Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Horii, Yuta; Hirooka, Shun; Uno, Hiroki*; Ogasawara, Masahiro*; Tamura, Tetsuya*; Yamada, Tadahisa*; Furusawa, Naoya*; Murakami, Tatsutoshi; Kato, Masato
Journal of Nuclear Materials, 588, p.154799_1 - 154799_20, 2024/01
Times Cited Count:1 Percentile:63.33(Materials Science, Multidisciplinary)The thermal conductivities of near-stoichiometric (U,Pu,Am)O doped with NdO/SmO, which is major fission product (FP) generated by a uranium-plutonium mixed oxides (MOX) fuel irradiation, as simulated fission products are evaluated at 1073-1673 K. The thermal conductivities are calculated from the thermal diffusivities that are measured using the laser flash method. To evaluate the thermal conductivity from a homogeneity viewpoint of Nd/Sm cations in MOX, the specimens with different homogeneity of Nd/Sm are prepared using two kinds of powder made by ball-mill and fusion methods. A homogeneous Nd/Sm distribution decreases the thermal conductivity of MOX with increasing Nd/Sm content, whereas heterogeneous Nd/Sm has no influence. The effect of Nd/Sm on the thermal conductivity is studied using the classical phonon transport model (A+BT). The dependences of the coefficients A and B on the Nd/Sm content (C and C, respectively) are evaluated as: A(mK/W)=1.70 10 + 0.93C + 1.20C, B(m/W)=2.39 10.
Hanus, G.*; Sato, Ikken; Iwama, Tatsuya*
Proceedings of International Waste Management Symposia 2016 (WM2016) (Internet), 12 Pages, 2016/03
JAEA plans a large-scale test to evaluate damage and relocation behavior of BWR core materials consisting of fuel rods, channel boxes, control blade and lower support structures. Its purpose is to contribute to understanding of core material relocation behavior in the event of severe accidents with the BWR design conditions for which existing experimental database is quite limited. Prior to large-scale testing, JAEA desires preliminary investigations to examine melting test pieces. The purpose of such tests is to verify the materials and test piece will be heated by plasma to the target temperature (ca.2900K) and to collect data about the material relocation behavior. Results from preliminary computational simulations are presented illustrating the effectiveness of a 150 kW non-transferred plasma jet. An experimental test program using the computational analyses as a basis and a plasma torch is described.
Moriyama, Kiyofumi; Nakamura, Hideo; Maruyama, Yu*
Nuclear Engineering and Design, 236(19-21), p.2010 - 2025, 2006/10
Times Cited Count:23 Percentile:81.94(Nuclear Science & Technology)A computer code JASMINE-pre was developed for the prediction of premixing conditions of fuel-coolant interactions and the debris bed formation behavior relevant to severe accidents of light water reactors. JASMINE-pre consists of three melt component models: melt jet, melt particles and melt pool, coupled with a two-phase flow model derived from the ACE-3D code developed at JAERI. Simulations of the FARO corium quenching experiments with a saturated water pool and with a subcooled water pool were performed with JASMINE-pre and . JASMINE-pre reproduced the pressurization and fragmentation behaviors observed in the experiments with a reasonable accuracy. The results by pmjet showed qualitatively the same trend with JASMINE-pre in the fragmentation behavior.
Harada, Katsuya; Nakata, Masahito; Harada, Akio; Nihei, Yasuo; Yasuda, Ryo; Nishino, Yasuharu
JAERI-Tech 2004-034, 13 Pages, 2004/03
The Department of Hot Laboratories has been aiming the establishment of the melting temperature measuring technique for small samples obtained from the micro-region of irradiated fuel pellet. Due to the modification of the shape of tungsten capsule contained sample and the improvement of the detection method for melting temperature from indistinct thermal arrest point owing to small sample, it is possible to determine the melting temperature of small sample and to utilize effectively for the irradiated fuel pellet by using the existing apparatus. This paper describes the technique of the melting temperature measurement for small sample and the experimental results by using tantalum, molybdenum, hafnium oxide and un-irradiated UO pellet.
Kiuchi, Kiyoshi; Ioka, Ikuo; Tachibana, Katsumi; Suzuki, Tomio; Fukaya, Kiyoshi*; Inohara, Yasuto*; Kambara, Shozo; Kuroda, Yuji*; Miyamoto, Satoshi*; Ogura, Kazutomo*
JAERI-Research 2002-008, 63 Pages, 2002/03
no abstracts in English
Yanagisawa, Kazuaki; Omichi, Toshihiko*; Shirasu, Noriko; Muromura, Tadasumi;
JAERI-Tech 99-032, 65 Pages, 1999/03
no abstracts in English
Fuketa, Toyoshi; Ishijima, Kiyomi; ; Soyama, Kazuhiko; Ichikawa, Hiroki; Kodaira, Tsuneo
JAERI-Research 95-077, 28 Pages, 1995/10
no abstracts in English
W.Hering*; Minato, Kazuo; Nagase, Fumihisa
Nuclear Technology, 102, p.100 - 115, 1993/04
Times Cited Count:2 Percentile:29.75(Nuclear Science & Technology)no abstracts in English
Sobajima, Makoto; Katanishi, Shoji;
SMiRT 11 Transactions,Vol. C, p.191 - 194, 1991/08
no abstracts in English
;
Journal of Nuclear Science and Technology, 23(12), p.1051 - 1063, 1986/12
Times Cited Count:0 Percentile:0.02(Nuclear Science & Technology)no abstracts in English
; ; ; ;
Genshiryoku Kogyo, 32(12), p.17 - 31, 1986/00
no abstracts in English
; ;
JAERI-M 82-141, 74 Pages, 1982/10
no abstracts in English
; ; Murao, Yoshio; ; ; ; ; ; ; Ueda, Shuzo; et al.
JAERI-M 82-039, 201 Pages, 1982/05
no abstracts in English
;
JAERI-M 8035, 94 Pages, 1979/01
no abstracts in English
JAERI-M 7267, 36 Pages, 1977/09
no abstracts in English
Kai, Tetsuya; Abe, Yuta; Matsumoto, Yoshihiro*; Parker, J. D.*; Shinohara, Takenao; Oishi, Yuji*; Nagae, Yuji; Sato, Ikken
no journal, ,
Seya, Michio; Hajima, Ryoichi*; Hayakawa, Takehito*; Koizumi, Mitsuo
no journal, ,
The NRF-base NDA using monochromatic -rays would be used in nuclear security for secure detection of NM in thick shield and also for precise checking of interior structures of detected / suspicious objects. This NDA also would be used in nuclear safeguards for precise quantification of U/Pu isotopes in high radiation background, such as spent fuel assemblies / melted fuel debris in a canister. It is also useful for precise measurement of quantities of minor actinide isotopes in ADS (Accelerator Driven Sub-critical System; for transmutation of long-half-life minor actinides (MA)) fuels before and after irradiation in the ADS reactor core. In this presentation, we show actual NRF-NDA methods for these objects.
Morimoto, Kyoichi; Hirooka, Shun; Akashi, Masatoshi; Watanabe, Masashi
no journal, ,
The influence of Gd on characteristics of debris is important for removing the debris from the reactors of Fukushima Daiichi Nuclear Power Plant because subassemblies of nuclear fuels containing GdO were loaded in the some reactor cores. Additionally, it is important to assess the distribution state of Gd from the anxiety of re-criticality caused by the relocation of debris while removing them. In this study, sintered pellets of (UGdZr)O (y=0,0.5, 2-x=1.989-2.000) were melted and solidified to prepare specimens of simulated corium debris. Phase states and fundamental properties of them were evaluated.