Evaluation of lifecycle CO2 emissions from the Japanese electric power sector in the 21st century under various nuclear scenarios

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Energy Policy 34 (2006) 833–852 www.elsevier.com/locate/enpol

Evaluation of lifecycle CO2 emissions from the Japanese electric power sector in the 21st century under various nuclear scenarios Koji Tokimatsua,, Takanobu Kosugib, Takayoshi Asamia, Eric Williamsc, Yoichi Kayaa a

Systems Analysis Group, Research Institute of Innovative Technology for the Earth (RITE), 9th Floor, No. 3 Toyokaiji Bldg., Minato, Tokyo 1050003, Japan b College of Policy Science, Ritsumeikan University, 56-1 Toji-in Katamachi, Kita-ku, Kyoto 603-8577, Japan c United Nations University (UNU) 53-70 Jingumae 5-chome Shibuya-ku, Tokyo 1508925, Japan Available online 27 September 2004

Abstract The status and prospects of the development of Japanese nuclear power are controversial and uncertain. Many deem that nuclear power can play key roles in both supplying energy and abating CO2 emissions; however, due to severe nuclear accidents, public acceptance of nuclear power in Japan has not been fully obtained. Moreover, deregulation and liberalization of the electricity market impose pressure on large Japanese electric power companies with regard to both the operation of nuclear power plants and the development of the nuclear fuel cycle. Long-term Japanese CO2 reduction strategies up to 2100 are of environmental concern and are socially demanded under the circumstances described above. Taking these factors into account, we set the following two objectives for this study. One is to estimate lifecycle CO2 (LCCO2) emissions from Japanese nuclear power, and the other is to evaluate CO2 emissions from the Japanese electric power sector in the 21st century by quantifying the relationship between LCCO2 emissions and scenarios for the adoption of nuclear power. In the pursuit of the above objectives, we first create four scenarios of Japanese adoption of nuclear power, that range from nuclear power promotion to phase-out. Next, we formulate four scenarios describing the mix of the total electricity supply in Japan till the year 2100 corresponding to each of these nuclear power scenarios. CO2 emissions from the electric power sector in Japan till the year 2100 are estimated by summing those generated by each respective electric power technology and LCCO2 emission intensity. The LCCO2 emission intensity of nuclear power for both light water reactors (LWR) and fast breeder reactors (FBR) includes the uranium fuel production chain, facility construction/operation/ decommission, and spent fuel processing/disposal. From our investigations, we conclude that the promotion of nuclear power is clearly a strong option for reducing CO2 emissions by the electric power sector. The introduction of FBR has the effect of further reducing CO2 emissions in the nuclear power sector. Meeting energy demand and reducing CO2 emissions while phasing out nuclear power appears challenging given its importance in the Japanese energy supply. r 2005 Elsevier Ltd. All rights reserved. Keywords: Japanese nuclear energy scenarios; Lifecycle CO2 analysis; CO2 emissions from the Japanese electric power sector

1. Introduction The status and prospects of Japanese nuclear power development are controversial and uncertain. Many believe that nuclear power will play key roles in both energy policy and CO2 abatement strategy, by providing a stable electricity supply by base-load operation, Corresponding author. Tel.: +81334372850; fax: +81334371699.

E-mail address: [email protected] (K. Tokimatsu). 0301-4215/$ - see front matter r 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.enpol.2004.08.011

improving national energy security, and largely by freeing both from carbon emissions. On the other hand, the rigid nuclear policy of the Japanese government and several serious nuclear accidents have led to a distrust of nuclear power among the majority of the public. Deregulation and liberalization of the electricity market have put pressure on large Japanese electric power companies regarding both the operation of nuclear power plants and the development of a nuclear fuel cycle. Nuclear power development programs are not

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always fully debated within the contexts of these positive and negative aspects of nuclear power.

2. Objectives Taking into account the social background outlined above, we set the following two objectives for this study. One is to estimate lifecycle CO2 (LCCO2) emissions from nuclear power, and the other is to evaluate CO2 emissions from the Japanese power sector in the 21st century under various nuclear scenarios including fast breeder reactors (FBRs). Many studies have addressed the evaluation of CO2 emissions in the lifecycle of the electric power technologies (Chapman, 1975; Vate and van de, 1997a, b, 2002; Uchiyama and Yamamoto, 1992; Yoshioka et al., 1994; IAEA, 1996, 2000; Tahara et al., 1997; Tokimatsu, 2000; Hondo et al., 2000; Hondo, 2001; Izuno et al., 2001; Gagnon et al., 2001) by applying lifecycle assessment (LCA) to typical power plants models that specify capacity, availability, and plant lifetime (hereafter we call this methodology ‘‘reference model plant-based’’ LCA). However, a methodology using such a reference model plant-based LCA study is not suitable to evaluate LCCO2 of FBR, which inherently creates additional plutonium fuel. Plutonium is created, or bred, in a FBR plant and this additional fuel can be loaded to a new FBR plant. This breeding characteristic evolves substantially over time, the overall cycle has a transitional phase before reaching equilibrium. The ‘‘doubling time’’ of a breeder reactor, typically 20–30 years, is the number of years it takes before the reactions create as much new plutonium as the initial input. Because of these special characteristics, the estimation of LCCO2 for FBRs is carried out by using what we call ‘‘scenario-based’’ lifecycle analysis. In contrast to the conventional methodology of reference model plant based LCA, in ‘‘scenario-based’’ lifecycle analysis LCCO2 is calculated by summing all CO2 emissions associated with fuels and materials consumed in the supply chain, with plant characteristics and operation fixed by scenarios. This study can contribute to the debate in the context of the development program and CO2 abatement of Japanese nuclear power.

3. Present policy issues regarding Japanese nuclear energy (details in Appendix A) In order to formulate Japanese nuclear power scenarios, we have surveyed long-term Japanese energy policy perspectives formulated by special governmental committees. We consider the reports of three such committees as most relevant for indicating future plans

