NUCLEAR ENERGY ROLE AND POTENTIAL FOR GLOBAL SUSTAINABLE DEVELOPMENT

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1 NUCLEAR ENERGY ROLE AND POTENTIAL FOR GLOBAL SUSTAINABLE DEVELOPMENT Ujita H. 1 and Matsui K. 1 1 The Institute of Applied Energy 1. Introduction It is necessary to examine the strategy for the sustainable development on overall world scale with a longterm (around 1 years) aspect, if we consider that energy and environmental problems are related in the future of the earth with the all mankind. From another viewpoint, when the nuclear power system of which big role is expected as one of global warming prevention measures is paid attention, the necessity of a longterm and international consideration is apparent. The long term period is required for breeding of plutonium by the fast breeder reactor (FBR) developing as a sustainable energy source, and time and cost required for the research, development, and construction of FBR are also very long and huge. Based on the review result of effectiveness of nuclear power energy of long-term and worldwide viewpoint, we search essential conditions for following questions [1]: What will happen in Asian countries if Kyoto Protocol will be extended? What will happen in Asian countries if Pu transportation is allowed?. Evaluation by simulation.1 Optimization method The long-term energy supply simulation that optimizes the energy system cost until 1 for the world is discussed, by using the energy module structure of GRAPE model []. Where demand for energy under the environment of the CO emission constraint etc. is assumed. The GRAPE model has been taken up for the trial calculation in "Intergovernmental Panel on Climate Change (IPCC) the third report" [3].. Equations and constraints Some equations of energy cost and CO constraints that are important for forecast are shown here. The region- and time-wise energy structures are optimized so that the global and long-term energy cost ET is to be minimized. That is, ET is the target function on optimization problem. ET rg,yr E ( rg, yr ) (1+ρ ) ( yr to ). (1) Where, E(rg,yr) : region- and time-wise total energy cost, ρ : discount rate, rg: region, yr: period, and to: length of one period (1 years) Here, the energy cost is discounted at % annually so that the future cost is not regarded as too small from generation fairness viewpoint. This leads that the cheaper energy resources is used at first. Energy cost E is as follows. E(rg,yr) = { P(ensup,rg,yr) + T(ensup,rg,yr)+ R(ensup,rg,yr)+ C(ensup,rg,yr)+ D(ensup,rg,yr) en sup + COD (ensup,rg,yr)+ COTR (ensup,rg,yr)+ COTX (ensup,rg,yr)}. () Where, P: production cost, T: transport cost, R: royalty, C: conversion cost, D: distribution cost, COD: CO disposal related cost (only IGCC), COTR: emission certificate trading related cost (to be neglected below calculations), COTX: carbon tax related cost (to be neglected and marginal cost for carbon reduction is given as shadow cost under CO constraint), and ensup: kind of energy sources, such as coal, oil, natural gas, wind, biomass, nuclear power, etc. Finally, Equation of CO constraint is

2 CT= rg,yr C (rg,yr) CTUL. (3) Where, CT: global and long-term total emission, C (rg,yr): region-wise and time-wise emission, and CTUL: the upper limit of emission. The carbon dioxide in the atmosphere changes very slowly and its cumulative value is assumed to be the constraint..3 Calculation condition.3.1 Energy and CO emissions B case (Medium case, Importance to environment/ regional mutual coexistence) in "Special Report on Emission Scenarios (SRES), Intergovernmental Panel on Climate Change (IPCC)" [] is adopted as basic condition for social economy scenario of the 1st century in the simulation. Here, survey is divided broadly into two cases. One is case of BAU (Business As Usual) condition and another is case of CO Constraint. The primary energy supply in 1 would become 3Gtoe (ton oil equivalent) in the BAU condition of the energy demand increase according to economic growth, where there is no environmental restriction. On the other hand, the stabilization scenario, saturated 5ppm up to 1ppm in 1 from 37ppm now with CO density in the atmosphere, is examined for the global warming prevention in " The third IPCC global warming report " [3]. The accumulation value of the CO emission route stabilizing by 55ppm in the WRE55 scenario proposed by Wigley, Richles, and Edmons is taken as the CO constraint. This restriction of CO emissions is accomplished by the assumption that energy efficiency improves and energy demand decreases by about 1Gtoe as of 35% of the amount of conservation of energy in the BAU condition [5]-[]..3. Regions and time span Global model covers ten regions; North America, Western Europe, Japan, Oceania, China, Southeastern Asia and other Asia (India and ASEAN), Middle East and North Africa, Sub-Sahara Africa, Latin America, and Former Soviet Union and Eastern Europe. Time span (length of one period) is ten years. Calculation is performed until 15 to reject terminal effect, and then the result is indicated in the range of Energy sources Supply curves of energy sources are the same form as New Earth 1 [9]. Exhaustible energy source are natural gas, oil, and coal. Renewable energy sources are divided to biomass, wind, hydropower, geothermal energy, and photovoltaic. Integrated Coal Gasification Combined Cycle (IGCC) with CO capture is also considered. Cost of exhaustible energy is assumed to increase linearly as the cumulative consumption and that of renewable energy, as the annual amount used. Kinds of energy sectors are electricity, transport, and heat..3. Nuclear power The electricity generation cost for light water reactor (LWR) and FBR is a key parameter and therefore the construction cost is adjusted. Electricity generating cost of nuclear power is taken as, 5, or cents/kwh for parametric survey. The total uranium resource is 15,ktU, as shown in the report of OECD/ NEA []. The upper limit of natural uranium cost is 13$/kgU. 3. Role of energy conservation, nuclear and renewable energy under co constraint In the BAU condition, primary energy 3Gtoe assumed to be necessary for 1 can be supplied enough by coal, natural gas, and so on as shown in Figure 1. On the other hand, the expansion of the nuclear power energy and renewable energy supplies in addition to promotion of energy conservation (1Gtoe is expected in 1) are important, to achieve the CO constraint in the WRE55 scenario. The total CO emission of BAU is 1GtC in 1, while it must be reduced to 7GtC in the CO constraint of 55ppm as shown in Figure. Renewable energy is 7 % of Electricity generation in 1 in the world by the CO constraint. First 5 years nuclear electricity was generated mainly by LWR and replaced by FBR gradually. Finally, nuclear power supply over % of electricity generation and reduce 3GtC of CO emissions in 1.

