A hopeless pursuit? National efforts to promote small modular nuclear reactors and revive nuclear power

2022 ◽  
Author(s):  
Stephen Thomas ◽  
M. V. Ramana
Keyword(s):  
Nuclear Power ◽  
Nuclear Reactors

scholarly journals Model-Driven Architectural Framework towards Safe and Secure Nuclear Power Reactors

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5136
Author(s):  
Bassem Ouni ◽  
Christophe Aussagues ◽  
Saadia Dhouib ◽  
Chokri Mraidha
Keyword(s):  
Nuclear Power ◽  
Nuclear Reactors ◽  
System Development ◽  
Levels Of Abstraction ◽  
Model Driven ◽  
Case System ◽  
Architectural Framework ◽  
Performance Check ◽  
High Level ◽  
Different Levels

Sensor-based digital systems for Instrumentation and Control (I&C) of nuclear reactors are quite complex in terms of architecture and functionalities. A high-level framework is highly required to pre-evaluate the system’s performance, check the consistency between different levels of abstraction and address the concerns of various stakeholders. In this work, we integrate the development process of I&C systems and the involvement of stakeholders within a model-driven methodology. The proposed approach introduces a new architectural framework that defines various concepts, allowing system implementations and encompassing different development phases, all actors, and system concerns. In addition, we define a new I&C Modeling Language (ICML) and a set of methodological rules needed to build different architectural framework views. To illustrate this methodology, we extend the specific use of an open-source system engineering tool, named Eclipse Papyrus, to carry out many automation and verification steps at different levels of abstraction. The architectural framework modeling capabilities will be validated using a realistic use case system for the protection of nuclear reactors. The proposed framework is able to reduce the overall system development cost by improving links between different specification tasks and providing a high abstraction level of system components.

scholarly journals French Energy Sector in Search for Optimal Model

2019 ◽  
Vol 12 (5) ◽  
pp. 156-171
Author(s):  
A. V. Zimakov
Keyword(s):  
Power Generation ◽  
Nuclear Power ◽  
Nuclear Reactors ◽  
Current Model ◽  
Energy Transition ◽  
Clean Energy ◽  
Green Energy ◽  
Electricity Production ◽  
Low Carbon ◽  
The Eu

Clean energy transition is one of major transformation processes in the EU. There are different approaches among EU countries to decarbonization of their energy systems. The article deals with clean energy transition in France with the emphasis on power generation. While this transformation process is in line with similar developments in the EU, the Franch case has its distinct nature due to nuclear power domination in electricity production there. It represents a challenge for the current model as the transition is linked to a sharp drop of nuclear share in the power mix. It is important to understand the trajectory of further clean energy transition in France and its ultimate model. The article reviews the historical roots of the current model (which stems from Messmer plan of the 1970-es) and its development over years, as well as assesses its drawbacks and merits in order to outline possible future prospects. The conclusion is that the desired reduction of nuclear energy is linked not solely to greening process but has a complex of reasons, the ageing of nuclear reactors being one of them. Nuclear power remains an important low-carbon technology allowing France to achieve carbon neutrality by 2050. A desired future energy model in France can be understood based on the analysis of new legislation and government action plans. The targeted model is expected to balance of nuclear and green energy in the generation mix in 50% to 40% proportion by 2035, with the rest left to gas power generation. Being pragmatic, French government aims at partial nuclear reactors shut down provided that this will not lead to the rise of GHG emissions, energy market distortions, or electricity price hikes. The balanced French model is believed to be a softer and socially comfortable option of low-carbon model.

Circulator Design/Technology Evolution for Gas-Cooled Nuclear Reactors

1992 ◽  
Author(s):  
Colin F. McDonald ◽  
Ian R. Marshall ◽  
John Donaldson ◽  
Davdrin D. Kapich
Keyword(s):  
Nuclear Power ◽  
State Of The Art ◽  
Nuclear Reactors ◽  
Power Conversion ◽  
Electrical Power ◽  
Operating Experience ◽  
Lessons Learned ◽  
Future Trends ◽  
Design Technology ◽  
Conversion System

The circulator is a key component in a gas-cooled nuclear power plant since it facilitates transfer of the reactor thermal energy (via the steam generator) to the electrical power conversion system. Circulator technology is well established and about 200 machines, which, in their simplest form, consist of an electrical motor driven compressor, have operated for many millions of hours worldwide in gas-cooled reactors. This paper covers the evolution of circulator design, technology and operating experience, with particular emphasis on how lessons learned over the last four decades (dominantly from the carbon dioxide cooled plants in the U.K.) are applicable to the helium cooled Modular High Temperature Gas-Cooled Reactor (MHTCR) which should see service in the U.S. at the turn of the next century. State-of-the-art technologies are covered in the areas of impeller selection, bearings, drive system, machine operation, and future trends are Identified.

