- Email: [email protected]
An action plan of Japan toward development of demo reactor
Fusion Engineering and Design xxx (xxxx) xxx–xxx
Contents lists available at ScienceDirect
Fusion Engineering and Design journal homepage: www.elsevier.com/locate/fusengdes
An action plan of Japan toward development of demo reactor ⁎
Kunihiko Okanoa, , Ryuta Kasadab, Yasushi Ikebec, Yasutomo Ishiid, Kyoko Obaf, Mieko Kashiwagie, Ryuichi Sakamotog, Naoki Sawah, Hidenobu Takenagae, Arata Nishimurag, Masaru Fukuiei, Shinsuke Fujiokaj, Yoshio Uedaj, Tsuyoshi Akiyamag a
Keio University, Yokohama, Japan Kyoto University, Kyoto, Japan c National Museum of Emerging Science and Innovation, Tokyo, Japan d National Institutes for Quantum and Radiological Science and Technology, Rokkasho, Japan e National Institutes for Quantum and Radiological Science and Technology, Naka, Japan f Japan Atomic Energy Agency, Tokai, Japan g National Institute for Fusion Science, Toki, Japan h Mitsubishi Heavy Industries Ltd., Kobe, Japan i Toshiba Corporation, Kawasaki, Japan j Osaka University, Osaka, Japan b
A R T I C L E I N F O
A B S T R A C T
Keywords: Demonstration Reactor design Strategy Roadmap Commercial fusion reactor Task-force
An action plan presented here is the plan toward construction of a Demo reactor in Japan. A Task-force for development strategy of Tokamak Demo Reactors was established and has considered an action plan to construct the Demo in the 2040s. The action plan will lead works in a Joint Special Design Team for Fusion Demo established for design and R&D of the Demo reactor in Japan. Although the first version of action plan was reported in March 2016, a revised version, presented here, is being drafted in order to correspond to the new schedule of the ITER project agreed in 2016, because the ITER progress is one of critical issues in the action plan.
1. Introduction Japanese fusion development strategy is in the phase targeting to achieve self-ignition and long-pulse burn by ITER to establish technology for Demonstration fusion reactor (hereafter referred to as “Demo”). This phase is called the Third Phase Program. The research and development in this Third Phase is conducted in the framework of the “Third Phase Basic Program of Fusion Research and Development” decided by the Atomic Energy Commission (AEC) in 1992 [1]. The next Fourth Phase, in which the core project will be the Demo, have been shown in the “Future Fusion Research and Development Strategy” [2] determined by the AEC's Advisory Committee on Nuclear Fusion in 2005. It is supported by the AEC's decision; “Future Fusion Research and Development Strategy in the Third Phase Basic Program of Fusion Research and Development” published in 2005 [3] An action plan presented here is the plan toward construction of the Demo in the Forth Phase. A Task-force for development strategy of Tokamak Demo Reactors (hereafter referred as TF) was established in 2015 in accordance with the request of the Fusion Science and Technology Committee on R&D Planning and Evaluation, the Council
⁎
for Science, Technology and Innovation (hereafter referred as Fusion Science and Technology Committee), which has been established in the Ministry of Education, Culture, Sports, Science and Technology (hereafter referred as MEXT). The TF has considered an Action Plan (AP) to construct Demo reactor in 2040s. The AP will lead works in a Joint Special Design Team for Fusion Demo established for design and R&D of the Demo reactor (hereafter referred as Joint Special Design Team). The first version of AP which was reported in March 2016 was based on the Report by the Joint-Core Team for the Establishment of Technology Bases Required for the Development of a Fusion Demo Reactor (hereafter referred as Joint-Core Team), published in 2014 fiscal year [4] and in 2015 [5]. This AP has been revised in order to correspond to the new schedule of the ITER project agreed in 2016. This is because the ITER progress is one of critical issues in the AP. In this paper, the revised version of the AP is shown. The AP consists of 14 technological issues, including a Demo design study numbered as “0” which should coordinate the all other issues; 0) Demo Design,
Corresponding author. E-mail address: [email protected] (K. Okano).
https://doi.org/10.1016/j.fusengdes.2018.01.040 Received 1 December 2017; Received in revised form 15 January 2018; Accepted 16 January 2018 0920-3796/ © 2018 Published by Elsevier B.V.