for nuclear adoption; one is by the Advisory Committee on Natural Resources and Energy (ACNRE) described in Section 3.1, another is by the Atomic Energy Commission of Japan (AECJ) in Section 3.2, and another is by the Fast Breeder Reactor Council in Section 3.3. These reports, among other things, suggest future installation of nuclear capacity, implementation of the nuclear fuel cycle (including plutonium-thermal), and long-life operation of presently operating nuclear power plants.1 3.1. Nuclear power in Japanese energy policy (installed power generation capacity, generated electricity) Three cases for the period up to 2010 are studied in the report titled ‘‘Future Energy Policy’’ by the General Subcommittee and Demand/Supply Subcommittee of the ACNRE (Yoichi Kaya, chairman) of the General Policy Division of the Agency of Natural Resources and Energy (ANRE) (ACNRE, 2001). These are the base2 and target cases3, premised on the additional construction of 10–13 nuclear power plants, and a third case in which no additional nuclear power plants are constructed (no-additional-construction case). The installed capacity and generated electricity are 61.85 Giga Watts (GW) and 418.6 Terra Watt hours (TWh) in the base case; 57.55–61.85 GW and 418.6 TWh in the target case; and 44.92 GW and 314.9 TWh in the no-additionalconstruction case, respectively, in 2010. In developing future nuclear scenarios and the structure of the total electricity supply in 2010, we refer the figures of nuclear power capacity and generated electricity of the target case in (ACNRE, 2001). 3.2. Development of nuclear fuel cycle and plutonium utilization in electricity generation A uranium enrichment plant, a low-level radioactive waste disposal center, and a high-level radioactive waste storage center (temporal interim storage) began operation in the early 1990s. A reprocessing plant and a mixed oxide (hereafter MOX) fuel plant are planned to start operation in 2005 and 2009, respectively (FEPC, 2003). According to the report ‘‘Long-term Plan for Research, Development, and Use of Nuclear Power’’, 1 An article by Picket provides a useful reference for understanding Japanese nuclear energy policy (Pickett, 2002). 2 The energy demand scenario in 2010 is assumed in which the present energy policy framework is maintained. 3 Energy supply scenario for realizing ‘‘stable energy supply accommodating demands for environmental conservation and efficiency.’’ In this case, two possibilities are assumed. That is, (A) developments will be carried out in an economically rational manner with the installed capacity indicated in the 2001 Power Supply Plan being set as the upper limit, or (B) the Supply Plan will be implemented as it is.

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prepared by the AECJ, ‘‘the implementation of the plutonium-thermal plan with a total of 16 to 18 power plants by the year 2010 is being planned by electric utilities and its realization is just beginning’’ (AECJ, 2000). The MOX fuel can be used in current LWRs (i.e., boiling water reactors (BWR) and Pressurized Water Reactors (PWR)). The composition of the MOX fuel is as follows: 1% uranium-235, 2–3% fissile plutonium, 1% non-fissile plutonium, and rest uranium-238, compared with 3–4% uranium-235 and the rest uranium-238 for conventional Uranium fuel. It should be noted, however, that although implementation of plutonium thermal is based on the so-called plutonium economy and energy security, that there has been a remarkably negative public reaction to the idea from those who believe that the plutonium thermal leads to military use of plutonium. From the report, we assume a future proportion of MOX-use operating capacity to total number of LWR nuclear plants by attempting to balance the desire to improve Japanese energy security while addressing the attitudes of the public by minimizing domestic stocks of plutonium. In other words, we assume that the proportion of MOX-use in LWR reactors will increase to balance the need for energy security while simultaneously reducing plutonium stocks. 3.3. FBR There is no explanation in the AECJ report (AECJ, 2000) concerning what year FBRs will be introduced. Since the accident of the Japanese FBR prototype reactor named ‘‘Monju’’ (Pickett, 2002), research and development (R&D) strategies have been examined by a separate ‘‘Fast Breeder Reactor Council’’ formed by the AECJ. The following is described in their main report: ‘‘the Council considers the promotion of R&D of FBR to be valid for social and technical pursuit of future nuclear power and the possibility of realization of FBR as a promising choice of non-fossil energy source.’’ (FBR Council, 1997) A report published from the Japanese Nuclear Cycle Development Institute (JNC, 2001) assumes that competitive FBR cycle technologies will be ready by 2015 (completion of technical infrastructure for practical use) and that the technological development of FBR plants comparable to present LWR technologies will be completed by around 2030 (in other words, a target year of introduction of a commercial FBR plant by 2030). In development of the nuclear scenario, we assume that FBR is introduced from 2030 if it is utilized. The installed capacity of FBR is set based on the assumption that they are introduced through replacement of LWR (FBR Council, 1997).

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3.4. Long-lifetime operation of presently operating light water reactors (LWR) Since their introduction in the early 1970s, the number of LWRs in Japan with 30 years or more of operation is increasing. Although the limit of lifetime of these nuclear power plants is prescribed in accordance with the related regulations, securing safety according to long-lifetime operation is important, and technological inspections have started. The inspections suggest that extension of operating life to 60 years after start of commercial operation is feasible (ANRE, 1999). Therefore in this study we assume a 60-year operation of present-day LWR.

4. Analytical methodologies 4.1. Outline of the analytical process First, we create four scenarios for the Japanese adoption of nuclear power and their respective electricity generation capacities in the 21st century. The scenarios range from promotion of nuclear power beyond the Japanese government policy to phase-out. Next, we generate four scenarios of the mix of electricity generation technologies in Japan till the year 2100 that correspond to the four Japanese nuclear power scenarios. CO2 emissions from the electric power sector in Japan till the year 2100 are estimated by multiplying the output from each electric power technology by its LCCO2 emission intensity and summing over technologies. Here electric power technologies include those of LWR and FBR. For technologies other than nuclear power, we use LCCO2 intensities from previous studies (Hondo et al., 2000). 4.2. Scenarios of nuclear power and total electricity supply in Japan up to the year 2100 4.2.1. Basic idea of scenarios development Our four scenarios attempt to cover a wide range of views and opinions regarding Japanese nuclear power. The first scenario is the so-called ‘‘Policy case’’, in which nuclear power development follows the plan described in Section 3. The second one is the ‘‘Promotion case’’, which follows the belief of some in the technological superiority of nuclear power for supplying energy and reducing carbon emissions. In this case, the increase in future electricity power demand is mainly met by nuclear power generation. The third one we call the ‘‘LWR case’’, in which nuclear power is recognized as an indispensable power source in the energy supply, but assumes that FBRs are not adopted. Contrary to the rigid Japanese policy

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prescribing a nuclear fuel cycle including FBR, some believe that flexibility in Japanese nuclear power development is required to meet uncertainties such as deregulation of the electricity market and electricity demand growth. One concrete feature of this idea is to delay the nuclear fuel cycle development planned by the Japanese government for the time being and to supply nuclear energy only by LWR. The final case is called ‘‘Phase-out’’, in which nuclear power is not accepted in public and any form of future nuclear power development is not allowed. This case is the opposite side of the other three cases in the sense that nuclear power is not recognized as a necessary energy source. Although it is difficult to categorically identify supporting actors for all scenarios, it can be roughly said that the Policy case corresponds to the position of the national government, the Promotion case would be backed by utility companies and supporters of nuclear power, the LWR case by some scholars and researchers, and the Phase-out case is close to the wishes of public groups opposing nuclear power. It should be notified, however, that such a categorization is too simple; some in utility companies support the LWR case and many scholars believe that nuclear power should be adopted along the lines of the Promotion case. We developed the four scenarios to represent different views of nuclear power. We emphasize, however, not all actors have quantified their positions in the scenario form as we have. Next, we investigate nuclear power capacity, expressed in GW, that represents the above four nuclear scenarios and corresponding total electricity supply structures in GWh up to the year 2100. We believe these figures should be based on transparent, easy-tounderstand, and easy-to-access analyses, and thus the ANRE report for determining future nuclear capacity (ANRE, 2000) and the ACNRE study for projecting future total demand of electricity (ACNRE, 2001) should be selected. Since these two reports give projections till around the year 2010, we make appropriate extrapolations up to the year 2100. The Japanese government policy directions described in the previous chapters are used to create the ‘‘Policy case’’; the other cases are made by a modification of this. 4.2.2. Nuclear power scenarios (Table 1 and Fig. 1) (1) Policy case (Table 1 and Fig. 1(a)) In this case, all policy plans recommended by the AECJ, such as the plutonium-thermal, nuclear fuel cycle, and FBR plans explained in the previous section, are assumed to be executed as planned. The operation of the existing LWR plants (ANRE, 2000) is extended, and operational life of all the LWR and FBR plants is set at 60 years (ANRE, 1999). The

