Irradiation

• Project/Area Number: 23760822
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Nuclear engineering
• Research Institution: Tohoku University
• Principal Investigator: TOYAMA Takeshi 東北大学, 金属材料研究所, 講師 (50510129)
• Project Period (FY): 2011 – 2013
• Project Status: Completed (Fiscal Year 2013)
• Budget Amount: ¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000); Fiscal Year 2013: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2012: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000); Fiscal Year 2011: ¥2,340,000 (Direct Cost: ¥1,800,000、Indirect Cost: ¥540,000)
• Keywords: 析出物 / ３次元アトムプローブ / 中性子照射 / ステンレス鋼 / 照射損傷 / 微小析出物 / 国際研究者交流 / 照射欠陥 / ステンレス / 照射誘起析出

Research Abstract

Irradiation-induced precipitates/grain boundary segregation are one of the main origins for irradiation-induced degradation of a stainless steel. For instance, fine precipitates causes irradiation-induced hardening. This study investigated a stainless steel irradiated to a dose of over twenty displacement per atom at the temperature of a light water reactor operation in the fuel wrapper plates of a commercial pressurized water reactor by using three-dimensional atom probe. A high number density of Ni-Si precipitates was observed, which is one order of magnitude higher than that of Frank loops observed by transmission electron microscope. The morphology of the precipitate, such as size, number density and chemical composition, were analyzed in detail, then the hardening due to the precipitates was estimated by using Orowan-model. It is found that the Ni-Si precipitates have an important contribution to irradiation-hardening.

