This article proposes to associate a Deuterium-Deuterium (D-D) fusion reactor with a PWR (fission Pressurized Water Reactor) in a hybrid reactor. Even if the mechanical gain (Q factor) of the D-D fusion reactor is bel...This article proposes to associate a Deuterium-Deuterium (D-D) fusion reactor with a PWR (fission Pressurized Water Reactor) in a hybrid reactor. Even if the mechanical gain (Q factor) of the D-D fusion reactor is below the unity and consequently consumes more energy than it supplies, due to the high energy amplification factor of the PWR fission reactor, the global yield is widely superior to 1. As the energy supplied by the fusion reactor is relatively low and as the neutrons supplied are mainly issued from D-D fusions (at 2.45 MeV), the problems of heat flux and neutrons damage connected with materials, as with D-T fusion reactors are reduced. Of course, there is no need to produce Tritium with this D-D fusion reactor. This type of reactor is able to incinerate any mixture of natural Uranium, natural Thorium and depleted Uranium (waste issued from enrichment plants), with natural Thorium being the best choice. No enriched fuel is needed. So, this type of reactor could constitute a source of energy for several thousands of years because it is about 90 more efficient than a standard fission reactor, such as a PWR or a Candu one, by extracting almost completely the energy from the fertile materials U238 and Th232. For the fission part, PWR technology is mature. For the fusion part, it is based on a reasonable hypothesis done on present Stellarators projects. The working of this reactor is continuous, 24 hours a day. In this paper, it will be targeted a reactor able to provide net electric power of about 1400 MWe, as a big fission power plant.展开更多
In the standard fusion reactors, mainly tokamaks, the mechanical gain obtained is below 1. On the other hand, there are colliding beam fusion reactors, for which, the not neutral plasma and the space charge limit the ...In the standard fusion reactors, mainly tokamaks, the mechanical gain obtained is below 1. On the other hand, there are colliding beam fusion reactors, for which, the not neutral plasma and the space charge limit the number of fusions to a very small number. Consequently, the mechanical gain is extremely low. The proposed reactor is also a colliding beam fusion reactor, configured in Stellarator, using directed beams. D+/T+ ions are injected in opposition, with electrons, at high speeds, so as to form a neutral beam. All these particles turn in a magnetic loop in form of figure of “0” (“racetrack”). The plasma is initially non-thermal but, as expected, rapidly becomes thermal, so all states between non-thermal and thermal exist in this reactor. The main advantage of this reactor is that this plasma after having been brought up near to the optimum conditions for fusion (around 68 keV), is then maintained in this state, thanks to low energy non-thermal ions (≤15 keV). So the energetic cost is low and the mechanical gain (</span><i><span style="font-family:Verdana;">Q</span></i><span style="font-family:Verdana;">) is high (</span></span><span style="font-family:Verdana;">>></span><span style="font-family:Verdana;">1). The goal of this article is to study a different type of fusion reactor, its advantages (no net plasma current inside this reactor, so no disruptive instabilities and consequently a continuous working, a relatively simple way to control the reactor thanks to the particles injectors), and its drawbacks, using a simulator tool. The finding results are valuable for possible future fusion reactors able to generate massive energy in a cleaner and safer way than fission reactors.展开更多
Activation analyses play a vital role in nuclear reactor design.Activation analyses,along with nuclear analyses,provide important information for nuclear safety and maintenance strategies.Activation analyses also help...Activation analyses play a vital role in nuclear reactor design.Activation analyses,along with nuclear analyses,provide important information for nuclear safety and maintenance strategies.Activation analyses also help in the selection of materials for a nuclear reactor,by providing the radioactivity and dose rate levels after irradiation.This information is important to help define maintenance activity for different parts of the reactor,and to plan decommissioning and radioactive waste disposal strategies.The study of activation analyses of candidate structural materials for near-term fusion reactors or ITER is equally essential,due to the presence of a highenergy neutron environment which makes decisive demands on material selection.This study comprises two parts; in the first part the activation characteristics,in a fusion radiation environment,of several elements which are widely present in structural materials,are studied.It reveals that the presence of a few specific elements in a material can diminish its feasibility for use in the nuclear environment.The second part of the study concentrates on activation analyses of candidate structural materials for near-term fusion reactors and their comparison in fusion radiation conditions.The structural materials selected for this study,i.e.India-specific Reduced Activation Ferritic-Martensitic steel（IN-RAFMS）,P91-grade steel,stainless steel 316 LN ITER-grade（SS-316 LN-IG）,stainless steel 316 L and stainless steel 304,are candidates for use in ITER either in vessel components or test blanket systems.Tungsten is also included in this study because of its use for ITER plasma-facing components.The study is carried out using the reference parameters of the ITER fusion reactor.The activation characteristics of the materials are assessed considering the irradiation at an ITER equatorial port.The presence of elements like Nb,Mo,Co and Ta in a structural material enhance the activity level as well as the dose level,which has an impact on design considerations.IN-RAFMS was shown to be a more effective low-activation material than SS-316 LN-IG.展开更多