installed capacity of LWR is determined corresponding to (1) LWR currently operating (see (1) in Fig. 1(a)), as well as those being constructed and planned (2) (ANRE, 2000). The installed capacity of nuclear power plants is set as fixed from 2015 onwards by these assumptions. The installed capacity of FBR is set based on the assumption that they are introduced through replacement of LWRs (4) and replacement of installed FBRs (5) (FBR Council, 1997). The introduction year of FBRs is set as 2030, when all the existing LWRs are expected to reach the end of their operational life (set at 60 years). It is assumed that the plutonium-thermal operation starts in 2009 when domestic MOX fuel production will begin, and that the proportion of MOX-use to LWRs increases beginning in the introduction year at rates fixed by constraints of improving Japanese energy security while minimizing plutonium stock (Yamaji and Nagano, 1998). (2) Promotion case (Fig. 1(b)) This differs from the Policy case in that the increase in electricity power demand from 2010 onwards is met mainly by nuclear power generation. In order to reflect the difference, we assume additional LWR capacity from 2011 to 2050 ((3) in Fig. 1(b)) to that of the (ANRE, 2000) report in order to meet the total electricity demand growth. As in the Policy case, it is assumed that all the policy plans recommended by the AECJ, such as the plutonium-thermal operation, nuclear fuel cycle, and FBR plans, are executed as planned, and that the operation of the existing LWR plants are extended, and operational lives of LWR and FBR plants are 60 years. (3) LWR case (Fig. 1(c)) The difference from the Policy case is that FBR is not adopted and that future demand for nuclear power is entirely met through additional LWR plants. Deregulation, e.g., tends to favor established technologies such as LWR where fewer additional R&D funds are needed in comparison with FBR. Long-lifetime operation of LWR is set as 60 years. The total capacity of installed nuclear power facilities is fixed from 2015 onwards. It is assumed that additional LWR plants are constructed in order to keep the installed nuclear power capacity since those indicated in ANRE, 2000, as being in operation, construction, and planning, are successively decommissioned from 2030 onwards. All spent fuel (SF) is reprocessed and disposed as low-level waste (LLW) and high-level waste (HLW) (i.e., we did not assumed direct disposal (no reprocessing) because no official plan can be seen.) (4) Phase-out case (Fig. 1(d)) This scenario assumes that nuclear power does not obtain public acceptance and that further nuclear

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Table 1 Summary of the four nuclear power scenarios Promotion case Main point

Electric power demand scenario Installed capacity of nuclear power

Plutonium-thermal

FBR

Policy case

LWR case

Phase-out case

FBR cycle will not be Future nuclear power Nuclear power Nuclear power development is equal to development will proceed introduced. development will not be accepted. Policy case+main supplier according to government of future increases in plans. power demand. Electric power demand is set as indicated in ACNRE (2001) for 2010, then increasing annually at specified annual growth rates thereafter. These growth rates are 0.75%/yr for 2011–2020, 0.5%/yr for 2021–2030, 0.25%/yr for 2031–2040, and 0.125%/yr for 2041–2050. Electricity demand is assumed to be constant from 2050 onwards. Plant life is set to 60 years and the overall capacity is Nuclear power will be the determined by the light water reactors indicated as being main supplier of power in operation, construction, and planning in ANRE demand increases. (2000). Overall capacity is fixed from 2015 onwards. Installed capacity will grow from 2011 onwards Amounts corresponding to Amounts corresponding to and up to 2050. Plant life is the decommissioning of set to 60 years. Shortfall of the decommissioning of LWR from 2030 onwards installed capacity provided LWR from 2030 onwards are covered by newly are covered by newly by currently planned LWR installed FBR. installed LWR. (ANRE, 2000) and FBR will be met by additional light water reactors. Will not be introduced. Introduction to be started at the same time as the operation of the Rokkasho Reprocessing Facility in 2005. Introduced amounts are expressed as yearly introduction rates with respect to the total equipment capacity of LWR. The introduction speed of FBR is assumed to be equal in pace to that of LWR and FBR is assumed to be introduced in accompaniment to the decommissioning of LWR (JAIF, 1999).

power development is not allowed in any form. Only existing LWR continue to operate and nuclear power capacity is gradually decreased as part of the decommissioning process. Furthermore, all plans for construction and development of further LWR, processing nuclear fuel (except reprocessing and disposal of radioactive waste), and FBR are interrupted. Extending operation lifetime is not promoted and plants are closed after 40 years4. All SF is reprocessed and disposed as low-level waste and high-level waste. 4.2.3. Electric power supply scenarios Electric power supply scenarios are prepared based on the ‘‘target case’’ presented in ACNRE, 20015. The increase in power demand from 2010 onwards is expressed in terms of annual growth rates, and these are set to decrease every 10 years, i.e., 0.75% per annum 4 Note that the No. 1 Tsuruga reactor (that started operation in March 1970) of the Japan Atomic Power Company is still in operation. 5 For the phase-out case, the ‘‘case of no additional construction of nuclear power plants in the future’’ in (ACNRE, 2001) was used.

LWR indicated as being in operation in ANRE (2000) are decommissioned successively. Plant life is set to 40 years.

Will not be introduced.

from 2011 to 2020, and then for every 10 years to 0.5%, 0.25%, 0.125%, and 0% after 2050. The structure of electricity supply after 2020 is determined by means of the following procedures: 1. The electricity generated from hydropower, geothermal, and other renewables is taken as constant after 2010, as no official long-term supply plan has been provided by the Japanese government. 2. It is assumed that the electricity generated by oil-fired plants will decrease at the rate of 33% per decade from 2010 and set at zero after 2040. This assumption is due to the IEA (International Energy Agency) recommendation to curb additional construction of oil-fired power plants. 3. The share of electricity in 2010 supplied by coal-fired power generation is assumed to be maintained after 2020. 4. The remaining share is allocated to LNG-fired power and nuclear power. In the Promotion case, electricity generated by LNG-fired power is set constant after 2010, with the rest being allocated to nuclear power generation. For other cases except

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Fig. 1. Nuclear power scenarios: (a) Policy case, (b) Promotion case, (c) LWR case, (d) Phase-out case.