Please cite this article as: Okano, K., Fusion Engineering and Design (2018), https://doi.org/10.1016/j.fusengdes.2018.01.040
Fusion Engineering and Design xxx (xxxx) xxx–xxx
K. Okano et al.
Table 1a Action plan for Demo design.
Phase must be decided in the late 2030 s in order to realize the Demo by the 2040s. In addition, for this decision making, the following facilities will be indispensable; a new fusion neutron source (A-FNS) and a cold test facility for divertor heat load by the middle 2020’s, and then, by around 2030, a facility for handling of huge amount of tritium and a facility for maintenance technology development in large scale. The AP also pointed out an importance of a strategic outreach activities to and with the public.
1) SC coil, 2) Blanket, 3) Divertor, 4) Heating and Current Drive, 5) Theory and Numerical Simulation, 6) Plasma, 7) Fuel Systems, 8) Fusion Material and Establishment of Codes and Standards, 9) Safety, 10) Availability and Maintainability, 11) Diagnostics and Control Systems, 12) Social Outreach. In addition, the possible and common contributions to the Tokamak Demo by 13) Helical Reactor Study, 14) Laser Reactor Study. have been included. Finally, the action plan is complemented with an Appendix on “Development of Science Issues for Laser Fusion System”. Since the action plan, which was accepted by the Fusion Science and Technology Committee of MEXT, is a strategy of Japan toward construction of the Demo, the original version has been written in Japanese, rightfully. However, considering an importance to share our analysis on the action plan with the world fusion community, the English version has been prepared [6] while the translation process and the deliverables in English were informal. The draft AP has implied that the transition to a Demo Construction
2. Overview of the action plan 2.1. Examples of full description for some issues Since full descriptions of the action plan are heavy to show in this paper, we would like to show just two examples of the technological issues, i.e., ‘Demo Design (Chapter 0)' and ‘Divertor (Chapter 3) ', which are shown in Tables 1a and 1b, respectively. This is because the plan of Demo design is a common guide-line for all other technological issues and the issue of divertor has been regarded as the most critical issue toward the future Demo construction. Summarized charts covered all the action plan is shown in the next section. As shown in Tables 1a and 1b, three phases of action were defined based on the design phases of Demo: (1) Basic design of concept (to about 2020) (2) Conceptual design (to about 2025) (3) Engineering design (to about 2035) 2
Fusion Engineering and Design xxx (xxxx) xxx–xxx
K. Okano et al.
Table 1b Action plan for Divertor.
(Note that this “phase” is different from the Third and Fourth “Phase”, described in Section 1). In order to keep some flexibility in the plan, the definition of boundaries of each phases are not rigorous. Each year number should be reviewed and refined based on the progress in ITER, JT-60SA and other important projects. We are planning two intermediate Check and Reviews (C&R). The 1st C&R will be done at the ends of the basic design phase (about 2020–021). In this point, the basic concept of Demo design must be decided to begin a conceptual design in the next phase. The 2nd C&R will be done at the end of conceptual design phase (about 2025–2027) to make some decisions of commencement of the Engineering Phase for the Demo and to incorporate the initial results of JT-60SA and some experiences obtained by ITER construction process. At the end of Demo engineering design phase, a judgment on criteria for transition to Demo construction phase will be done at 2035 or somewhat later, just after confirming the ITER DT experiment. The left side columns of Tables 1a and 1b show the technological items. And in the three columns in line rightward corresponding to the design phases, the start year (in black) and the final year (in red) of each development item are shown in brackets, such as [19], which means “2019”. Organizations expected to be in charge for developing the items are also shown using some denotations. The definition of the denotations are shown in the bottom of Table 1a; for example, G is Japanese government, S is Joint special team for Demo Design and R&D, Q is QST (National Institutes for Quantum and Radiological Science and Technology), N is NIFS (National Institute for Fusion Science), U is universities, D is industries, etc.