Nuclear energy driven magnetic confinement via donut shape device known as Tokamak,a toroidal apparatus,for producing controlled fusion reactions in hot plasma,was originally suggested as a basic yet more promising fu...Nuclear energy driven magnetic confinement via donut shape device known as Tokamak,a toroidal apparatus,for producing controlled fusion reactions in hot plasma,was originally suggested as a basic yet more promising fusion reactor.Today the more innovative version of this apparatus that is known as an ITER(international thermonuclear experimental reactor)shows a way toward MCF(magnetic confinement fusion)of hot plasma goal by satisfying Lawson’s Criteria to some degree of achievement.However,since this fusion driven reactor of hot plasma needs to operate at almost 150 million Celsius,the internal material of this reactor is a matter of concern for scientists that are involved with its fabrication.Uniqueness of nanomaterials from the point of view of physical and chemical properties is suggested as a possible potential application for this special and innovative reactor for a nuclear fusion device.Convergence of nanotechnology in study of new generation of materials of this kind can shape the path for various technological developments and a large variety of disciplines,including MCF driven plasma of hot fusion as well.This short TM(technical memorandum)written by these two authors will cover this aspect of technology in a holistic way and the more granular level is left to the reader of this TM to investigate further.展开更多
New research developments suggest that nuclear reactors using fusion may enter the market sooner than imagined even for mobile applications, like merchant ship propulsion and remote power generation. This article aims...New research developments suggest that nuclear reactors using fusion may enter the market sooner than imagined even for mobile applications, like merchant ship propulsion and remote power generation. This article aims at pointing such developments and how they could affect nuclear fusion. The method is enumerating the main nuclear reactors concepts, identifying new technological or theoretical developments useful to nuclear field, and analysing how new recombination could affect feasibility of nuclear fusion. New technologies or experimental results do not always work the way people imagine, being better or worse for intended effects or even bringing completely unforeseen effects. Results point the following designs could be successful, in descending order of potential: aneutronic nuclear reactions using lattice confinement, aneutronic nuclear reactions using inertial along magnetic confinement, hybrid fission-lattice confinement fusion, and fission reactions.展开更多
Concerning the increasing global energy demand, the current paper considers nuclear energy as a solution. Within this context, the 2011 disaster in Fukushima Nuclear Power Plant and, particularly, the technical disord...Concerning the increasing global energy demand, the current paper considers nuclear energy as a solution. Within this context, the 2011 disaster in Fukushima Nuclear Power Plant and, particularly, the technical disorders in boiling water reactors are explained. The deficiency of safety technique in boiling water reactors is explained. The deficiencies in safety procedure of this type of reactors manifested during 2011 earthquake and subsequent tsunami are explained. To complete the discussion, the newer technologies of reactors enabling them to act more safely during natural disasters are introduced. These investigations indicate that despite improvement in the fission reactor technologies, the danger embedded in them still remains. Therefore, the nuclear fusion using Deuterium-Tritium reaction is the best way forward for energy production in the future, and the best candidate of this type of reactors is Tokamak.展开更多
文摘This article proposes to associate a Deuterium-Deuterium (D-D) fusion reactor with a PWR (fission Pressurized Water Reactor) in a hybrid reactor. Even if the mechanical gain (Q factor) of the D-D fusion reactor is below the unity and consequently consumes more energy than it supplies, due to the high energy amplification factor of the PWR fission reactor, the global yield is widely superior to 1. As the energy supplied by the fusion reactor is relatively low and as the neutrons supplied are mainly issued from D-D fusions (at 2.45 MeV), the problems of heat flux and neutrons damage connected with materials, as with D-T fusion reactors are reduced. Of course, there is no need to produce Tritium with this D-D fusion reactor. This type of reactor is able to incinerate any mixture of natural Uranium, natural Thorium and depleted Uranium (waste issued from enrichment plants), with natural Thorium being the best choice. No enriched fuel is needed. So, this type of reactor could constitute a source of energy for several thousands of years because it is about 90 more efficient than a standard fission reactor, such as a PWR or a Candu one, by extracting almost completely the energy from the fertile materials U238 and Th232. For the fission part, PWR technology is mature. For the fusion part, it is based on a reasonable hypothesis done on present Stellarators projects. The working of this reactor is continuous, 24 hours a day. In this paper, it will be targeted a reactor able to provide net electric power of about 1400 MWe, as a big fission power plant.
