Multi-scale/multi-physics modeling of long-term evolution of material properties in solid breeding materials

2014 Fiscal Year Final Research Report

• Project/Area Number: 23246161
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Nuclear fusion studies
• Research Institution: The University of Tokyo
• Principal Investigator: TANAKA Satoru 東京大学, 工学(系)研究科(研究院), 教授 (10114547)
• Co-Investigator(Kenkyū-buntansha): OYA Yasuhisa 静岡大学, 理学部, 准教授 (80334291) ; OCHIAI Kentaro 日本原子力研究開発機構, 核融合研究開発部門, 研究副主幹 (30370373) ; TANIGAWA Hisashi 日本原子力研究開発機構, 核融合研究開発部門, 研究副主幹 (70370426)
• Project Period (FY): 2011-04-01 – 2015-03-31
• Keywords: 核融合炉 / 固体増殖材料 / トリチウム / チタン酸リチウム / 照射損傷 / 分子動力学計算 / 量子力学計算

Outline of Final Research Achievements

We studied the physical/chemical property change and radiation damage processes, which are expected to occur during fusion reactor operation, in solid breeding materials. In Li2TiO3, it was found that the hydrogen inventory on the surface is several tens times of the number of atoms on the topmost surface. Even for materials of the same grain size, the surface inventory can differ by several times, according to the physical/chemical condition of the surface. In the bulk, the tritium inventory will increase and the tritium diffusivity will decrease during the reactor operation, due to the Li deficiency induced by the lithium burning. Regarding radiation damages, Li2O deficiency, which is caused by the lithium burning and subsequent hydrogen release, and Ti anti-site defect are important. Especially, the antis-site defect should play a key role because it is easily formed by displacement and it largely changes the material property.

Free Research Field

核融合炉工学，トリチウム工学