2.2. Summarized charts of the action plan A summarized chart of the action plan is shown in Tables 2a, 2b and 2c. Hereafter, we would like to explain briefly the key points of actions and targets. 0. Demo Design: In our Demo design, we have assumed implicitly that the ITER project will be successful and the targets of ITER will be achieved. Therefore, the recent delay in the ITER project plan does not result in any serious change of plan before 2025. On the other hand, after 2025, there are a lot of shifts of plan have been necessary. An important decisions is a site for Demo. In order to keep the Demo construction before 2040, we have planned the site decision before 2035. This means that we have to choose the Demo construction site before ITER DT experiment. It might be very difficult decision, but if not, the construction may not be kicked off before 2040. Since we cannot obtain any irradiation data with ITER before 2035, it is an essential request to commence operations of the A-FNS before 2030. 1. Super-conducting Coils: The major option for Super conductor coils (SC) should be decided before the 1st C&R. It was pointed out that BOPs related to SC operation should be developed in line with the SC coil design concept and SC-related materials. 2. Blanket: ITER TBM plan has been shifted rightfully with changing the ITER project plan. As the result, Demo blanket will be designed on a parallel with the construction process of ITER TBM. We have to carefully reflect all the experiences in construction of ITER-TBM to the design of the Demo blanket as soon as possible. A major option of our Demo blanket is “water cooled, solid breeder” concept. However, other advanced concepts will be important to achieve a higher reliability, higher economy, and higher safety in commercial fusion plants after the Demo plant. In our Demo design, “Demo TBM port” will be prepared in 3
Fusion Engineering and Design xxx (xxxx) xxx–xxx
K. Okano et al.
Table 2a Summary chart of Action plan (1).
order to develop some advanced concepts of blanket. 3. Divertor: The divertor have been regarded as the most critical issue toward the future Demo construction. It will be developed by
maximum use of JT-60SA, ITER and simulation codes. But, in addition, a new engineering cold test facility will be indispensable in the phase of the Engineering Design. Nonetheless, the divertor physics and a 4
Fusion Engineering and Design xxx (xxxx) xxx–xxx
K. Okano et al.
Table 2b Summary chart of Action plan (2).
5
Fusion Engineering and Design xxx (xxxx) xxx–xxx
K. Okano et al.
Table 2c Summary chart of Action plan (3).
Study toward safety regulation and evaluation of released tritium behavior will be done throughout the conceptual design phase. 10. Availability & Maintenance: Since the maintenance method and scenario have an essential effect on the Demo design, it must be decided at the early stage of development. A large scale facility for maintenance study should be constructed during the conceptual design phase, before the judgment on criteria for transition to Demo construction phase. 11. Diagnostics & Control: Construction of data base for plasma control by JT-60SA and ITER in line with the development of SMCs might be essential for realizing a Demo operation in the 2040s. Nonetheless, the reliability of the Demo plasma simulator must be confirmed by ITER DT plasma. 12. Cooperation with Society: Strategic outreach activities to and with public for fusion research and development, including Demo design, have been regarded as a very important issue. A collaborative framework of related institutions will be established, along with a headquarters for overall management of activities across Japan. This issue should be equivalent in the importance of the technological issues. In the chapter 13 and the chapter 14, the scientific and technological contributions toward the tokamak Demo by Herical system and Laser system are listed.
reliability of simulation codes must be confirmed by ITER DT plasma. 4. Heating and Current Drive Systems: In comparison with the systems for ITER, further high reliability and high robustness against neutron irradiation should be required for the systems for Demo. Since such development will take long-term, we should launch it in the early phase of the action plan. 5. Theory and Simulation: The role of simulation codes (SMCs) might become more important due to the delay of ITER project. Especially, the divertor SMC is an indispensable item for the Demo design. The plant simulator is also required before the Demo construction. Nonetheless, reliability of these SMCs must be confirmed by ITER DT plasma. 6. Core Plasma: Understanding on plasma for Demo will make a lot of progress with JT-60SA experiments, i.e., plasma control, intensively heated plasma, ELM control, high beta, high confinement, particle control, steady state operation, etc. However, we have to confirm them with the ITER DT plasma for final optimization of the core plasma of Demo. 7. Fuel System: This issue includes a strategy for securement of Lithium and initially loaded tritium, which are especially important for Japan. A facility for treatment of large amount of tritium should be constructed during the conceptual design phase. 8. Fusion Materials, Standard and Codes: In this issue, start of operation of the fusion neutron source (A-FNS) by 2030 is highly indispensable. This is because no irradiation data by ITER will be available before 2035. 9. Safety: Safety policy for Demo plant will be decided by 2020.
