Sustainability by combining nuclear,fossil, and renewable energy sources

The energy industries face two sustainability challenges: the need to avoid climate change and the need to replace traditional crude oil as the basis of our transport system. Radical changes in our energy system will be required to meet these challenges. These challenges may require tight coupling of different energy sources (nuclear, fossil, and renewable) to produce liquid fuels for transportation, match electricity production to electricity demand, and meet other energy needs. This implies a paradigm shift in which different energy sources are integrated together, rather than being considered separate entities that compete. Several examples of combined-energy systems are described. High-temperature nuclear heat may increase worldwide light crude oil resources by an order of magnitude while reducing greenhouse gas releases from the production of liquid fossil fuels. Nuclear–biomass liquid-fuels production systems could potentially meet world needs for liquid transport fuels. Nuclear–hydrogen peak power systems may enable renewable electricity sources to meet much of the world's electric demand by providing electricity when the wind does not blow and the sun does not shine.     

The nuclear fuel cycle

In the first half of the 21st century, a redistribution of the energy data should occur, where nuclear will play a more important role, particularly as coal will become more and more costly to extract.On a worldwide basis, the unability of oil to be replaced in some areas like transportation, and the difficulty of developing countries to find substitutes for this energy source, could also lead developed countries to keep the energy resources for a better utilization, and give the countries which have no access to other resources, a possibility to develop.Thus, France has extensively enhanced nuclear energy for its electricity production, and, consequently, makes the necessary efforts for the knowledge of the whole fuel cycle.     

South Africa's opportunity to maximise the role of nuclear power in a global hydrogen economy

Global concern for increased energy demand, increased cost of natural gas and petroleum, energy security and environmental degradation are leading to heightened interest in using nuclear energy and hydrogen to leverage existing hydrocarbon reserves. The wasteful use of hydrocarbons can be minimised by using nuclear as a source of energy and water as a source of hydrogen. Virtually all hydrogen today is produced from fossil fuels, which give rise to CO₂ emissions. Hydrogen can be cleanly produced from water (without CO₂ pollution) by using nuclear energy to generate the required electricity and/or process heat to split the water molecule. Once the clean hydrogen has been produced, it can be used as feedstock to fuel cell technologies, or in the nearer term as feedstock to a coal-to-liquids process to produce cleaner synthetic liquid fuels. Clean liquid fuels from coal - using hydrogen generated from nuclear energy - is an intermediate step for using hydrogen to reduce pollution in the transport sector; simultaneously addressing energy security concerns. Several promising water-splitting technologies have been identified. Thermo-chemical water-splitting and high-temperature steam electrolysis technologies require process temperatures in the range of 850 °C and higher for the efficient production of hydrogen. The pebble bed modular reactor (PBMR), under development in South Africa, is ideally suited to generate both high-temperature process heat and electricity for the production of hydrogen. This paper will discuss South Africa's opportunity to maximise the use of its nuclear technology and national resources in a global hydrogen economy.     

Nuclear energy for transportation: Paths through electricity, hydrogen and liquid fuels

The transportation sector consumes about a quarter of final energy in Japan and worldwide, and presently most of the energy is supplied by petroleum. For global environment and resources, it is important to seek possibilities of replacing a substantial part of the transportation energy by nuclear energy.

For supplying nuclear energy to the transportation sector, investigated are the paths through such ‘energy carriers’ as electricity, hydrogen and synthetic liquid fuels, to the means of transportation such as automobiles. These energy carriers can be produced from nuclear energy, by itself or synergistically with other primary energies like fossil fuels or biomass.

In this paper, possibilities and impacts of these energy carriers to power transportation means are reviewed, and measures and tasks to supply these energy carriers from nuclear energy are examined.

In converting the primary energies into the energy carriers, the synergistic process may be more advantageous than the individual process. Some of the exploratory processes to produce synthetic liquid fuels from fossil fuels and nuclear energy are presented.     