Development Trends in Nuclear Technology and Related Safety Aspects

2002 ◽  
Author(s):  
B. Kuczera ◽  
P. E. Juhn ◽  
K. Fukuda
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Fuel Cycle ◽  
Nuclear Reactors ◽  
Nuclear Technology ◽  
User Requirements ◽  
Safety Standards ◽  
Safety Requirements ◽  
Fuel Cycles ◽  
High Level

The IAEA Safety Standards Series include, in a hierarchical manner, the categories of Safety Fundamentals, Safety Requirements and Safety Guides, which define the elements necessary to ensure the safety of nuclear installations. In the same way as nuclear technology and scientific knowledge advance continuously, also safety requirements may change with these advances. Therefore, in the framework of the International Project on Innovative Nuclear Reactors and Fuel Cycles (INPRO) one important aspect among others refers to user requirements on the safety of innovative nuclear installations, which may come into operation within the next fifty years. In this respect, the major objectives of the INPRO subtask “User Requirements and Nuclear Energy Development Criteria in the Area of Safety” have been: a. to overview existing national and international requirements in the safety area, b. to define high level user requirements in the area of safety of innovative nuclear technologies, c. to compile and to analyze existing innovative reactor and fuel cycle technology enhancement concepts and approaches intended to achieve a high degree of safety, and d. to identify the general areas of safety R&D needs for the establishment of these technologies. During the discussions it became evident that the application of the defence in depth strategy will continue to be the overriding approach for achieving the general safety objective in nuclear power plants and fuel cycle facilities, where the emphasis will be shifted from mitigation of accident consequences more towards prevention of accidents. In this context, four high level user requirements have been formulated for the safety of innovative nuclear reactors and fuel cycles. On this basis safety strategies for innovative reactor designs are highlighted in each of the five levels of defence in depth and specific requirements are discussed for the individual components of the fuel cycle.

Pseudo-Capacitor Structure for Direct Nuclear Energy Conversion

2008 ◽  
Vol 1100 ◽  
Author(s):  
Liviu Popa-Simil
Keyword(s):  
Energy Conversion ◽  
Nuclear Power ◽  
Nuclear Energy ◽  
Nuclear Reactor ◽  
High Efficiency ◽  
Nuclear Reactors ◽  
Direct Conversion ◽  
Space Applications ◽  
Power Sources ◽  
Conversion Efficiencies

AbstractThe advanced space missions need for more power opened the way for advanced nuclear reactors and for alternative power conversion procedures. The most advanced power systems available in space are the fuel cells and nuclear reactors. Both systems manifest low efficiencies for converting the primary energy into electricity and as consequence are requiring high heat dump into space mainly by infrared radiation. The thermo-nuclear power generator also requires a high temperature gas turbine and a mechano-electric generator, finally driving to low conversion efficiencies. The new nano-materials offer the possibility of creating direct energy conversion devices able of achieving high conversion efficiencies up to 99% in the cryogenic versions. The interest for direct conversion of the nuclear energy into electricity appeared in early 1940th, by the invention of the thermo-ionic fission device by Linder. Then a series of patents and scientific papers improved gradually the designs and performances of the devices, up to the actual concepts of beta-voltaic and liquid-electronics. The most intuitive direct conversion device looks mainly like a super mirror- or a heterogeneous super-capacitor. The issues on its operation are related to global conversion efficiencies and the stable operation life-time in high radiation field. There are combinations of nano-structures and actinides assuring both the neutron flux stability, by meeting criticality conditions and the direct conversion or the nuclear energy into electricity. Achieving a high efficiency internal conversion of the nuclear energy into electricity is not enough if it is not completed by a high efficiency power extraction system from the nuclear reactor core into the outside load. The development of the new MEMS devices and micro electronics in the 40 nm technologies provides an excellent background for the production of the electric power harvesting and conversion devices embedded in the fuel. The new nano-structured materials may be produced as radiation energy harvesting tiles that are free of actinides, using them for harvesting the energy of radioactive sources and controlled fusion devices, or may include actinides in their structure achieving critical or sub-critical accelerator driven nuclear reactor assemblies. Another predictable advantage of the nano-structure is the property of self-repairing and self-organizing to compensate the radiation damage and improve the lifetime. Due to direct conversion the power density of the new materials may increase from the actual average of 0.2 kw/cm3 to about 1 kw/mm3 driving to miniaturization of nuclear power sources and reductions of the shield weight. At these dimensions and power densities of few thousands horse power per liter the nuclear power source becomes suitable for mobile applications as powering trains, strategic airplanes, etc. These new developments may drive to the production of high power solid-state compact nuclear battery for space applications, leading to a new development stage.