Research Products

• [Journal Article] Effects of post-irradiation annealing and re-irradiation on microstructure in surveillance test specimens of the Loviisa-1 reactor studied by atom probe tomography and positron annihilation (2014)
  • Author(s): Toyama, T., Kuramoto, A., Nagai, Y,. Inoue, K,. Nozawa, Y,. Shimizu, Y,. Matsukawa, Y,. Hasegawa, M,. Valo, M.
  • Journal Title: Journal of Nuclear Materials Volume: in press
• [Journal Article] Intergranular Segregation in the Pressure Vessel Steel of a Commercial Nuclear Reactor Studied by Atom Probe Tomography (2013)
  • Author(s): T. Toyama, Y. Nagai, A. Al Mazouzi, M. Hatakeyama, M. Hasegawa, T. Ohkubo, E. Van Walle, R. Gerard
  • Journal Title: Mater. Trans. Volume: 54 Pages: 2119-2124
  • NAID: 130004824987
• [Journal Article] Microstructural changes in Russian-type reactor weld material after neutron irradiation, post-irradiation annealing and re-irradiation studied by atom probe tomography and positron annihilation spectroscopy (2013)
  • Author(s): A. Kuramoto, T. Toyama, Y. Nagai, K. Inoue, Y. Nozawa, M. Hasegawa, M. Valo
  • Journal Title: Acta. Mater. Volume: 61 Pages: 5236-5246
• [Journal Article] Positron annihilation study of neutron-irradiated nuclear reactor pressure vessel steels and their model alloy : Effect of purity on the post-ittadiation annealig behavior (2013)
  • Author(s): A. Kuramoto, Y. Nagai, T. Toyama, T. Takeuchi, M. Hasegawa
  • Journal Title: Mater. Sci. Forum Volume: 733 Pages: 257-263
• [Journal Article] Intergranular Segregation in the Pressure Vessel Steel of a Commercial Nuclear Reactor Studied by Atom Probe Tomography (2013)
  • Author(s): Toyama, T., Y. Nagai, A. Al Mazouzi, M. Hatakeyama, M. Hasegawa, T. Ohkubo, E. Van Walle and R. Gerard
  • Journal Title: Materials Transactions Volume: 54 Pages: 2119-2124
  • NAID: 130004824987
  • Peer Reviewed
• [Journal Article] Microstructural changes in Russian-type reactor weld material after neutron irradiation, post-irradiation annealing and re-irradiation studied by atom probe tomography and positron annihilation spectroscopy (2013)
  • Author(s): Kuramoto, A., T. Toyama, Y. Nagai, K. Inoue, Y. Nozawa, M. Hasegawa and M. Valo
  • Journal Title: Acta Materialia Volume: 61 Pages: 5236-5246
  • Peer Reviewed
• [Journal Article] Positron annihilation study of neutron-irradiated nuclear reactor pressure vessel steels and their model alloy: Effect of purity on the post-ittadiation annealig behavior (2013)
  • Author(s): Kuramoto, A., Y. Nagai, T. Toyama, T. Takeuchi and M. Hasegawa
  • Journal Title: Materials Science Forum Volume: 733 Pages: 257-263
  • Peer Reviewed
• [Journal Article] Grain boundary segregation in neutron-irradiated 304 stainless steel studied by atom probe tomography (2012)
  • Author(s): T. Toyama, Y. Nozawa, W. Van Renterghem, Y. Matsukawa, M. Hatakeyama, Y. Nagai, A. Al Mazouzi, S. Van Dyck
  • Journal Title: J. Nucl. Mater. Volume: 425 Pages: 71-75
• [Journal Article] Microstructural changes of a thermally aged stainless steel submerged arc weld overlay cladding of nuclear reactor pressure vessels (2012)
  • Author(s): T. Takeuchi, J. Kameda, Y. Nagai, T. Toyama, Y. Matsukawa, Y. Nishiyama, K. Onizawa
  • Journal Title: J. Nucl. Mater. Volume: 425 Pages: 60-64
• [Journal Article] Post-irradiation annealing behavior of microstructure and hardening of a reactor pressure vessel steel studied by positron annihilation and atom probe tomography (2012)
  • Author(s): A. Kuramoto, T. Toyama, T. Takeuchi, Y. Nagai, M. Hasegawa, T. Yoshiie, Y. Nishiyama
  • Journal Title: J. Nucl. Mater. Volume: 425 Pages: 65-70
• [Journal Article] Grain Boundary Segregation in Neutron-irradiated 304 Stainless Steel Studied by Atom Probe Tomography (2012)
  • Author(s): T.Toyama, Y.Nozawa, W.Van Renterghem, Y.Matsukawa, M.Hatakeyama, Y.Nagai, A.Al Mazouzi & S.Van Dyck
  • Journal Title: Journal of Nuclear Materials Volume: 425 Issue: 1-3 Pages: 71-75
  • DOI: 10.1016/j.jnucmat.2011.11.072
  • Peer Reviewed