成熟市场经济国家铀矿业活动一瞥

铀是重要的能源矿产和战略资源,在成熟市场经济国家里,能源矿产勘查属商业性矿产勘查活动。铀勘查活动风险大、回报高,成熟市场经济国家用法规、纳税、环保等规则规范铀勘查活动。中国今后也将把煤炭、油气、铀、油页岩、煤层气等能源矿产放在商业性矿产勘查的首位,了解成熟市场经济国家铀勘查活动的现状十分必要。     

An accelerated fusion power development plan

Energy for electricity and transportation is a national issue with worldwide environmental and political implications. The world must have energy options for the next century that are not vulnerable to possible disruption for technical, environmental, public confidence, or other reasons. Growing concerns about the greenhouse effect and the safety of transporting oil may lead to reduced burning of coal and other fossil fuels, and the incidents at Three Mile Island and Chernobyl, as well as nuclear waste storage problems, have eroded public acceptance of nuclear fission. Meeting future world energy needs will require improvements in energy efficiency and conservation. However, the world will soon need new central station power plants and increasing amounts of fuel for the transportation sector. The use of fossil fuels, and possibly even fission power, will very likely be restricted because of environmental, safety, and, eventually, supply considerations. Time is running out for policymakers. New energy technologies cannot be brought to the marketplace overnight. Decades are required to bring a new energy production technology from conception to full market penetration. With the added urgency to mitigate deleterious environmental effects of energy use, policymakers must act decisively now to establish and support vigorous energy technology development programs. The U.S. has invested $8 billion over the past 40 years in fusion research and development. If the U.S. fusion program proceeds according to its present strategy, an additional 40 years, and more money, will be expended before fusion will provide commercial electricity. Such an extended schedule is neither cost-effective nor technically necessary. It is time to launch a national venture to construct and operate a fusion power pilot plant. Such a plant could be operational within 15 years of a national commitment to proceed.Prepared Under Contract for the Agency for Advancement of Fusion Power, Inc., George S. Clemens, President.     

The tokamak hybrid reactor

At a time when the potential benefits of various energy options are being seriously evaluated in many countries throughout the world, it is both timely and important to evaluate the practical application of fusion reactors for their economical production of nuclear fissile fuels from fertile fuels. The fusion hybrid reactor represents a concept that could assure the availability of adequate fuel supplies for a proven nuclear technology and have the potential of being an electrical energy source as opposed to an energy consumer as are the present fuel enrichment processes. Westinghouse Fusion Power Systems Department, under Contract No. EG-77-C-02-4544 with the Department of Energy, Office of Fusion Energy, has developed a preliminary conceptual design for an early twenty-first century fusion hybrid reactor called the Commercial Tokamak Hybrid Reactor (CTHR) [1]. This design was developed as a first generation commercial plant producing fissile fuel to support a significant number of ‘client’ Light Water Reactor (LWR) Plants. To the depth this study has been performed, no insurmountable technical problems have been identified. The study has provided a basis for reasonable cost estimates of the hybrid plants as well as the hybrid/LWR system busbar electricity costs. This energy system can be optimized to have a net cost of busbar electricity that is equivalent to the conventional LWR plant, yet is not dependent on uranium ore prices or standard enrichment costs, since the fusion hybrid can be fueled by numerous fertile fuel resources. A nearer-term concept is also defined using a beam driven fusion driver in lieu of the longer term ignited operating mode.     

Safety characteristics of the multipurpose fast reactor (MPFR)

The safety characteristics of a long-life multipurpose nuclear reactor (MPFR) with self-sustained liquid metallic fuel and lead coolant, which is proposed to meet the requirements for the energy production in the future, were investigated. The application of liquid plutonium–uranium metallic alloys used as a nuclear fuel demonstrated high potential to reach excellent reactor shutdown characteristics against anticipated transients without scram such as unprotected loss-of-flow and unprotected transient overpower. The calculations indicated that the thermal expansion of liquid fuels would cause the negative reactivity insertion that would be larger in magnitude than any other thermally induced reactivity changes. This created the reactivity balance for the passive shutdown and power stabilization capabilities of the MPFR core. It was found that MPFR satisfies such design characteristics to be a potential candidate providing the replacement of fossil fuels by alternative energy sources in the next century.     

