scholarly journals A Small-Sized HTGR System Design for Multiple Heat Applications for Developing Countries

2013 ◽  
Vol 2013 ◽  
pp. 1-18 ◽  
Author(s):  
Hirofumi Ohashi ◽  
Hiroyuki Sato ◽  
Minoru Goto ◽  
Xing Yan ◽  
Junya Sumita ◽  
...  
Keyword(s):  
Developing Countries ◽  
Conceptual Design ◽  
Heat Removal ◽  
District Heating ◽  
Safety Analysis ◽  
Coolant Temperature ◽  
Reactor Outlet ◽  
Energy Agency ◽  
Commercial Plant ◽  
High Level

Japan Atomic Energy Agency has conducted a conceptual design of a 50 MWt small-sized high temperature gas cooled reactor (HTGR) for multiple heat applications, named HTR50S, with the reactor outlet coolant temperature of 750°C and 900°C. It is first-of-a-kind of the commercial plant or a demonstration plant of a small-sized HTGR system to be deployed in developing countries in the 2020s. The design concept of HTR50S is to satisfy the user requirements for multipurpose heat applications such as the district heating and process heat supply based on the steam turbine system and the demonstration of the power generation by helium gas turbine and the hydrogen production using the water splitting iodine-sulfur process, to upgrade its performance compared to that of HTTR without significant R&D utilizing the knowledge obtained by the HTTR design and operation, and to fulfill the high level of safety by utilizing the inherent features of HTGR and a passive decay heat removal system. The evaluation of technical feasibility shows that all design targets were satisfied by the design of each system and the preliminary safety analysis. This paper describes the conceptual design and the preliminary safety analysis of HTR50S.

Conceptual Design of Small-Sized HTGR System for Steam Supply and Electricity Generation (HTR50S)

2011 ◽  
Author(s):  
Hirofumi Ohashi ◽  
Hiroyuki Sato ◽  
Yujiro Tazawa ◽  
Xing L. Yan ◽  
Yukio Tachibana ◽  
...  
Keyword(s):  
Developing Countries ◽  
High Temperature ◽  
System Design ◽  
Conceptual Design ◽  
Electricity Generation ◽  
District Heating ◽  
Market Potential ◽  
Outlet Temperature ◽  
Design Philosophy ◽  
Commercial Plant

Japan Atomic Energy Agency (JAEA) has started a conceptual design of a small-sized HTGR for steam supply and electricity generation (HTR50S) to deploy the high temperature gas cooled reactor (HTGR) in developing countries at an early date (i.e., in the 2030s). Its reactor power is 50MWt and the reactor outlet temperature is 750°C. It is a first-of-kind of the commercial plant or a demonstration plant of a small-sized HTGR system for steam supply to the industries and the district heating, and electricity generation using a steam turbine. The design philosophy of the HTR50S is to upgrade the performance from the Japanese first HTGR (HTTR) and to reduce the cost for the commercialization by utilizing the knowledge obtained by the HTTR operation and the design of an advanced commercial plant of 600 MWt-class Very High Temperature Reactor (GTHTR300 series). The major specifications of the HTR50S were determined based on its design philosophy. And the targets of the technology demonstration using the HTR50S for the future commercial small-sized HTGR were identified. The system design of HTR50S was performed to offer the capability of electricity generation, cogeneration of electricity and steam for a district heating and industries. The market potential for the small-sized HTGR in the developing countries was evaluated for the application of the electricity, process heat, district heating and pure water production. It was confirmed that there is enough market potential for the small-sized HTGR in the developing countries. This paper described the major specification and system design of the HTR50S and the market potential for the small-sized HTGR in the developing countries.

Low Alkaline Cement Used in the Construction of a Gallery in the Horonobe Underground Research Laboratory

2010 ◽  
Author(s):  
Masashi Nakayama ◽  
Haruo Sato ◽  
Yutaka Sugita ◽  
Seiji Ito ◽  
Masashi Minamide ◽  
...  
Keyword(s):  
Fly Ash ◽  
Research Laboratory ◽  
Concrete Lining ◽  
Energy Agency ◽  
Tunnel Support ◽  
Long Term Stability ◽  
Alkaline Conditions ◽  
High Level ◽  
Underground Research Laboratory

