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.

Nanotube Potential Future in Nuclear Power

2008 ◽  
Vol 1081 ◽  
Author(s):  
Liviu Popa-Simil
Keyword(s):  
Carbon Nanotubes ◽  
Composite Structures ◽  
Nuclear Power ◽  
Nuclear Reactor ◽  
High Efficiency ◽  
Gamma Ray ◽  
Direct Conversion ◽  
Nuclear Radiation ◽  
X Rays ◽  
Theoretical Approaches

AbstractThe nanotubes presents high potential of applications in nuclear power, integrating them both in advanced fuels developments nano-breeding and in nano-shielding. The carbon nanotubes may be successfully used to create fuel wires used in high temperature applications and near perfect burning generating new procedures in nuclear reactor waste management while reducing the waste by two orders of magnitude. The modified nanowire may hold various other materials as conductors and insulators being useful in direct conversion of the nuclear energy into electricity, by including in the center a sequence of high and low electron density conductors. As direct conversion structures they can handle all the required functions into a nuclear reactor or energy harvesting blanket to assure high power density, high efficiency and minimal waste. Another very challenging application is the usage of nanotube to channel low energy nuclear radiation and guide it, similar to the GHz wave-guides or to hundreds of THz optic fibers. The operation domain of the nanotubes is placed mainly in the domain of UV to X rays, being the role of composite structures or nanowire channeling to cover the gamma ray domain. The carbon nanotubes may become useful cold neutrons transport devices with directive capabilities as short bending or focusing. The theoretical approaches and simulations predicted these new application capabilities of nanowires for nuclear materials with exceptional properties.

scholarly journals Developing skills for neutronic modelling of nuclear power reactors in South Africa

2016 ◽  
Vol 27 (4) ◽  
pp. 64 ◽  
Author(s):  
Gezekile Nyalunga ◽  
Vishana Naicker ◽  
Maria Du Toit
Keyword(s):  
South Africa ◽  
Energy Demand ◽  
Nuclear Power ◽  
Nuclear Energy ◽  
Nuclear Reactor ◽  
Infrastructure Development ◽  
Social Infrastructure ◽  
Power Sources ◽  
North West ◽  
The North

In recent years, due to economic and social infrastructure development and growth, South Africa has been facing growth in energy demand. Addressing this demand includes building more coal power stations, however with attention paid in designing them to reduce greenhouse gas emissions. A second response is to deploy more power sources using renewable and nuclear energy. The South African government has plans to add about 9.6 GW of nuclear energy to the electricity grid. Accepting that South Africa will seek an international vendor or vendors to supply nuclear plants, a certain degree of localisation of manufacture and operation should be planned. One localisation task that can be actively pursued is reactor analysis, including criticality, burnup, shielding and accident analysis of the reactor. Such development of expertise will support both economic and safety aspects of building and running a nuclear reactor. With this in mind, neutronic analysis of the VVER 1000 reactor was initiated. The government’s intention to build a new fleet of reactors means it is important that the VVER-1000 reactor be included in studies done by the reactor analysis group at the School of Mechanical and Nuclear Engineering at the North-West University. The analysis was performed using MCNP6 for the cold zero power state at the beginning of cycle with the specifications obtained from the open literature. The input file was generated using the in-house code NWURCS. To ensure accuracy and precision of the results produced by the MCNP6 code, convergence studies of the MCNP6 models were carried out. Once a satisfactory model was obtained, the critical reactor state was calculated by adjusting the boron concentration in the water. Furthermore, the control rod worth, reactivity coefficients and beff were also calculated and are reported in this paper.

scholarly journals Emission of Noble Gases Binary Mixtures under Excitation by the Products of the 6Li (n, α)3 H Nuclear Reaction

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Kuanysh Samarkhanov ◽  
Mendykhan Khasenov ◽  
Erlan Batyrbekov ◽  
Inesh Kenzhina ◽  
Yerzhan Sapatayev ◽  
...  
Keyword(s):  
Nuclear Reaction ◽  
Nuclear Energy ◽  
Alkali Metals ◽  
Nuclear Reactor ◽  
Noble Gases ◽  
Noble Gas ◽  
Direct Conversion ◽  
Reaction Products ◽  
Gas Molecules ◽  
Sodium And Potassium