3 GTOE/y Wind PV Biom ath Hyd/Geo Methanole Coal Oil Nat. Gas Nuclear Net Emission (GtC) 3 1 Energy Conservation Nuclear Energy CO Recovery Other Energy Net Emission in CO Figure 1 Primary energy supply (World, BAU) Figure Reduction of CO emission (World, CO) How nuclear power introduction rate will be affected by carbon control and nuclear cost conditions is illustrated in Figure 3 [1]. First case is eventually a nuclear phase out case. Even under high cost of nuclear, the world needs it anyway in CO constraint, but the demand start to grow around middle of century. But in the latter half of the century, introduction rate slows down because insufficient amount of fissile material, namely Plutonium. If nuclear has competitive production cost, it starts rather quickly in the former part of century, but slows down in the middle due to the same reason, and it catches up again towards the end of century. It is clear that nuclear will not be installed further under market economy if it does not have economic competitiveness. 5 Nuclear Generation (W orld) Nuclear Generation igwe j 3 1 CO,,3 CO, CO, BAU, Generation Cost Market Mechanism CO Constraint Phase Out? Figure 3 Nuclear generation in the World.. What will happen in Asian countries if Kyoto Protocol will be extended? There are two calculation cases for the CO emission constraint in this paper [11]. In one case, the CO emission constraint is only by WRE-55 on all countries in the world (WRE). In other case, the constraints are Extended Kyoto Protocol on developed countries in which amount of CO emission is the same as the Kyoto Protocol in 1s and will be reduced 5% for each ten years thereafter, and WRE-55 on the world (EKP)..1 CO emission in each region The net CO emission in developed countries and that in developing countries for two cases are shown in Figure. Compared with WRE, EKP reduces the CO emission in Annex I Parties (developed countries) by 1%, and Non-Annex I Parties (developing countries) can release more by 13%, that is it can use fossils

4 more in the 1st century. The CO reduction in developed countries in the first half of the 1st century is found to give relaxation of emission constraint on developing countries. However, developing countries will encounter the crisis to reduce carbon by about GtC/y in the latter half of the century. Carbon Emission GtC/y) (a) Only WRE-55 constraint (b) Extended Kyoto Protocol Figure Net CO emission.. Growth of nuclear power The electricity generation of developing countries consists of fossil without ; 1%, fossil with ; 5%, renewable energy; % and nuclear; 5% under WRE, as shown in Figure 5. While EKP changes the energy sources for electricity to fossil without ; 1%, fossil with ; 3%, renewable energy; %, and then nuclear decreases to 9% from5%. E le c tr ic ity G e n e ra tio n ( P W h /y ) X X Developed Countries Developing Countries (a) Only WRE-55 constraint (b) Extended Kyoto Protocol Figure 5 Electricity generation in developing countries. The significant feature is that the electricity generation by FBR decreases by PWh/y in developing countries and increases by PWh/y in developed countries in 1. EKP promotes the nuclear power from 7 GWe to 19 GWe only in developed countries, and the relaxation of emission constraint delays the growth from 1 GWe to 57 GWe in developing countries..3 Average generating cost 1 Nuclear Renewable Fossil with Fossil without Under WRE, the average generating cost of five regions; Japan, North America, Western Europe, China, India and ASEAN, rise to 5.-. cents per kwh in 1, as shown in Figure. China has a lot of coal and is forecasted to use it with CO in the end of century. This is why their cost is higher. Under EKP and WRE, the average costs of three regions of Annex I Parties appear.-5.9 cents per kwh in 1, while the costs of two regions of Non-Annex I Parties become cents per kwh. That is, EKP raises the cost of the developing countries by about cents per kwh in 1. The relaxation policy on the developing countries, EKP is found to delay the restructuring of energy systems in them and to give penalty to them in the future. Carbon Emission GtC/y) E lectricity G eneration (PW h/y)xx Developed Countries Developing Countries Nuclear Renewable Fossil with Fossil without