scholarly journals CO2 power cycle chemistry in the CV Řež experimental loop

2021 ◽  
Vol 61 (4) ◽  
pp. 504-510
Author(s):  
Jan Berka ◽  
Jakub Vojtěch Ballek ◽  
Ladislav Velebil ◽  
Eliška Purkarová ◽  
Alice Vagenknechtová ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Steam Turbine ◽  
Control Systems ◽  
Nuclear Power ◽  
Nuclear Reactors ◽  
Gas Purification ◽  
Supercritical State ◽  
Steam Power ◽  
Power Cycles ◽  
Power Cycle

Power cycles using carbon dioxide in a supercritical state (sc-CO2) can be used in both the nuclear and non-nuclear power industry. These systems are characterized by their advantages over steam power cycles, e. g., the sc-CO2 turbine is more compact than the steam turbine with a similar performance. The parameters and lifespan of the system are influenced by the purity of the CO2 in the circuit, especially the admixtures, such as O2, H2O, etc., cause the enhanced structural materials to degrade. Therefore, gas purification and purity control systems for the sc-CO2 power cycles should be proposed and developed. The inspiration for the proposal of these systems could stem from the gas, especially the CO2-cooled nuclear reactors operation. The first information concerning the CO2 and sc-CO2 power cycle chemistry was gathered in the first period of the project and it is summarized in the paper.

scholarly journals The Importance of Probabilistic Safety Assessment in the Careful Study of Risks Envolved to New Nuclear Power Plant Projects

2021 ◽  
Vol 9 (2A) ◽  
Author(s):  
Jônatas Franco Campos da Mata ◽  
Amir Zacarias Mesquita
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Safety Assessment ◽  
Nuclear Reactors ◽  
The United States ◽  
Careful Study ◽  
Tree Analysis ◽  
Probabilistic Safety Assessment ◽  
Probabilistic Safety

The Fukushima Daiichi nuclear accident in Japan in 2011 has raised public fears about the actual safety of nuclear power plants in several countries. The response to this concern by government agencies and private companies has been objective and pragmatic in order to guarantee best practices in the several phases of nuclear reactors. In countries where the nucleo-electric matrix is consolidated, such as the United States, France and the United Kingdom, the safety assessment is carried out considering deterministic and probabilistic criteria. In the licensing stages of new projects, it is necessary to analyze and simulate the behavior of the nuclear power plant, when subjected to conditions that can lead to sequences of accidents. Probabilistic Safety Assessment (PSA) is fundamental in this process, as it studies in depth the sequences of events that can lead to damage to the reactor core. Such sequences should be quantified in terms of probability of occurrence and your possible consequences, and organized through techniques such as Fault Tree Analysis and Event Tree Analysis. The present work will describe the procedures for the realization of PSA and its applicability to the assurance of the operational reliability of the nuclear reactors, as well as a brief comparative between the approaches used in some countries traditionally users of thermonuclear energy and Brazil. By means of this analysis, it can be concluded that nuclear power is increasingly reliable and safe, being able to provide the necessary tranquility for the population of the countries where it is inserted.

Nuclear Power

2020 ◽  
pp. 41-67
Author(s):  
Savannah Fitzwater
Keyword(s):  
Nuclear Power ◽  
Nuclear Energy ◽  
Nuclear Reactors ◽  
Nuclear Technology ◽  
Costs And Benefits ◽  
Power Development ◽  
Current State ◽  
Nuclear Power Development ◽  
Under Construction ◽  
Advanced Generation

This chapter provides an overview of nuclear power around the world, the fundamentals of nuclear technology, and nuclear energy’s costs and benefits. Nuclear energy accounts for 10.6 percent of energy produced for electricity globally. Although a relatively small percentage of production, it has often been in the spotlight for its great potential, both good and bad. As of 2018, there were 451 operational commercial nuclear reactors globally and many more under construction. This chapter explores some of the key arguments made for and against nuclear energy and examines future areas of nuclear power development, including small modular reactors, advanced Generation IV reactor designs, and the expansion of non-electric applications, in light of the current state of nuclear power.

Sign in / Sign up

Export Citation Format

Share Document