South-Western Sub-Centre: Chairman's address. The impact of nuclear power stations on the generating system

1960 ◽  
Vol 107 (32) ◽  
pp. 109
Author(s):  
A.G.R. Bell
Keyword(s):  
Nuclear Power ◽  
Power Stations ◽  
The Impact ◽  
Generating System

Thermo-Hydraulic Analysis in a Assembly Representative of a Feedwater Nozzle

2003 ◽  
Author(s):  
Xavier Boissiere ◽  
Christian Laine ◽  
Louis Doubliez
Keyword(s):  
Steam Generator ◽  
Nuclear Power ◽  
Thermal Loading ◽  
Thermal Stresses ◽  
Experimental Testing ◽  
Flow Behavior ◽  
Life Time ◽  
Technical Problems ◽  
Power Stations ◽  
The Impact

One of the ways to reduce costs in modern nuclear power stations is to increase the life time of the steam generator. Much research is being carried out to gain a better understanding of the mechanical and thermal loads, which are generally overestimated in the interest of safety. One of the main technical problems is the feedwater of the reactor at a relatively cold (40 °C) temperature into the hot steam generator (270 °C). The connection zone, i.e. where the cold pipe is connected to the steam generator, is protected by an annulus inside the feedwater nozzle to reduce the thermal stresses. We have to identify the thermo-hydraulic behavior in that zone in order to accurately assess thermal information. This will give reliable boundary conditions for thermo-mechanical calculations. The configuration of the flows is a superposition of well known elementary fluid mechanic problems which interact strongly. No databases are available for this typical configuration, so we need to qualify the flow before using CFD modelisations. Therefore, a specific experimental testing bench was developed. In this paper, we focus our attention on the understanding of the flow in the one eyed cavity. PIV measurements allows us to identify the flow behavior. Our hypothesizes are demonstrated by a frequencies analysis, and finally confirmed with a numerical model. We also present and discuss the impact on a low thermal loading.

Safety Performance Evaluation of Nuclear Power Station Containment

2014 ◽  
Vol 672-674 ◽  
pp. 418-421
Author(s):  
Yu Lan Wang
Keyword(s):  
Nuclear Power Station ◽  
Nuclear Power ◽  
Clean Energy ◽  
Safety Performance ◽  
Power Station ◽  
The Public ◽  
Power Stations ◽  
The World ◽  
Nuclear Events ◽  
The Impact

Nuclear energy as an economical, safe and clean energy is being increasingly concerned, and nuclear power stations have also been widely built in the world. However, because of the impact from nuclear events, the safety of nuclear power station has been suspected by the public. First, the development situation of the nuclear power station in the world is described. Then the nuclear power station containment is introduced. Meanwhile, the safety performance of nuclear power station containment under external events are analyzed. Some advices on guaranteeing the security work of nuclear power station containment are given.

An evaluation of the equipment tagging process in nuclear power stations

1983 ◽  
Author(s):  
Peter Doyle ◽  
Lothar Schroeder ◽  
Stephen Brewer
Keyword(s):  
Nuclear Power ◽  
Power Stations

Overcoming stereotypes of renewable energy

2019 ◽  
pp. 124-136
Author(s):  
Victor D. Gazman
Keyword(s):  
Renewable Energy ◽  
Empirical Analysis ◽  
Energy Generation ◽  
New Paradigm ◽  
Financial Instrument ◽  
Promising Direction ◽  
Investment Projects ◽  
Power Stations ◽  
New Generation ◽  
The Impact

The article considers prerequisites for the formation of a new paradigm in the energy sector. The factors that may affect the imminent change of leadership among the energy generation are analyzed. The variability of the projects of creation and functioning of power stations is examined. The focus is made on problematic aspects of the new generation, especially, storage and supply of energy, achieving a system of parity that ensures balance in pricing generations. The author substantiates the principles of forming system of parities arising when comparing traditional and new generations. The article presents the results of an empirical analysis of the 215 projects for the construction of facilities for renewable energy. The significance and direction of the impact of these factors on the growth in investment volumes of transactions are determined. The author considers leasing as an effective financial instrument for overcoming stereotypes of renewable energy and as a promising direction for accelerated implementation of investment projects.

Environmental Protection Meets Security of Electricity Supply

2021 ◽  
pp. 1-18
Author(s):  
Ilina Cenevska
Keyword(s):  
Environmental Protection ◽  
Nuclear Power ◽  
Habitats Directive ◽  
Electricity Supply ◽  
The European Union ◽  
Power Stations ◽  
Court Of Justice ◽  
National Energy Policy ◽  
The Relationship ◽  
Practical Implications

Abstract This case comment explores the relationship between two intertwined objectives – ensuring security of electricity supply and environmental protection – in the context of the judgment of the Court of Justice of the European Union in Inter-Environnement Wallonie ASBL and Bond Beter Leefmilieu Vlaanderen ASBL v. Conseil des ministres. The analysis focuses on the application of the Environmental Impact Assessment Directive and the Habitats Directive to the facts of the case, which concerns the extension by a ten-year period of the operation of two Belgian nuclear power stations (Doel 1 and Doel 2) as part of a national energy policy strategy to ensure the security of Belgium's electricity supply. The case comment also considers the legal and practical implications that arise as a result of employing the ‘security of electricity supply’ exemption to enable derogation from the requirements of the aforementioned Directives in circumstances where a Member State considers the security of its electricity supply to be under threat.

