Futures for hydrogen produced using nuclear energy

What is the future of hydrogen (H₂) produced from nuclear energy? Assuming that economically competitive nuclear H₂ can be produced, production of H₂ may become the primary use of nuclear energy and the basis for both a nuclear-H₂ renewable (solar, wind, etc.) energy economy and a nuclear-H₂ transport system. The technical and economic bases for these conclusions are described. In a nuclear-H₂ renewable energy economy, nuclear energy is used to produce H₂ that is stored and becomes the energy-storage component of the electrical generating system. The stored H₂ replaces piles of coal and tanks of liquid fuel. Capital-intensive renewable energy sources and nuclear reactors produce electricity at their full capacity. The stored H₂ is used in fuel cells to produce the highly variable quantities of electricity needed to fill the gap between the electricity demand by the customer and the electricity generated by the rest of the electrical generating system. Hydrogen is also used to produce the liquid or gaseous transport fuels. This energy-system architecture is a consequence of the fundamental differences between the characteristics of electricity (movement of electrons) and those of H₂ (movement of atoms). Electricity can be generated, transformed, and used economically on either a small or a large scale. However, it is difficult to generate, store, and transform H₂ economically on a small scale. This distinction favors the use of large-scale nuclear systems for H₂ production.     

田湾核电厂一回路水化学优化与辐射源项控制

压水堆核电厂一回路辐射场的影响因素众多,主要有两个方面,一是系统设备的材料,二是一回路水化学参数。本文对田湾核电厂溶解H₂、硼碱协调曲线控制、注Zn技术、停堆氧化对辐射源项的影响进行探讨,最后提出建议。     

Comparison of Investment and Related Requirements for Selected Hydrogen Vehicle System Pathways

A model was developed for production, transmission, delivery, and consumption of hydrogen for large-scale systems ultimately providing shaft-work for hydrogen-based vehicles. (See Glossary, after References). Presently, the supply technologies are limited to solar photovoltaic, wind, nuclear, and nuclear thermochemical sources. Transmission technologies include electric power, hydrogen pipeline, and liquid hydrocarbon pipeline. Delivery technologies include both liquid and gaseous hydrogen and liquid hydrocarbon. Storage modes were selected as appropriate for the pathway transmission and delivery modes. Finally, consumption technologies are fuel-cell based, with and without a fuel processor (reformer). Overall, there were 39 separate pathways in this initial analysis. Subsystem efficiencies, capital costs, and capacity factors were derived from a literature search and supported by calculations where necessary. Overall systems efficiency, system peak power capital costs, and systems average power capital costs were calculated to indicate the potential capital investment requirements. The model was exercised to assess the capital cost (and related aspects) requirements to provide the equivalent automobile shaftwork of eleven million barrels of oil per day by the year 2040 (the Administration's objective). These costs range from $650 billion to $11.7 trillion and primarily depend on the selected energy source. The results reveal that nuclear thermochemical systems based on liquid hydrocarbon transmission and delivery lie at the low-cost end of the range, followed by nuclear or wind electric, then nuclear or wind hydrogen pipeline, and finally by solar electric and solar hydrogen pipeline. It is noted that thermochemical systems based on liquid hydrocarbons was the least-cost option for all of the energy sources. One vehicle storage technology, chemical hydride, was determined to be too costly to be included for later analysis. The results were compared against what might be expected of fusion energy. It was found that fusion hydrogen plant capital costs did not compete with Nuclear or Wind (but did with current Solar Photovoltaics) unless fusion plants were very large. The model is planned to be expanded to include coal-based hydrogen production (with CO₂ sequestration) and extended to calculate the total cost of energy delivered to the wheels.     

Sustainable futures using nuclear energy

We present the role of nuclear energy in a sustainable future. This addresses the social, economic and environmental concerns of us all. Nuclear energy today avoids the emission of nearly two billion tonnes of greenhouse gases (GHGs) each year, thanks to over 400 reactors operating worldwide.

Nevertheless, there is no real recognition of real incentives for large-scale non-emitters like nuclear energy and for emissions avoidance in current Kyoto and other policies. These approaches rely heavily on conservation, renewables and efficiency. These measures alone also will not significantly reduce the atmospheric greenhouse burden, because the world is still growing. Also, our (the world's) future economic growth (in all countries) is tied to energy and electricity use. Our prosperity, the alleviation of poverty and the sustainability of the world depend on having a supply of emissions-free and safe energy.

Recent price hikes in fossil fuels and power blackouts also emphasize our need for reliable, safe and cheap power, as is offered by nuclear energy when coupled with effective and secure waste disposal.

