Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Inagawa, Jun; Kitatsuji, Yoshihiro; Otobe, Haruyoshi; Nakada, Masami; Takano, Masahide; Akie, Hiroshi; Shimizu, Osamu; Komuro, Michiyasu; Oura, Hirofumi*; Nagai, Isao*; et al.
JAEA-Technology 2021-001, 144 Pages, 2021/08
JAEA-Technology-2021-001.pdf:12.98MB
Plutonium Research Building No.1 (Pu1) was qualified as a facility to decommission, and preparatory operations for decommission were worked by the research groups users and the facility managers of Pu1. The operation of transportation of whole nuclear materials in Pu1 to Back-end Cycle Key Element Research Facility (BECKY) completed at Dec. 2020. In the operation included evaluation of criticality safety for changing permission of the license for use nuclear fuel materials in BECKY, cask of the transportation, the registration request of the cask at the institute, the test transportation, formulation of plan for whole nuclear materials transportation, and the main transportation. This report circumstantially shows all of those process to help prospective decommission.
Sasaki, Yuji; Morita, Keisuke; Matsumiya, Masahiko*; Ono, Ryoma*; Shiroishi, Hidenobu*
JOM, 73(4), p.1037 - 1043, 2021/04
Times Cited Count：4 Percentile：34.69(Materials Science, Multidisciplinary)The separation of Dy from Nd is studied from the viewpoint of recycling Dy from Nd magnets. Both metals are lanthanide elements, which means their mutual separation is difficult because of their similar chemical behaviors. All lanthanide elements can be extracted easily by using tetradodecyl-diglycolamide (TDdDGA) extractants, and it has a relatively high separation factor (SF) between Dy and Nd (SF over 10). In the present study, by performing eight extraction steps with the organic phase (0.1M TDdDGA in dodecane), ten steps with an aqueous phase (0.7 M HNO
with metals), and six steps with another aqueous phase (0.7 M HNO without metals), approximately 99% Dy was recovered into the organic phase with 1% co-extraction of Nd.
Sasaki, Yuji; Ban, Yasutoshi; Morita, Keisuke; Matsumiya, Masahiko*; Ono, Ryoma*; Shiroishi, Hidenobu*
Solvent Extraction Research and Development, Japan, 27(1), p.63 - 67, 2020/00
Times Cited Count：6 Percentile：31.74(Chemistry, Multidisciplinary)Mutual separation technique of Dy and Nd in Nd magnet is studied. Dy is more valuable than Nd, then Dy might be isolated and reused. Lanthanide elements can be extracted thoroughly by diglycolamide (DGA) extractants, we use this reagent for the recovery and isolation of Dy. Tetradodecyl-DGA (TDdDGA) has relatively high separation factors(SF) between Dy and Nd (SF=17-18) in HNO extraction system, counter-current extraction using TDdDGA was applied for their mutual separation. From the present study, using the condition, four extraction stages, organic phase: 0.1M TDdDGA in n-dodecane, aqueous phase: 0.3M HNO, 92% Dy can be recovered with 0.7% co-extraction of Nd.
Phan, L. H. S.*; Ohara, Yohei*; Kawata, Ryo*; Liu, X.*; Liu, W.*; Morita, Koji*; Guo, L.*; Kamiyama, Kenji; Tagami, Hirotaka
Proceedings of 12th International Topical Meeting on Nuclear Reactor Thermal-Hydraulics, Operation and Safety (NUTHOS-12) (USB Flash Drive), 12 Pages, 2018/10
Self-leveling behavior of core fuel debris beds is one of the key phenomena for the safety assessment of core disruptive accidents (CDAs) in sodium-cooled fast reactors (SFRs). The SIMMER code has been developed for CDA analysis of SFRs, and the code has been successfully applied to numerical simulations for key thermal-hydraulic phenomena involved in CDAs as well as reactor safety assessment. However, in SIMMER's fluid-dynamics model, it is always difficult to represent the strong interactions between solid particles as well as the discrete particle characteristics. To solve this problem, a new method has been developed by combining the multi-fluid model of the SIMMER code with the discrete element method (DEM) for the solid phase to reasonably simulate the particle behaviors as well as the fluid-particle interactions in multi-phase flows. In this study, in order to validate the multi-fluid model of the SIMMER code coupled with DEM, numerical simulations were performed on a series of self-leveling experiments using a gas injection method in cylindrical particle beds. The effects of friction coefficient on the simulation results were investigated by sensitivity analysis. Though more extensive validations are needed, the reasonable agreement between simulation results and corresponding experimental data preliminarily demonstrates the potential ability of the present method in simulating the self-leveling behaviors of debris bed. It is expected that the SIMMER code coupled with DEM is a prospective computational tool for analysis of safety issues related to solid particle debris bed in SFRs.
