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Uesawa, Shinichiro; Yamashita, Susumu; Shibata, Mitsuhiko; Yoshida, Hiroyuki
no journal, ,
To estimate the heat transfer of fuel debris in the primary containment vessel (PCV) of the Fukushima Daiichi Nuclear Power Station, JAEA has developed a numerical simulation method with JUPITER. In the previous report, JUPITER underestimated the heat transfer of a porous body in comparison with a natural convective heat transfer experiment. In this report, we report a forced convection experiment with a porous body in a rectangular tube for the validation of flow. As a result, the measured differential pressure of the porous body was in good agreement with the simulation result, and the same velocity distributions as the experiment were obtained with JUPITER. Therefore, the numerical simulation method is correct for the flow with a porous body.
Tada, Kenichi; Yamamoto, Akio*; Endo, Tomohiro*; Chiba, Go*; Ono, Michitaka*; Tojo, Masayuki*
no journal, ,
JAEA released the nuclear data processing code FRENDY version 2 in January 2022. This presentation explains the overview of new functions implemented in FRENDY version 2, e.g., multi-group cross section generation, uncertainty quantification for probability tables, perturbation of ACE file, and modification of evaluated nuclear data file.
Asakura, Kazuki; Shimomura, Yusuke
no journal, ,
no abstracts in English
Yamamoto, Akio*; Endo, Tomohiro*; Chiba, Go*; Tada, Kenichi
no journal, ,
The treatment of the resonance up-scattering effect for arbitrary nuclide is implemented in the nuclear data processing code FRENDY. The Mosteller benchmark is used to verify this new function. The fuel temperature coefficient differences between with and without consideration of the resonance up-scattering effect show good agreement with the previous study.
Kinase, Sakae; Uno, Kiichiro*; Ojima, Emi*; Kanaizuka, Seiichi*; Shikaze, Yoshiaki; Ando, Masaki; Mikami, Satoshi; Saito, Kimiaki
no journal, ,
no abstracts in English
Nakahara, Masaumi; Sakamoto, Atsushi; Sano, Yuichi; Takeuchi, Masayuki
no journal, ,
A novel separation technology with combination of solvent extraction and low pressure loss extraction chromatography has been proposed for minor actinides recovery. A hot experiment was carried out with a solvent extraction method to confirm the extraction behavior of minor actinides and the decontamination performance of fission products. A solution containing minor actinides was used as feed solution in the experiment at Chemical Processing Facility. The experimental results will be reported in our presentation.
AmRovira Leveroni, G.; Kimura, Atsushi; Nakamura, Shoji; Endo, Shunsuke; Iwamoto, Osamu; Iwamoto, Nobuyuki; Katabuchi, Tatsuya*; Kodama, Yu*; Nakano, Hideto*
no journal, ,
Takai, Toshihide; Yamano, Hidemasa; Emura, Yuki; Higashi, Hideo*; Fukuyama, Hiroyuki*; Morita, Koji*; Nakamura, Kinya*; Fukai, Hirofumi*; Furuya, Masahiro*; Hong, Z.*; et al.
no journal, ,
A research project has been conducting thermophysical property measurement of a eutectic melt, eutectic melting reaction and relocation experiments, eutectic reaction mechanism investigation, and physical model development on the eutectic melting reaction for reactor application analysis in order to simulate the eutectic melting reaction and relocation behavior of boron carbide as a control rod material and stainless steel during a core disruptive accident in an advanced sodium-cooled fast reactor designed in Japan. This paper describes the project overview and progress until JFY2021.
Sano, Yuichi; Arai, Tsuyoshi*; Nakatani, Kiyoharu*; Matsuura, Haruaki*; Kunii, Shigeru*
no journal, ,
A MA(III)+Ln(III) co-recovery flowsheet by solvent extraction using TBP and a MA(III)/Ln(III) separation flowsheet by simulated moving bed (SMB) chromatography using HONTA impregnated adsorbent with a large particle size porous silica support that enables low pressure drop operation were designed. The proposed process was confirmed to have advantages in terms of waste generation, safety, and economics compared to previously proposed processes consisting only of solvent extraction or extraction chromatography.
