著者

小西 哲之

出版者

一般社団法人 日本原子力学会

雑誌

日本原子力学会誌ATOMOΣ (ISSN:18822606)

巻号頁・発行日

vol.61, no.9, pp.680-686, 2019 (Released:2020-04-02)

参考文献数

10

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トリチウム研究の現状と今後の展開と課題について,炉内の工学研究のみならず,環境,生物影響,社会との関係まで視野を広げて概観する。核融合炉ではトリチウムは法規制を十分に守っていても一定量のトリチウムを定常放出するため,周辺環境モニターで濃度上昇が検出されるのは不可避であり,その影響の評価と社会による理解,合意まで含めて考える必要がある。工学のみならず環境,生物関連研究や社会との連携の進展は,核融合原型炉の実現に向けて,着実なトリチウム取り扱い技術と経験の蓄積に基づく展開を開始する段階を迎えている。

著者

小西 哲之

出版者

一般社団法人 日本原子力学会

雑誌

日本原子力学会誌ATOMOΣ (ISSN:18822606)

巻号頁・発行日

vol.64, no.10, pp.557-560, 2022 (Released:2022-10-10)

参考文献数

1

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核融合研究開発は巨額の投資を要する基礎的科学研究として,世界的に長らく公費により実施されてきたが,近年民間努力による実用化研究が脚光を浴びている。ここでは,核融合工学の今後の展開においてスタートアップ企業が担う役割とその方法論について報告する。具体的には,京都大学発ベンチャーとして2019年10月に設立された京都フュージョニアリング(KF)社の事例をもとに,以後順調に進展している組織,資金,研究開発活動を説明し,世界の核融合開発の推進に対するユニークな貢献とともに,豊富な原子力研究の基盤を持つわが国の次世代の重要な産業分野としての意義を論ずる。

著者

小西 哲之 榎枝 幹男

出版者

一般社団法人 日本原子力学会

雑誌

日本原子力学会誌 (ISSN:00047120)

巻号頁・発行日

vol.47, no.7, pp.488-494, 2005 (Released:2019-01-31)

参考文献数

8

被引用文献数

1 1

著者

小西 哲之

出版者

社団法人 プラズマ・核融合学会

雑誌

プラズマ・核融合学会誌 (ISSN:09187928)

巻号頁・発行日

vol.78, no.11, pp.1157-1164, 2002 (Released:2005-12-08)

参考文献数

9

被引用文献数

1

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Based on the fundamental approach for safety of ITER, a possible extension of it to assure the safety of fusion power plant was considered. Although the entire an alysis and licensing preparation are specific for ITER, its methodology which takes full advantage of the inherent features of fusion is expected to be applied to the fundamental logic of fusion power plants. Both energy and radioactive source terms that could be potential hazards are typically operative for a number of days rather than for a year, as in the case of fission. The major differences from the test reactor ITER were identified as the power blanket, coolant loop, and a generator train that will hold high temperature and a considerable amount of tritium. It is anticipated that the tritium inventory and most of the tritium plant would essentially be same as those for ITER, tritium recovery and removal from the blanket loop will dominate the fusion power plant tritium systems. Such a tritium system will actively remove tritium at a daily throughput of the order of plant inventory. This feature suggests that no dedicated off-normal systems are needed to assure the safety of the fusion plant in terms of environmental tritium release.

著者

日渡 良爾 岡野 邦彦 朝岡 善幸 時松 宏治 小西 哲之 小川 雄一

出版者

社団法人プラズマ・核融合学会

雑誌

プラズマ・核融合学会誌 (ISSN:09187928)

