Measurement of void fraction distribution in a sphere-packed bed using X-ray imaging

Yamamoto, Seishiro*; Odaira, Naoya*; Ito, Daisuke*; Ito, Kei*; Saito, Yasushi*; Imaizumi, Yuya; Matsuba, Kenichi; Kamiyama, Kenji

Konsoryu, 37(1), p.79 - 85, 2023/03

Sodium-cooled Fast Reactors

Ohshima, Hiroyuki; Morishita, Masaki*; Aizawa, Kosuke; Ando, Masanori; Ashida, Takashi; Chikazawa, Yoshitaka; Doda, Norihiro; Enuma, Yasuhiro; Ezure, Toshiki; Fukano, Yoshitaka; et al.

Sodium-cooled Fast Reactors; JSME Series in Thermal and Nuclear Power Generation, Vol.3, 631 Pages, 2022/07

https://shop.elsevier.com/books/sodium-cooled-fast-reactors/morishita/978-0-12-824076-2

This book is a collection of the past experience of design, construction, and operation of two reactors, the latest knowledge and technology for SFR designs, and the future prospects of SFR development in Japan. It is intended to provide the perspective and the relevant knowledge to enable readers to become more familiar with SFR technology.

Two-phase flow structure in a particle bed packed in a confined channel

Ito, Daisuke*; Kurisaki, Tatsuya*; Ito, Kei*; Saito, Yasushi*; Imaizumi, Yuya; Matsuba, Kenichi; Kamiyama, Kenji

Proceedings of 18th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-18) (USB Flash Drive), p.6430 - 6439, 2019/08

In core disruptive accident of sodium-cooled fast reactor, cooling of residual fuel debris formed in the reactor core is one of important factors to achieve in-vessel retention of the fuel. To clarify the feasibility of the cooling which is called "in-place cooling", characteristics of gas-liquid two-phase flow in the debris bed must be well understood. Since the debris bed can be formed in a confined flow channel in the core, effect of the channel wall cannot be neglected. Thus, this study aims to clarify the effect of the wall on two-phase flow characteristics in the debris bed, which was simulated as a particle bed packed in a pipe. The pressure drop was measured and compared with results by previous models, and porosity and void fraction distributions were measured by X-ray radiography. Then, the pressure drop evaluation model was modified considering the wall effect, and the applicability of the models was discussed.

Estimation of porosity and void fraction profiles in a packed bed of spheres using X-ray radiography

Ito, Daisuke*; Ito, Kei*; Saito, Yasushi*; Aoyagi, Mitsuhiro; Matsuba, Kenichi; Kamiyama, Kenji

Nuclear Engineering and Design, 334, p.90 - 95, 2018/08

https://doi.org/10.1016/j.nucengdes.2018.05.003

Two-phase flow through porous media must be well understood to develop a severe accident analysis code not only for light water reactor but also sodium-cooled fast reactor. When a core disruptive accident occurs in sodium-cooled fast reactor, the fuel inside the core become melted and interacts with the coolant. As a result, gas-liquid two-phase flow will be formed in the debris bed, which may have porous nature depending on the cooling process. In such condition, the local porosity and its distribution are very important to characterize two-phase flow field in the porous media. In this study, X-ray radiography was applied to measure the local porosity in the packed bed of spheres. The radial profiles were estimated from the chordal profiles measured by the X-ray method and compared with the previous porosity model. In addition, the void fraction radial profiles were also obtained in air-water two-phase flow.

Measurements of two-phase pressure drop in a simulated debris bed

Nava, M.*; Ito, Daisuke*; Saito, Yasushi*; Aoyagi, Mitsuhiro; Kamiyama, Kenji; Suzuki, Toru*

Proceedings of 25th International Conference on Nuclear Engineering (ICONE-25) (CD-ROM), 5 Pages, 2017/07

Improvement in oil seal performance of Gas Compressor in HTTR

Oyama, Sunao*; Hamamoto, Shimpei; Kaneshiro, Noriyuki*; Nemoto, Takahiro; Sekita, Kenji; Isozaki, Minoru; Emori, Koichi; Ito, Yoshiteru*; Yamamoto, Hideo*; Ota, Yukimaru; et al.

JAEA-Technology 2007-047, 40 Pages, 2007/08

JAEA-Technology-2007-047.pdf:18.83MB

High-Temperature engineering Test Reactor (HTTR) built by Japan Atomic Energy Agency (JAEA) has commonly used reciprocating compressor to extract helium gas and discharge helium gas into primary/secondary coolant helium loop from helium purification system. Rod-seal structure of the compressor is complicated from a prevention coolant leak standpoint. Because of frequently leakage of seal oil in operation, Rod seal structure isn't as reliable as it should be sustainable in the stable condition during long term operation. As a result of investigations, leakage's root is found in that seal were used in a range beyond limit sliding properties of seal material. Therefore a lip of the seal was worn and transformed itself and was not able to sustain a seal function. Endurance test using materials testing facility and verification test using a actual equipment on candidate materials suggest that a seal of fluorine contained resin mixed graphite is potentially feasible material of seal.

Study on Three-Dimensional Seismic Isolation System Applied to Advanced Nuclear Power Plants, 5; Study on Development Planning

Takahashi, Kenji; Kato, Asao*; Ito, Kei; Fushimi, Minoru*; Fujita, Takafumi*; Inoue, Kazuhiko*

Dynamics and Design Conference 2005 (D&D 2005) Koen Rombunshu (CD-ROM), 6 Pages, 2005/09

In order to reduce the cost of plant design and construction, and to enhance the credibility, a study for Three-Dimensional isolation system was permormed. There are two types of isolation system. One is a 3D entire building isolaiton system. The other is a vertical isolation system which is added on the horizontal entire building isolation system. For both systems, outlines of development,requirements of the sytems, process of the verification tests, test results and applicabilities to the fast breeder reactor are mentioned.

Replacement of the drain system of secondary circuit MONJU plant

Ito, Kenji

Proceedings of 11th International Conference on Nuclear Engineering (ICONE-11) (CD-ROM), 0 Pages, 2003/00

None

Fabrication of full-scale sector model for ITER vacuum vessel

Koizumi, Koichi; Nakahira, Masataka; *; Takahashi, Hiroyuki*; Tada, Eisuke; Ioki, Kimihiro*; Johnson, G.*; Onozuka, Masanori*; Y.Utin*; Sonnazzaro, G.*; et al.

Proceedings of 17th IEEE/NPSS Symposium Fusion Engineering (SOFE'97), 2, p.933 - 936, 1998/00

no abstracts in English

Development of hydride neutron absorber for fast reactor, 8; Preparation and implementation of the irradiation test in Experimental Fast Reactor Joyo

Ito, Kazuhiro; Yamamoto, Masaya; Maeda, Koji; Akasaka, Naoaki; Harada, Akio; Konashi, Kenji*

no journal, , 

As part of "Development of Hydride Neutron Absorber for Fast Reactor", a series of neutron irradiation experiment with in HfH, (Gd+ZR)H and stainless steel specimens was performed in experimental fast reactor Joyo. Here, the stainless steel specimens were coated by oxide film to simulate a cladding tube. In this report, the irradiation examination plan and a result were summarized.