2.3. Toward a new roadmap The present Action Plan has included the plan of all the development issues toward the Demo construction. Therefore the contents 6
Fusion Engineering and Design xxx (xxxx) xxx–xxx
K. Okano et al.
References
might be somewhat detail-oriented. Our next step will be to release a more simplified Roadmap, which indicate clearly some important milestones, critical points of the fusion development and a kind of priority order for the issues.
[1] http://www.aec.go.jp/jicst/NC/senmon/kakuyugo2/siryo/kettei/kettei920609. htm. (in Japanese). [2] http://www.aec.go.jp/jicst/NC/senmon/kakuyugo2/siryo/kettei/houkoku051026_ e/index.htm. [3] http://www.aec.go.jp/jicst/NC/iinkai/teirei/siryo2005/kettei/kettei051101.pdf. (in Japanese). [4] H. Yamada and Joint-core team, Report by the Joint-Core Team for the Establishment of Technology Bases Required for the Development of Fusion Demo Reactor: – Basic Concept of Demo and Structure of Technological Issues –, NIFS-MEMO-71, Feb. 2015. [5] H. Yamada and Joint-core team, Report by the Joint-Core Team for the Establishment of Technology Bases Required for the Development of Fusion Demo Reactor: – Chart of Establishment of Technology Bases for Demo –, NIFS-MEMO-73, Mar. 2015. [6] http://www.mext.go.jp/b_menu/shingi/gijyutu/gijyutu2/078/shiryo/__icsFiles/ afieldfile/2017/08/02/1388593_004.pdf.
Acknowledgments The authors highly acknowledged members of the Fusion Science and Technology Committee because of their encouragement and fruitful advices to the Task-force. Also the members of the Joint-Core Team (but not member of the Task-force) are acknowledged by their achievement of the background of the AP. A lot of Discussion with the members of the Joint Special Design Team was invaluable to improve the contents of AP in a more completed and convenient form. The authors also thank the officials of the MEXT who kindly supported us throughout the development of the action plan.
7
Contents lists available at ScienceDirect
Fusion Engineering and Design journal homepage: www.elsevier.com/locate/fusengdes
An action plan of Japan toward development of demo reactor ⁎
Kunihiko Okanoa, , Ryuta Kasadab, Yasushi Ikebec, Yasutomo Ishiid, Kyoko Obaf, Mieko Kashiwagie, Ryuichi Sakamotog, Naoki Sawah, Hidenobu Takenagae, Arata Nishimurag, Masaru Fukuiei, Shinsuke Fujiokaj, Yoshio Uedaj, Tsuyoshi Akiyamag a
Keio University, Yokohama, Japan Kyoto University, Kyoto, Japan c National Museum of Emerging Science and Innovation, Tokyo, Japan d National Institutes for Quantum and Radiological Science and Technology, Rokkasho, Japan e National Institutes for Quantum and Radiological Science and Technology, Naka, Japan f Japan Atomic Energy Agency, Tokai, Japan g National Institute for Fusion Science, Toki, Japan h Mitsubishi Heavy Industries Ltd., Kobe, Japan i Toshiba Corporation, Kawasaki, Japan j Osaka University, Osaka, Japan b
A R T I C L E I N F O
A B S T R A C T
Keywords: Demonstration Reactor design Strategy Roadmap Commercial fusion reactor Task-force
An action plan presented here is the plan toward construction of a Demo reactor in Japan. A Task-force for development strategy of Tokamak Demo Reactors was established and has considered an action plan to construct the Demo in the 2040s. The action plan will lead works in a Joint Special Design Team for Fusion Demo established for design and R&D of the Demo reactor in Japan. Although the first version of action plan was reported in March 2016, a revised version, presented here, is being drafted in order to correspond to the new schedule of the ITER project agreed in 2016, because the ITER progress is one of critical issues in the action plan.