文摘In the standard fusion reactors, mainly tokamaks, the mechanical gain obtained is below 1. On the other hand, there are colliding beam fusion reactors, for which, the not neutral plasma and the space charge limit the number of fusions to a very small number. Consequently, the mechanical gain is extremely low. The proposed reactor is also a colliding beam fusion reactor, configured in Stellarator, using directed beams. D+/T+ ions are injected in opposition, with electrons, at high speeds, so as to form a neutral beam. All these particles turn in a magnetic loop in form of figure of “0” (“racetrack”). The plasma is initially non-thermal but, as expected, rapidly becomes thermal, so all states between non-thermal and thermal exist in this reactor. The main advantage of this reactor is that this plasma after having been brought up near to the optimum conditions for fusion (around 68 keV), is then maintained in this state, thanks to low energy non-thermal ions (≤15 keV). So the energetic cost is low and the mechanical gain (</span><i><span style="font-family:Verdana;">Q</span></i><span style="font-family:Verdana;">) is high (</span></span><span style="font-family:Verdana;">>></span><span style="font-family:Verdana;">1). The goal of this article is to study a different type of fusion reactor, its advantages (no net plasma current inside this reactor, so no disruptive instabilities and consequently a continuous working, a relatively simple way to control the reactor thanks to the particles injectors), and its drawbacks, using a simulator tool. The finding results are valuable for possible future fusion reactors able to generate massive energy in a cleaner and safer way than fission reactors.
文摘Activation analyses play a vital role in nuclear reactor design.Activation analyses,along with nuclear analyses,provide important information for nuclear safety and maintenance strategies.Activation analyses also help in the selection of materials for a nuclear reactor,by providing the radioactivity and dose rate levels after irradiation.This information is important to help define maintenance activity for different parts of the reactor,and to plan decommissioning and radioactive waste disposal strategies.The study of activation analyses of candidate structural materials for near-term fusion reactors or ITER is equally essential,due to the presence of a highenergy neutron environment which makes decisive demands on material selection.This study comprises two parts; in the first part the activation characteristics,in a fusion radiation environment,of several elements which are widely present in structural materials,are studied.It reveals that the presence of a few specific elements in a material can diminish its feasibility for use in the nuclear environment.The second part of the study concentrates on activation analyses of candidate structural materials for near-term fusion reactors and their comparison in fusion radiation conditions.The structural materials selected for this study,i.e.India-specific Reduced Activation Ferritic-Martensitic steel（IN-RAFMS）,P91-grade steel,stainless steel 316 LN ITER-grade（SS-316 LN-IG）,stainless steel 316 L and stainless steel 304,are candidates for use in ITER either in vessel components or test blanket systems.Tungsten is also included in this study because of its use for ITER plasma-facing components.The study is carried out using the reference parameters of the ITER fusion reactor.The activation characteristics of the materials are assessed considering the irradiation at an ITER equatorial port.The presence of elements like Nb,Mo,Co and Ta in a structural material enhance the activity level as well as the dose level,which has an impact on design considerations.IN-RAFMS was shown to be a more effective low-activation material than SS-316 LN-IG.
文摘Nuclear energy driven magnetic confinement via donut shape device known as Tokamak,a toroidal apparatus,for producing controlled fusion reactions in hot plasma,was originally suggested as a basic yet more promising fusion reactor.Today the more innovative version of this apparatus that is known as an ITER(international thermonuclear experimental reactor)shows a way toward MCF(magnetic confinement fusion)of hot plasma goal by satisfying Lawson’s Criteria to some degree of achievement.However,since this fusion driven reactor of hot plasma needs to operate at almost 150 million Celsius,the internal material of this reactor is a matter of concern for scientists that are involved with its fabrication.Uniqueness of nanomaterials from the point of view of physical and chemical properties is suggested as a possible potential application for this special and innovative reactor for a nuclear fusion device.Convergence of nanotechnology in study of new generation of materials of this kind can shape the path for various technological developments and a large variety of disciplines,including MCF driven plasma of hot fusion as well.This short TM(technical memorandum)written by these two authors will cover this aspect of technology in a holistic way and the more granular level is left to the reader of this TM to investigate further.
文摘New research developments suggest that nuclear reactors using fusion may enter the market sooner than imagined even for mobile applications, like merchant ship propulsion and remote power generation. This article aims at pointing such developments and how they could affect nuclear fusion. The method is enumerating the main nuclear reactors concepts, identifying new technological or theoretical developments useful to nuclear field, and analysing how new recombination could affect feasibility of nuclear fusion. New technologies or experimental results do not always work the way people imagine, being better or worse for intended effects or even bringing completely unforeseen effects. Results point the following designs could be successful, in descending order of potential: aneutronic nuclear reactions using lattice confinement, aneutronic nuclear reactions using inertial along magnetic confinement, hybrid fission-lattice confinement fusion, and fission reactions.
文摘Concerning the increasing global energy demand, the current paper considers nuclear energy as a solution. Within this context, the 2011 disaster in Fukushima Nuclear Power Plant and, particularly, the technical disorders in boiling water reactors are explained. The deficiency of safety technique in boiling water reactors is explained. The deficiencies in safety procedure of this type of reactors manifested during 2011 earthquake and subsequent tsunami are explained. To complete the discussion, the newer technologies of reactors enabling them to act more safely during natural disasters are introduced. These investigations indicate that despite improvement in the fission reactor technologies, the danger embedded in them still remains. Therefore, the nuclear fusion using Deuterium-Tritium reaction is the best way forward for energy production in the future, and the best candidate of this type of reactors is Tokamak.
