scholarly journals MAINTENANCE OF VARIOUS REACTOR TYPES

1957 ◽  
Author(s):  
B.D. Draper
Keyword(s):  
Reactor Types

Fuel Cycle Incentives for Market Introduction of New Reactor Types in Europe

2006 ◽  
pp. 63-66
Author(s):  
Aliki Van Heek ◽  
Frodo Klaassen ◽  
Frederic Blom
Keyword(s):  
Fuel Cycle ◽  
Reactor Types

ASTEC: An Integral Code for Simulation of Severe Light Water Reactor Accidents

2006 ◽  
Author(s):  
N. Reinke ◽  
K. Neu ◽  
H.-J. Allelein
Keyword(s):  
Fission Products ◽  
Feasibility Studies ◽  
Current Status ◽  
Light Water ◽  
Fast Running ◽  
Severe Accidents ◽  
Loss Of Coolant Accident ◽  
Station Blackout ◽  
Water Reactors ◽  
Reactor Types

The integral code ASTEC (Accident Source Term Evaluation Code) commonly developed by IRSN and GRS is a fast running programme, which allows the calculation of entire sequences of severe accidents (SA) in light water reactors from the initiating event up to the release of fission products into the environment, thereby covering all important in-vessel and containment phenomena. Thus, the main fields of ASTEC application are intended to be accident sequence studies, uncertainty and sensitivity studies, probabilistic safety analysis level 2 studies as well as support to experiments. The modular structure of ASTEC allows running each module independently and separately, e.g. for separate effects analyses, as well as a combination of multiple modules for coupled effects testing and integral analyses. Among activities concentrating on the validation of individual ASTEC modules describing specific phenomena, the applicability to reactor cases marks an important step in the development of the code. Feasibility studies on plant applications have been performed for several reactor types such as the German Konvoi PWR 1300, the French PWR 900, and the Russian VVER-1000 and −440 with sequences like station blackout, small- or medium-break loss-of-coolant accident, and loss-of-feedwater transients. Subject of this paper is a short overview on the ASTEC code system and its current status with view to the application to severe accidents sequences at several PWRs, exemplified by selected calculations.

scholarly journals Investigation of Corrosion Resistance of Alloys with Potential Application in Supercritical Water-cooled Nuclear Reactors

2019 ◽  
Vol 63 (2) ◽  
pp. 328-332 ◽  
Author(s):  
Ákos Horváth ◽  
Attila R. Imre ◽  
György Jákli
Keyword(s):  
Corrosion Resistance ◽  
Supercritical Water ◽  
Power Plants ◽  
Fuel Cladding ◽  
Pressurized Water ◽  
Water Reactors ◽  
Reactor Types ◽  
Materials Used ◽  
Supercritical Water Cooled Reactor ◽  
Nuclear Applications

The Supercritical Water Cooled Reactor (SCWR) is one of the Generation IV reactor types, which has improved safety and economics, compared to the present fleet of pressurized water reactors. For nuclear applications, most of the traditional materials used for power plants are not applicable, therefore new types of materials have to be developed. For this purpose corrosion tests were designed and performed in a supercritical pressure autoclave in order to get data for the design of an in-pile high temperature and high-pressure corrosion loop. Here, we are presenting some results, related to corrosion resistance of some potential structural and fuel cladding materials.

Reactor Design for Complex Reactions

2001 ◽  
Author(s):  
L. K. Doraiswamy
Keyword(s):  
Batch Reactor ◽  
Plug Flow ◽  
Reaction Network ◽  
Reactor Design ◽  
Batch Reactors ◽  
Complex Reaction ◽  
Mixed Flow ◽  
Flow Reactors ◽  
Design Procedures ◽  
Reactor Types

Procedures were formulated in Chapter 5 for treating complex reactions. We now turn to the design of reactors for such reactions. Continuing with the ethylation reaction, we consider the following reactor types for which design procedures were formulated earlier in Chapter 4 for simple reactions: batch reactors, continuous stirred reactors (or mixed-flow reactors), and plug-flow reactors. However, we use the following less formal nomenclature: A = aniline, B = ethanol, C = monoethyaniline, D = water, E = diethylaniline, F = diethyl ether, and G = ethylene. The four independent reactions then become Using this set of equations as the basis, we now formulate design equations for various reactor types. Detailed expositions of the theory are presented in a number of books, in particular Aris (1965, 1969) and Nauman (1987). Consider a reaction network consisting of N components and M reactions. A set of N ordinary differential equations, one for each component, would be necessary to mathematically describe this system. They may be concisely expressed in the form of Equation 5.5 (Chapter 5), or . . . d(cV)/dt = vrV (11.1) . . . The use of this equation in developing batch reactor equations for a typical complex reaction is illustrated in Example 11.1.

scholarly journals Thermal and Torrefaction Characteristics of a Small-Scale Rotating Drum Reactor

Processes ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 489
Author(s):  
Nitipong Soponpongpipat ◽  
Suwat Nanetoe ◽  
Paisan Comsawang
Keyword(s):  
Heat Loss ◽  
Small Scale ◽  
Reactor Wall ◽  
Energy Yield ◽  
Exhaust Gas ◽  
Mass Yield ◽  
Rotating Drum ◽  
Reactor Types ◽  
Purge Gas ◽  
Rotating Drum Reactor