A particularly important role for nuclear power in the future will be its links to the hydrogen economy. It is now recognised that the introduction of hydrogen into the transportation sector will benefit the environment only when low carbon sources, such as nuclear reactors, are the primary energy source for hydrogen production. The future could well be the Hydrogen Age. We show that a major reduction in GHGs worldwide can be obtained by nuclear-electric production of hydrogen, thus alleviating their potential effects on future generations. We also demonstrate a potential key synergism with renewable wind power in the hybrid production of distributed hydrogen. Thus, nuclear energy supports and enables the World in its journey to a sustainable, safe and secure energy future.     

Roles of nuclear energy in Japan's future energy systems

The roles of nuclear energy in Japan's future energy systems were analyzed from the viewpoint of securing stable energy supply and reducing carbon dioxide (CO₂) emissions. The MARKAL model, developed in the Energy Technology Systems Analysis Programme (ETSAP) of the IEA, was used for establishing several energy scenarios with different assumptions on the availability of nuclear energy, natural gas, and a CO₂ disposal option. Nuclear energy was assumed to apply for synthetic fuel production as well as for conventional electric power generation. By comparing the CO₂ emission and system costs between these energy scenarios, following results were obtained. Without nuclear energy, the CO₂ emissions will hardly be reduced because of substantial increases in coal utilization. CO₂ disposal will be effective in reducing the emissions, however at much higher costs than the case with nuclear energy. The expansion of natural gas imports, if alone, will not reduce the emissions at enough low levels.     

Safety aspects of the combined HTTR/steam reforming complex for nuclear hyrogen production

The High-Temperature Engineering Test Reactor (HTTR) in Oarai, Japan, has the potential to demonstrate the production of hydrogen by steam reforming and using nuclear process heat as primary energy input. Particular safety aspects for such a combined nuclear/chemical complex have been investigated such as fire and explosion hazard at presence of flammable gases (LNG, H₂, CO) near the reactor building. A methane vapor cloud in the open atmosphere or partially obstructed areas is highly unlikely to detonate and damage the reactor building. Theoretical assessments and experimental studies significant to the HTTR-steam reforming system, include the spreading and combustion behavior of cryogens and flammable gases providing the basis for a comprehensive safety analysis of the nuclear/chemical facility.     

Reducing future CO2 emissions — The role of nuclear energy

A study was made to analyze the potential of reducing CO₂ emissions and to identify important energy and technology options in future energy systems of Japan. The energy market optimum allocation model MARKAL was used for the analysis with a time horizon from 1990 to 2050.

The analytical procedures were as follows. First, a reference energy system was established by incorporating all important energy sources, energy carriers, and energy technologies that existed already or that might be introduced during the above time horizon. Second, future demand for energy services was estimated based on the two economic growth scenarios, high and low. Also, assumptions were made about the evolution of imported fuel prices, availability of energy resources, and so on. Third, under the above assumptions, the optimum energy and technology options were selected by minimizing a discounted system cost under different carbon tax schemes, and thereby the potential of reducing CO₂ emissions was analyzed.

The following results were obtained by the analysis. Without utilization of nuclear energy, the CO₂ emissions can be hardly stabilized at the 1990 emission level even in the case of the low economic growth and large scale deployment of CO₂ recovery and disposal assumed. A significant amount of fossil fuels will be used for power generation in order to meet the rapidly growing demand for electricity. Nuclear energy, by substituting fossil fuels for electric power generation, is expected to contribute to the reduction of CO₂ emissions. In addition, the average cost of reducing the emissions will be substantially lowered compared with a non nuclear scenario.     

Parametric study of sulfuric acid decomposer for hydrogen production

It is proposed to use a ceramic high-temperature heat exchanger as a sulfuric acid decomposer for hydrogen production within the sulfur–iodine thermo-chemical cycle portion of the hydrogen production process. In this cycle, hot helium from a nuclear reactor is used to heat the SI (sulfuric acid) feed components (H₂O, H₂SO₄, SO₃) to obtain appropriate conditions for the SI decomposition reaction. The inner walls of the SI decomposition channels of the decomposer are coated by a catalyst to decompose sulfur trioxide into sulfur dioxide and oxygen. The heat exchanger and decomposer are made of silicon carbide (SiC).

A three-dimensional computational model is developed to investigate fluid flow, heat transfer, chemical reaction, and stress analysis within the decomposer. Fluid/thermal/chemical analysis of the decomposer is conducted using FLUENT software. Thermal results of this analysis are exported to ANSYS software to perform a probabilistic failure analysis. Effects of using various channel geometries of the decomposer are investigated.     