• [Journal Article] Size estimation of embedded Cu nanoprecipitates in Fe by using affinitively trapped positrons (2012)
  • Author(s): Toyama, T. Tang, Z. Inoue, K. Chiba, T. Ohkubo, T. Hono, K. Nagai, Y. Hasegawa, M.
  • Journal Title: Physical Review B Volume: 86 Pages: 104106-104106
  • Peer Reviewed
• [Journal Article] Microstructural Changes of a Thermally Aged Stainless Steel Submerged Arc Weld Overlay Cladding of Nuclear Reactor Pressure Vessels (2012)
  • Author(s): T.Takeuchi, J.Kameda, Y.Nagai, T.Toyama, Y.Matsukawa, Y.Nishiyama, K.Onizuka
  • Journal Title: Journal of Nuclear Materials Volume: 425 Issue: 1-3 Pages: 60-64
  • DOI: 10.1016/j.jnucmat.2011.12.004
  • Peer Reviewed
• [Journal Article] Post-irradiation annealing behavior of microstructure and hardening of a reactor pressure vessel steel studied by positron annihilation and atom probe tomography (2012)
  • Author(s): A.Kuramoto, T.Toyama, T.Takeuchi, Y.Nagai, M.Hasegawa, T.Yoshiie, Y.Nishiyama
  • Journal Title: Journal of nuclear material Volume: (未定)(In press) Issue: 1-3 Pages: 65-70
  • DOI: 10.1016/j.jnucmat.2011.10.019
  • Peer Reviewed
• [Journal Article] Irradiation-induced precipitates in a neutron irradiated 304 stainless steel studied by three-dimensional atom probe (2011)
  • Author(s): T. Toyama, Y. Nozawa, W. Van Renterghem, Y. Matsukawa, M. Hatakeyama, Y. Nagai, A. Al Mazouzi, S. Van Dyck
  • Journal Title: J. Nucl. Mater. Volume: 418 Pages: 62-68
• [Journal Article] Study on microstructural changes in thermally-aged stainless steel weld-overlay cladding of nuclear reactor pressure vessels by atom probe tomography (2011)
  • Author(s): T. Takeuchi, J. Kameda, Y. Nagai, T. Toyama, Y. Nishiyama, K. Onizawa
  • Journal Title: J. Nucl. Mater. Volume: 415 Pages: 198-204
• [Journal Article] Irradiation-induced precipitates in a neutron irradiated 304 stainless steel studied by three-dimensional atom probe (2011)
  • Author(s): T.Toyama, Y.Nozawa, W.Van Renterghem, Y.Matsukawa, M.Hatakeyama, Y.Nagai, A.Al Mazouzi, S.Van Dyck
  • Journal Title: J.Nucl.Mater. Volume: 418 Issue: 1-3 Pages: 62-68
  • DOI: 10.1016/j.jnucmat.2011.07.027
  • Peer Reviewed
• [Presentation] Effects of post-irradiation annealing and re-irradiation on microstructure in surveillance test specimens of a VVER-type RPV steel (2013)
  • Author(s): T. Toyama, A. Kuramoto, Y. Nozawa, Y. Matsukawa, M. Hasegawa, Y. Nagai
  • Organizer: IGRDM-17
  • Place of Presentation: Les Embiez, French Riviera, France
• [Presentation] ベルギーBR2炉を用いた多段・多分割引き上げ照射計画 (2013)
  • Author(s): 外山 健、鳴井 実、山崎 正徳、鈴木 克弥、四竃 樹男
  • Organizer: 日本金属学会
  • Place of Presentation: 金沢大学
• [Presentation] Effects of post-irradiation annealing and re-irradiation on microstructure in surveillance test specimens of RPV steel studied by 3D-AP and positron annihilation (2013)
  • Author(s): T. Toyama, A. Kuramoto, Y. Nozawa, Y. Matsukawa, M. Hasegawa, Y. Nagai, M. Valo
  • Organizer: TMS-2013
  • Place of Presentation: San Antonio, USA
• [Presentation] 旧ソ連型炉圧力容器鋼監視試験片のミクロ組織分析：照射後焼鈍および再照射効果 (2012)
  • Author(s): 外山健、蔵本明、井上耕治、野沢康子、長谷川雅幸、永井康介、M.Valo
  • Organizer: 京都大学原子炉実験所専門研究会
  • Place of Presentation: 大阪府熊取町
• [Presentation] 旧ソ連型炉圧力容器鋼監視試験片のミクロ組織分析： 照射後焼鈍および再照射効果 (2012)
  • Author(s): 外山健、蔵本明、井上耕治、野沢康子、長谷川雅幸、永井康介、M.Valo
  • Organizer: 東北大学金属材料研究所ワークショップ
  • Place of Presentation: 宮城県仙台市
• [Presentation] Irradiation-induced precipitates and grain boundary segregation in 304 stainless steel neutron-irradiated to 24 dpa studied by atom probe tomography (2011)
  • Author(s): T. Toyama, Y. Nozawa, Y. Matsukawa, M. Hatakeyama, Y. Nagai, W. Van Renterghem, A. Al Mazouzi, S. Van Dyck
  • Organizer: IGRDM-16
  • Place of Presentation: アメリカ・Santa Barbara
  • Year and Date: 2011-12-09
• [Presentation] Irradiation-induced precipitates and grain boundary segregation in 304 stainless steel neutron-irradiated to 24 dpa studied by atom probe tomography (2011)
  • Author(s): T. Toyama et al.
  • Organizer: IGRDM-16
  • Place of Presentation: Santa Barbara, 米国
• [Remarks]
  • URL: http://www.imr-oarai.jp/index.html