Analysis of possible geological storage of CO2 and nuclear waste in Lithuania

Lithuania is currently dealing with two major problems in energy sector: final closure of Ignalina Nuclear Power plant (Ignalina NPP) in the end of 2009 and nuclear waste disposal and climate change mitigation issues having in mind replacement of nuclear capacities with fossil one and anticipated increase in GHG emissions. Lithuania has two options: to construct new nuclear power plant also taking into account nuclear waste disposal issue or to burn fossil fuel and to apply carbon capture and storage (CCS) for GHG emission reduction. These two options need to be investigated in Lithuania based on various studies conducted in Lithuania and abroad dealing with geological carbon storage and nuclear waste disposal potentials. There are no long-lived nuclear waste geological storage capacities in Lithuania and there is no pilot project on CCS developed in Lithuania. The aim of the article is to analyse and compare geological carbon and nuclear waste storage opportunities in Lithuania and to assess nuclear and carbon capture and storage technologies in terms of costs.     

我国核电及核能产业发展前景

从减排、能源结构调整、环境保护角度分析核电在我国能源结构和我国科技体系中的定位及核电发展的必要性,根据我国运行核电厂的实际情况和自主设计的先进核电厂特性说明核电的安全性,同时根据运行核电厂放射性排放数据论述核电厂对环境和公众不造成任何有害的影响,并对核燃料循环、核废物对策和处理措施进行了论述。预测核电中长期发展情景,通过评估核电及配套核燃料产业能力,以及装备及相关行业发展情况,表明我国工业基础能够支撑核电的规模化发展;并反过来,核电将促进相关行业大发展,提高其技术水平,高科技含量,发展成高端产业,有利于我国经济转型。     

The energy and environmental implications of UK more electric transition pathways: A whole systems perspective

Electricity generation contributes a large proportion of the total greenhouse gas emissions in the United Kingdom (UK), due to the predominant use of fossil fuel (coal and natural gas) inputs. Indeed, the various power sector technologies [fossil fuel plants with and without carbon capture and storage (CCS), nuclear power stations, and renewable energy technologies (available on a large and small {or domestic} scale)] all involve differing environmental impacts and other risks. Three transition pathways for a more electric future out to 2050 have therefore been evaluated in terms of their life-cycle energy and environmental performance within a broader sustainability framework. An integrated approach is used here to assess the impact of such pathways, employing both energy analysis and environmental life-cycle assessment (LCA), applied on a ‘whole systems’ basis: from ‘cradle-to-gate’. The present study highlights the significance of ‘upstream emissions’, in contrast to power plant operational or ‘stack’ emissions, and their (technological and policy) implications. Upstream environmental burdens arise from the need to expend energy resources in order to deliver, for example, fuel to a power station. They include the energy requirements for extraction, processing/refining, transport, and fabrication, as well as methane leakage that occurs in coal mining activities – a major cotribution – and from natural gas pipelines. The impact of upstream emissions on the carbon performance of various low carbon electricity generators [such as large-scale combined heat and power (CHP) plant and CCS] and the pathways distinguish the present findings from those of other UK analysts. It suggests that CCS is likely to deliver only a 70% reduction in carbon emissions on a whole system basis, in contrast to the normal presumption of a 90% reduction. Similar results applied to other power generators.     

Efficient utilization of waste heat from molten carbonate fuel cell in parabolic trough power plant for electricity and hydrogen coproduction

Direct steam generating parabolic trough power plant is an important technology to match future electric energy demand. One of the problems related to its emergence is energy storage. Solar-to-hydrogen is a promising technology for solar energy storage. Electrolysis is among the most processes of hydrogen production recently investigated. High temperature steam electrolysis is a clean process to efficiently produce hydrogen. In this paper, steam electrolysis process using solar energy is used to produce hydrogen. A heat recovery steam generator generates high temperature steam thanks to the molten carbonate fuel cell's waste heat. The analytical study investigates the energy efficiency of solar power plant, molten carbonate fuel cell and electrolyser. The impact of waste heat utilization on electricity and hydrogen generation is analysed. The results of calculations done with MATLAB software show that fuel cell produces 7.73 MWth of thermal energy at design conditions. 73.37 tonnes of hydrogen and 14.26 GWh of electricity are yearly produced. The annual energy efficiency of electrolyser is 70% while the annual mean electric efficiency of solar power plant is 18.30%.The proposed configuration based on the yearly electricity production and hydrogen generation has presented a good performance.     