Horiguchi, Naoki; Kaneko, Akiko*; Yoshida, Hiroyuki; Abe, Yutaka*
no journal, ,
In terms of improving the safety of LWRs, it is important to reproduce and evaluate the behavior of the melting core as a liquid jet when it falls into a shallow pool during the severe accident. JAEA has developed numerical simulation codes that can reproduce the behavior and has conducted experiments by using the 3D-LIF method for the validation. As a part of the experiment, we have investigated the effect of the liquid film structure on fragmentation amount based on the observation result of the changes of fragments amount and the structure. In this work, we estimated fragmentation time of the individual fragments by using the experimental data, calculated volume of fragments at the time and estimated fragmentation amount.
Suda, Shoya; Masai, Seita; Kawahara, Takahiro; Fujikura, Toshiki; Hoshi, Akiko; Wakai, Eiichi; Kondo, Keietsu; Nishimura, Akihiko; Minehara, Eisuke*
no journal, ,
no abstracts in English
Shimano, Hiroyuki*; Kakuto, Takeshi*; Nakajima, Junsaku; Hatakeyama, Tomoyoshi*; Sato, Yuki; Torii, Tatsuo
no journal, ,
At decommissioning sites, we are developing a visualization system that combines a spider-leg type multi-legged mobile robot, which travels on the ground by autonomous movement, with a gamma ray distribution measuring device and an optical (stereo) camera for environmental measurement and analysis. The system is designed to be able to climb over debris, pass through pipes, and climb up and down stairs, and to survey the surrounding environment in areas that are not easily accessible to workers. In this presentation, we report on the development status and characteristic tests of the prototype of the small multi-legged mobile robot system we have developed so far.
Nakamura, Satoshi; Ban, Yasutoshi; Sugimoto, Mie; Tambo, Masaki; Fukaya, Hiroyuki; Hiruta, Kenta; Yoshida, Takuya; Uehara, Hiroyuki; Obata, Hiroki; Kimura, Yasuhiko; et al.
no journal, ,
In Nuclear Science Research Institute at JAEA, detailed studies with regard to the elemental and nuclide compositions of fuel debris have been proceeding. We have conducted dissolution of the samples by alkaline fusion with sodium peroxide and chemical analysis by ICP-AES, alpha and gamma spectrometer, and TIMS. After studying the dissolution methods with various types of simulated debris, a demonstration test with TMI-2 debris was conducted. The elemental composition in the dissolved solution of TMI-2 debris consistent with the results of SEM/WDX and XRD analyses, and the validity of the present method was confirmed. In this presentation, the details of each analysis and the issues raised through the analysis will be introduced.
Konno, Chikara
no journal, ,
The latest version of Japanese Evaluated Nuclear Data Library, JENDL-5, was released at the end of 2021. The Monte Carlo transport codes PHITS and MCNP require ACE files of JENDL-5. The FRENDY code can produce ACE files without heating numbers and damage cross sections of the JENDL-5 neutron sub-library, but it cannot treat the JENDL-5 charged particle and photo-atomic sub-libraries. Thus I modified NJOY2016.65 in order to generate ACE files with heating numbers and damage cross sections of the JENDL-5 neutron, charged particle and photo-atomic sub-libraries.
Asahi, Yoshimitsu; Kodaka, Akira
no journal, ,
In the glass production of TVF melter, as raw material, fiberglass frit cartridges saturated with HAW are supplied to the melter. A lot of in-melting cartridges float on the molten glass surface and form a layer called cold-cap. A simulation model of the cold-cap, which enables reproduction of temperature distribution was developed. The cold-cap was modeled as a two-phase flow of cartridges and molten glass with fluid-particle interaction. The increasing of the apparent viscosity and the decreasing of joule heat current and thermal conductivity caused by floating cartridges are defined as a function of the concentration of solid particles. By involving these models simultaneously, a simulation in regard to an operation during glass production for the 2nd melter in TVF yields a slow fluid velocity at the cold-cap region and reproduced a thermally isolated layer, and the change of temperature observed at the bottom side of the cold-cap.