In Japan, any high level radioactive waste (HLW) repository is to be constructed at over 300 m depth below surface. Tunnel support is used for safety during the construction and operation, and shotcrete and concrete lining are used as the tunnel support. Concrete is a composite material comprised of aggregate, cement and various admixtures. Low alkaline cement has been developed for the long term stability of the barrier systems whose performance could be negatively affected by highly alkaline conditions arising due to cement used in a repository. Japan Atomic Energy Agency (JAEA) has developed a low alkaline cement, named as HFSC (Highly Fly-ash Contained Silicafume Cement), containing over 60 wt% of silica-fume (SF) and fly-ash (FA). HFSC was used experimentally as the shotcrete material in construction of part of the 140m deep gallery in the Horonobe Underground Research Laboratory (URL). The objective of this experiment was to assess the performance of HFSC shotcrete in terms of mechanics, workability, durability, and so on. HFSC used in this experiment is composed of 40 wt% OPC (Ordinary Portland Cement), 20 wt% SF, and 40 wt% FA. This composition was determined based on mechanical testing of various mixes of the above components. Because of the low OPC content, the strength of HFSC tends to be lower than that of OPC. The total length of tunnel using HFSC shotcrete is about 73 m and about 500 m3 of HFSC was used. The workability of HFSC shotcrete was confirmed in this experimental construction.

Nuclear Power in Latin America: An Overview of Its Present Status

1983 ◽  
Vol 25 (3) ◽  
pp. 377-415 ◽  
Author(s):  
Margarete K. Luddemann
Keyword(s):  
Developing Countries ◽  
Latin America ◽  
Nuclear Power ◽  
Nuclear Energy ◽  
Fuel Cycle ◽  
Field Studies ◽  
Energy Agency ◽  
Self Sufficiency ◽  
Policy Concern ◽  
Alternative Sources

The pivotal role energy plays in national economics not only converts the access to sources of supply into a vivid issue of foreign policy concern, but also causes an understandable preoccupation with investment capabilities and self-sufficiency. A report prepared by the International Atomic Energy Agency (IAEA) in 1974 predicted a bright future for nuclear energy in the i developing countries and encouraged use of this form of energy after numerous field studies.A nation that commits itself to nuclear energy by purchasing nuclear power-generating technology but not fuel cycle facilities incurs the risk of becoming dependent upon the supplier country because a quick switch to alternative sources of supply is difficult in cases of curtailment of fuel.

Development and Application of Multi-Physics Safety Analysis Code for Advanced Liquid Metal Cooled Reactor

2018 ◽  
Author(s):  
Chi Wang ◽  
Xuebei Zhang ◽  
Jingchao Feng ◽  
Muhammad Shehzad Khan ◽  
Minyou Ye ◽  
...  
Keyword(s):  
Nuclear Reactor ◽  
Safety Analysis ◽  
Coolant Temperature ◽  
Medium Size ◽  
High Tech ◽  
Fuel Temperature ◽  
Flow Phenomena ◽  
Nuclear Reactor Safety ◽  
Cfd Method ◽  
Point Kinetics

The simulation of 3D thermal-hydraulic problem for the pool type fast reactors, is one of the necessary and great importance. Most system codes can’t be used to simulate multi-dimensional thermal-hydraulics problems, whereas, the CFD method is suitable to deal with these type of simulation challenges. Based on the CFD method, a neutronics and thermohydraulic coupling code FLUENT/PK for nuclear reactor safety analysis by coupling the commercial CFD code FLUENT with the point kinetics model (PKM) and the pin thermal model (PTM) is developed by University of Science and Technology of China (USTC). The coupled code is verified by comparing with a series of benchmarks on beam interruptions in a lead-bismuth-cooled and MOX-fuelled accelerator-driven system. The variations of transient power, fuel temperature and outlet coolant temperature all agree well with the benchmark results. The validation results show that the code can be used to simulate the transient accidents of critical and sub-critical lead/lead-bismuth cooled reactors. Then this coupling code is used to evaluate the safety performance of MYRRHA (Multi-purpose Hybrid Research Reactor for High-tech Applications) at unprotected beam over-power (UBOP) accident, and M2LFR-1000 (Medium-size Modular Lead-cooled Fast Reactor) at the unprotected transient over-power (UTOP) and unprotected loss of flow (ULOF) accident. The transient power, the temperature of coolant and fuel and multi-dimensional flow phenomena in upper plenum and lower plenum are presented and discussed in this paper.