Future regional nuclear fuel cycle cooperation in East Asia: Energy security costs and benefits

Economic growth in East Asia has rapidly increased regional energy, and especially, electricity needs. Many of the countries of East Asia have sought or are seeking to diversify their energy sources and bolster their energy supply and/or environmental security by developing nuclear power. Rapid development of nuclear power in East Asia brings with it concerns regarding nuclear weapons proliferation associated with uranium enrichment and spent nuclear fuel management. This article summarizes the development and analysis of four different scenarios of nuclear fuel cycle management in East Asia, including a scenario where each major nuclear power user develops uranium enrichment and reprocessing of spent fuel individually, scenarios featuring cooperation in the full fuel cycle, and a scenario where reprocessing is avoided in favor of dry cask storage of spent fuel. The material inputs and outputs and costs of key fuel cycle elements under each scenario are summarized.     

A study of the probabilistic risk assessment to the dry storage system of spent nuclear fuel

Due to the large power supply in the energy market since 1960s, the nuclear power planets have been consistently constructed throughout the world in order to maintain and supply sufficient fundamental power generation. Up to now, most of the planets have been operated to a point where the spent fuel pool has reached its design capacity volume. To prevent the plant from shutdown due to the spent fuel pool exceeding the design capacity, the dry cask storage can provides a solution for both the spent fuel pool capacity and the mid-term storage method for the spent fuel bundles at nuclear power planet.     

A key review on emergy analysis and assessment of biomass resources for a sustainable future

The present study comprehensively reviews emergy analysis and performance evaluation of biomass energy. Biomass resources utilization technologies include (a) bioethanol production, (b) biomass for bio-oil, (c) biodiesel production, (d) straw as fuel in district heating plants, (e) electricity from Municipal Solid Waste (MSW) incineration power plant, (f) electricity from waste landfill gas. Systems diagrams of biomass, which are to conduct a critical inventory of processes, storage, and flows that are important to the system under consideration and are therefore necessary to evaluate, for biomasses are given. Emergy indicators, such as percent renewable (PR), emergy yield ratio (EYR), environmental load ratio (ELR) and environmental sustainability index (ESI) are shown to evaluate the environmental load and local sustainability of the biomass energy. The emergy indicators show that bio-fuels from crop are not sustainable and waste management for fuels provides an emergy recovery even lower than mining fossil fuel.     

Nuclear power and the environment: comparative assessment of environmental and health impacts of electricity-generating systems

This paper deals with comparative assessment of the environmental and health impacts of nuclear and other electricity-generation systems. The study includes normal operations and accidents in the full energy chain analysis. The comparison of environmental impacts arising from the waste-management cycles associated with non-emission waste are also discussed. Nuclear power, while economically feasible and meeting 17% of the world's demand for electricity, is almost free of the air polluting gases that threaten the global climate. Comparing nuclear power with other sources for electricity generation in terms of their associated environmental releases of pollutant such as SO₂, NOX, CO₂, CH₄ and radioisotopes, taking into account the full fuel chains of supply option, nuclear power will help to reduce environmental degradation due to electricity generation activities. In view of CO₂ emission, the ranking order commences with hydro, followed by nuclear, wind and photovoltaic power plants. CO₂ emissions from a nuclear power plant are by two orders of magnitude lower than those of fossil-fuelled power plants. A consequent risk comparison between different energy sources has to include all phases of the whole energy cycle. Coal mine accidents have resulted in several 1000 acute deaths over the years. Then came hydropower, also resulting in many catastrophes and loss of human lives, followed by the oil and gas energy industries, last in the list is commercial nuclear energy, which has had a “bad” press because of the Chernobyl accident, resulting officially in 31 acute fatalities, and at least 145 latent fatalities. The paper offers some findings and conclusions on the role of nuclear power in protecting the global environment.     

Carbon capture and storage potential in coal-fired plant in Malaysia—A review

Secure, reliable and affordable energy supplies are necessary for sustainable economic growth, but increases in associated carbon dioxide (CO₂) emissions, and the associated risk of climate change are a cause of major concern. Experts have projected that the CO₂ emissions related to the energy sector will increase 130% by 2050 in the absence of new policies or supply constraints as a result of increased fossil fuel usage. To address this issue will require an energy technology revolution involving greater energy efficiency, increased renewable energies and nuclear power, and the near-decarbonisation of fossil fuel-based power generation. Nonetheless, fossil fuel usage is expected to continue to dominate global energy supply. The only technology available to mitigate greenhouse gas (GHG) emissions from large-scale fossil fuel usage is carbon capture and storage (CCS), an essential part of the portfolio of technologies that is needed to achieve deep global emission reductions. However, CCS technology faces numerous issues and challenges before it can be successfully deployed. With Malaysia has recently pledged a 40% carbon reduction by 2020 in the Copenhagen 2009 Climate Summit, CCS technology is seen as a viable option in order to achieve its target. Thus, this paper studies the potential and feasibility of coal-fired power plant with CCS technology in Malaysia which includes the choices of coal plants and types of capture technologies possible for implementation.     

