Validation study on SFR core bowing codes using Joyo ex-core experiment data; Single duct bowing benchmark

Ohgama, Kazuya; Doda, Norihiro; Ota, Hirokazu*; Wozniak, N.*; Uwaba, Tomoyuki; Futagami, Satoshi; Tanaka, Masaaki; Yamano, Hidemasa; Ogata, Takanari*; Shemon, E.*; et al.

Progress in Nuclear Science and Technology (Internet), 8, p.160 - 164, 2025/09

https://doi.org/10.15669/pnst.8.160

To enhance the accuracy of the safety evaluations for sodium-cooled fast reactors, it is necessary to develop a method that can realistically evaluate the reactivity changes induced by core deformation. In this context, Japan and the United States jointly conducted a benchmark analysis of thermal bowing experiments using a single duct from a Joyo-type fuel assembly. The aim was to confirm the validity of the core bowing analysis codes. Comparisons of analysis and experimental results demonstrated that the codes used by both countries were able to reasonably predict the axial distribution of horizontal duct displacement caused by thermal bowing as well as the contact load on the duct pad.

Validation study on SFR core bowing codes using Joyo ex-core experiment data; Single duct bowing benchmark

Ohgama, Kazuya; Doda, Norihiro; Uwaba, Tomoyuki; Futagami, Satoshi; Tanaka, Masaaki; Yamano, Hidemasa; Ota, Hirokazu*; Ogata, Takanari*; Wozniak, N.*; Shemon, E.*; et al.

Proceedings of International Conference on Nuclear Fuel Cycle (GLOBAL2024) (Internet), 4 Pages, 2024/10

To enhance the accuracy of the safety evaluations in sodium-cooled fast reactors, it is necessary to develop a method to realistically evaluate the reactivity caused by core deformation. In this regard, Japan and the United States jointly conducted a benchmark analysis of thermal bowing experiments of a single duct of Joyo-type fuel assembly. The aim was to confirm the validity of the core bowing analysis codes. Comparisons of analysis and test results revealed that the core bowing analysis codes used by both countries were able to reasonably predict the axial distribution of horizontal duct displacement of a single duct due to thermal bowing and the contact load on the duct pad.

Space weathering acts strongly on the uppermost surface of Ryugu

Matsuoka, Moe*; Kagawa, Eiichi*; Amano, Kana*; Nakamura, Tomoki*; Tatsumi, Eri*; Osawa, Takahito; 51 of others*

Communications Earth & Environment (Internet), 4, p.335_1 - 335_12, 2023/09

https://doi.org/10.1038/s43247-023-00991-3

Visible and near-infrared (Vis-NIR) spectra of returned samples from Cb-type asteroid (162173) Ryugu exhibit very low reflectance values and absorptions that are generally consistent with observations from the Hayabusa2 ONC-T and NIRS3 instruments. A notable difference is that a metal-OH absorption at 2.72 misrometer is more than twice as deep in laboratory sample spectra compared with those of Ryugu's surface. Based on the laboratory experiments to investigate the range of spectral variation by physical properties and space weathering, we conclude that the spectral differences between returned samples and asteroid surface are best explained by a combination of (1) porosity, (2) particle size, and (3) degree of space weathering effects, with the latter being the most effective. Those effects can explain spectral variations between Cb-type asteroids, suggesting that these asteroids consist of the same CI-chondrite material with different physical properties and weathering degrees. Extremely homogeneous Vis-NIR spectra of the entire Ryugu surface in comparison with the heterogeneous spectra of a near-Earth S-type asteroid (25143) Itokawa indicate that the space weathering has been processing more rapidly on Cb-type asteroids compared with S-type asteroids. Because the major component of Cb-type asteroids are porous hydrous silicates that have lower melting temperature and lower material strength than anhydrous silicates, the surface of Cb-type asteroids are more susceptible to the alteration by impacts of interplanetary dust particles.

Determination of fusion barrier distributions from quasielastic scattering cross sections towards superheavy nuclei synthesis

Tanaka, Taiki*; Narikiyo, Yoshihiro*; Morita, Kosuke*; Fujita, Kunihiro*; Kaji, Daiya*; Morimoto, Koji*; Yamaki, Sayaka*; Wakabayashi, Yasuo*; Tanaka, Kengo*; Takeyama, Mirei*; et al.

Journal of the Physical Society of Japan, 87(1), p.014201_1 - 014201_9, 2018/01

https://doi.org/10.7566/JPSJ.87.014201

Excitation functions of quasielastic scattering cross sections for the Ca + Pb, Ti + Pb, and Ca + Cm reactions were successfully measured by using the gas-filled recoil-ion separator GARIS. Fusion barrier distributions were extracted from these data, and compared with the coupled-channels calculations. It was found that the peak energies of the barrier distributions for the Ca + Pb and Ti + Pb systems coincide with those of the 2n evaporation channel cross sections for the systems, while that of the Ca + Cm is located slightly below the 4n evaporation ones. This results provide us helpful information to predict the optimum beam energy to synthesize superheavy nuclei.

Density, porosity and grain size, 2; Irradiated ROX fuels to burn-up of 28%FIMA

Yanagisawa, Kazuaki; Yamashita, Toshiyuki; Kanazawa, Hiroyuki; Amano, Hidetoshi; Muromura, Tadasumi

Journal of Nuclear Science and Technology, 36(12), p.1153 - 1159, 1999/12

https://doi.org/10.3327/jnst.36.1153

no abstracts in English

Present status of PIEs in the department of hot laboratories

Kodaira, Tsuneo; Sukegawa, T.; Amano, Hidetoshi; Kanaitsuka, Fumio;

JAERI-Conf 99-009, p.20 - 31, 1999/09

https://jopss.jaea.go.jp/pdfdata/JAERI-Conf-99-009.pdf

no abstracts in English

Current status of PIE techniques in RFEF

Kodaira, Tsuneo; Yamahara, Takeshi; Sukegawa, T.; Nishino, Yasuharu; Kanazawa, Hiroyuki; Amano, Hidetoshi; Nakata, Masahito

HPR-349, 11 Pages, 1998/00

no abstracts in English

Thermal durability of modified synroc material as reactor fuel matrix

; Kanazawa, Hiroyuki; Togashi, Yoshihiro; ; Nishino, Yasuharu; ; Nakata, Masahito; Amano, Hidetoshi;

JAERI-Research 94-008, 20 Pages, 1994/08

JAERI-Research-94-008.pdf:1.8MB

no abstracts in English

Study on reflection of knowledge obtained from the decommissioning of the prototype fast breeder reactor "MONJU" to the fuel handling system of the next generation FBR

Rekimoto, Masafumi; Hamano, Tomoharu; Shiohama, Yasutaka; Ando, Masato*; Miyagawa, Takayuki*; Hara, Hiroyuki*; Yamauchi, Kanau*; Eda, Yuhei*; Koga, Kazuhiro*; Tanabe, Kenichi*

no journal, , 

no abstracts in English

Molecular characterization of reactive deep underground dissolved organic matters for metal ion using fluorescence spectroscopy and high-resolution mass spectrometry

Sato, Hayato*; Toda, Kanako*; Beppu, Hikari*; Amano, Yuki; Miyakawa, Kazuya; Saito, Takumi*

no journal, ,