Experimental verification of operational conditions for the 3rd glass melter in TVF

Asahi, Yoshimitsu; Fukuda, Shigeki; Shiramizu, Daiki; Miyata, Koshi; Tone, Masaya; Katsuoka, Nanako; Maeda, Yuta; Aoyama, Yusuke; Niitsuma, Koichi; Kobayashi, Hidekazu; et al.

JAEA-Technology 2024-024, 271 Pages, 2025/03

JAEA-Technology-2024-024.pdf:33.98MB
JAEA-Technology-2024-024-hyperlink.zip:31.96MB

A glass melter for the vitrification process of highly active liquid waste in the Tokai Reprocessing Plant, TVF's 3rd melter, was built, and the glass of 18 vitrified waste canisters in weight was melted and poured through a cold test operation. The molten glass surface was covered by a cold cap from feeding fiberglass cartridges saturated with non-radioactive simulant liquid waste as raw material, whose components are equivalent to actual waste. Differences in inherent characteristics of the thermal behavior between the 2nd and the 3rd melter due to the difference in design were considered to establish the procedure to control the new melter. The melter's condition was stabilized at a higher glass temperature and the cooling of 1 kW less in each of the two main electrodes, compared to the 2nd one. Under 39 kW joule heating of the main electrodes with 26 Nm3/h coolant flow rate, it showed the capability to finish heating the bottom furnace in 5 hours before pouring, 2 hours shorter than the 2nd melter. Measurements of the temperature distributions in molten glass and casing surface yielded data that is efficient for developing a simulation model. After Platinum Group Elements (PGE) concentration saturates in the molten glass, feeding raw material and discharging glass were suspended to examine a holding state, indicating PGE settling could retard. During the holding test, observation of the melting process of the cold cap declared that the surface was covered by a thin layer with almost non-fluidity. It will be a reason for choosing the no-slip condition of a fluid calculation, even in the hot-top condition. The investigation of PGE discharging behavior by analyzing the elemental composition of poured glass showed the accumulated PGE amount in the 3rd melter is small compared to the 2nd melter. Inspection of the melter inside after draining out concluded that there were neither significant residual glass nor refractory fragments.

Evaluation of bond repair effect for ultra-high-strength concrete specimens by neutron diffraction method

Yasue, Ayumu*; Kobayashi, Kensuke*; Yoshioka, Masahiro*; Noma, Takashi*; Okuno, Koichi*; Tanaka, Seiichiro*; Hirata, Yoshikazu*; Ooka, Tokunao*; Kimura, Yoshiharu*; Nagai, Tomoya*; et al.

Journal of Advanced Concrete Technology, 21(5), p.337 - 350, 2023/05

https://doi.org/10.3151/jact.21.337

The purpose of this study was to evaluate the use of resin injection to repair cracks in ultra-high-strength concrete (UHSC) members. As a preliminary step, the applicability of the neutron diffraction method (NDM) to investigate the effect of repairs in UHSC specimens was examined. The experimental results showed that the NDM can measure stresses in rebars in UHSC and normal concrete specimens. Therefore, in this experiment, the NDM was used to measure the bond performance of repairs with epoxy resin around the slit in normal concrete and UHSC specimens and examine the effect of repair on the UHSC specimens. Displacement around the slit was measured using a PI-shape displacement transducer. The evaluation confirmed that the bond performance of the repaired area was recovered by resin injection regardless of the concrete strength. In addition, the displacement around the slit was smaller for the injected specimens than the noninjected specimens. These experimental results clarified that by injecting resin, the same bond repair effect could be obtained in UHSC and normal concrete specimens.

Optimizing TiO through water-soluble Ti complexes as raw material for controlling particle size and distribution of synthesized BaTiO nanocubes

Nakashima, Koichi*; Hironaka, Kota*; Ouchi, Kazuma*; Ajioka, Mao*; Kobayashi, Yoshio*; Yoneda, Yasuhiro; Yin, S.*; Kakihana, Masato*; Sekino, Toru*

ACS Omega (Internet), 6(48), p.32517 - 32527, 2021/12

https://doi.org/10.1021/acsomega.1c04013

The BaTiO nanoparticles synthesized by the hydrothermal method is examined by synchrotron X-ray and TEM observation. It was found that the particle size of synthesized BaTiO depends on the particle size of the raw material of TiO. Succeeded in synthesizing 100 nm size BaTiO nanocrystals showing uniform particle size distribution using TiO nanoparticles with optimized particle size. The obtained BaTiO nanocrystal is a tetragonal system of ferroelectric phase. A three-dimensional structure of BaTiO nanoparticles could be obtained by the electron beam tomography.

Consideration of relationship between decommissioning with digital-twin and knowledge management

Taruta, Yasuyoshi; Yanagihara, Satoshi*; Hashimoto, Takashi*; Kobayashi, Shigeto*; Iguchi, Yukihiro; Kitamura, Koichi; Koda, Yuya; Tomoda, Koichi

Proceedings of 2020 International Conference on Nuclear Engineering (ICONE 2020) (Internet), 8 Pages, 2020/08

https://doi.org/10.1115/ICONE2020-16457

Decommissioning is a long-term project during which generations are expected to change. Therefore, it is necessary to appropriately transfer knowledge and technology to the next generation. In recent years, in the world of decommissioning, attempts have been made to apply advanced technologies such as utilization of knowledge management and virtual reality. This study describes adaptation in decommissioning from the viewpoint of utilizing IT technology called digital twin from the viewpoint of knowledge management.

Multi-step magnetic transitions in EuNiIn

Ikeda, Shugo*; Kaneko, Koji; Tanaka, Yuki*; Kawasaki, Takuro; Hanashima, Takayasu*; Munakata, Koji*; Nakao, Akiko*; Kiyanagi, Ryoji; Ohara, Takashi; Mochizuki, Kensei*; et al.