Grid-connected intermittent renewables are the last to be stored

When hydroelectric power systems became widespread, associated developments for energy storage, using pumped water, soon followed. Many other methods of storage have since been considered. Today's interest in other renewables, notably wind energy has led to assertions that, because it is intermittent, wind can make no contribution to the firm power on a power system (i.e., it has no capacity credit) but that storage can make it viable. Here we show that such assertions about intermittent renewables like wind are false – they can and do make contributions to firm power and storage has no special contribution to make for them. However, their main contribution is to fuel saving and storage is counter-productive for that because the losses in the storage and regeneration round-trip would represent a waste of fuel that had already been saved. More importantly, the energy being stored comes from those generators that were the last ones brought on line to supply the extra energy that is being stored, which would be the first to be shut down if the storage stopped, e.g., because the store was full or had broken down. These will be (marginally) the most expensive generation on line, the (marginally) cheapest generation always having being used first. Renewables have no fuel costs, so their (marginal) cost is zero, which must always make them (marginally) the cheapest power on the system, whenever they are available. So they will always be the last to be shut down or stored. When storage is installed, grid-connected intermittent renewables like wind energy will never be stored unless nothing else is available.     

Fourteen lessons learned from the successful nuclear power program of the Republic of Korea

This paper summarized a development history and lessons of Korean nuclear power infrastructures from the beginning of the nuclear power program in 1956 to the localization of complete scope of PWR technology in 1990. The objective of this paper is to show the guideline on the issues that the development of a national infrastructure for nuclear power using the realistic experiences in order to help the developing countries newly starting nuclear power program as a long-term energy supply option. Development strategies and lessons learned from the successful Korean experience have been presented based on milestones structure of IAEA in order to help decision makers, advisers, senior managers and national planners of nuclear power program. Lessons for national nuclear power programs include considerations before launching a program, preparation and decision making, and the construction of the first nuclear power plant. Scope of these lessons includes knowledge and human resources management, financial and industrial infrastructure development, nuclear safety, legislative and regulatory experiences, fuel cycle and waste management, international cooperation. Fourteen lessons learned either positive or not are derived from the Korean case and are suggested for incorporation in the IAEA's efforts in support of developing countries’ development of nuclear infrastructure and planning.     

Performance evaluation of an energy recovery system for fuel reforming of PEM fuel cell power plants

This paper describes an energy recovery system that recovers waste thermal energy from a fuel cell stack and uses it for fuel reforming purposes. The energy recovery system includes a throttling valve, a heat exchanger, and a compressor, and is coupled with a coolant loop of the fuel cell stack. The feed stock of a fuel reformer, which is primarily a mixture of water and fuel, is vaporized in the heat exchanger and is compressed to a sufficiently high pressure before it is ducted into the fuel reformer. The performance of a fuel cell power plant equipped with the energy recovery system is evaluated. The results indicate that the power plant efficiency can be increased by more than 40% compared to that of a fuel cell power plant without the energy recovery system. Additionally, up to 90% of the waste heat generated in the fuel cell stack is recovered. As a result, the required heat dissipation capacity of the radiator that is used for cooling the fuel cell stack can be drastically reduced.     

Experimental investigation on heat recovery from diesel engine exhaust using finned shell and tube heat exchanger and thermal storage system

The exhaust gas from an internal combustion engine carries away about 30% of the heat of combustion. The energy available in the exit stream of many energy conversion devices goes as waste, if not utilized properly. The major technical constraint that prevents successful implementation of waste heat recovery is due to its intermittent and time mismatched demand and availability of energy. In the present work, a shell and finned tube heat exchanger integrated with an IC engine setup to extract heat from the exhaust gas and a thermal energy storage tank used to store the excess energy available is investigated in detail. A combined sensible and latent heat storage system is designed, fabricated and tested for thermal energy storage using cylindrical phase change material (PCM) capsules. The performance of the engine with and without heat exchanger is evaluated. It is found that nearly 10–15% of fuel power is stored as heat in the combined storage system, which is available at reasonably higher temperature for suitable application. The performance parameters pertaining to the heat exchanger and the storage tank such as amount of heat recovered, heat lost, charging rate, charging efficiency and percentage energy saved are evaluated and reported in this paper.     

