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Kozawa, Takayuki; Suganuma, Takuro; Homma, Fumitaka; Higashimura, Keisuke*; Ukai, Takayuki*; Saito, Kenji
JAEA-Technology 2023-007, 24 Pages, 2023/06
JAEA-Technology-2023-007.pdf:2.24MB
To improve the reliability of the HTTR wide range monitor in a high-temperature environment, structural changes of the wide range monitor were investigated. It was clear that the structure for directly joins of the MI cable core wire and metal tube instead of the joins with lead wire is the most reliable method with shortest way. From a result of the thermal cycle tests and high temperature endurance tests for a mock-up connecting this connection parts, it was clear that the soundness of the connection part was maintained under the usage conditions of the HTTR.
C) conditionsOkamoto, Ryo*; Matsuura, Hideaki*; Ida, Yuma*; Koga, Yuki*; Suganuma, Takuro*; Katayama, Kazunari*; Otsuka, Teppei*; Goto, Minoru; Nakagawa, Shigeaki; Ishitsuka, Etsuo; et al.
no journal, ,
It has been proposed that lithium rods, which are cylindrical lithium compounds, are loaded into a HTGR and tritium for initial fusion reactors is produced by 
Li(n,
)T reaction. In this study, it was discussed that the lithium rods are covered with zirconium layers to prevent the produced tritium leak. The solubility and diffusion coefficient of hydrogen in zirconium were measured and the effectiveness of the zirconium layers on prevention of tritium leakage was estimated with the measured values. As a result, the tritium leakage ratio with the zirconium layers was estimated two orders lower than that without the zirconium layers, and hence it was considered that the zirconium layer is very effective on the prevention of the tritium leakage.
Suganuma, Takuro*; Matsuura, Hideaki*; Okamoto, Ryo*; Koga, Yuki*; Katayama, Kazunari*; Otsuka, Teppei*; Goto, Minoru; Nakagawa, Shigeaki; Tobita, Kenji*
no journal, ,
A study on the confinement of tritium, which is a fuel for fusion reactors and is produced by a HTGR, has been conducted for high temperature condition. The tritium is confined in the irradiation capsule with a zirconium layer. The relation between a H/Zr ratio and an apparent diffusion coefficient of tritium in the zirconium layer is needed to evaluate the tritium confinement performance of the irradiation capsule. This relation was examined with a experiment using deuteron. As a result, the apparent diffusion coefficient deceases with an increase of the H/Zr ratio. This phenomena should be caused by a generation of hydrogen. After that, the analysis for an amount of the release of the tritium from the irradiation capsule will be calculated using obtained data to evaluate the containment performance of the irradiation capsule.
Okamoto, Ryo*; Matsuura, Hideaki*; Koga, Yuki*; Suganuma, Takuro*; Katayama, Kazunari*; Otsuka, Teppei*; Goto, Minoru; Nakagawa, Shigeaki; Ishitsuka, Etsuo; Tobita, Kenji*
no journal, ,
Currently, the method to reduce the spilled tritium by using the lithium rod with zirconium layer under the high temperature condition was proposed in the study of the tritium production by using high temperature gas-cooled reactor (HTGR). In this study, the experiments to evaluate the performance of hydrogen absorption in the zirconium layer were conducted. The experimental result concerning hydrogen absorption properties of zirconium will be presented and discussed.
Koga, Yuki*; Matsuura, Hideaki*; Okamoto, Ryo*; Suganuma, Takuro*; Katayama, Kazunari*; Otsuka, Teppei*; Goto, Minoru; Nakagawa, Shigeaki; Ishitsuka, Etsuo; Tobita, Kenji*
no journal, ,
Production of tritium using a high temperature gas-cooled reactor (HTGR) has been studied for a prior engineering test with tritium handling and for the startup operation of a demonstration fusion reactor. For this purpose, Li-loading rods are installed at the moderator region of the HTGR. The tritium retention capability of Li-loading rod would decline due to high temperature condition from 1100K to 1200K during HTGR rated power operation. Therefore, the zirconium is employed as tritium absorber which is granular and is coated with nickel to prevent from declining the tritium absorption capability due to zirconium oxidation and so on. In this presentation, the design concept of Li-loading rods with granular zirconium coated with nickel and the method of irradiation test by using the HTTR which is a test reactor of HTGR are presented.