The luminescence of Kr-Xe, Ar-Kr, and Ar-Xe mixtures was studied in the spectral range 300–970 nm when excited by 6Li (n, α)3 H nuclear reaction products in the core of a nuclear reactor. Lithium was deposited on walls of experimental cell in the form of a capillary-porous structure, which made it possible to measure up to a temperature of 730 K. The temperature dependence of the radiation intensity of noble gas atoms, alkali metals, and heteronuclear ionic noble gas molecules was studied. Also, as in the case of single-component gases, the appearance of lithium lines and impurities of sodium and potassium is associated with vaporization during the release of nuclear reaction products from the lithium layer. The excitation of lithium atoms occurs mainly as a result of the Penning process of lithium atoms on noble gas atoms in the 1s states and subsequent ion-molecular reactions. Simultaneous radiation at transitions of atoms of noble gases and lithium, heteronuclear ion molecules of noble gases allows us to increase the efficiency of direct conversion of nuclear energy into light.

High Efficiency Gamma-Beta Blind Alpha Spectrometry for Nuclear Energy Applications

2014 ◽  
Author(s):  
Jeffrey A. Webster ◽  
Alexander Hagen ◽  
Brian C. Archambault ◽  
Nicholas Hume ◽  
Rusi Taleyarkhan
Keyword(s):  
Nuclear Energy ◽  
Nuclear Reactor ◽  
High Efficiency ◽  
Detection Efficiency ◽  
Power Level ◽  
Bubble Chamber ◽  
Alpha Decay ◽  
Sensor Technology ◽  
Spent Fuel ◽  
Selective Sensitivity

A novel, Centrifugally Tensioned Metastable Fluid Detector (CTMFD) sensor technology has been developed over the last decade to demonstrate high selective sensitivity and detection efficiency to various forms of radiation for wide-ranging conditions (e.g., power level, safeguards, security, and health physics) relevant to the nuclear energy industry. The CTMFD operates by tensioning a liquid with centrifugal force to weaken the bonds in the liquid to the point whereby even a femto-scale nuclear particle interactions can break the fluid and cause a detectable vaporization cascade. The operating principle has only peripheral similarity to the superheated bubble chamber based superheated droplet detectors (SDDs); instead, CTMFDs utilize mechanical “tension pressure” instead of thermal superheat offering a lot of practical advantages. CTMFDs have been used to detect a variety of alpha and neutron emitting sources in near real-time. The CTMFD is selectively blind to gamma photons and betas allowing for detection of alphas and neutrons in extreme gamma/beta background environments such as spent fuel reprocessing plants or under full power conditions within an operating nuclear reactor itself. The selective sensitivity allows for differentiation between alpha emitters including the isotopes of Plutonium. Mixtures of Plutonium isotopes have been measured in ratios of 1:1, 2:1, and 3:1 Pu-238:Pu-239 with successful differentiation. Due to the lack of gamma-beta background interference, the CTMFD’s LLD can be effectively reduced to zero and hence, is inherently more sensitive than scintillation based alpha spectrometers or SDDs and has been proven capable to detect below femtogram quantities of Plutonium-238. Plutonium is also easily distinguishable from Neptunium making it easy to measure the Plutonium concentration in the NPEX stream of a UREX reprocessing facility. The CTMFD has been calibrated for alphas from Americium (5.5 MeV) and Curium (∼6 MeV) as well. The CTMFD has furthermore, recently also been used to detect spontaneous and induced fission events which can be differentiated from alpha decay allowing for detection of fissionable material in a mixture of isotopes. This paper discusses these transformational developments which are also being entered for real-world commercial use.

