On Features of Thermal Design of Passive Evaporation-and-Condensation Systems of Reactor Thermal Shielding

2014 ◽  
Author(s):  
A. N. Gershuni ◽  
A. P. Nishchik ◽  
E. N. Pis'mennyi ◽  
V. G. Razumovskiy ◽  
I. L. Pioro
Keyword(s):  
Heat Removal ◽  
Fission Products ◽  
Thermal Design ◽  
Nuclear Engineering ◽  
Main Design ◽  
Evaporation And Condensation ◽  
The Third ◽  
Design Variables ◽  
Containment Shell ◽  
Further Development

Further development of nuclear engineering is inseparably linked with the requirement of vast application of the passive systems of heat removal running without human intervention. Creation of such systems is impossible, if only conventional engineering solutions are used. As known, to prevent propagation of the fission products into the environment there are three safety barriers. To provide operation of the third safety barrier (containment shell), in particular, of the reactor cavities both in operational and emergency modes a passive evaporation-and-condensation (EC) system of heat removal is proposed. The features of thermal design of the EC systems for thermal shielding of the reactor cavities are considered. They make it possible to determine the optimal main design variables of the EC systems and prove reasonability and efficiency of their application. The performed study validates engineering feasibility of an efficient EC system for thermal shielding of the reactor equipment.

Good Governance

2019 ◽  
Author(s):  
Henk Addink
Keyword(s):  
South Africa ◽  
Rule Of Law ◽  
Good Governance ◽  
National Level ◽  
Administrative Law ◽  
Modern State ◽  
The Rule Of Law ◽  
The Third ◽  
Legal Perspective ◽  
Further Development

The pivotal aim of this book is to explain the creation, development, and impact of good governance from a conceptual, principal perspective and in the context of national administrative law. Three lines of reasoning have been worked out: developing the concept of good governance; specification of this concept by developing principles of good governance; and implementation of these principles of good governance on the national level. In this phase of further development of good governance, it is important to have a clear concept of good governance, presented in this book as the third cornerstone of a modern state, alongside the concepts of the rule of law and democracy. That is a rather new national administrative law perspective which is influenced by regional and international legal developments; thus, we can speak about good governance as a multilevel concept. But the question is: how is this concept of good governance further developed? Six principles of good governance (which in a narrower sense also qualify as principles of good administration) have been further specified in a systematic way, from a legal perspective. These are the principles of properness, transparency, participation, effectiveness, accountability, and human rights. Furthermore, the link has been made with integrity standards. The important developments of each of these principles are described on the national level in Europe, but also in countries outside Europe (such as Australia, Canada, and South Africa). This book gives a systematic comparison of the implementation of the principles of good governance between countries.

History of the State and Law of Russia. Volume 3

2021 ◽  
Author(s):  
Aleksandr Smykalin ◽  
Tat'yana Bazhenova ◽  
Natal'ya Zipunnikova ◽  
Vladimir Motrevich ◽  
Elena Sokolova ◽  
...  
Keyword(s):  
Legal System ◽  
The State ◽  
Chronological Order ◽  
Soviet State ◽  
The Third ◽  
History Of ◽  
Further Development

The third part of the anthology contains materials reflecting the periods of formation of a limited monarchy in Russia and the further development of the legal system; the formation and development of the Soviet state and law in the XX century. The documents are arranged in chronological order.