Importance of nuclear generation in the struggles to reduce CO2 emission at Kansai Electric Power Co.

It has been pointed out in recent years that the potential impacts of global warming has been becoming more and more serious because of the rapid increase of anthropogenic CO₂ emission.

Japan's annual CO₂ emissions (fiscal 1994) amounted to 343 million tons of carbon. Although CO₂ emissions caused by fossil-fuel power generation accounted for 29.4% of total, on a sector basis, those directly from the energy conversion sector accounted for only 7.7%. Most CO₂ emissions (21.7% of total) resulted from electric power use in the industrial, commercial and domestic sectors. Thus, the reduction of CO₂ emissions caused by the use of electricity is a nationwide subject.

Understanding that both supply side and demand side approaches are necessary, Kansai Electric has been deploying “New ERA Strategy” as a comprehensive strategy to seek a potential for CO₂ reduction more broadly and deeply. Among a number of action items are the promotion of nuclear power generation, and improvement of overall energy efficiency, besides such demand side measures as leveling off the peak load.

The effectiveness of action items of the New ERA Strategy was evaluated in terms of CO₂ reduction. As a result, estimated CO₂ reduction related to nuclear power amounted to 88% of the total for fiscal 1995 in comparison with 1990, and that expected in 2000 is 84%. These results reconfirm that nuclear power is always the key to practical CO₂ reduction at present and in the future.

Comparison with candidate technology alternatives revealed that photovoltaic power generation needed 7 times greater rated capacity and 280 times larger area than nuclear power, so it is not realistic as a central power station alternative. The comparison also clarified that if wind power stations were constructed at all feasible sites in the Kansai region, they would not be a viable alternative to a single nuclear unit from CO₂ reduction viewpoint.     

Cost evaluation for centralized hydrogen production

Nuclear energy can provide heat and electricity to produce hydrogen. Thermo-chemical and electrical decomposition of water have been studied as a hydrogen source. In this study, the cost of hydrogen supply for transportation usage was evaluated. The total cost for a centralized hydrogen production consisted of production cost, delivery cost, and station cost. The total cost for hydrogen production using nuclear energy can be at least comparable to that of steam-methane reforming, if the cost of carbon dioxide fixation was included. The delivery cost can be reduced by optimizing the size of hydrogen production and delivery distances. The hydrogen station cost was found out to be about 50% of the hydrogen supply cost. The optimum thermal power of nuclear power plants for hydrogen production was estimated based on the cost evaluation.     

整体式除氚催化剂的制备及催化氧化性能

针对大型核设施产生的大流量废气的处理,发展低气阻的整体式催化剂尤为必要。本工作在整体式堇青石载体上生长分子筛涂层,以离子交换法负载活性组分Pt,获得的整体式催化剂具有高的金属分散度,达到了60%。使用该催化剂,在15℃、体积空速为10 000～40 000 h^-1、1.0%(体积分数)H₂的条件下实现大于99.9%的H₂转化率;在25℃、体积空速为50 000 h^-1、1.0%H₂的条件下实现H₂的完全转化。在更低的H₂浓度下(0.1%H₂和0.5%H₂),该催化剂在湿条件下的H₂转化率低于干条件下的H₂转化率,表明水蒸气会抑制室温催化活性。由于分子筛涂层较Al₂O₃涂层具有更低的吸水性,整体式Pt/sil-cord催化剂在湿条件下具有比Pt/Al₂O₃高得多的...     

Banquet Speech "Man's Conquest of Energy, Its Ecological and Human Consequences"

The world's energy resources suitable for power production are of two classes: (1) various channels of the continuous energy flux from extraterrestrial sources, and from the earth's interior, and (2) chemical, thermal, and nuclear energy stored in the outer part of the lithosphere and in the oceans. The continuous energy influxes are from: solar radiation, 178,000 × 1012 watts; geothermal energy, 32 × 1012 watts; and tidal energy, 3 × 1012 watts. Of the solar energy influx, the only fraction suitable at present for large-scale power production is the approximately 40,000 × 1012 watts expended in evaporation of water and in atmospheric and oceanic circulation. Of this, the world's potential water power is about 2.9 × 1012 watts. A very small fraction of the solar influx, 40 × 1012 watts, is stored chemically by photosynthesis. A minute fraction of this, stored during the geologic past, is the source of the energy of the fossil fuels, coal and petroleum. Tidal power is capable of large-scale development in a small number of coastal localities with a total potential power of about 64,000 megawatts. Of the sources of stored energy, geothermal energy is the least important. Installed capacity by 1970 is about 1,125 electrical megawatts, and the ultimate potential is estimated at about 60,000 megawatts, with a lifetime of probably less than a century. The largest sources of stored energy, other than nuclear, are the fossil fuels. The initial minable world reserves of coal and lignite are estimated to have been about 7.     