Promotion, the electricity generated by nuclear power is calculated by multiplying the installed capacities of both LWR and FBR by the assumed average capacity utilization factor, rest being allocated to LNG-fired power. The average capacity utilization factors of LWR in 2000 and that of FBR in 2030 are set to approximately at 80% and 70%, respectively, with 90% assumed to be achieved by 2040–2050 (JNC, 2001). 4.3. The analysis of lifecycle CO2 emissions from nuclear power 4.3.1. Outline of the lifecycle analysis The analytical procedure is indicated in Fig. 2. Blocks on the left indicate the procedure, and shaded boxes on the right give additional explanations. Scenarios of both nuclear generation capacity and electricity supply are explained in Section 4.2. The general data and calculation formula indicated in

the shaded boxes are used for calculating core characteristics in (2) (i.e., nuclear burn-up, enrichment, and thermal efficiency) and nuclear fuel specifications in (3) (i.e., nuclear fuel consumption, condensation feeds, and separative work unit (hereafter SWU)). These specifications are calculated by using the annual nuclear fuel consumption and annual uranium requirement (TEPCO, 2002) for a 1 GW class BWR. Construction, operation, and decommissioning of the power plant are also taken into consideration. The quantity of SF generated is calculated based on operating and decommissioning capacities as well as nuclear fuel specifications. Low-level waste is assumed to be emitted solely from power plants. The volume of vitrified wastes is calculated assuming that domestic radioactive waste processing facilities output an annual 1000 units of vitrified wastes based on a maximum of annual input of 800 t of uranium or heavy metal (hereafter tHM/yr). In order to calculate the annual amounts of reprocessing and disposal, scenarios are required for SF storage, domestic reprocessing, interim

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Fig. 2. Procedure of the lifecycle analysis.

storage of vitrified waste canisters, vitrified canister disposal, cementation, and disposal. All input materials and energies for each process facility can be estimated via the nuclear fuel cycle scenarios above. LCCO2 from

nuclear energy is calculated by multiplying the input materials and energies by CO2 emission intensities of the materials and energies used and spent for energy production.

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Table 2 Scenarios of nuclear fuel cycle in Japan till 2100 (the shaded portions are the hypothetical)

. . . . Domestic uranium enrichment

. .

. .

. Off-site storage of spent fuel

. 


LWR Start operation from 1992. Operating presently at a scale of 1,050 tSWU/yr. A final scale of 1,500 tSWU/yr is planned. From 1992 onwards, it is assumed that, for the total amount of separation work required, the domestic uranium enrichment is performed first and remaining demand is procured from the united states. Operation of 1,050 tSWU/yr is to be carried out from 1992 to 2031 with an installed capacity of 1,200 tSWU/yr (corresponding to 2 facilities, each with a rated capacity of 600 tSWU). Operation of a maximum of 1,500 tSWU/yr is to be carried out from 2032 to 2071 with an installed capacity of 1,800 tSWU/yr (corresponding to 3 facilities, each with a rated capacity of 600 tSWU). From 2072 onwards, the installed capacity is set to 1,800 tSWU in the light water reactor case, the installed capacity is set to 1,200 tSWU due to decrease of light water reactor power generation in the promotion case. In the Policy case, use up to 2075 is accomplished by prolonging life of equipment to 2032. With the phase out case, the 1,200 tSWU facility, the operation of which was started in 1992, is to be elongated in life and used until phase out in 2042. Presently, onsite storage is carried out,via power plant accessory pool (presently, 6,400 tHM/maximum capacity of 12,000 tHM; the same applies below), power plant common-use pool (3,159/6,840 units), dry cask method (564/860 casks) and, reprocessing facility accessory pool (605/3,000 tHM)). A recycled fuel storage center based on the dry cask method is constructed and used from 2010 onwards [ACNRE 1998] (2010−: 6,000 tHM; 2020−: 15,000 tHM). The material amount for onsite storage is calculated for each facility. The required amount of offsite storage was calculated under the following assumptions. The storage capacities of the onsite storage facilities of the power plant accessory pool, power plant common-use pool, and reprocessing facility accessory pool are to be filled in this order. All of the volume exceeding that of .  is to be subject to offsite storage via the dry cask method.

Domestic reprocessing

. Reprocessing of 800 tHM/yr from 2015 onwards is planned. . The continuation of reprocessing at a rate of 800 tHM/yr with an installed capacity of 800 tHM until 2100 is assumed for scenarios besides the Phase-out case. Equipment are renewed at each end of the facility service life (40 years). . With the phase-out case, domestic reprocessing is carried out until the reprocessing of all spent fuel is completed (2050). It is assumed that facilities that have started operation in 2005 will be prolonged in life and used until 2050.

Disposal of cemented waste

. From 1992 onwards. As of 2002, 130,000 units have been disposed of. . From 1992 onwards, disposal of 10,000 units per year is assumed.

Inter temporal storage of vitrified waste canisters

. Implementation for fuel processed overseas started in 1995 and is planned to begin in 2005 for domestically processed fuel. . It is assumed that interim storage will start at the same time as the start of reprocessing in 2005. . Interim storage term is assumed to be 30 years or more.

Disposal of vitrified waste canisters

. Plan to be implemented from the latter half of the 2030’s onwards. . Disposal of 1,000 units per year is assumed for 2035 onwards (in cases besides the phase-out case). . In the phase-out case, implemented until the disposal of all vitrified waste canisters is ended (2081).

FBR

Unnecessary

Reprocessing of spent fuel that accompanies the introduction of FBR is assumed to be carried out without delay and offsite storage of spent fuel will not be carried out.

The following are assumed based on the results of analysis of the required processing amounts and fuel production amounts: . 2030–:600-tHM equipment (corresponding to 3 units with a rating of 200 tHM) . 2050–: 800 tHM . 2070–: 1,000 tHM . 2090–: 1,200 tHM The amount generated within each year will be disposed with the upper limit is set to 10,000 units per year from the start of operation (2030). . Starts in 2035 (5 years after start of operation of reprocessing and fuel production facilities in 2030 (4 years of SF cooling period and 1 year of reprocessing time)). . Storage term is assumed to be 50 years. The amount generated within each year will be disposed with the upper limit is set to 1,000 canisters per year from 2085.