Nuclear fuel considerations for the 21 century

There are many external influences that may control the path that nuclear power deployment follows. In the next 50 years several events may unfold. Fear of the consequences of the greenhouse effect may produce a carbon tax that would make nuclear power economically superior very quickly. This, in turn, would increase the rate at which uranium reserves diminish due to the increased rate of nuclear power deployment. However, breakthroughs in the extraction of uranium from the sea or deployment of fast breeder reactors would greatly extend the uranium reserves and, as well, utilize the thorium cycle.On the other hand, carbon sequestering technology breakthroughs could keep fossil fuels dominant for the remainder of the century. Nuclear power may only then continue, as today, in a lesser role or even diminish. Fusion power or new developments in solar power could completely displace nuclear power as we know it today.Even more difficult to predict is when the demand for mobile fuel for transportation will develop such that hydrogen and hydrogen rich fuel cells will be in common use. When this happens, nuclear power may be the energy source of choice to produce this fuel from water or methane. In a similar vein, the demand for potable and irrigation water may be another driver for the advent of increased deployment of nuclear power.With all these possibilities of events that could happen it appears impossible to predict with any certainty which path nuclear power deployment may take. However, it is necessary to define a strategy that is flexible enough to insure that when a technology is needed, it is ready to be deployed.For the next few decades there will be an evolutionary improvement in the performance of uranium oxide and mixed uranium oxide-plutonium oxide (MOX) LWR fuels. These improvements will be market driven to keep the cost of fuel and the resulting cost of nuclear power electricity as competitive as possible. The development of fuels for accelerator transmutation and for reactor transmutation with inert matrix fuels is in its infancy. A great deal of research has been initiated in a number of countries, which has been summarized in recent conferences. In Europe the work on these fuels is directed at the same problem as their utilization of MOX; namely to reduce the inventory of separated plutonium, minor actinides, and Long Lived Fission Products (LLFP). In the United States there is no reprocessing and thus no inventory of separated civilian plutonium. However, in the United States there is a resistance to a permanent spent fuel repository and thus accelerator transmutation presents a possible alternative. If nuclear power does have a long-term future, then the introduction of the fast reactor is inevitable. Included in the mission of the fast reactors would be the elimination of the inventory of separated plutonium while generating useful energy. The work that is ongoing now on the development of fuel concepts for assemblies that contain actinides and LLFP would be useful for fast reactor transmutation.There is still a great deal of work required to bring the fast breeder reactor option to maturity. Fortunately there is perhaps a fifty-year period to accomplish this work before fast breeders are necessary. With regard to fast reactor fuel development, future work should be considered in three stages. First, all the information obtained over the past forty years of fast reactor fuel development should be completely documented in a manner that future generations can readily retrieve and utilize the information. Fast reactor development came to such an abrupt halt world-wide that a great deal of information is in danger of being lost because most of the researchers and facilities are rapidly disappearing. Secondly, for all of the existing fast reactor fuels, and this includes, oxides, carbides, nitrides, and metallic fuels, the evolutionary work was far from being completed. Although mixed oxide fuels were probably the furthest advanced, there were many concepts for improved claddings and advanced fabrication methods that were never fully explored. Finally, with such an extended period before fast reactors are needed there is ample time for truly innovative fuels to be developed that are capable of performing over a wide range of conditions and coolants.     

What is the potential use of thorium in the future energy production technology?

Today's nuclear technology has principally been based on the use of fissile U-235 and Pu-239. While the natural thorium isotope Th-232 can finally be transformed to a fissile U-233 nucleus following a thermal neutron capture reaction, the existence of thorium in the nature and its potential use in the nuclear technology were not unfortunately into account with a sufficient importance. This was probably because of the geological availability of natural resources of thorium and uranium. Global distributions of thorium and uranium reserves clearly indicate that in general some developed countries such as the USA, Canada, Australia have considerable uranium reserves and contrarily only some developing countries such as Brazil, Turkey, India, Egypt have considerable thorium reserves as being totally about 70 % of the global reserve. All technical parameters obtained from the studies on thorium fuel cycle during the last 50 years indicate that thorium fuel cycle can be used in most of reactor types already operated. In addition, accelerated-driven hybrid systems promise to use the thorium based nuclear fuels. So, thorium will probably be a nuclear material much more valuable than uranium in the future. For this reason, all developing countries having thorium reserves should focus their technological attentions to the evaluation of their national thorium resources like in the case of India. In this paper a brief story on the studies of thorium and its potential use in the future energy production technology have been summarized.     

