a decreasing mortality trend, whereas the increase of hospital admissions is confirmed in the younger generations. The issue of birth defects is recurrent in this area: a suitable register is lacking so that updated figures cannot be presented. However, data previously published showed excesses of prevalence rates of several specific birth defects, mainly urinary tract and genital anomalies. The same is worth in the incidence of new cancer cases since the development of a proper register is yet in progress. Tools and methodologies that should be applied in Gela to study environment-health relations are proposed, like Life Cycle Analysis, dispersion patterns and an air-quality monitoring system. A conceptual model considering all pollution sources and different exposure patterns present in Gela, developed by the Multidisciplinary Working Group, is presented. Among the activities carried out by regional authorities, two Reports on the Regional Environment Protection Agency monitoring activity and on the EU Program SEARCH, School Environment And Respiratory Health in Children, are included. A section is devoted to understanding what is necessary to build an epidemiological monitoring system specifically designed for this area, in order to keep under permanent control environment-related health outcomes. This includes a systematic and continuative collection, storage and analysis of environmental-induced diseases, exposure and risk factors, as well as a timely dissemination of those information to the decision-makers. The final article describes the research activities carried out to design and implement a human biomonitoring survey in the area. These activities included relation-building with local communities, information collection, meetings, involvement of stake-holders. This experience will reach its climax when the community-exposure data feedback will be provided, because it will mark the consolidation of present knowledge and its possible processing into public health action plans. The present publication can represent an important tool and a model for all interest-bearers to assess environmental pollution impacts on human health in contaminated areas. A local system to assess the relation between environmental pollution and population health is therefore urgently needed to provide risk managers with ad-hoc tools to improve environmental protection and prevent further risks for local communities.