Synthesis of vertical graphene nanowalls by cracking n-dodecane using RF inductively-coupled plasma-enhanced chemical vapor deposition

A facile and controllable one-step method to treat liquid hydrocarbons and synthesize vertical graphene nanowalls has been developed by using the technique of inductively-coupled plasma-enhanced chemical vapor deposition for plasma cracking of n-dodecane.Herein,the morphology and microstructure of solid carbon material and graphene nanowalls are characterized in terms of different operating conditions,i.e.input power,H2/Ar ratio,injection rate and reaction temperature.The results reveal that the optimal operating conditions were 500 W,5:10,30μl min^-1 and 800℃ for the input power,H2/Ar ratio,injection rate and reaction temperature,respectively.In addition,the degree of graphitization and the gaseous product are analyzed by Raman spectroscopy and gas chromatography detection.It can be calculated from the Raman spectrum that the relative intensity of ID/IG is approximately 1.55,and I2D/IG is approximately 0.48,indicating that the graphene prepared from n-dodecane has a rich defect structure and a high degree of graphitization.By calculating the mass loading and detecting the outlet gas,we find that the cracking rate of n-dodecane is only 6%-7%and that the gaseous products below C2 mainly include CH4,C2H2,C2H4,C2H6 and H2.Among them,the proportion of hydrogen in the outlet gas of n-dodecane cracking ranges from 1.3%-15.1%under different hydrogen flows.Based on our research,we propose a brand new perspective for both liquid hydrocarbon treatment and other value-added product syntheses.     

LiH和LiT与H2O反应机理研究

氢材料在微量H₂O、CO₂、O₂和N₂存在下可能发生物理化学反应,使材料的物理品位下降。由于反应过程十分复杂,很难从实验上准确获取这类反应的最佳通道和具体产物信息,因此,从理论上研究氢材料分子的物理化学性质及其化学反应机制,了解化学反应过程具有十分重要的意义。本文使用Gaussian03软件包和Gaussview工具软件,在6-311G(d)全电子基函数水平上,应用二阶微扰理论优化得到了⁶LiH、⁶LiT与H₂O反应的中间体、过渡态及产物的结构,总能量,振动频率和零点能等。通过计算发现⁶LiH、⁶LiT均只有1个反应通道,⁶LiH与H₂O反应的焓变、活化能和反应速率常数分别为-156.99 kJ/mol、8.95 kJ/mol和3.75×10¹⁰(mol•dm^-3)^-1/s,⁶LiT与H₂O反应的焓变、活化能和反应速率常数分别为-159.02 kJ/mol、9.92 kJ/mol和1.72×10¹⁰ (mol•dm^-3)^-1/s。     

The role of nuclear power in the sustainable energy future of Korea

The purpose of this study is to analyze the role of nuclear power in the sustainable energy supply future of Korea. For this purpose, an energy-economy interaction model of the computational general equilibrium (CGE) approach, the Korean Energy and Environmental Policy model(KEEP) was adapted. The model is a non-linear optimization model that maximizes the discounted value of Korean economic utility. The model operates over the time horizon of 1995–2040 in annual steps.

Some scenarios are established in accordance with three possible nuclear growth rate and the strength of the carbon tax imposed. At first, business as usual(BAU) nuclear growth scenario was set up and maintaining the current installed capacity and phasing out the nuclear power options are considered. After that, the investigation has been done on each scenario in the case that a tax for CO₂ emission regulation was imposed.

Results show that limiting CO₂ emissions with a nuclear phase out scenario will have the most serious impact on the economic welfare compared with the other scenarios. If the CO₂ emission target will be imposed in Korea in the foreseeable future, nuclear power will play an important role in mitigating the economic impacts.

This analysis gives us a chance to consider the trade-offs between the most important energy issues of today-concerns with the risk of nuclear power, those involving future climate change, and energy security.     