A concept of the multipurpose liquid metallic-fueled fast reactor system (MPFR)

Against fossil fuels, the nuclear energy is the only alternative energy source in the next century. Such energy source as the future nuclear power plant is expected to meet the following requirements. First, high temperature output for the multiple energy conversion capability as the electricity generation and the production of alternative fuels (hydrogen), which can be used widely in transportation systems. Second, the capability for siting close to the energy consumption area without onsite refueling. Third, the capability for nuclear fuel breeding and incineration of long-lived fission products, and fourth, the harmonization between active and passive safety features. This paper describes the basic concept of the Multipurpose liquid metallic-fueled Fast Reactor system (MPFR), which satisfies all mentioned requirements with introducing the U-Pu-x (x: Mn, Fe, Co) liquid metallic alloys for the fuel. We can obtain such characteristics as high operational temperature of the reactor (between 550 °C and 1200 °C) and elongation of the core operational lifetime by the inherent fission product separation in the liquid fuel by using these alloys. The enhanced self-controllability is achieved by the thermal expansion of liquid fuel; and the re-criticality phenomenon at the core compaction events can be eliminated by discharging of the liquid fuel from the core.     

新世纪初全球铀矿山生产的基本态势

新世纪初，全球铀矿山产量略有下降，铀的现货价则明显有上涨势头。全球核电耗铀量未出现大波动，总体平淡。虽然铀矿山生产出现若干突发事件，但是铀生产整体呈平稳状态。铀的供需基本平衡。在新世纪初的全球铀矿山产量中，来自硬岩铀矿的产量依旧是主角，而来自可地浸砂岩铀矿的产量小幅度增长，并占全球矿山总铀产量的1／5。少数跨国铀业公司已成为世界各地低成本铀矿生产中心的主要股东，全球大部分开采中的铀矿床、铀生产中心主要集中在少数几个国家中。铀资源全球化配置的世界经济全球化进程已在铀矿业界中初具雏形。     

The design of the Prototype Fast Breeder Reactor

India has a moderate uranium reserve and a large thorium reserve. The primary energy resource for electricity generation in the country is coal. The potential of other resources like gas, oil, wind, solar and biomass is very limited. The only viable and sustainable resource is the nuclear energy. Presently, Pressurised Heavy Water Reactors utilizing natural uranium are in operation/under construction and the plutonium generated from these reactors will be multiplied through breeding in fast breeder reactors. The successful construction, commissioning and operation of Fast Breeder Test Reactor at Kalpakkam has given confidence to embark on the construction of the Prototype Fast Breeder Reactor (PFBR). This paper describes the salient design features of PFBR including the design of the reactor core, reactor assembly, main heat transport systems, component handling, steam water system, electrical power systems, instrumentation and control, plant layout, safety and research and development.     

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.     

Synergistic hydrogen production by nuclear-heated steam reforming of fossil fuels

Processes and technologies to produce hydrogen synergistically by the nuclear-heated steam reforming reaction of fossil fuels are reviewed. Formulas of chemical reactions, required heats for reactions, saving of fuel consumption, reduction of carbon dioxide emission, and possible processes are investigated for such fossil fuels as natural gas, petroleum and coal.

In this investigation, examined are the steam reforming processes using the “membrane reformer” and adopting the recirculation of reaction products in a closed loop configuration. The recirculation-type membrane reformer process is considered to be the most advantageous among various synergistic hydrogen production processes. Typical merits of this process are; nuclear heat supply at medium temperature around 550°C, compact plant size and membrane area for hydrogen production, efficient conversion of a feed fossil fuel, appreciable reduction of carbon dioxide emission, high purity hydrogen without any additional process, and ease of separating carbon dioxide for future sequestration requirements.

The synergistic hydrogen production using fossil fuels and nuclear energy can be an effective solution in this century for the world which has to use fossil fuels to some extent, according to various estimates of global energy supply, while reducing carbon dioxide emission.     