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4.3.2. Scenarios of the nuclear fuel cycle in Japan up to the year 2100 (see Table 2 and details in Appendix A) (1) Domestic uranium enrichment (Table 2) All domestic uranium enrichment is assumed to be done via centrifuge, corresponding to the existing facility that started its operation in 1992. We make the following assumptions about this process. An annual 1050 t of Separative Work Units (hereafter tSWU/yr) by 1200 tSWU/yr (2 units of 600 tSWU/yr unit) will be processed from 1992 to 2031 and a maximum 1500–1800 tSWU/yr (3 units of 600 tSWU/yr unit) will be processed after 2032 for LWR except in the Phase-out case. In the Phase-out case, a domestic facility of 1,200 tSWU/yr starting its operation in 1992 will continue until the phase-out year of 2042 by long-lifetime utilization of the facility. In all the cases, the remaining demand for enriched uranium is imported from a uranium enrichment facility using gas diffusion technology in the United States. Uranium enrichment for FBR is not necessary due to the utilization of reprocessed uranium from LWR. The uranium burnt in FBR is recycled after 4 years of cooling and 1 year of reprocessing. (2) SF storage Onsite storage is accomplished via accessory pools in plants, which currently hold 6400 tons of Heavy Metal (tHM), and have a total capacity of 12,000 tHM (expressed as 6400/12,000 tHM), common pools on plant sites (3159/6840 casks), accessory pools of domestic reprocessing facilities (605/ 3000 tHM)), and offsite storage (564/860 dry casks). Since it is anticipated that additional storage capacity is required to meet the demand of interim storage around the year 2010, the report from ACNRE estimates that the required capacity is 6000 tHM in 2010 and 15,000 tHM in 2020 (ACNRE, 1998). The SF from LWR is assumed to be disposed of in the following order: accessory pools of plants, the common pool on plant sites, and the accessory pools of domestic reprocessing facilities. All SF that exceeds these capacities is assumed to be stored offsite in dry casks. All SF from FBR is assumed to be reprocessed without delay and offsite storage is not required. (3) Domestic Reprocessing A domestic reprocessing facility of 800 tHM/yr capacity starting operation in 2005 at Rokkasho is the only plan in the LWR cycle. We hence assume in the cases other than Phase-out that the reprocessing capacity of 800 tHM/yr continues until 2100 by continuous renewal of the facility every 40 years of its lifetime. In the Phase-out case, it is assumed that a domestic facility starting its operation in 2005 will be used until 2050 provided that all the reprocessing

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is executed by long-lifetime utilization of the facility. In all the cases, SF reprocessing is assumed to begin in 2005 and be carried out only by the domestic facility; we neglect the cumulative reprocessed SF overseas (some 1300 tHM till the year 2001), because over the long term it will have played but a very minor role. No official plan exists for the development of a facility to reprocess fuel from the FBR cycle (including MOX fuel factory). We assume that all SF from FBR is reprocessed without delay under the assumption of the following reprocessing capacity: 600 tHM/yr (3 units using 200 tSWU/yr unit) from 2030, 800 tHM/yr (4 units) from 2050, 1000 tHM/yr (5 units) from 2070, and 1200 tHM/yr (6 units) from 2090, respectively. (4) Cementation disposal Annually, 10,000 cementations from the LWR cycle are assumed based on extrapolation from current trends. As of 2002, 130,000 cementations have been disposed of since 1992. It is assumed that annual bodies for disposal from the FBR cycle can be handled at a maximum of 10,000 per year starting in 2030. (5) Interim storage of vitrified waste canisters Interim storage of the vitrified canisters from overseas began in 1995 and storage of those from domestic plants is planned from 2005. It is assumed for the LWR cycle that interim storage of 30 years or more will begin in 2005 along with reprocessing; 50 years’ storage for the FBR cycle will start in 2030. (6) Vitrified waste canister disposal Disposal of the vitrified canisters from the LWR cycle is planned to begin from the latter half of 2030. Annually, disposal of 1000 canisters will start in 2035; in the Phase-out case, the disposal will end in 2081 when the disposal of all the canisters will have been completed. It is assumed that a maximum output of 1000 units of canisters from the FBR cycle will be disposed of annually starting in 2080. 4.3.3. Data used for the analysis Input data of materials and energy for the LWR include those of the following processes: uranium mining and refining, conversion to UF6, uranium enrichment (domestic and overseas), reconversion, manufacturing of fuel rod material, fuel assembly manufacturing, power plant construction, operation, and decommission, SF storage, reprocessing, cementation and disposal of LLW, interim storage and disposal of vitrified canisters of HLW, and transportation (distance, means (i.e., ship and truck) and their fuel efficiencies, and vessels) between all the processing sites. The data used to describe these processes are all from actual facilities (Izuno et al., 2001) except those for conversion, overseas uranium enrichment, reconversion

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and disposal of vitrified HLW (Hondo, 2001; IPS, 1977). The nuclear plant considered is a 1.1 GW class BWR. For the FBR cycle, we assume a combination of a Na cooling plant, advanced wet reprocessing, and MOX pellet type fuel. This combination seems most feasible based on current scientific and technological knowledge, with the caveat that technologies are still in the R&D stage. We used data based on a 1.5 GW twin plant with Na cooling and joint facility of MOX fuel fabrication and reprocessing (centralized reprocessing and fuel manufacturing with 200 tHM/yr capacity) (JNC, 2001). Data regarding materials and energy required for decommissioning, cementation and disposal, vitrified interim storage, and disposal of the FBR are assumed to be the same as for LWR. Data for CO2 emissions intensities for input materials and process energy consumption are based primarily on those used in the nuclear power LCA studies by Hondo (Hondo et al., 2000; Hondo, 2001).

construction and maintenance of facilities, we add 20% to the energy needed for construction and other materials (a common assumption in life cycle assessments). In addition to this increment, energy consumption required in the entire process of the construction of the power plants’ components (e.g., power generator, motor, electric devices such as switchgears, etc.) is considered using the auxiliary factors developed by Hondo (Hondo et al., 2000). Normalizing all the input materials and energies by annual 1 tHM for SF storage and vitrified canister interim storage, by one body/cask for the disposal of both cementation and vitrified casks, respectively, is applied in calculation of all input materials and energies for these processes. CO2 emissions along with the energy required for transportation are estimated via specification of vessel type, distances traveled, and respective fuel efficiencies.

5. Results 4.3.4. Calculation of the analysis The procedure for calculating LCCO2 emissions is as follows: First, based on scenarios for the demand for nuclear-based electricity, we estimate annual capacity requirements, from which the operation levels of plants, related processes and disposal are calculated. Second, required quantities of input materials and energy corresponding to processes are calculated by multiplying the annual implementation of the process by input materials/energy per unit process. Finally, LCCO2 emissions are obtained by multiplying all input materials and energy by CO2 emission intensities for each material and energy source. Treatment of input materials as well as energy consumption for the construction and operation of the facilities/plants is as follows. For all facilities/plants whose input requirement of carbon steels or concrete is less than 1 million tons (Mt), material and energy inputs for construction is allocated over their operational lifetime. Materials input for maintenance are assumed to be negligible. For facilities/plants with steel and concrete requirements over 1 Mt (domestic uranium enrichment, power plants and reprocessing plants), it is assumed that construction takes 5 years and that all input materials and energy are allocated over the duration of construction. We assumed for the annual input materials necessary for the maintenance of the three types of plants (i.e., domestic uranium enrichment, power plants and reprocessing plants) during their lifetime that (i) 3% of all the construction materials are used for power plants (LWR, FBR), and (ii) 20% of all the construction materials consumed for domestic uranium enrichment and domestic reprocessing, are allocated over a 30-year period. Given the lack of data on energy used in CO2 emissions and energy required in the processes for