Pu-H2相互作用的反应机理及电子密度分析

通过量子力学中密度泛函理论的相关方法和相对论有效原子实模型(RECP),应用Gaussian09程序对钚与氢气的相互作用进行了计算和分析。计算得到了钚与氢气的详细微观反应机理：Pu+H2→FC→TS→PuH2,优化了沿反应路径的特殊结构（能量极小点及过渡态）,并通过能量分析画出了势能剖面图。基于优化的几何结构,通过多种拓扑分析方法分析了反应路径中所有特殊结构的电子密度相关性质,如自旋密度分析、Mulliken自旋布居分析、电子定域泛函理论分析,得到了电子密度在反应过程中的详细变化。     

Design of a MT-DBD reactor for H_2S control

This study aimed to discuss the removal of hydrogen sulfide(H_2S)with non-thermal plasma produced by a multilayer tubular dielectric barrier discharge reactor,which is useful in the field of plasma environmental applications.We explored the influence of various factors upon H_2S removal efficiency(η_(H_2S))and energy yield(Ey),such as specific energy density(SED),initial concentration,gas flow velocity and the reactor configuration.The study showed that we can achieveη_(H_2S)of 91%and the best Ey of 3100 mg kWh~(-1)when we set the SED,gas flow velocity,initial H_2S concentration and layers of quartz tubes at 33.2 J 1~(-1),8.0 m s~(-1),30 mg m~(-3)and five layers,correspondingly.The average rate constant for the decomposition of hydrogen sulfide was 0.206 gm~(-3)s~(-1).In addition,we also presented the optimized working conditions,byproduct analysis and decomposition mechanism.     

Nuclear energy system for the global environmental regulation in Korea— Energy-economy interaction model analysis

Global environmental regulation such as limits on CO₂ emissions will change the energy cost as well as energy mix, and it will eventually affect the potential economic growth and future energy demand. The rise of energy price from the environmental regulation will encourage the efficiency increase of energy use, fuel switching and the substitution between the energy and the other factors of production like labour and capital. Such situations can be successfully simulated through an energy-economy model which permits two-way interaction between energy and economy.

An analysis on the role of nuclear energy system for meeting the global environmental constraint like CO₂ emission regulation, has been performed through an energy-economy interaction model - EFOM-MACRO-KOREA.

In case carbon taxation which is a widely discussed policy measure for CO₂ abatement should be introduced, the role of nuclear energy in the domestic sustainable energy system as well as the economic impacts has been assessed. For the analysis, various scenarios in tax rate have been considered. Levying carbon tax will decrease future economic growth, and the decrease will be bigger in case that there are some restrictions on nuclear installation. It is shown that nuclear energy system will play an important role in Korean sustainable development up to 2040 in most cases.     

应用于等离子体排灰气处理的甲烷水汽重整反应的热力学分析

Tokamak装置中的等离子体反应一段时间后,需对产生的排灰气进行净化处理,以回收其中的氘氚。目前拟采用甲烷水汽重整反应将化合态的氘氚转化为单质并回收。本文运用Gibbs自由能最小化方法,对应用于等离子体排灰气处理的水汽重整反应进行热力学分析,考查反应温度、原料比例、反应压力、O₂、CO₂、H₂、CO等因素对反应平衡的影响,确定了适宜的反应条件,即反应温度范围650～700 ℃,压力1×105 Pa,水碳比1.5～2.0。此外,原料气中O₂或CO₂的存在有利于减少积碳的生成量,并获得较高的氢同位素平衡转化率;H₂的存在对重整反应的热力学平衡无明显影响;CO的存在会使积碳量增加,对反应产生不利影响,在进入重整反应器前应将其去除。     

硼氢化物(B2Hn)(n=1~6)电子特性的动力学研究

采用密度泛函(DFT)B3P86方法,结合Dunning的相关一致三重基cc-pVTZ,优化计算硼氢化物 (B₂H_n) (n=1~6)可能的几何构型,得出最稳定结构的几何参数、电子结构和振动频率等参数,给出了最稳定结构的总能量(E_T)、结合能(E_BT)、平均结合能(E_av)、电离势(E_IP)、能隙(E_g)、费米能级(E_F)和氢原子差分吸附能(E_diff)等。结果表明,硼氢化物基态稳定结构的电子态分别为：n为奇数时为双重态2A,n为偶数时为单重态1A。由于B原子属于缺电子原子,能与等电子原子H化合,通过桥键形成多中心键的氢化物,优化计算发现,硼氢化物最稳定结构都存在桥键,且n为奇数的桥键作用比相邻偶数的强。通过分析最稳定结构的电子特性发现,B₂H_n(n=1~6)中B₂H₆的电离势和能隙最大,桥键比端键长,红外光谱强度最大,说明该硼氢化物最稳定,且其氢原子差分吸附能最大,储氢性能相对最好。