Improvement of Temperature Evaluation Model of Biological Shielding Concrete for HTTR Test Simulating LOFC With VCS Inactive

2013 ◽  
Author(s):  
Shoji Takada ◽  
Shunki Yanagi ◽  
Kazuhiko Iigaki ◽  
Masanori Shinohara ◽  
Daisuke Tochio ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Thermal Radiation ◽  
Cooling System ◽  
Evaluation Model ◽  
Reactor Core ◽  
Reactor Power ◽  
Coolant Temperature ◽  
Water Cooling ◽  
Reactor Outlet

HTTR is a helium gas cooled graphite-moderated HTGR with the rated power 30 MWt and the maximum reactor outlet coolant temperature 950°C. The vessel cooling system (VCS), which is composed of thermal reflector plates, cooling panel composed of fins connected between adjacent water cooling tubes, removes decay heat from reactor core by heat transfer of thermal radiation, conduction and natural convection in case of loss of forced cooling (LOFC). The metallic supports are embedded in the biological shielding concrete to support the fins of VCS. To verify the inherent safety features of HTGR, the LOFC test is planned by using HTTR with the VCS inactive from an initial reactor power of 9 MWt under the condition of LOFC while the reactor shut-down system disabled. In this test, the temperature distribution in the biological shielding concrete is prospected locally higher around the support because of thermal conduction in the support. A 2-dimensional symmetrical model was improved to simulate the heat transfer to the concrete through the VCS support in addition to the heat transfer thermal radiation and natural convection. The model simulated the water cooling tubes setting horizontally at the same pitch with actual configuration. The numerical results were verified in comparison with the measured data acquired from the test, in which the RPV was heated up to around 110 °C without nuclear heating with the VCS inactive, to show that the temperature is locally high but kept sufficiently low around the support in the concrete due to sufficient thermal conductivity to the cold temperature region.

scholarly journals Gender and feminist considerations in Artificial Intelligence from a developing-world perspective, with India as a case study

2021 ◽  
Author(s):  
SANGHAMITRA CHOUDHURY ◽  
Shailendra Kumar
Keyword(s):  
Artificial Intelligence ◽  
Developing Countries ◽  
Developing World ◽  
Developed Countries ◽  
High Level ◽  
The Impact ◽  
The Relationship ◽  
Precarious Situation ◽  
And Robotics

<p>The relationship between women, technology manifestation, and likely prospects in the developing world is discussed in this manuscript. Using India as a case study, the paper goes on to discuss how ontology and epistemology views utilised in AI (Artificial Intelligence) and robotics will affect women's prospects in developing countries. Women in developing countries, notably in South Asia, are perceived as doing domestic work and are underrepresented in high-level professions. They are disproportionately underemployed and face prejudice in the workplace. The purpose of this study is to determine if the introduction of AI would exacerbate the already precarious situation of women in the developing world or if it would serve as a liberating force. While studies on the impact of AI on women have been undertaken in developed countries, there has been less research in developing countries. This manuscript attempts to fill that need.</p>

E-government and transformation of service delivery in developing countries

2016 ◽  
Vol 10 (3) ◽  
pp. 368-390 ◽  
Author(s):  
Noore Alam Siddiquee
Keyword(s):  
Developing Countries ◽  
Service Delivery ◽  
Lessons Learned ◽  
Political Support ◽  
Primary Data ◽  
Content Type ◽  
Secondary Sources ◽  
Intimate Knowledge ◽  
Secondary Information ◽  
High Level

Purpose Since 2009, e-government has been high on governmental agenda in Bangladesh. Seen as a vehicle for improving governance and service delivery, it is also presented as a key to fighting poverty and achieving the millennium development goals. Thus, the goals of e-government remain broad and ambitious. Can a developing country such as Bangladesh realize its e-government vision? The purpose of this paper is to explore this and other related questions seeking to draw lessons that the Bangladesh experience may offer. Design/methodology/approach The paper draws primarily on secondary information, complemented by primary data gathered from various sources. In addition to an extensive review of secondary sources, necessary information was derived from websites of relevant government departments/agencies and through interviews and conversations with selected government officials having intimate knowledge on e-government projects at the field and local levels. Findings The paper demonstrates the ways in which various e-initiatives have transformed traditional administrative systems and practices, notwithstanding the nation’s limited overall e-development. It also shows how e-innovations have helped tackle some complex challenges, thereby adding to convenience and benefits to service users. A major conclusion of the paper is that although e-government is yet to make a breakthrough in governance and service delivery, it has set the wheels of change in motion. Practical implications E-government must be seen as a long term project, it must attract high-level political support and it requires fruitful collaboration between the public, private and non-governmental actors. Originality/value This paper adds to the limited knowledge in the field. Lessons learned from the Bangladesh experience have much relevance to other developing countries with similar socioeconomic circumstances. The policymakers and practitioners are expected to benefit from the insights of the paper.