1. Introduction Japanese fusion development strategy is in the phase targeting to achieve self-ignition and long-pulse burn by ITER to establish technology for Demonstration fusion reactor (hereafter referred to as “Demo”). This phase is called the Third Phase Program. The research and development in this Third Phase is conducted in the framework of the “Third Phase Basic Program of Fusion Research and Development” decided by the Atomic Energy Commission (AEC) in 1992 [1]. The next Fourth Phase, in which the core project will be the Demo, have been shown in the “Future Fusion Research and Development Strategy” [2] determined by the AEC's Advisory Committee on Nuclear Fusion in 2005. It is supported by the AEC's decision; “Future Fusion Research and Development Strategy in the Third Phase Basic Program of Fusion Research and Development” published in 2005 [3] An action plan presented here is the plan toward construction of the Demo in the Forth Phase. A Task-force for development strategy of Tokamak Demo Reactors (hereafter referred as TF) was established in 2015 in accordance with the request of the Fusion Science and Technology Committee on R&D Planning and Evaluation, the Council
⁎
for Science, Technology and Innovation (hereafter referred as Fusion Science and Technology Committee), which has been established in the Ministry of Education, Culture, Sports, Science and Technology (hereafter referred as MEXT). The TF has considered an Action Plan (AP) to construct Demo reactor in 2040s. The AP will lead works in a Joint Special Design Team for Fusion Demo established for design and R&D of the Demo reactor (hereafter referred as Joint Special Design Team). The first version of AP which was reported in March 2016 was based on the Report by the Joint-Core Team for the Establishment of Technology Bases Required for the Development of a Fusion Demo Reactor (hereafter referred as Joint-Core Team), published in 2014 fiscal year [4] and in 2015 [5]. This AP has been revised in order to correspond to the new schedule of the ITER project agreed in 2016. This is because the ITER progress is one of critical issues in the AP. In this paper, the revised version of the AP is shown. The AP consists of 14 technological issues, including a Demo design study numbered as “0” which should coordinate the all other issues; 0) Demo Design,
Corresponding author. E-mail address: [email protected] (K. Okano).
https://doi.org/10.1016/j.fusengdes.2018.01.040 Received 1 December 2017; Received in revised form 15 January 2018; Accepted 16 January 2018 0920-3796/ © 2018 Published by Elsevier B.V.
Please cite this article as: Okano, K., Fusion Engineering and Design (2018), https://doi.org/10.1016/j.fusengdes.2018.01.040
Fusion Engineering and Design xxx (xxxx) xxx–xxx
K. Okano et al.
Table 1a Action plan for Demo design.
Phase must be decided in the late 2030 s in order to realize the Demo by the 2040s. In addition, for this decision making, the following facilities will be indispensable; a new fusion neutron source (A-FNS) and a cold test facility for divertor heat load by the middle 2020’s, and then, by around 2030, a facility for handling of huge amount of tritium and a facility for maintenance technology development in large scale. The AP also pointed out an importance of a strategic outreach activities to and with the public.
1) SC coil, 2) Blanket, 3) Divertor, 4) Heating and Current Drive, 5) Theory and Numerical Simulation, 6) Plasma, 7) Fuel Systems, 8) Fusion Material and Establishment of Codes and Standards, 9) Safety, 10) Availability and Maintainability, 11) Diagnostics and Control Systems, 12) Social Outreach. In addition, the possible and common contributions to the Tokamak Demo by 13) Helical Reactor Study, 14) Laser Reactor Study. have been included. Finally, the action plan is complemented with an Appendix on “Development of Science Issues for Laser Fusion System”. Since the action plan, which was accepted by the Fusion Science and Technology Committee of MEXT, is a strategy of Japan toward construction of the Demo, the original version has been written in Japanese, rightfully. However, considering an importance to share our analysis on the action plan with the world fusion community, the English version has been prepared [6] while the translation process and the deliverables in English were informal. The draft AP has implied that the transition to a Demo Construction
2. Overview of the action plan 2.1. Examples of full description for some issues Since full descriptions of the action plan are heavy to show in this paper, we would like to show just two examples of the technological issues, i.e., ‘Demo Design (Chapter 0)' and ‘Divertor (Chapter 3) ', which are shown in Tables 1a and 1b, respectively. This is because the plan of Demo design is a common guide-line for all other technological issues and the issue of divertor has been regarded as the most critical issue toward the future Demo construction. Summarized charts covered all the action plan is shown in the next section. As shown in Tables 1a and 1b, three phases of action were defined based on the design phases of Demo: (1) Basic design of concept (to about 2020) (2) Conceptual design (to about 2025) (3) Engineering design (to about 2035) 2
Fusion Engineering and Design xxx (xxxx) xxx–xxx
K. Okano et al.
Table 1b Action plan for Divertor.