The small-scale rotating drum reactor (SS-RDR) was designed and constructed without using purge gas for the purpose of household application. The thermal and torrefaction characteristics of SS-RDR were studied and compared with other reactor types. It was found that the heat loss at the reactor wall and heat loss from exhaust gas of the SS-RDR were in the range of 6.3–12.4% and 27.9–42.8%, respectively. The increase of flue gas temperature resulted in the decrease of heat loss at the reactor wall and the increase of heat loss from exhaust gas. The heating rate of the SS-RDR was in the range of 7.3–21.4 °C/min. The higher heating value (HHV) ratio, mass yield, and energy yield ofthe SS-RDR were in the range of 1.2–1.6, 35.0–81.0%, and 56.2–96.5%, respectively. A comparison of torrefaction characteristics of various reactor types on HHV ratio-mass yield-iso-energy yield diagram indicated that the torrefaction characteristics of the SS-RDR were better than that of the rotating drum reactor with purge gas.

scholarly journals EVALUATION METRICS APPLIED TO ACCIDENT TOLERANT FUEL CLADDING CONCEPTS FOR VVER REACTORS

2016 ◽  
Vol 4 ◽  
pp. 89 ◽  
Author(s):  
Martin Sevecek ◽  
Mojmir Valach
Keyword(s):  
Severe Accident ◽  
Evaluation Metrics ◽  
Development Phase ◽  
Fuel System ◽  
Fuel Cladding ◽  
High Interest ◽  
Severe Accidents ◽  
Time Period ◽  
Fukushima Daiichi ◽  
Reactor Types

Enhancing the accident tolerance of LWRs became a topic of high interest in many countries after the accidents at Fukushima-Daiichi. Fuel systems that can tolerate a severe accident for a longer time period are referred as Accident Tolerant Fuels (ATF). Development of a new ATF fuel system requires evaluation, characterization and prioritization since many concepts have been investigated during the first development phase. For that reason, evaluation metrics have to be defined, constraints and attributes of each ATF concept have to be studied and finally rating of concepts presented. This paper summarizes evaluation metrics for ATF cladding with a focus on VVER reactor types. Fundamental attributes and evaluation baseline was defined together with illustrative scenarios of severe accidents for modeling purposes and differences between PWR design and VVER design.

Business strategy and tax aggressiveness in Brazil

2019 ◽  
Vol 12 (4) ◽  
pp. 522-535
Author(s):  
Antonio Lopo Martinez ◽  
Bruno Afonso Ferreira
Keyword(s):  
Business Strategy ◽  
Stock Exchange ◽  
Content Type ◽  
Tax Aggressiveness ◽  
Strategy Type ◽  
Clear Result ◽  
The Usa ◽  
Reactor Types ◽  
Using Data ◽  
The Relationship

Purpose The purpose of this paper is to analyse the relationships between company business strategy type and tax aggressiveness for companies listed on the Brazilian Bovespa stock exchange. Design/methodology/approach Following the concepts of Miles and Snow (1978, 2003), we classified company strategies into four types, analyser, defender, prospector and reactor, using data from 2012 to 2016. The authors excluded financial companies due to a differential tax regime. Next, prospector and defender companies were identified, and the relationship of these strategies with tax aggressiveness assessed using regression analysis; analyser and reactor types were not included as these are defined as a combination of the prospector and defender type, or non-strategic, respectively. To assess aggressiveness, the authors used effective tax rates on corporate profits, as well as a metric that captures tax burden in terms of all taxes paid by a company. Findings Most Brazilian companies were analysers (76.66 per cent), with prospector companies being a minority, and defenders representing a little over 21 per cent. Unlike the findings of Higgins et al. (2015), the authors found that defender companies also have a tendency to practice aggressive tax planning. Practical implications The authors found the Brazilian defender companies similar to prospectors, tended to be more tax aggressive or to take higher tax risks. Thus, findings in economies such as the USA may not be generalizable to other countries, such as Brazil, Russia, India or China (i.e. the BRICs), for example. The particularities of each country, such as ease of access to the capital market, tax deductibility of investment in research and development and legal issues must be considered before applying generalized prognostics. Originality/value This paper offers original empirical evidence from Brazil of the relationship between company strategy type and the tax aggressiveness, offering a clear result that differs in part from results from American companies. It therefore encourages further studies on this topic.

scholarly journals Electrochemical Reactors for CO2 Conversion

Catalysts ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 473 ◽  
Author(s):  
Roger Lin ◽  
Jiaxun Guo ◽  
Xiaojia Li ◽  
Poojan Patel ◽  
Ali Seifitokaldani
Keyword(s):  
Carbon Capture ◽  
Performance Metrics ◽  
Co2 Reduction ◽  
Reduction Reaction ◽  
Carbon Markets ◽  
Industrial Processing ◽  
Carbon Capture And Utilization ◽  
Co2 Diffusion ◽  
Challenges And Opportunities ◽  
Reactor Types

Increasing risks from global warming impose an urgent need to develop technologically and economically feasible means to reduce CO2 content in the atmosphere. Carbon capture and utilization technologies and carbon markets have been established for this purpose. Electrocatalytic CO2 reduction reaction (CO2RR) presents a promising solution, fulfilling carbon-neutral goals and sustainable materials production. This review aims to elaborate on various components in CO2RR reactors and relevant industrial processing. First, major performance metrics are discussed, with requirements obtained from a techno-economic analysis. Detailed discussions then emphasize on (i) technical benefits and challenges regarding different reactor types, (ii) critical features in flow cell systems that enhance CO2 diffusion compared to conventional H-cells, (iii) electrolyte and its effect on liquid phase electrolyzers, (iv) catalysts for feasible products (carbon monoxide, formic acid and multi-carbons) and (v) strategies on flow channel and anode design as next steps. Finally, specific perspectives on CO2 feeds for the reactor and downstream purification techniques are annotated as part of the CO2RR industrial processing. Overall, we focus on the component and system aspects for the design of a CO2RR reactor, while pointing out challenges and opportunities to realize the ultimate goal of viable carbon capture and utilization technology.

Reactor Types and Safety

2021 ◽  
pp. 105-138
Author(s):  
Dirk Eidemüller
Keyword(s):  
Reactor Types
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