5 G eneration Cost /kw h) Japan North Am erica Western Europe China India ASEAN Generation Cost /kwh) Japan North Am erica Western Europe China India ASEAN (a) Only WRE-55 constraint (b) Extended Kyoto Protocol Figure Average generating cost. The principal results of impacts by EKP compared with WRE are followings: The average cost decreases by % in developed countries and increases by % in developing countries in 1. Nuclear power grows by 91% in developed countries and shrinks to one-third in developing countries. The total carbon emissions look the same and the carbon tax rises by 9%. It is important for mitigation of global warming that the developed countries will use nuclear power effectively. 5. What will happen in Asian countries if Pu transportation is allowed? As for the nuclear electricity generation, FBR usage increases in developing countries, while LWR usage is prolonged in developed countries, if Pu transportation is allowed, as shown in Figure 7. The transportation cost is assumed to be 19. ($/toe), which is blanket fuel fabrication and reprocessing cost (Puf 3%, Lower value). Therefore, the plan of International Nuclear Fuel Supply Center to reprocess spent fuel and to supply nuclear fuel under the international non-proliferation control is proposed here for FBR usage improvement in developing countries. No Pu Transport Pu Transport /toe Electricity Generation (GWe) LWR m Ž- LW q q e a q m Ž m Ž- e a q q (a) No Pu transportation (b) Pu transportation with $/toe Figure 7 Nuclear electricity generation- Pu transportation. Electricity Generation (GWe) LWR m Ž- LW q q e a q m Ž m Ž- 1 3 e a q q

6 . Discussions Energy conservation is the most important issue to achieve sustainable development in the energy policy of the 1st century. Furthermore, the nuclear power energy is necessary in addition to the improvement of the renewable energy and the development of the carbon dioxide isolation technology for the fossil fuel in order to maintain the global environment. It is necessary to continue technological development so as to demonstrate each potential as for the basic energy in 1. Especially, the fast breeder reactor with the feature of resource proliferation is expected to be greatly introduced and to become the main energy sources as 1 is approaching. Extended Kyoto Protocol decreases nuclear capacity of developing countries and swings up their average generation costs in 1. Carbon emission constraint should be covered all countries in the world not only for developed countries but also for developing countries. The policy that nuclear power is considered as CDM, Clean Development Mechanism would mitigate the problem mentioned here. Cooperative and continuous efforts of each country are required, for example, validity establishment of the framework of the Kyoto Protocol, the long-term adjustment for international collaboration which realizes WRE55 scenario, continuation of model development and mitigation measure planning in Intergovernmental Panel on Climatic Change, support of the developing countries such as International Nuclear Fuel Supply Center, etc. 7. Conclusion Role and potential of nuclear energy system in the energy options is discussed from the viewpoint of sustainable development with protecting from global warming. Taking the effort for energy-saving as major premise, carbon- for fossil fuel, renewable energy and nuclear energy should be altogether developed under the CO constraint. Especially, FBR will be attached importance to, due to its carbon free and resource limitless features, as the nd century is approaching. It is important for mitigation of global warming that the developing countries will use nuclear power effectively from the viewpoint of harmonization of sustainable energy growth and global environment. The policy that nuclear power is considered as Clean Development Mechanism and proposal of International Nuclear Fuel Supply Center plan would be the good measures for that. The work is sponsored by Ministry of Economy, Trade and Industry, JAPAN.. References [1] The Institute of Applied Energy, "Investigation on Nuclear Energy Potential" fiscal year report (5) (in Japanese). [] Kurosawa, A. et al., Analysis of Carbon Emission Stabilization Targets and Adaptation by Integrated Assessment Model, The Energy Journal, Kyoto Special Issue, pp (1999). [3] The third IPCC global warming report (climate change 1) (). [] Special Report on Emission Scenarios (SRES), Intergovernmental Panel on Climate Change (IPCC), Cambridge University Press (). [5] Word Energy Outlook, IEA (). [] Uranium-Resources, Production and Demand-1999, OECD/NEA (). [7] Rogner, H. H., An Assessment of World Hydrocarbon Resources, Annual Review of Energy and the Environment, vol., pp. 17- (1997). [] Yamaji, K., Yamamoto, H., Fujino, J., Biotechnology Energy, Mioshin Publisher (1) (in Japanese). [9] Fujii, Y., CO Problem Assessment in Energy System (in Japanese), Dr. Thesis, Univ. of Tokyo, 199. [1] Ujita, H. et al., Survey on Future Energy System Structure under Co Constraints and Generation Cost, 9th IAEE International Conference, June 7-1,, Potsdam, Germany. [11] Ujita, H. et al., Nuclear System for Problems of Environment, Economy, and Energy, Nuclear Energy Role and Potential for Energy System in Asia, GLOBAL 5, Tsukuba, Japan, Oct 9-13, 5.