(Note that this “phase” is different from the Third and Fourth “Phase”, described in Section 1). In order to keep some flexibility in the plan, the definition of boundaries of each phases are not rigorous. Each year number should be reviewed and refined based on the progress in ITER, JT-60SA and other important projects. We are planning two intermediate Check and Reviews (C&R). The 1st C&R will be done at the ends of the basic design phase (about 2020–021). In this point, the basic concept of Demo design must be decided to begin a conceptual design in the next phase. The 2nd C&R will be done at the end of conceptual design phase (about 2025–2027) to make some decisions of commencement of the Engineering Phase for the Demo and to incorporate the initial results of JT-60SA and some experiences obtained by ITER construction process. At the end of Demo engineering design phase, a judgment on criteria for transition to Demo construction phase will be done at 2035 or somewhat later, just after confirming the ITER DT experiment. The left side columns of Tables 1a and 1b show the technological items. And in the three columns in line rightward corresponding to the design phases, the start year (in black) and the final year (in red) of each development item are shown in brackets, such as [19], which means “2019”. Organizations expected to be in charge for developing the items are also shown using some denotations. The definition of the denotations are shown in the bottom of Table 1a; for example, G is Japanese government, S is Joint special team for Demo Design and R&D, Q is QST (National Institutes for Quantum and Radiological Science and Technology), N is NIFS (National Institute for Fusion Science), U is universities, D is industries, etc.
2.2. Summarized charts of the action plan A summarized chart of the action plan is shown in Tables 2a, 2b and 2c. Hereafter, we would like to explain briefly the key points of actions and targets. 0. Demo Design: In our Demo design, we have assumed implicitly that the ITER project will be successful and the targets of ITER will be achieved. Therefore, the recent delay in the ITER project plan does not result in any serious change of plan before 2025. On the other hand, after 2025, there are a lot of shifts of plan have been necessary. An important decisions is a site for Demo. In order to keep the Demo construction before 2040, we have planned the site decision before 2035. This means that we have to choose the Demo construction site before ITER DT experiment. It might be very difficult decision, but if not, the construction may not be kicked off before 2040. Since we cannot obtain any irradiation data with ITER before 2035, it is an essential request to commence operations of the A-FNS before 2030. 1. Super-conducting Coils: The major option for Super conductor coils (SC) should be decided before the 1st C&R. It was pointed out that BOPs related to SC operation should be developed in line with the SC coil design concept and SC-related materials. 2. Blanket: ITER TBM plan has been shifted rightfully with changing the ITER project plan. As the result, Demo blanket will be designed on a parallel with the construction process of ITER TBM. We have to carefully reflect all the experiences in construction of ITER-TBM to the design of the Demo blanket as soon as possible. A major option of our Demo blanket is “water cooled, solid breeder” concept. However, other advanced concepts will be important to achieve a higher reliability, higher economy, and higher safety in commercial fusion plants after the Demo plant. In our Demo design, “Demo TBM port” will be prepared in 3
Fusion Engineering and Design xxx (xxxx) xxx–xxx
K. Okano et al.
Table 2a Summary chart of Action plan (1).
order to develop some advanced concepts of blanket. 3. Divertor: The divertor have been regarded as the most critical issue toward the future Demo construction. It will be developed by
maximum use of JT-60SA, ITER and simulation codes. But, in addition, a new engineering cold test facility will be indispensable in the phase of the Engineering Design. Nonetheless, the divertor physics and a 4
Fusion Engineering and Design xxx (xxxx) xxx–xxx
K. Okano et al.
Table 2b Summary chart of Action plan (2).
5
Fusion Engineering and Design xxx (xxxx) xxx–xxx
K. Okano et al.
Table 2c Summary chart of Action plan (3).