Design and analysis of a waste gasification energy system with solid oxide fuel cells and absorption chillers

Energy saving is an open point in most European countries where energy policies are oriented to reduce the use of fossil fuels, greenhouses emissions and energy independence, and to increase the use of renewable energies. In the last several years, new technologies have been developed and some of them received subsidies to increase installation and reduce cost. This article presents a new sustainable trigeneration system (power, heat and cool) based on a solid oxide fuel cell (SOFC) system integrated with an absorption chiller for special applications such as hotels, resorts, hospitals, etc. with a focus on plant design and performance. The proposal system is based on the idea of gasifying the municipal waste, producing syngas serving as fuel for the trigeneration system. Such advanced system when improved is thus self-sustainable without dependency on net grid, district heating and district cooling. Other advantage of such waste to energy system is waste management, less disposal to sanitary landfills, saving large municipal fields for other human activity and considerable less environmental impact. Although plant electrical efficiency of such system is not significant but fuel utilization factor along with free fuel, significant less pollutant emissions and self-sustainability are importance points of the proposed system. It is shown that the energy efficiency of such small tri-generation system is more than 83% with net power of 170 kW and district energy of about 250 kW.     

Process simulation of a SOFC and double bubbling fluidized bed gasifier power plant

The development of reliable fuel cells power plant based on renewable fuels stands out as one of the promising energy systems solutions for the future. Indeed fuel cells can increase the efficiency and the cleaning of the electrical energy production from renewable fuels. Process simulations of advanced power plants fed by low cost renewable fuels like biomass waste are a key step to develop renewable resources based on high temperature fuel cells applications. The aim of this work is to predict the component behaviour of a specific power plant mainly composed of a small indirectly heated gasifier and a Solid Oxide Fuel Cell (SOFC) and fed by chestnut coppice, waste available in great quantity in Central Italy, as well as in several other European regions. The plant's thermodynamic behaviour is analysed by means of the process simulator CHEMCAD© in which particular models for the SOFC and the gasifier have been developed in FORTRAN by the authors and then interfaced to commercial software. The results of the predictive model are presented and discussed, showing the possibility of an extremely interesting “carbon neutral” small plant configuration with high electrical and global efficiency exclusively based on the use of low cost renewable resources.     

Investigating the need of nuclear power plants for sustainable energy in Iran

Over the decades, the consumption of all types of energy such as electricity increased rapidly in Iran. Therefore, the government decided to redevelop its nuclear program to meet the rising electricity demand and decrease consumption of fossil fuels. In this paper, the effect of this policy in four major aspects of energy sustainability in the country, including energy price, environmental issues, energy demand and energy security have been verified. To investigate the relative cost of electricity generated in each alternative generator, the simple levelized electricity cost was selected as a method. The results show that electricity cost in fossil fuel power plants presumably will be cheaper than nuclear. Although the usage of nuclear reactor to generate power is capable of decreasing hazardous emissions into the environment, there are many other effective policies and technologies that can be implemented. Energy demand growth in the country is very high; neither nuclear nor fossil fuel cannot currently cope with the growth. So, the only solution is rationalizing energy demand by price amendment and encouraging energy efficiency. The major threats of energy security in Iran are high energy consumption growth and economic dependency on crude oil export. Though nuclear energy including its fuel cycle is Iran's assured right, constructing more nuclear power plants will not resolve the energy sustainability problems. In fact, it may be the catalyst for deterioration since it will divert capital and other finite resources from top priority and economic projects such as energy efficiency, high technology development and energy resources management.     

Tubular ceramic performance as separator for microbial fuel cell: A review

The depletion of unsustainable conventional energy sources and global warming issues create world demand for green energy sources. The microbial fuel cell (MFC) technology with the capability to convert environmental waste to energy can be improved with cheap ceramic material. The ceramic is structurally porous, thus allow a direct exchange of cation. The ceramic material also enhances stability thermally and chemically, non-ion selective characteristic, high mechanical strength, and easily washable. Commercially produced ceramic structures have been proven to reduce Chemical Oxygen Demand up to 92% and allow high power output. It is also comparatively durable in the long-term operation of MFC, compared to the commercially available membrane. The novelty of using tubular design is the efficient use of space, which leads to the possibility of scaling up. As a conclusion, a combination of both ceramic material and tubular design could be an excellent alternative separator for MFC.