巻号頁・発行日

vol.81, no.11, pp.903-916, 2005-11-25

被引用文献数

1 3

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The present study reveals forthcoming break-even conditions of tokamak plasma performance for the fusion energy development. The first condition is the electric break-even condition, which means that the gross electric power generation is equal to the circulating power in a power plant. This is required for fusion energy to be recognized as a suitable candidate for an alternative energy source. As for the plasma performance (normalized beta value β_N, confinement improvement factor for H-mode HH, the ratio of plasma density to Greenwald density fn_<GW>), the electric break-even condition requires the simultaneous achievement of 1.2<β_N<2.7, 0.8<HH, and 0.3<fn_<GW><1.1 under the conditions of a maximum magnetic field on the TF coil B_<max>=16 T, thermal efficiency η_e=30%, and current drive power P_<NBI><200 MW. It should be noted that the relatively moderate conditions of β_N〜1.8, HH〜1.0, and/fn_<GW>〜0.9, which correspond to the ITER reference operation parameters, have a strong potential to achieve the electric break-even condition. The second condition is the economic break-even condition, which is required for fusion energy to be selected as an alternative energy source in the energy market. By using a long-term world energy scenario, a break-even price for introduction of fusion energy in the year 2050 is estimated to lie between 65 mill/kWh and 135 mill/kWh under the constraint of 550 ppm CO_2 concentration in the atmosphere. In the present study, this break-even price is applied to the economic break-even condition. However, because this break-even price is based on the present energy scenario including uncertainties, the economic break-even condition discussed here should not be considered the sufficient condition, but a necessary condition. Under the conditions of β_<tmax>=16 T, η_e=40%, plant availability 60%, and a radial build with/without CS coil, the economic break-even condition requires β_N〜5.0 for 65 mill/kWh of lower break-even price case. Finally, the present study reveals that the demonstration of steady-state operation with β_N〜3.0 in the ITER project leads to the upper region of the break-even price in the present world energy scenario, which implies that it is necessary to improve the plasma performance beyond that of the ITER advanced plasma operation.

著者

小西 哲之 時松 宏治

出版者

社団法人 プラズマ・核融合学会

雑誌

プラズマ・核融合学会誌 (ISSN:09187928)

巻号頁・発行日

vol.78, no.11, pp.1192-1198, 2002 (Released:2005-12-08)

参考文献数

7

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Energy model analysis estimates the significant contribution of fusion in the latter half of the century under the global environment constraints if it will be successfully developed and introduced into the market. The total possible economical impact of fusion is investigated from the aspect of energy cost savings, sales, and its effects on Gross Domestic Products. Considerable economical possibility will be found in the markets for fusion related devices, of currently developing countries, and for synthesized fuel. The value of fusion development could be evaluated from these possible economic impact in comparison with its necessary investment.

著者

西尾 敏 飛田 健次 牛草 健吉 小西 哲之 動力炉設計チーム 動力炉設計チーム

出版者

社団法人プラズマ・核融合学会

雑誌

プラズマ・核融合学会年会予稿集

巻号頁・発行日

no.18, 2001-11-20

著者

飛田 健次 小西 哲之 時松 宏治 西尾 敏 日渡 良爾

出版者

社団法人 プラズマ・核融合学会

雑誌

プラズマ・核融合学会誌 (ISSN:09187928)

巻号頁・発行日

vol.81, no.11, pp.875-891, 2005 (Released:2007-01-12)

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This section describes the future of fusion energy in terms of its impact on the global energy supply and global warming mitigation, the possible entry scenarios of fusion into future energy market, and innovative technologies for deploying and expanding fusion's share in the market. Section 5.1 shows that fusion energy can contribute to the stabilization of atmospheric CO2 concentration if fusion is introduced into the future energy market at a competitive price. Considerations regarding fusion's entry scenarios into the energy market are presented in Sec. 5.2, suggesting that fusion should replace fossil energy sources and thus contribute to global warming mitigation. In this sense, first generation fusion power plants should be a viable energy source with global appeal and be so attractive as to be employed in developing countries rather than in developed countries. Favorable factors lending to this purpose are fusion's stability as a power source, and its security, safety, and environmental frendliness as well as its cost-of-electricity. The requirements for core plasma to expand the share of fusion in the market in the latter half of this century are given in Sec.5.3, pointing out the importance of high beta access with low aspect ratio and plasma profile control. From this same point of view, innovative fusion technologies worthy of further development are commented on in Sec. 5.4, addressing the high temperature blanket, hydrogen production, high temperature superconductors, and hot cell maintenance.

著者

飛田 健次 小西 哲之 西尾 敏 小迫 和明 田原 隆志

出版者

社団法人プラズマ・核融合学会

雑誌

プラズマ・核融合学会誌 (ISSN:09187928)

巻号頁・発行日

vol.77, no.10, pp.1035-1039, 2001-10-25

被引用文献数

4

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A new concept of fusion reactor design is proposed to minimize the radioactive waste of the reactor. The main point of the concept is to clear massive structural components located outside the neutron shield from regulatory control. The concept requires some reinforcement of shielding with an advanced shield material such as a metal hydride, detriation, and tailoring of a detrimental element from the superconductor. Our assessment confirmed a large impact of the concept on radwaste reduction, in that it reduces the radwaste fraction of a fusion reactor A-SSTR2 from 92wt.% to 17wt.%.