Study toward safety regulation and evaluation of released tritium behavior will be done throughout the conceptual design phase. 10. Availability & Maintenance: Since the maintenance method and scenario have an essential effect on the Demo design, it must be decided at the early stage of development. A large scale facility for maintenance study should be constructed during the conceptual design phase, before the judgment on criteria for transition to Demo construction phase. 11. Diagnostics & Control: Construction of data base for plasma control by JT-60SA and ITER in line with the development of SMCs might be essential for realizing a Demo operation in the 2040s. Nonetheless, the reliability of the Demo plasma simulator must be confirmed by ITER DT plasma. 12. Cooperation with Society: Strategic outreach activities to and with public for fusion research and development, including Demo design, have been regarded as a very important issue. A collaborative framework of related institutions will be established, along with a headquarters for overall management of activities across Japan. This issue should be equivalent in the importance of the technological issues. In the chapter 13 and the chapter 14, the scientific and technological contributions toward the tokamak Demo by Herical system and Laser system are listed.
reliability of simulation codes must be confirmed by ITER DT plasma. 4. Heating and Current Drive Systems: In comparison with the systems for ITER, further high reliability and high robustness against neutron irradiation should be required for the systems for Demo. Since such development will take long-term, we should launch it in the early phase of the action plan. 5. Theory and Simulation: The role of simulation codes (SMCs) might become more important due to the delay of ITER project. Especially, the divertor SMC is an indispensable item for the Demo design. The plant simulator is also required before the Demo construction. Nonetheless, reliability of these SMCs must be confirmed by ITER DT plasma. 6. Core Plasma: Understanding on plasma for Demo will make a lot of progress with JT-60SA experiments, i.e., plasma control, intensively heated plasma, ELM control, high beta, high confinement, particle control, steady state operation, etc. However, we have to confirm them with the ITER DT plasma for final optimization of the core plasma of Demo. 7. Fuel System: This issue includes a strategy for securement of Lithium and initially loaded tritium, which are especially important for Japan. A facility for treatment of large amount of tritium should be constructed during the conceptual design phase. 8. Fusion Materials, Standard and Codes: In this issue, start of operation of the fusion neutron source (A-FNS) by 2030 is highly indispensable. This is because no irradiation data by ITER will be available before 2035. 9. Safety: Safety policy for Demo plant will be decided by 2020.
2.3. Toward a new roadmap The present Action Plan has included the plan of all the development issues toward the Demo construction. Therefore the contents 6
Fusion Engineering and Design xxx (xxxx) xxx–xxx
K. Okano et al.
References
might be somewhat detail-oriented. Our next step will be to release a more simplified Roadmap, which indicate clearly some important milestones, critical points of the fusion development and a kind of priority order for the issues.
[1] http://www.aec.go.jp/jicst/NC/senmon/kakuyugo2/siryo/kettei/kettei920609. htm. (in Japanese). [2] http://www.aec.go.jp/jicst/NC/senmon/kakuyugo2/siryo/kettei/houkoku051026_ e/index.htm. [3] http://www.aec.go.jp/jicst/NC/iinkai/teirei/siryo2005/kettei/kettei051101.pdf. (in Japanese). [4] H. Yamada and Joint-core team, Report by the Joint-Core Team for the Establishment of Technology Bases Required for the Development of Fusion Demo Reactor: – Basic Concept of Demo and Structure of Technological Issues –, NIFS-MEMO-71, Feb. 2015. [5] H. Yamada and Joint-core team, Report by the Joint-Core Team for the Establishment of Technology Bases Required for the Development of Fusion Demo Reactor: – Chart of Establishment of Technology Bases for Demo –, NIFS-MEMO-73, Mar. 2015. [6] http://www.mext.go.jp/b_menu/shingi/gijyutu/gijyutu2/078/shiryo/__icsFiles/ afieldfile/2017/08/02/1388593_004.pdf.
Acknowledgments The authors highly acknowledged members of the Fusion Science and Technology Committee because of their encouragement and fruitful advices to the Task-force. Also the members of the Joint-Core Team (but not member of the Task-force) are acknowledged by their achievement of the background of the AP. A lot of Discussion with the members of the Joint Special Design Team was invaluable to improve the contents of AP in a more completed and convenient form. The authors also thank the officials of the MEXT who kindly supported us throughout the development of the action plan.
7