Journal of the Physical Society of Japan, 89(1), p.014707_1 - 014707_7, 2020/01

https://doi.org/10.7566/JPSJ.89.014707

Study on optimizing microwave heating denitration method and powder characteristics of uranium trioxide

Segawa, Tomoomi; Kawaguchi, Koichi; Kato, Yoshiyuki; Ishii, Katsunori; Suzuki, Masahiro; Fujita, Shunya*; Kobayashi, Shohei*; Abe, Yutaka*; Kaneko, Akiko*; Yuasa, Tomohisa*

Proceedings of 2019 International Congress on Advances in Nuclear Power Plants (ICAPP 2019) (Internet), 9 Pages, 2019/05

A solution of plutonium nitrate and uranyl nitrate is converted into a mixed oxide by microwave heating denitration method. In the present study, for improving the efficiency of microwave heating and achieving high-temperature uniformity to produce homogeneous UO powder, the microwave heating test of potassium chloride and uranyl nitrate solution, and numerical simulation analysis were conducted. The potassium chloride agar was adjusted to the dielectric loss, which is close to that of the uranyl nitrate solution and the optimum support table height was estimated to be 50 mm for denitration of the uranyl nitrate solution by microwave heating. The adiabator improved the efficiency of microwave heating denitration. Moreover, the powder yield was improved by using the adiabator owing to ease of scraping of the denitration product from the bottom of the denitration vessel.

Excited configurations of hydrogen in the BaTiOH perovskite lattice associated with hydrogen exchange and transport

Ito, Takashi; Koda, Akihiro*; Shimomura, Koichiro*; Higemoto, Wataru; Matsuzaki, Teiichiro*; Kobayashi, Yoji*; Kageyama, Hiroshi*

Physical Review B, 95(2), p.020301_1 - 020301_5, 2017/01

https://doi.org/10.1103/PhysRevB.95.020301

Development of a design support system for geological disposal using a CIM concept

Sugita, Yutaka; Kawaguchi, Tatsuya; Hatanaka, Koichiro; Shimbo, Hiroshi*; Yamamura, Masato*; Kobayashi, Yuichi*; Fujisawa, Yasuo*; Kobayashi, Ichiro*; Yabuki, Nobuyoshi*

Proceedings of 16th International Conference on Computing in Civil and Building Engineering (ICCCBE 2016) (Internet), p.1173 - 1182, 2016/07

http://www.see.eng.osaka-u.ac.jp/seeit/icccbe2016/Proceedings/Full_Papers/148-365.pdf

This paper presents status of development of the iSRE (integrated system for repository engineering) as a design supporting system that enables rational designing of a geological disposal repository. The complimentary technique of construction information modeling/management (CIM) has been employed for the development of iSRE. CIM uses a shared three dimensional (3D) model of associated data through common data models. The contents of this paper are the goal of the development, design requirements and required functions, the basic structure of iSRE. The main databases of the iSRE could then be designed with an interface to coordinate with external systems and other databases. Some of the databases and the interfaces were trialed and a data model was then built. A scenario of iSRE operation was also created and the applicability of iSRE using a data model was also examined. Thanks to the use of the existing software, the development process could be conducted while solving problems for realistic test cases. The prospect of the development of the iSRE for geological disposal projects was realized and the iSRE was confirmed as being a useful tool for designing a repository.

Development of phase rotation system for RF-chopper at J-PARC Linac

Futatsukawa, Kenta*; Kobayashi, Tetsuya*; Sato, Fumiaki; Shinozaki, Shinichi; Chishiro, Etsuji; Hirano, Koichiro; Fang, Z.*; Fukui, Yuji*; Hori, Toshihiko; Michizono, Shinichiro*

Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1317 - 1320, 2015/09

In the J-PARC linac, an RF deflector installed in 3-MeV Medium Energy Beam Transport (MEBT1) is used to kick the unnecessary beam and the intermediate-pulse like a comb is created. The kicked beam leads to a scraper downstream the RF deflector and lose all kinetic energy. When the beam current increases to 50 mA of the design value, the heat load of a scraper to irradiate the kicked beam increases and its surface is predicted to be damaged. Therefore, we are preparing the tandem scrapers to reduce the damage. The half of the kicked beam leads to a scraper and the residual is to the other. The chopping operation is achieved by rotating the phase of the RF deflector in the periodic cycles by the LLRF system. We will introduce the phase rotation system and the test results.

Development of mineralization techniques for organic solvents by the silver mediated electrochemical oxidation process with the ultrasound agitation

Kobayashi, Fuyumi; Ishii, Junichi; Shirahashi, Koichi; Umeda, Miki; Sakuraba, Koichi

Kakuhan, Kongo Gijutsu To Toraburu Taisaku, p.341 - 344, 2014/10

The silver mediated electrochemical oxidation (Ag/MEO) process with the ultrasound agitation has been developed for the purpose of the mineralization of organic wastes containing transuranium nuclides at the nuclear fuel reprocessing process. In the Ag/MEO process, organic solvents are decomposed by divalent silver cations under the relatively low temperature and the ambient pressure condition. The ultrasound agitation is effective in mixing the electrolytic solutions and the organic solvents, and is expected to promote the oxidation of the organic solvents. Therefore, the Ag/MEO process with the ultrasound agitation could be a candidate for the treatment of organic solvents. Destruction tests of TBP and dodecane by the Ag/MEO process were conducted to optimize some treatment conditions. Under optimized conditions, the destruction tests of kerosene and TODGA were carried out. It was confirmed that the Ag/MEO process is effective for the mineralization of these organic solvents.