Kondo, Ryoichi; Nagaya, Yasunobu
no journal, ,
A functional expansion tally (FET) method expanded by numerical basis functions has been developed for Monte Carlo transport simulation. The numerical basis functions were extracted from various flux distributions by singular value decomposition, to expand the target flux distribution with low order bases. In this work, multi-group Monte Carlo calculations were carried out for one-dimensional geometry. The accuracy of the spatial flux distributions obtained by the proposed method was confirmed in comparison with the traditional discrete cell tally method and the FET method expanded by Legendre polynomials.
Kamiya, Tomohiro; Ono, Ayako; Tada, Kenichi; Akie, Hiroshi; Nagaya, Yasunobu; Yoshida, Hiroyuki
no journal, ,
JAEA is developing a platform JAMPAN for multiphysics simulation to realize advanced neutronics/thermal-hydraulics coupling simulation for improving design and safety of light water reactors. Flexibility and modularity are required for the platform; users can perform various multiphysics simulation by choosing combination of codes simulating various phenomena such as neutron transport, heat transfer/multi-phase flow, chemical reactions etc., and can easily replace and add independent codes. To meet these requirements, JAMPAN has a common data container and every data exchange between independent codes is conducted through the data container. In this presentation, we will explain an overview of JAMPAN and show results of neutronics/thermal-hydraulics simulation on 4
4 bundle system using MVP and JUPITER as an example of JAMPAN simulation.
Iwamoto, Hiroki; Meigo, Shinichiro; Satoh, Daiki; Iwamoto, Yosuke; Sugihara, Kenta; Nakano, Keita; Nishio, Katsuhisa; Ishi, Yoshihiro*; Uesugi, Tomonori*; Kuriyama, Yasutoshi*; et al.
no journal, ,
For the purpose of research and development of accelerator-driven nuclear transmutation systems, neutron yields of 107-MeV proton incident on iron, lead and bismuth targets were measured by the flight time method using the FFAG accelerator at Kyoto University. The energy spectra of the neutron yield obtained by the measurements were compared with results of particle transport analysis with the nuclear reaction models (INCL4.6/GEM, Bertini/GEM, JQMD/GEM and JQMD/SMM/GEM) incorporated in the Monte Carlo particle transport calculation code PHITS and the nuclear data library JENDL-4.0/HE. As a result, it was found that the INCL4.6/GEM, which was the reference model of PHITS, best reproduced the experimental values.
Kazama, Hiroyuki; Sekio, Yoshihiro; Maeda, Koji; Koyama, Shinichi; Suzuki, Tatsuya*; Konashi, Kenji*; Abe, Chikage*; Nagai, Yasuyoshi*
no journal, ,
Triple-quadrupole inductively coupled plasma mass spectrometry (ICP-MS/MS) is attractive technique to perform rapid and accurate analysis of fuel debris in Fukushima Daiichi Nuclear Power Plant. The collision/reaction cell technology incorporated in ICP-MS/MS is an available option to eliminate isobaric interferences, being expected to simplify the pretreatment of fuel debris analysis. When fuel debris contains Am and Cm, the pretreatment involving Am/Cm separation is difficult due to similarly chemical behavior of these actinides. In this study, ICP-MS/MS measurements of Am and 
Cm injecting CO
were carried out. From the obtained results, we suggest candidate conditions to discriminate the isobars of these actinides by use of the differences in their molecular ion formation tendency with variation of CO flow rate.
Nakamura, Shoji; Kimura, Atsushi; Endo, Shunsuke; Shizuma, Toshiyuki*; Shibahara, Yuji*
no journal, ,
In recent years, research has been advanced on lead-cooled fast reactors and accelerator drive systems, and it is required to improve the accuracy of the neutron capture cross section of Pb isotopes. Although 
Pb has a small natural abundance, it is of importance because it produces the long-lived radionuclide 
Pb (17.3 million years) by neutron capture reaction. However, it is difficult to measure its cross section by a conventional activation method using a nuclear reactor because the induced radioactivity of Pb is weak. Hence, the cross-section measurement was performed by applying mass spectrometry. This presentation gives the details of the experiment and the results obtained in the neutron capture cross-section measurement of Pb using mass spectroscopy.