Multiobjective Design Optimization of Microchannel Cooling System Using High Performance Thermal Vias in LTCC Substrates

2013 ◽  
Vol 10 (1) ◽  
pp. 40-47 ◽  
Author(s):  
Aparna Aravelli ◽  
Singiresu S. Rao ◽  
Hari K. Adluru
Keyword(s):  
Heat Transfer ◽  
Design Optimization ◽  
High Performance ◽  
Cooling System ◽  
Optimization Technique ◽  
Optimization Theory ◽  
Thermal Design ◽  
Design Variables ◽  
Microchannel Cooling ◽  
Multiobjective Design

Increased heat generation in semiconductor devices for demanding applications leads to the investigation of highly efficient cooling solutions. Effective options for thermal management include passing of cooling liquid through the microchannel heat sink and using highly conductive materials. In the author's previous work, experimental and computational analyses were performed on LTCC substrates using embedded silver vias and silver columns forming microchannels. This novel technique of embedding silver vias along with forced convection using a coolant resulted in higher heat transfer rates. The present work investigates the design optimization of this cooling system (microheat exchanger) using systems optimization theory. A new multiobjective optimization problem was formulated for the heat transfer in the LTCC model using the log mean temperature difference (LMTD) method of heat exchangers. The goal is to maximize the total heat transferred and to minimize the coolant pumping power. Structural and thermal design variables are considered to meet the manufacturability and energy requirements. Pressure loss and volume of the silver metal are used as constraints. A hybrid optimization technique using sequential quadratic programming (SQP) and branch and bound method of integer programming has been developed to solve the microheat exchanger problem. The optimal design is presented and sensitivity analysis results are discussed.

Optimum Design of the Continuously Variable Transmission for a Motorcycle

2001 ◽  
Author(s):  
Yuan Mao Huang ◽  
Bi Shyang Hu
Keyword(s):  
Simulated Annealing Algorithm ◽  
Continuous Variable ◽  
Design Parameters ◽  
Objective Functions ◽  
Design Variables ◽  
Continuous Variable Transmission ◽  
Product Method ◽  
Variable Transmission ◽  
Annealing Algorithm ◽  
Further Development

Abstract Many design parameters affect the performance of continuous variable transmissions. This paper presents the optimization of a continuous variable transmission by using the simulated annealing algorithm. The Bessel method of curve fitting and the tensor product method of surface fitting were used to facilitate the discrete fuel consumption, emissions of carbon monoxide (CO) and HC compound of experimental engine data. A compromise method was used to analyze the multi-objective functions. The values for design variables are recommended for further development.

Instrumentation for X-Ray Diffraction Studies of Highly Radioactive Samples

1958 ◽  
Vol 2 ◽  
pp. 107-115
Author(s):  
Vincent G. Scotti ◽  
James I. Mueller ◽  
John J. Little
Keyword(s):  
Radiation Damage ◽  
Gamma Ray ◽  
Pulse Height ◽  
Fission Products ◽  
Analytical Tool ◽  
Nuclear Engineering ◽  
X Ray Diffraction ◽  
X Ray ◽  
Background Ratio ◽  
Gamma Ray Irradiation

AbstractWith the advent of nuclear engineering, x-ray diffraction has become an important analytical tool in the study of radiation damage due to neutron and gamma-ray irradiation. The materials under study in this work have rdioactive levels up to 40 R/hr. at 17 centimeters combined β and γ. The activity of the various samples under study may be due to (n, γ) reactions or fission products or both.Data are presented to illustrate the use of sample shielding, detector shielding pulse height discrimination and the combination of all three aids in an effort to attain the most favorable peak to background ratio.

Originality in Free and Controlled Association Responses

1963 ◽  
Vol 13 (3) ◽  
pp. 923-929 ◽  
Author(s):  
Howard F. Gallup
Keyword(s):  
Vocabulary Test ◽  
Main Design ◽  
The Third ◽  
Exact Replication

Three experiments were carried out in an attempt to replicate the training in originality reported by Maltzman and his colleagues. The first experiment showed that Maltzman's two lists of words were not comparable in their elicitation of original responses, and that all Ss showed an increase in originality from a first list to a second list. The second experiment required Ss to produce different responses each time through a training list without specifically asking them to be different. All Ss were more original on a second list than on the first, whether they were trained, worked on arithmetic problems, or worked on a vocabulary test between trials. The third experiment was an exact replication of Maltzman's main design, with the addition of interpolated arithmetic or vocabulary tests. Again, all Ss showed more originality on the second list, regardless of how they spent the time between trials. It is concluded that originality training as defined by Maltzman has not been demonstrated here.