Evaluation of the residual stress in stainless steel 304L hydraulically expanded joints

2020 ◽  
pp. 095440892096401
Author(s):  
Ying Hong ◽  
Xuesheng Wang ◽  
Yan Wang ◽  
Zhao Zhang ◽  
Yong Han
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Yield Strength ◽  
Residual Stresses ◽  
Heat Exchangers ◽  
Nuclear Power ◽  
The Finite Element Method ◽  
Power Stations ◽  
Stainless Steel 304 ◽  
Initial Clearance

Stainless steel 304 L tubes are commonly used in the fabrication of heat exchangers for nuclear power stations. The stress corrosion cracking (SCC) of 304 L tubes in hydraulically expanded tube-to-tubesheet joints is the main reason for the failure of heat exchangers. In this study, 304 L hydraulically expanded joint specimens were prepared and the residual stresses of a tube were evaluated with both an experimental method and the finite element method (FEM). The residual stresses in the outer and inner surfaces of the tube were measured by strain gauges. The expanding and unloading processes of the tube-to-tubesheet joints were simulated by the FEM. Furthermore, an SCC test was carried out to verify the results of the experimental measurement and the FEM. There was good agreement between the FEM and the experimental results. The distribution of the residual stress of the tube in the expanded joint was revealed by the FEM. The effects of the expansion pressure, initial tube-to-hole clearance, and yield strength of the tube on the residual stress in the transition zone that lay between the expanded and unexpanded region of the tube were investigated. The results showed that the residual stress of the expanded joint reached the maximum value when the initial clearance was eliminated. The residual stress level decreased with the decrease of the initial tube-to-hole clearance and yield strength. Finally, an effective method that would reduce the residual stress without losing tightness was proposed.

scholarly journals The Environmental Effects of the April 2020 Wildfires and the Cs-137 Re-Suspension in the Chernobyl Exclusion Zone: A Multi-Hazard Threat

Atmosphere ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 467
Author(s):  
Rocío Baró ◽  
Christian Maurer ◽  
Jerome Brioude ◽  
Delia Arnold ◽  
Marcus Hirtl
Keyword(s):  
Air Quality ◽  
Nuclear Power ◽  
Transport Model ◽  
Atmospheric Transport ◽  
Point Of View ◽  
Plume Dispersion ◽  
Exclusion Zone ◽  
Fire Plume ◽  
Mean Values ◽  
The Impact

This paper demonstrates the environmental impacts of the wildfires occurring at the beginning of April 2020 in and around the highly contaminated Chernobyl Exclusion Zone (CEZ). Due to the critical fire location, concerns arose about secondary radioactive contamination potentially spreading over Europe. The impact of the fire was assessed through the evaluation of fire plume dispersion and re-suspension of the radionuclide Cs-137, whereas, to assess the smoke plume effect, a WRF-Chem simulation was performed and compared to Tropospheric Monitoring Instrument (TROPOMI) satellite columns. The results show agreement of the simulated black carbon and carbon monoxide plumes with the plumes as observed by TROPOMI, where pollutants were also transported to Belarus. From an air quality and health perspective, the wildfires caused extremely bad air quality over Kiev, where the WRF-Chem model simulated mean values of PM2.5 up to 300 µg/m3 (during the first fire outbreak) over CEZ. The re-suspension of Cs-137 was assessed by a Bayesian inverse modelling approach using FLEXPART as the atmospheric transport model and Ukraine observations, yielding a total release of 600 ± 200 GBq. The increase in both smoke and Cs-137 emissions was only well correlated on the 9 April, likely related to a shift of the focus area of the fires. From a radiological point of view even the highest Cs-137 values (average measured or modelled air concentrations and modelled deposition) at the measurement site closest to the Chernobyl Nuclear Power Plant, i.e., Kiev, posed no health risk.

scholarly journals Aircraft Impact Effects on an Aged NPP

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 816
Author(s):  
Rosa Lo Frano
Keyword(s):  
Nuclear Power ◽  
Military Aircraft ◽  
Residual Resistance ◽  
Plant Safety ◽  
Need To Evaluate ◽  
Target Wall ◽  
Impact Area ◽  
Wall Perforation ◽  
The Impact ◽  
Loss Of Strength

The impact of an aircraft is widely known to be one of the worst events that can occur during the operation of a plant (classified for this reason as beyond design). This can become much more catastrophic and lead to the loss of strength of/collapse of the structures when it occurs in the presence of ageing (degradation and alteration) materials. Therefore, since the performance of all plant components may be affected by ageing, there is a need to evaluate the effect that aged components have on system performance and plant safety. This study addresses the numerical simulation of an aged Nuclear Power Plant (NPP) subjected to a military aircraft impact. The effects of impact velocity, direction, and location were investigated together with the more unfavorable conditions to be expected for the plant. The modelling method was also validated based on the results obtained from the experiments of Sugano et al., 1993. Non-linear analyses by means of finite element (FE) MARC code allowed us to simulate the performance of the reinforced concrete containment building and its impact on plant availability and reliability. The results showed that ageing increases a plant’s propensity to suffer damage. The damage at the impact area was confirmed to be dependent on the type of aircraft involved and the target wall thickness. The greater the degradation of the materials, the lower the residual resistance capacity, and the greater the risk of wall perforation.

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