Kawata, Ryo*; Ohara, Yohei*; Sheikh, Md. A. R.*; Liu, X.*; Matsumoto, Tatsuya*; Morita, Koji*; Guo, L.*; Kamiyama, Kenji; Suzuki, Toru
Proceedings of 17th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-17) (USB Flash Drive), 14 Pages, 2017/09
Tomita, Takuro*; Nishikino, Masaharu; Hasegawa, Noboru; Minami, Yasuo*; Takei, Ryota*; Baba, Motoyoshi*; Eyama, Tsuyoshi*; Takayoshi, Shodai*; Kaihori, Takeshi*; Morita, Toshimasa; et al.
Journal of Laser Micro/Nanoengineering, 9(2), p.137 - 142, 2014/06
Times Cited Count：5 Percentile：29.55(Nanoscience & Nanotechnology)Femtosecond laser ablation processes on platinum, gold, and tungsten were observed by the single shot pump and probe reflective imaging using a soft X-ray laser probe. To avoid the timing error due to the jitter, we adopted a posteriori correction technique by simultaneous measurement of timing between the pump and probe pulses for every single shot, using a soft X-ray streak camera. A clear difference was found in the temporal behavior of the dynamical response of the soft X-ray reflectivity depending on the irradiated laser fluence in these three materials. On the other hand, the narrow dark rings were found in Pt and W, while an additional bright ring was found outside the dark disk in Au. Our result gives the experimental data comparable with various numerical simulations.
Suzuki, Toru; Nakai, Ryodai; Kamiyama, Kenji; Seino, Hiroshi; Koyama, Kazuya*; Morita, Koji*
NEA/CSNI/R(2012)2, p.381 - 391, 2012/07
For the probabilistic safety assessment (PSA) of sodium-cooled fast reactors (SFRs), JAEA consolidated the analytical methodologies and technical basis for all phases/sequences to be evaluated in the Level 2 PSA. In addition to the existing computational codes such as SAS4A, SIMMER-III, DEBNET, ARGO and APPLOHS, JAEA newly developed MUTRAN and SIMMER-LT in order to evaluate the long term behaviors of the material-relocation in the degraded core. These tools enabled the systematic assessment for the in-vessel accident sequences. For the ex-vessel accident sequences, JAEA also improved CONTAIN/LMR taking into account the feature of SFRs and verified the analytical models utilizing the new experiments such as sodium-concrete reaction test. In addition, the technical basis for constructing event trees was compiled, in which the dominant factors having significant effects on the event progression were corresponded to the related experiments and analytical results.
Nakai, Ryodai; Suzuki, Toru; Kamiyama, Kenji; Seino, Hiroshi; Koyama, Kazuya*; Morita, Koji*
Proceedings of 8th International Topical Meeting on Nuclear Thermal-Hydraulics, Operation and Safety (NUTHOS-8) (CD-ROM), 12 Pages, 2010/10
The evaluation technology of Level-2 PSA for Sodium-Cooled Fast Reactors (SFRs) was established in order to systematically assess the core damage sequences. In addition to the existing computational tools for Level-2 PSA, the computational tools, MUTRAN and SIMMER-LT were developed for core material relocation phase. Also the analytical models, CORCON and VANESA, were improved based on newly performed experiments for the ex-vessel phase taking into account the feature of SFRs. The technical information was compiled as technical database used in the construction and quantification of level-2 PSA event trees for SFRs. The technical basis was established for the Level-2 PSA for SFRs.