CYCLE BIOLOGIQUE DE PISSODES NOTATUS (COLEOPTERA, CURCULIONIDAE) DANS LA REGION TOULOUSAINE (FRANCE)

1977 ◽  
Vol 109 (4) ◽  
pp. 597-603 ◽  
Author(s):  
Claude Alauzet
Keyword(s):  
Adult Emergence ◽  
Egg Laying ◽  
Emergence Period ◽  
Cycle Biologique ◽  
Complete Development ◽  
The Third ◽  
Pissodes Notatus ◽  
Field Temperature ◽  
Further Development ◽  
Two Populations

AbstractThe maximal emergence of Pissodes notatus (F.) adults takes place during July and August. It results from the different evolution of two populations:— a first population, whose complete development (from egg to adult) takes 11 or 12 months. This population corresponds to eggs laid after the middle of July (maximum egg laying during September). Most of the larvae having reached the third instar, it shows no more evolution during the winter; the further development takes place during the next spring, and adults emerge from mid-June to mid-July.— a second population resulting from egg laying, between February and July, of hibernated adults (maximum egg laying during April and May). The whole development being very short (2 to 3 months), the adults, corresponding to these eggs, emerge from the middle of July to the end of August.The observed differences between durations of the under-bark development (from 2 to 12 months) appear free of diapause and probably result from rates of development changing with temperature and instar.In our regional field temperature conditions, all the individuals reach finally their under-bark development approximatively at the same time, so that the adult emergence period takes place in July and August.

The Persona and the Addressee in Juvenal Satire 11

Ramus ◽  
1990 ◽  
Vol 19 (2) ◽  
pp. 160-168
Author(s):  
F.M.A. Jones
Keyword(s):  
Small Scale ◽  
Ad Hominem ◽  
The Third ◽  
The Difference ◽  
Further Development ◽  
The Voice

The approach to the Satires of Juvenal via the persona theory is well-known and has been productive. Somewhat less notice has been given to the fact that a considerable number of the satires have their persona moulded around another character, an addressee or an interlocutor, or sometimes an important narrative figure. Such characters ‘justify’ the persona, which can now be seen as a kind of ad hominem irony. This matter is intricately linked with the role of indignatio. Thus indignation, programmed in the first satire, becomes a little suspect in Laronia's mouth in the second. Laronia is a small scale character, but the techniques used in her regard appear again in the third satire, where the difference between Juvenal and Umbricius reveals the inadequacy of indignatio a little more clearly. The difference between the treatment of Crispinus and of Domitian in the fourth satire carries this process further. In the fifth, Juvenal tries to rouse the abject Trebius, but in his own apostrophe to Virro (Sat. 5.107f.) shows that indignatio is not, perhaps, appropriate at all. The role of indignatio diminishes further in the later satires, noticeably in the ninth, where Juvenal's tone is one of banter and Naevolus reveals his own unpleasantness. Much of this process has been charted by S. Braund in a book on the seventh, eighth, and ninth satires. The argument can be resumed with the eleventh satire where there is a further development. In the earlier satires which use address or dialogue there is an impressive realism in dramatic terms about the confrontation and psychology. In the eleventh (and even more, the twelfth) the development of the techniques of irony begins to intrude on the dramatic plausibility: the voice assumed in the poem becomes more aware of the audience as well as the addressee. As the beginning of a demonstration of this change I now provide an analysis of the use of Persicus in the eleventh satire.