煤型铀矿井辐射防护的技术措施和工程管理措施

我国煤型铀矿资源的储量在我国铀矿资源总储量中占有一定比例.20世纪60年代后期我国开始了这类铀矿床的地下开采,在开采期间,对控制这类铀矿床地下开采中辐射危害的技术与管理措施开展了大量研究.20世纪80年代后期,因为多种原因,这类矿山被关闭.近年来,我国电力持续出现紧缺,经济建设受到严重影响,为了缓解这种局势,国家决定大力发展核电.在这样的形势下,煤型铀矿床的开采又提到了议事日程.为了使这类铀矿床地下开采中的辐射防护受到高度重视、辐射危害得到有效控制,本文介绍了煤型铀矿井辐射防护的基本知识、煤型铀矿井各类辐射对人体的危害、我国煤型铀矿井执行的剂量标准以及我国过去在煤型铀矿床地下开采中为控制辐射危害所采取的技术措施和工程管理措施.     

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.     

Energy sustainability and economic stability with Breed and Burn reactors

The purpose of the present study is to evaluate the impact a successful development of Breed and Burn (B&B) fast reactors and their fuel reconditioning technologies could have on the uranium ore utilization, uranium enrichment capacity, nuclear waste and energy security. It is found that a successful development of B&B reactors will offer 40-folds increase in the uranium ore utilization versus that presently achieved. A successful development of a fuel reconditioning technology could increase the attainable uranium utilization to 100-folds its present value. The growth rate of the installed capacity of B&B reactors possible to achieve using the “spawning” mode of operation is estimated to be nearly 4% per year. The amount of natural uranium required for starting a fleet of B&B reactors that will reach an electricity generation capacity of 1000 GWe by the end of this century is estimated to be the equivalent of 10 years of supply to the presently operating commercial fleet of LWRs in the US (86 GWe). No natural uranium and no enrichment capacity will be required to support this fleet beyond the later part of this century. The energy value of the depleted uranium stockpiles (“waste”) that will be accumulated in the US by that time is equivalent to, when used in the B&B reactors, up to 20 centuries of the total 2010 supply of electricity in the USA. It is therefore concluded that a successful development of B&B reactors and associated fuel reconditioning could provide a great measure of energy security, proliferation resistance and cost stability.     

加速增产核燃料的天然安全“核热泉”快中子增殖堆

为保证21世纪中国经济的持续稳定地高速增长,必须充分发挥核能的巨大潜力,使之配合其他可再生能源同步增长,及早大规模替代煤炭等化石能源。由于目前国内大量兴建的核电站以压水堆为主,需要消费大量天然铀资源,倚靠廉价铀供应难于维持长期增长,必须依靠快中子增殖生产人造裂变燃料——钚,才能摆脱天然铀原料短缺的束缚。然而,传统的快中子增殖堆的核燃料增产速度较慢,难于配合中国核电的高速增长。本文介绍一种先进快中子增殖堆(AFBR)方案,其中利用在线连续换料的空心球形燃料元件,依靠载热剂的出入口之间的温度差实现满功率自然循环,可以成倍地提高燃料比功率与核燃料增殖速度。本快中子增殖堆改进了俄罗斯称为"天然安全"的BREST铅冷快堆设计方案,成为无须人为控制的"核热泉",它能在不设置加压泵及高位铅池的情况下,自动按外部负荷需要供应必要的热量,完全依靠自然循环将全部裂变热能及停堆后堆芯余热散出,不至对环境产生放射性污染。     

世界铀资源概况

随着核电技术的逐步成熟和完善,核电作为一种清洁、高效、绿色的能源已为人们所接受。新一轮核电建设热潮已经掀起,未来25 a内,全球将新建100～300座核电站。随之而来,对核电站燃料天然铀已引起足够的重视。世界各大铀矿业公司加紧了对铀资源的勘探和开发力度。铀资源已经成为世界核领域的焦点之一。简要介绍了世界铀资源、铀勘查、铀生产、铀需求、铀价格,以及分析了近年铀价走势原因。