-rays; Guineagrass and sorghumNakagawa, Hitoshi*; Inafuku, Masashi*; Kusaba, Makoto*; Yamaguchi, Hiroyasu*; Morishita, Toshikazu*; Morita, Ryohei*; Nishimura, Minoru*; Hoeman, S.*; Yokota, Yuichiro; Hase, Yoshihiro; et al.
JAEA-Review 2007-060, JAEA Takasaki Annual Report 2006, P. 72, 2008/03
no abstracts in English
rayMorita, Ryohei*; Morishita, Toshikazu*; Nakagawa, Hitoshi*; Nishimura, Minoru*; Yamaguchi, Hiroyasu*; Yokota, Yuichiro; Hase, Yoshihiro; Tanaka, Atsushi
JAEA-Review 2006-042, JAEA Takasaki Annual Report 2005, P. 78, 2007/02
no abstracts in English
Watanabe, Masayuki; Tatsugae, Ryozo*; Morita, Yasuji; Kubota, Masumitsu*
Journal of Radioanalytical and Nuclear Chemistry, 252(1), p.53 - 57, 2002/04
Times Cited Count：7 Percentile：44.35(Chemistry, Analytical)no abstracts in English
Watanabe, Masayuki; Tatsugae, Ryozo*; Shirahashi, Koichi; Morita, Yasuji; Kubota, Masumitsu*
Journal of Radioanalytical and Nuclear Chemistry, 250(2), p.377 - 379, 2001/11
Times Cited Count：7 Percentile：48.68(Chemistry, Analytical)no abstracts in English
Watanabe, Masayuki; Tatsugae, Ryozo*; *; Morita, Yasuji; Kubota, Masumitsu
JAERI-Research 99-034, 55 Pages, 1999/05
JAERI-Research-99-034.pdf:1.7MB
no abstracts in English
Watanabe, Masayuki; Morita, Yasuji; Kubota, Masumitsu*; Tatsugae, Ryozo*
Radiochimica Acta, 87(3-4), p.115 - 119, 1999/00
no abstracts in English
rays in rice plantNishimura, Minoru*; Morita, Ryohei*; Yamaguchi, Hiroyasu*; Hase, Yoshihiro
no journal, ,
no abstracts in English
raysMorita, Ryohei*; Morishita, Toshikazu*; Nakagawa, Hitoshi*; Nishimura, Minoru*; Yamaguchi, Hiroyasu*; Yokota, Yuichiro; Hase, Yoshihiro; Tanaka, Atsushi
no journal, ,
no abstracts in English
ray; Guinea grass and sorghumNakagawa, Hitoshi*; Inafuku, Masashi*; Kusaba, Makoto*; Yamaguchi, Hiroyasu*; Morishita, Toshikazu*; Morita, Ryohei*; Nishimura, Minoru*; Hoeman, S.*; Yokota, Yuichiro; Hase, Yoshihiro; et al.
no journal, ,
no abstracts in English
Morita, Ryohei*; Yamaguchi, Hiroyasu*; Yokota, Yuichiro; Hase, Yoshihiro; Nishimura, Minoru*
no journal, ,
no abstracts in English
rays irradiation in rice plantNishimura, Minoru*; Morita, Ryohei*; Kusaba, Makoto*; Yamaguchi, Hiroyasu*; Hase, Yoshihiro
no journal, ,
no abstracts in English
Nakai, Ryodai; Kurisaka, Kenichi; Sato, Ikken; Tobita, Yoshiharu; Kamiyama, Kenji; Yamano, Hidemasa; Miyahara, Shinya; Ohno, Shuji; Seino, Hiroshi; Ishikawa, Hiroyasu; et al.
no journal, ,
To develop a core damage evaluation technology (level-2 PSA) in sodium-cooled fast reactors, a new analysis method is developed for core-material relocation phase and internal containment vessel event. This study also develop technical basis necessary for the level-2 PSA.
