Analytical investigations of transitional operating modes of the second circuit of units at NPP with water-moderated reactors with consideration of control systems

A mathematical model for analysis of process parameters of equipment in the second circuit of nuclear power plants is presented, and the structure of the program and principles used for analysis of the equipment are described. A mathematical model for analysis of the deaerator and steam generator is described in detail. A computational analysis of several transitional modes, which is made possible on the basis of the mathematical model in question, is also presented in this paper, and a comparison is made with test data. __________ Translated from élektricheskie Stantsii, No. 3, March 2007, pp. 16–22.     

Effective lake basin management institutions: lessons from African lakes.

Weak or non-existent institutions are often cited as a major constraint facing management of many lake basins in Africa. By their nature lake basins cut across many sectoral and jurisdictional interests and therefore it is always the case that management of the basins is affected by actions within the various sectors and jurisdictions. Because of the complex nature of issues within lake basins, authority over management of lake basins is dispersed among several institutions, with no single institution having overall authority. Under these circumstances, a major challenge in lake basin management is how to ensure effective coordination among the various players. This paper reviews the situation of lake basin management at eight African lake basins and draws important lessons about lake basin management institutions. It is noted that fragmented approaches, lack of coordination across sectors, and lack of monitoring and enforcement are major institutional weaknesses. Also, it is observed that political will and commitment are essential for the management of African lake basins.     

Prospects for successful introduction of pisciculture to reservoirs intended for water-power generation

Successful introduction of pisciculture to reservoirs by the method of migratory fish-farm pasturing is described. __________ Translated from Gidrotekhnicheskoe Stroitel’stvo, No. 9, September 2007, pp. 36–40.     

WINDOW ON EASTERN EUROPE: Ethical Perceptions of Polish Business Students

An experienced educationalist comments on the views of top Polish business students on ethics in public life, government and business in modern Poland. The author is Wicklander Professor of Professional Ethics at DePaul University, Chicago, and also served recently as Visiting Fulbright Professor at the Adam Mickiewicz University in Poznan, Poland. He is currently President of the Society of Business Ethics in the USA.     

Three Level Rule Curve for Optimum Operation of a Multipurpose Reservoir using Genetic Algorithms

Finding optimal policies for real-life reservoir systems operation (RSO) is a challenging task as the available analytical methods cannot handle the arbitrary functions of the problem. Most of the methods employed are numerical or iterative type and are computer dependent. Since the computer resources in terms of memory and CPU time are limited efficient algorithms are necessary to deal with the RSO problems. In this paper we present a Genetic Algorithms (GA) optimized rule curve (RC) model for monthly operation of a multipurpose reservoir which maximizes hydropower produced while meeting the irrigation demands with a given reliability. Instead of the usual single target storage for each period the proposed model considers three sets of target storages, namely dry, normal, and wet storages, based on the beginning of the period storage level. The reservoir considered is Bhadra Multipurpose Reservoir, in the state of Karnataka, India, which supplies water to irrigation fields through two canals while generating hydropower with turbines installed at each of the canal heads and at the river bed. Optimization ability and robustness of GA-RC approach are ascertained through simulation with a different inflow sequence for which global optimum is computed using Dynamic Programming. Further, a 15 year real-time simulation of the reservoir using historical inflows and demands showed significant improvement in the benefit, i.e. power produced, without compromising on the irrigation demands throughout the operation period.

     

Burst Detection by Water Demand Nowcasting Based on Exogenous Sensors

Bursts of drinking water pipes not only cause loss of drinking water, but also damage below and above ground infrastructure. Short-term water demand forecasting is a valuable tool in burst detection, as deviations between the forecast and actual water demand may indicate a new burst. Many of burst detection methods struggle with false positives due to non-seasonal water consumption as a result of e.g. environmental, economic or demographic exogenous influences, such as weather, holidays, festivities or pandemics. Finding a robust alternative that reduces the false positive rate of burst detection and does not rely on data from exogenous processes is essential. We present such a burst detection method, based on Bayesian ridge regression and Random Sample Consensus. Our exogenous nowcasting method relies on signals of all nearby flow and pressure sensors in the distribution net with the aim to reduce the false positive rate. The method requires neither data of exogenous processes, nor extensive historical data, but only requires one week of historical data per flow/pressure sensor. The exogenous nowcasting method is compared with a common water demand forecasting method for burst detection and shows sufficiently higher Nash-Sutcliffe model efficiencies of 82.7% - 90.6% compared to 57.9% - 77.7%, respectively. These efficiency ranges indicate a more accurate water demand prediction, resulting in more precise burst detection.

     

Research on Clay-Cement Concrete in Anti-Filtration Elements of Earth Dams at Freeze-Thaw Temperatures

Power Technology and Engineering - This article presents and analyzes the results of a study on the frost resistance of clay-cement concrete used for repairing the anti-filtration element of the...     

Repair of Welded Joints Made of Steel P91 (X10CrMoVNb9-1) by a Backing Run of the Selected Site with Heat Treatment

Power Technology and Engineering - The results of complex studies of welded joints made of steel P91 (X10CrMoVNb9-1) with repair welding performed in OAO VTI are presented. A control weld joint was...     

Updated Characteristics of Torrential Pools

Power Technology and Engineering - Advanced methods for determining the hydrological and geomorphological characteristics of torrential pools, which are important for the design of reliable and...     

Results of Processing Data from the Automated Seismometric Monitoring System of the Zeya HPP

Power Technology and Engineering - The results of processing annual data of the automated seismometric monitoring system (ASMS) of the Zeya HPP are presented. They are compared with the results of...