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.

scholarly journals Nuclear Restart Politics: How the ‘Nuclear Village’ Lost Policy Implementation Power

2020 ◽  
Author(s):  
Florentine KOPPENBORG
Keyword(s):  
Decision Making ◽  
Policy Implementation ◽  
Goal Setting ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Nuclear Reactor ◽  
Nuclear Reactors ◽  
Nuclear Industry ◽  
Nuclear Policy

Abstract The March 2011 nuclear accident (3.11) shook Japan’s nuclear energy policy to its core. In 2012, the Liberal Democratic Party (LDP) returned to government with a pro-nuclear policy and the intention to swiftly restart nuclear power plants. In 2020, however, only six nuclear reactors were in operation. Why has the progress of nuclear restarts been so slow despite apparent political support? This article investigates the process of restarting nuclear power plants. The key finding is that the ‘nuclear village’, centered on the LDP, Ministry of Economy Trade and Industry, and the nuclear industry, which previously controlled both nuclear policy goal-setting and implementation, remained in charge of policy decision making, i.e. goal-setting, but lost policy implementation power to an extended conflict over nuclear reactor restarts. The main factors that changed the politics of nuclear reactor restarts are Japan’s new nuclear safety agency, the Nuclear Regulation Authority (NRA), and a substantial increase in the number of citizens’ class-action lawsuits against nuclear reactors. These findings highlight the importance of assessing both decision making and implementation in assessments of policy change.

scholarly journals Anthropogenic Radiocarbon: Past, Present, and Future

Radiocarbon ◽  
1986 ◽  
Vol 28 (2A) ◽  
pp. 668-672 ◽  
Author(s):  
Pavel Povinec ◽  
Martin Chudý ◽  
Alexander Šivo
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Reactor ◽  
Nuclear Reactors ◽  
Pressurized Water Reactors ◽  
Anthropogenic Radionuclides ◽  
Pressurized Water ◽  
Heavy Water Reactor ◽  
Weapon Testing ◽  
Water Reactors

14C is one of the most important anthropogenic radionuclides released to the environment by human activities. Weapon testing raised the 14C concentration in the atmosphere and biosphere to +100% above the natural level. This excess of atmospheric C at present decreases with a half-life of ca 7 years. Recently, a new source of artificially produced 14C in nuclear reactors has become important. Since 1967, the Bratislava 14C laboratory has been measuring 14C in atmospheric 14CO2 and in a variety of biospheric samples in densely populated areas and in areas close to nuclear power plants. We have been able to identify a heavy-water reactor and the pressurized water reactors as sources of anthropogenic 14C. 14C concentrations show typical seasonal variations. These data are supported by measurements of 3H and 85Kr in the same locations. Results of calculations of future levels of anthropogenic 14C in the environment due to increasing nuclear reactor installations are presented.

Nuclear Energy in Eastern Europe and the Former Sovient Union: How Safe and How Much?

1995 ◽  
Vol 6 (4) ◽  
pp. 337-359 ◽  
Author(s):  
Y. Sinyak
Keyword(s):  
Climate Change ◽  
Soviet Union ◽  
Eastern Europe ◽  
Former Soviet Union ◽  
Nuclear Power ◽  
Nuclear Energy ◽  
Nuclear Reactors ◽  
Political Climate ◽  
Nuclear Policy ◽  
Near Future

Nuclear power in Eastern Europe and the Former Soviet Union (FSU) is one of the mostly debated issues. There are many controversial opinions around this topic, but lack of data and unstable economic and political climate have prevented the situation from guaranteed improvements in the near future. The goal of this study is to look for a reasonable nuclear policy in the region based on numerical estimates of expected risks and economic assessments of possible options of phasing-out unsafe and obsolete nuclear reactors. A long-tern future of nuclear energy is analyzed for three main energy scenarios with a different impacts to the response to climate change. The study creates a good background for the negotiations on nuclear energy in Eastern Europe and the FSU between Western investors and local states.

High efficiency Bi2Te3-based materials and devices for thermoelectric power generation between 100 and 300 °C

2016 ◽  
Vol 9 (10) ◽  
pp. 3120-3127 ◽  
Author(s):  
Feng Hao ◽  
Pengfei Qiu ◽  
Yunshan Tang ◽  
Shengqiang Bai ◽  
Tong Xing ◽  
...  
Keyword(s):  
Power Generation ◽  
Temperature Gradient ◽  
Energy Conversion ◽  
Thermoelectric Power ◽  
Thermoelectric Materials ◽  
High Efficiency ◽  
Thermoelectric Power Generation ◽  
Conversion Efficiencies

High efficiency Bi2Te3-based thermoelectric materials and devices with energy conversion efficiencies of up to 6.0% under a temperature gradient of 217 K.

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