Labour Emigration From Ethiopia

2021 ◽  
Vol 1 (2) ◽  
pp. 33-50
Author(s):  
Ebabu Chekole Mengistu
Keyword(s):  
Developing Countries ◽  
Migrant Workers ◽  
Document Analysis ◽  
Economic Factors ◽  
Analysis Techniques ◽  
Depth Interview ◽  
Key Informant ◽  
The World ◽  
High Level ◽  
Key Informant Interview

In recent years, the magnitude and complexity of movements have brought increased attention to the phenomenon of emigration which affects nearly all countries in the world. In developing countries, labour emigration is extremely complex. The main objective of the study is to explore the trends, causes, and challenges of labour emigration from Ethiopia. In-depth interview, key informant interview, observation, and document analysis were used as methods of data collection. Content and document analysis techniques were used to analyze the data. The results of the study show that there is a high level of labour emigration from Ethiopia. Labour emigration from Ethiopia is mostly associated with economic factors such as unemployment, underemployment, and the search for better life in the destination countries. The institutional structure and inter-institutional collaboration in relation to labour emigration are informed by a fragmented framework. As a result, Ethiopian migrant workers are highly vulnerable to human rights violations.

Conceptual Design for Assembly

1999 ◽  
Author(s):  
Santiago V. Lombeyda ◽  
William C. Regli
Keyword(s):  
Conceptual Design ◽  
Collaborative Design ◽  
Collaborative Work ◽  
Level Structure ◽  
Knowledge Bases ◽  
Design Engineers ◽  
Cad Databases ◽  
Design Activities ◽  
High Level ◽  
Case Based

Abstract This paper presents an approach to support computer-aided conceptual design of mechatronic assemblies in a collaborative, multi-user environment. We describe a system, Conceptual Understanding and Prototyping (CUP), that allows a team of design engineers, collaborating over the Internet, to develop a high-level structure-function-behavior (S-B-F) description of an assembly in a VRML-based virtual environment. Our goal is to enable users to navigate intricate product data management (PDM) and case-based design knowledge-bases, providing the ability to perform design at conceptual level and have intelligent CAD tools that can draw on details from large repositories of previously archived designs. This work furthers research efforts in computer support for collaborative design activities — drawing on work in Human-Computer Interaction (HCI) and Computer Supported Collaborative Work (CSCW). We envision CUP to be a network interface to next-generation of engineering PDM systems and CAD databases. We are deploying CUP as query interface to the National Design Repository (http://repos.mcs.drexel.edu). This will enable CAD users to interrogate large quantities of legacy data and identify artifacts with structural and functional similarities — allowing designers to perform case-based and variant design.

Productive Capacities, Economic Growth and Economic Growth Volatility in Developing Countries: Does Structural Economic Vulnerability Matter?

2021 ◽  
Author(s):  
Sena Kimm Gnangnon
Keyword(s):  
Economic Growth ◽  
Developing Countries ◽  
International Institutions ◽  
Economic Vulnerability ◽  
Global Shocks ◽  
The 2008 Financial Crisis ◽  
Environmental Shocks ◽  
High Level ◽  
Sustainable Economic Growth ◽  
Growth Volatility

Recent years’ global shocks (e.g., the 2008 financial crisis and the COVID-19 pandemic) and environmental shocks — such as natural disasters — have heightened the vulnerability of developing countries to future shocks, and can compromise their development prospects. International institutions and researchers have advocated that the strengthening of productive capacities in these countries would help enhance the resilience of their economies to shocks, and promote sustainable development. This paper has examined the effect of productive capacities on economic growth and economic growth volatility in developing countries, in particular when they face a high level of structural economic vulnerability. The analysis covers 117 developing countries over the period of 2000–2018. It shows that productive capacities not only promote economic growth, but also reduce economic growth volatility. On the other hand, structural economic vulnerability reduces economic growth (in particular when it exceeds a certain level), and induces greater volatility of economic growth. Interestingly, productive capacities promote economic growth and reduce economic growth volatility in countries that face a high degree of structural economic vulnerability. These findings support the recommendation by international institutions and researchers that if they were to enhance the resilience of their economies to shocks, and promote sustainable economic growth, developing countries (in particular the poorest ones) should strengthen their productive capacities.

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