5.1. Lifecycle CO2 emissions from nuclear power 5.1.1. Breakdown of CO2 emissions in all the processes of the nuclear chain Fig. 3 indicates total CO2 emissions from all processes in the nuclear chain in the case of LWR, with (a) expressing the amount of annual CO2 emissions, (b) showing the annual CO2 emissions as a percentage, and (c) showing the total CO2 emissions from 1960 to 2100 as a percentage. The annual CO2 emissions shown in Fig. 3(a) indicate an increase from zero in 1970 when Japan started to utilize nuclear power to some 6 Mt of CO2 annually (hereafter MtCO2/yr) around 2030, and visible reductions in uranium enrichment are observed around 1990 and around 2030 that are caused by the introduction of domestic centrifuge uranium enrichment plants, and by capacity enhancement of the plants, respectively. The percentage of CO2 emissions shown in Fig. 3(b) indicates that the share of power plant construction is dominant at the beginning then rapidly decreases as nuclear facilities come to replace existing power plants, while the share of uranium enrichment remains almost constant. Three spikes are visible in reprocessing when a domestic facility is constructed, indicating the huge volume of steel and concrete used. The sum of CO2 emissions from 1970 to 2100 as a percentage shown in Fig. 3(c) indicates that the share of uranium enrichment is dominant (51%), followed by the operation (20%) and construction of the power plant (13%). In comparison with the LWR case, in the Policy case shown in Figs. 4 (a)–(c), FBR will provide the main share of nuclear power in the latter half of the 21st century, annual CO2 emissions shown will be greatly reduced by 4 MtCO2/yr from the 2030 when FBR is

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Fig. 3. (a)–(c) Breakdown of CO2 emissions in all the processes of nuclear chain in LWR case. (a) Annual amount of CO2 emissions in tCO2/yr, (b) annual amount of CO2 emissions in percentage, (c) total CO2 emissions from 1960 to 2100 in percentage.

introduced. This is because of CO2 emission reductions from the avoided uranium enrichment, which can be seen in Figures (a)–(c). Fig. 4(b) indicates that the total share of enrichment, construction, operation, and

decommissioning for LWR/FBR decreases from some 90% in 2030 to around 50–60% in 2100. Fig. 4(c) also demonstrates that the share of the uranium enrichment process decreases from some 50% in the LWR case to

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Fig. 4. (a)–(c) Breakdown of CO2 emissions in all the processes of nuclear chain in Policy case. (a) Annual amount of CO2 emissions in tCO2/yr, (b) annual amount of CO2 emissions in percentage, (c) total CO2 emissions from 1960 to 2100 in percentage.

some 40% in the Policy case, and that the construction/ operation/decommission of LWR/FBR in both the cases seems to be of a similar scale. The Promotion case shown in Figs. 5 (a)–(c) is quite similar to the Policy case. In the Phase-out case CO2 emission profile in Fig. 6(b) is quite different compared with the LWR case (in Fig. 3(b)). It is however understandable that as CO2 emissions in tCO2/yr in

Fig. 6(a) decreases in accordance with the phasing-out of nuclear power the SF reprocessing continues. 5.1.2. Comparison of lifecycle CO2 among nuclear scenarios CO2 intensities of nuclear power plants can be obtained by dividing annual CO2 emissions from all the processes of the nuclear chain by the annual

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Fig. 5. (a)–(c) Breakdown of CO2 emissions in all the processes of nuclear chain in Promotion case. (a) Annual amount of CO2 emissions in tCO2/yr, (b) annual amount of CO2 emissions in percentage, (c) total CO2 emissions from 1960 to 2100 in percentage.

electricity generated. The results are shown in Fig. 7(a) in log scale from 1970 to 2100, while Fig. 7(b) shows the same results in normal scale from 1990 to 2100. It is seen that CO2 intensities of nuclear power generation diminish rapidly by one order of magnitude, from some 200 gCO2/kWh in 1970 to about 10 gCO2/kWh in 2000. After 2000, CO2 intensities will be approximately 1013 gCO2/kWh in the case in which only LWR will be

introduced. In the Promotion and Policy cases, CO2 intensities produced by nuclear power as a whole will decrease according to the introduction of FBR from 13 in 2030, to approximately 5 gCO2/kWh in the final decades of the 21st century, due to the reduction of CO2 emitted from the uranium enrichment process, as previously discussed. It has thus been confirmed that the introduction of FBR results in the further reduction

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Fig. 6. (a)–(c) Breakdown of CO2 emissions in all the processes of nuclear chain in Phase-out case. (a) Annual amount of CO2 emissions in tCO2/yr, (b) annual amount of CO2 emissions in percentage, (c) total CO2 emissions from 1960 to 2100 in percentage.

of CO2 emission intensity in nuclear power generation. CO2 emissions in the Promotion case are slightly greater than those in the Policy case in the first half of the 21st century since the former case has additional LWR

capacity during this period. CO2 emissions in the Phaseout case go down to a minimum of some 8 gCO2/kWh and finally increases to about 70 gCO2/kWh, somewhat lower than other cases up to the year 2030.

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CO2 intensities from nuclear power generation [gCO2/kWh]

1,000

CO2 intensities from nuclear power generation [gCO2/kWh]

(a)

(b)

100

Promotion case Policy case LWR case Phase-out case

 

10




1 1960

1980

2000

2020 2040 year

50


 

 40 30

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20



10

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the same amongst the cases, differing from those of nuclear and LNG plants. The electricity generated from LNG-fired plants remains constant until 2100 in the Promotion case because this case assumes that the growth in electricity demand is satisfied solely by nuclear energy. The share of electricity generated by FBR grows during the period of 2030–2080 in the Promotion case and the Policy case, while the electricity produced by LNG-fired plants becomes dominant in the Phase-out case. The CO2 emission intensities in the electric power sector in the latter half of the 21st century will be (i) approximately 60% of that of 1990 in the Promotion case, (ii) approximately 75% of that of 1990 in the cases of Policy and LWR, and (iii) larger by approximately 30% than the 1990 level in the Phase-out case. The total CO2 emissions will be (i) at the level of 1990 in the Promotion case, (ii) larger by approximately 20% than the level of 1990 in the cases of Policy and LWR, and (iii) twice the level of 1990 in the Phase-out case.




0 1990

2080

847

2050 year

2070

2090

Fig. 7. Comparison of lifecycle CO2 among cases of nuclear scenarios. (a) from 1970 to 2100 in log scale, (b) from 1990 to 2100 in normal scale.