Analyses of Severe Accidents in GFR Demonstrator ALLEGRO With MELCOR 2.1

2016 ◽  
Author(s):  
Petr Vácha ◽  
Ladislav Bělovský
Keyword(s):  
Fast Reactor ◽  
Heat Removal ◽  
Computer Code ◽  
Full Scale ◽  
Severe Accident ◽  
The Road ◽  
Passive Safety Systems ◽  
Station Blackout ◽  
On The Road ◽  
Further Development

The helium-cooled Gas Fast Reactor (GFR) is one of the six reactor concepts selected for further development in the frame of the Generation IV International Forum (GIF). Since no gas cooled fast reactor has ever been built, a small demonstration reactor is necessary on the road towards the full-scale GFR reactor. A concept of this demonstrator is called ALLEGRO. The French Commissariat à l’énergie atomique et aux énergies alternatives (CEA) developed between 2001–2009 a pre-conceptual design of both the full-scale GFR called GFR2400 and the small demonstration unit called ALLEGRO (75 MWt). Since 2013 ALLEGRO has been under development by several partners from Czech Republic, France, Hungary, Poland and Slovakia. No severe accident study of ALLEGRO using a dedicated computer code has been published so far. This paper is the first attempt to perform computer simulations of the ALLEGRO CEA 2009 concept, using MELCOR version 2.1. A model of the ALLEGRO CEA 2009 concept has been developed with the aim to perform safety analyses; to confirm that MELCOR can be used for such a study, to investigate what scenarios lead to a severe accident and to study in detail the progression of the severe accident during the in-vessel phase. Several pressurized and depressurized protected scenarios were investigated; four of them are presented in this paper. It was observed that even long-lasting station blackout (SBO) without further failures of the passive safety systems does not lead to a severe accident as long as there is enough water in the decay heat removal (DHR) system. Loss of coolant (LOCA) transients with DHR system in the forced-convection mode can lead to peak cladding temperatures causing limited core damage in the early phase of the accidents, but without further development into core meltdown. On the other hand, LOCA combined with SBO leads to excessive core melting in orders of minutes, which represents a weak point of ALLEGRO 2009 concept. Recommendations were formulated for the further development of the ALLEGRO concept.

Development of High Efficiency Containment Venting System by Using AgX

2016 ◽  
Author(s):  
Tadashi Narabayashi ◽  
Yuuhei Sugano ◽  
Hiroki Imaeda ◽  
Go Chiba ◽  
Nobuaki Sato ◽  
...  
Keyword(s):  
High Efficiency ◽  
Water Injection ◽  
Heat Removal ◽  
Fission Products ◽  
Radioactive Material ◽  
Severe Accident ◽  
Test Facility ◽  
Silver Coating ◽  
Fukushima Daiichi ◽  
Filter Thickness

Fukushima Daiichi NPP accident would be terminated, if sufficient accident countermeasures, such as water proof door, mobile power, etc [1, 2]. In case of Europe, it had already installed the heat removal system and filtered containment venting system (FCVS) from the lessons of TMI and Chernobyl Accidents. The new regulatory standard in Japan, the filtered vent system (FCVS) should be installed, and prevent the radioactive material in case of the severe accident and the overpressure breakage prevention of a primary containment vessel (PCV) and also the robustization of the FCVS. The authors examined the severe accident process in the 2nd unit of Fukushima Daiichi NPS, and found the vent by FCVS should be done before water injection into the core. The PCV spray and water injection into the pedestal basement should be also the countermeasures to the severe accident. Countermeasures for an intentional aircraft collision should be installed too. Upon occurrence of a severe accident (SA), vent gas with radioactive fission products is blown out to a scrubbing pool through numerous venturi nozzles. Mist in steam moves upward to a metal fiber filter through a multi-hole baffle plate. After the mist is removed by that filter, radioactive methyl iodine (CH3I) is captured on the surface of a molecular sieve or AgX, made from zeolite particles with silver coating. A FCVS visualized test facility was installed at Hokkaido University. An AgX filter is used down-stream of the scrubbing pool and metal fiver filter. Thickness of AgX filter is very important parameter to obtain enough decontamination factor (DF). The DF for the radioactive iodine exceeds 10,000 at bed depth (AgX filter thickness) greater than 75mm.

Sign in / Sign up

Export Citation Format

Share Document