5.2. Estimation of CO2 emissions from the electric power sector in Japan till 2100 CO2 emissions from the entire electric power sector in each nuclear power scenario are shown in Figs. 8 (a–d) in the form of total CO2 amounts (solid line with open circle) and CO2 emission intensities (solid line with solid circle). The result shown in Fig. 7(b) is used to calculate the amount of LCCO2 produced by nuclear power. The LCCO2 emissions from other types of power generation are quoted from the report of Hondo (Hondo et al., 2000). These are shown in Table 3 note that these are taken to be constant over the period 1990–2100. The electricity generated by LNG-fired steam cycle plants and by LNG-fired combined cycle plants is assumed to be allocated equally between the two kinds of LNGfired plants, and therefore the CO2 emission intensity of the LNG-fired plants is calculated based on the weighted average of the respective emission intensities. The CO2 emission intensity produced by renewable sources such as wind and photovoltaic (using amorphous silicon capability of 1 GW annual production technology) generators is calculated using the same methodology applied to the LNG-fired plants. The electricity generated from coal, oil, hydropower, geothermal, and other renewables and new energies is

6. Discussion 6.1. Comparison with existing work Our lifecycle analysis demonstrated annual CO2 emission intensities of different nuclear scenarios up to the year 2100, as indicated in Figs. 3–7. Our result for the LWR case in the long run (to the year 2100) should be comparable to that of Hondo for LWR plants; our result for the year 2000 is about 13 g/kWh and Hondos’ is some 23 g/kWh (Hondo, 2001). The gap between the two results is mainly due to differences in assumed plant life (60 years here as opposed to 30 in the Hondo study), capacity utilization factor in the latter half of the 21st century (90% here vs. 70% in Hondo study), and the proportion of uranium enrichment done by centrifuge method (About 33% here vs. 10% in Hondo study). The large use of centrifuge enrichment reduces its share of CO2 emissions to some 50%, see Fig. 3(c) compared with the Hondo study (around 65%). 6.2. Comparing the environmental action plan and the 1990 level emissions from the electric power sector The Federation of Electric Power Companies of Japan (FEPC), comprising twelve Japanese electric power companies, made public in November 1996 the ‘‘Environmental Action Plan by the Japanese Electric Utility Industry.’’ This plan establishes the targets to be achieved voluntarily, as well as the measures to achieve them (FEPC, 2002). It aims to reduce the CO2 intensity of the electricity sector by 20% in 2010 compared with the 1990 level.

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Fig. 8. (a)–(d) Estimation of CO2 emissions from the electricity sector in Japan till 2100. (a) Policy case, (b) Promotion case, (c) LWR case, (d) Phaseout case. Table 3 LCCO2 values used for power generation other than nuclear power (Hondo et al., 2000) Power generation technology

LCCO2 value (gCO2/kWh)

Coal Petroleum LNG Hydraulic Geothermal Renewables

975 742 563a 11.3 15.0 27.7b

a The electricity generated by LNG-fired steam cycle and by LNGfired combined cycle was assumed allocated equally between the two for the LNG-fired and therefore, the CO2 emissions intensity of the LNG-fired is calculated by weighted average of the respective emissions intensities. b The CO2 emissions intensity of the renewables of both wind and photovoltaic (using amorphous silicon capability of 1 GW annual production technology) is calculated by the same methodology of that of the LNG-fired.

It is possible to reduce CO2 intensities by some 20% of the 1990 level by the year 2010 and by around 30–40% in the year 2100 in the Promotion, Policy, and LWR cases. In contrast, in the Phase-out case it appears

that CO2 intensities will first decrease by 10% by 2010, but increase by 30% by 2100 as compared with l990, and that a 20% reduction appears quite difficult. Thus, in order to meet this voluntary target, a significant degree of increase in nuclear power or the large introduction of the CO2 abatement technologies to large fossil-fired power plants as well as introduction of renewables will be required. It is worth mentioning that the total CO2 emissions from the electric power sector will (i) maintain its 1990 level throughout the 21st century in the Promotion case, (ii) increase by 20% with respect to the 1990 level in the Policy and the LWR cases, and (iii) be much higher than the 1990 level for the Phase-out case. Capacity enhancement as in the Promotion case is required in order to maintain the 1990 level. 6.3. A consideration of technological change and the obtained results The following factors that lead to reductions in the CO2 intensity of generating electricity are not considered in this study: (i) technological improvements such as thermal efficiency of both fossil-fired and nuclear power

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generation as well as the economic and efficiency potential of photovoltaic and wind-based power, (ii) the expected increase in the share of advanced technologies such as the LNG-fired combined cycle and integrated gasification with combined cycle (IGCC) plants, and (iii) the introduction of CO2 abatement technologies such as CO2 recovery. These factors are excluded here because our main concern is to investigate the effects of different patterns of adopting nuclear power, including FBR, on CO2 emissions, and because we want to focus on the potential of existing technologies (LWR and Phase-out cases). 6.4. Discussion on scenario assumptions and its influence on results Here we discuss relationships between scenario assumptions, in particular SF storage, and obtained results. As there are no official long-term plans till 2100 for reprocessing and storage of SF, the amount of reprocessing and storage of SF is uncertain. Therefore, even if our assumption that ‘‘storing all the SF is possible by use of offsite SF storage’’ is infeasible, other options might be possible such as increasing reprocessing capability or direct disposals for the LWR case. Even if direct disposal (no reprocessing) of SF is assumed for calculating the LCCO2 of nuclear power, the result by Hondo (2001) suggests that the overall LCCO2 value is changed at most by 1%. Therefore, LCCO2 is not sensitive to the way SF is reprocessed and/ or stored. While there are many uncertainties related to SF reprocessing/storage, plutonium peaceful utilization, and public acceptance, we feel we can assert that the future of Japanese nuclear energy will fall somewhere within the four scenarios we developed.

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LWR, and (iii) increase by about 30% in the Phaseout case. The total CO2 emissions will (i) be of the 1990 level in the Promotion case (ii) increase by some 20% in the cases of Policy and LWR, and (iii) be double in the Phase-out case. From our investigations, we conclude that the promotion of nuclear power is clearly a strong option for reducing CO2 emissions by the electric power sector. The introduction of FBR has the effect of further reducing CO2 emissions. Meeting future energy demand and reducing CO2 emissions while phasing-out nuclear power appear challenging given its importance in the Japanese energy supply.

Acknowledgements We would like to express our appreciation to Prof. Kenji YAMAJI of the University of Tokyo, Prof. Yohji UCHIYAMA of Tsukuba University, Dr. Atsushi INABA of AIST (National Institute of Advanced Industrial Science and Technology), Mr. Ryosuke AOKI of JEMAI (The Japan Environmental Management Association for Industry), and Prof. Ryuji MATSUHASHI of the University of Tokyo. We also greatly acknowledge TEPCO (Tokyo Electric Power Company) for LWR data, the Feasibility Study on Commercialized Fast Reactor Cycle Systems, and a joint study on FBR coordinated by the nine Japanese electric power companies with Electric Power Development Co. Ltd., and Japan Atomic Power Company for FBR data.

Appendix A 7. Conclusion We investigated CO2 emissions from the Japanese electric power sector in the 21st century as derived from a lifecycle analysis, in order to quantify emissions according to different patterns of adoption of nuclear power. The main results obtained are as follows: 1. The CO2 intensity of nuclear power generation was some 200 gCO2/kWh in 1970 but went down to about 10 gCO2/kWh in 2000. In the future it will range from 5 to 13 gCO2/kWh in the Promotion and Policy cases, 10–13 gCO2/kWh in the LWR case, and a minimum of some 8 gCO2/kWh to a maximum of about 70 gCO2/kWh in the Phase-out case after 2000. 2. The CO2 intensities produced by the electric power sector in the latter half of the 21st century will be (i) approximately 60% of those of 1990 in the Promotion case (ii) some 75% in the cases of Policy and

Status and plans for uranium enrichment, MOX fuel fabrication, reprocessing, and radioactive waste disposal in Japan. A.1. Domestic uranium enrichment a. Operating organization and operation year of the process (JNFL, 2002a, b) Japan Nuclear Fuel Limited (JNFL) is the operating organization. Operation at 150 tSWU/yr began in 1992. Capacity of the facility has been increased by 150 tSWU/yr up to 1050 tSWU/yr in 2003. The capacity is scheduled to be increased to 1500 tSWU/ yr in the future. b. Input/output of the processes Enrichment is carried out by the centrifuge process. The input/output data for the above facility are not known, we assume that in order to obtain 1 kg of 3% 235U, 1 kgU of enriched uranium UF6 and

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4.479 kgU-depleted uranium are produced from 5.479 kgU raw uranium UF6, by 4.306 kgSWU processing (JAERO, 1996). c. Post-processes for the products Enriched uranium and depleted uranium is forwarded for reprocessing and to manufacturing a blanket for FBR fuel rods.

made available for use by 2010. The required capacity is estimated on a net basis to be 6000 tU in 2010 and 15,000 tU in 2020.’’ (ACNRE, 1998). We assume new facilities based on this information. b. Input/output of the processes SF is input/output. c. Post-processes for the products Reprocessing.

A.2. Onsite storage (accessory pool of plants, storage and preservation within plant sites)

A.5. Reprocessing

a. Operating organization and operation year of the process Individual power companies are the operating organizations. The facilities include pools equipped in each power reactor, dry casks, and common-use pools6 installed inside independent buildings within the plant site (TEPCO, 2002). b. Input/output of the processes SF is input/output. There is a capacity of 12,000 tHM for all of Japan, and 6400 thave been stored (as of late December 1997) (Yamaji, 1998; SFWG 1998). c. Post-processes for the products Reprocessing. A.3. JNFL offsite storage a. Operating organization and operation year of the process JNFL is the operating organization. Receiving of SF began in 1998. b. Input/output of the processes SF is input/output. JNFL has a capacity of 3000 tHM in which 605 tHM has already been stored (JNFL, 2002c). c. Post-processes for the products Reprocessing. A.4. Power Company offsite storage (Recycled Fuel Storage Center) a. Operating organization and operation year of the process These facilities to be operated by each power company are still in the planning stage. It is not yet clear when these facilities will be built and used. The ‘‘Intermediate Report of the Nuclear Power Subcommittee of the Advisory Committee on Energy—–Towards Realization of Interim storage of Recycled Fuel Resources’’ reads as follows: ‘‘A facility (referred to hereinafter as ‘recycled fuel resource interim storage facility’) for the purpose of interim storage of SF outside power plants must be 6 Dry cask storage is being carried from 1997 out at the Fukushima No. 1 Nuclear Power Plant of the Tokyo Electric Power Company.

a. Operating organization and operation year of the process JNFL is the operating organization. Operation is scheduled to start in 2005. b. Input/output of the processes SF of 800 tHM/yr is the input to the process. The outputs are as follows: (i) uranium products (reprocessed uranium UO3), (ii) PuO2
UO2 of plutonium (Pu) products (JNFL, 2002d) (1% of Pu is produced with respect to the reprocessing quantity, i.e., 8 t each of PuO2 and UO2 are produced from the SF quantity. 4.8 t of fissile Pu are contained since 60% of the product is fissile Pu), and (iii) vitrified waste canisters (HLW: 1000 units). c. Post-processes for the products (JNFL, 2002d) The fissile Pu will be mixed with natural uranium or depleted uranium (uranium with an approximately 0.2% 235U concentration produced from the enrichment process) and fabricated to MOX fuel. At the planned MOX fabrication facility by JNFL in Rokkasho in Aomori prefecture, MOX fuel will be produced using the zinc alloy clad fuel rods at the Tokai facility in Ibaraki prefecture. The uranium products (e.g., UO3) are stocked, though in principle may be returned to the conversion process in the nuclear fuel cycle. There are two reasons for assuming stocking: (i) there are presently no authorized Japanese government plans for reuse; (ii) the reprocessing cost for uranium recycling is expensive as the products contain several types of uranium, such as 236U, etc. The vitrified waste canisters are transferred to the temporal interim storage facility.

A.6. MOX fabrication a. Operating organization and operation year of the process (JNFL, 2002a) JNFL is the operating organization. Operation is scheduled to start around 2009. b. Input/output of the processes (JNFL, 2002a) The capacity of the MOX production facility is 130 tHM/yr whose other specifications are not clear. MOX will be produced using the PuO2
UO2 and UO2 from reprocessing, and the fuel clad manufactured by Kobe Special Tube Co., Ltd.

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c. Post-processes for products (JNFL, 2002a; JNFL, 2002b) Plutonium-thermal combustion. A.7. Cementation (LLW) disposal a. Operating organization and operation year of the process JNFL is the operating organization. Receival started in 1992. b. Input/output of the processes (JNFL, 2002a) Cemented LLW is the input. No outputs exist from this process. JNFL presently has two disposal centers and a total capacity of 400,000 units. Disposal of 3,000,000 units is scheduled at present. c. Post-processes for the products None. A.8. Interim storage of vitrified waste canisters a. Operating organization and operation year of the process (JNFL, 2002d) JNFL is the operating organization. Interim storage is divided into vitrified waste canisters from overseas and those from domestic sector. Receiving those from overseas was started in 1995; those from domestic sector are scheduled to start in 2005. b. Input/output of the processes Vitrified waste canisters are input and output. The cooling time span is from 30 to 50 years. The storage capacity for overseas treatment is presently 1440 units and is scheduled to be doubled to 2880 units (JNFL, 2002a). Presently, 616 units have been received7. The facility for domestic treatment is presently under construction and the storage capacity is 5000 units (JNFL, 2002d). c. Post-processes for the products Vitrified waste disposal. A.9. Vitrified waste (HLW) disposal a. Operating organization and operation year of the process The Nuclear Waste Management Organization of Japan8 is the operating organization. Final disposal is planned to begin by the late 2030s. b. Input/output of the processes Vitrified waste canisters are the input. No outputs exist from this process. An installed capacity of 40,000 units is planned (TEPCO, 2002). c. Post-processes for the products None. 7

Of these, 464 units have been contained. Licensed body founded in October 2000 based on the ‘‘Law for Final Disposal of Specific Radioactive Wastes,’’ which was established in May 2000. 8

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