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Higemoto, Wataru; Yokoyama, Makoto*; Ito, Takashi; Suzuki, Taiga*; Raymond, S.*; Yanase, Yoichi*
Proceedings of the National Academy of Sciences of the United States of America, 119(49), p.e2209549119_1 - e2209549119_6, 2022/11
Times Cited Count：0 Percentile：0(Multidisciplinary Sciences)no abstracts in English
Kakehi, Isao; Nakabayashi, Hiroki
JNC TN9400 2000-051, 237 Pages, 2000/04
JNC-TN9400-2000-051.pdf:8.14MB
In this study, we have proposed the concept of safety systems (solutions of safety problems) in pyrochemical reprocessing systems (lt consists of pyrochemical reprocessing methods and the injection casting process for the metal fuel fabrication, or vibro-packing process for the oxide fuel fabrication.) which has different concept from the existing PUREX reprocessing method and pellet fuel fabrication process. And we performed its safety evaluations. FoIlowing the present Japanese safety regulations for reprocessing facilities, we pointed out functions, design requirements and equipments relating to its safety systems and picked up subjects. For the survey of safety evaluations, we first selected anticipated events and accident events, and second by evaluated 6the correspondence of the limitation of the public exposure to the accidents above, by using two parameters, the safety design parameter (the filter performance to confine radioactive matelials) and the leak inventory of radioactivities, and last by picked up its problems. ln addition to the above evaluations we performed basic criticality analyses for its systems to utilize these results for the design and evaluation of the criticality safety management system. Thus this study specified the concept of safety systems for pyrochemical reprocessing processes and then issues in order to establish safety design policies (matters which must consider for the safety design) and guides and to advance more definite safety design.
JNC TN9400 2000-038, 98 Pages, 2000/04
JNC-TN9400-2000-038.pdf:7.49MB
As an effort in the feasibility study on commercialized Fast Breeder Reactor cycle systems, an evaluation of the measures to prevent the energetic re-criticality in sodium-cooled large MOX core, which is one of the candidates for the commercialized reactor, has been performed. The core disruptive accident analysis of Demonstration FBR showed that the fuel compaction of the molten fuel by radial motion in a large molten core pool had a potential to drive the severe super-prompt re-criticality phenomena in ULOF sequence. ln order to prevent occurrence of the energetic re-criticality, a subassembly with an inner duct and the removal of a part of LAB are suggested based on CMR (Controlled Material Relocation) concept. The objective of this study is the comparison of the effectiveness of CMR among these measures by the analysis using SIMMER-III. The molten fuel in the subassembly with inner duct flows out faster than that from other measures. The subassembly with inner duct will work effectively in preventing energetic re-criticality. Though the molten fuel in the subassembly without a part of LAB flows out a little slower, it is still one of the promising measures. However, the UAB should be also removed from the same pin to prevent the fuel re-entries into the core region due to the pressurization by FCl below the core, unless it disturbs the core performance. The effect of the axial fuel length of the center pin to CMR behavior is small, compared to the effect of the existence of UAB.
Kishimoto, Yasuaki; Tajima, Toshiki*; LeBrun, M. J.*; W.Horton*; J.Y.Kim*; J.Q.Dong*; F.L.Waelbroeck*; Tokuda, Shinji; *; Fukuda, Takeshi
IAEA-CN-60/D-10, 0, p.299 - 307, 1996/00
no abstracts in English
AIP Conference Proceedings 248; Computer-aided Statistical Physics, p.136 - 142, 1992/00
no abstracts in English
Physica A, 106A(1), p.311 - 325, 1981/00
no abstracts in English
Physical Review Letters, 42(8), p.536 - 540, 1979/00
Times Cited Count：6no abstracts in English
Watanuki, Tetsu; Mizumaki, Masaichiro*; Kawamura, Naomi*; Watanabe, Shinji*; Nitta, Kiyofumi*; Tanaka, Yukinori*; Ishimasa, Tsutomu*
no journal, ,
no abstracts in English
Tokunaga, Yo
no journal, ,
The field-induced reentrant superconductivity in uranium-based ferromagnet URhGe highlights the close interplay between superconductivity (SC) and magnetism in strongly correlated electron systems. Our NMR experiments in URhGe revealed that the inherent FM fluctuations in URhGe at lower fields is robust to the direction of the applied field, although the field-induced fluctuations at higher fields near HR show strong field-angular dependence. This makes a clear contrast with the case of its sister compound UCoGe, where the FM fluctuations show strong field dependence even at lower fields. We can see that the different character of the FM fluctuations is indeed reflected in their phase diagram of the upper critical field Hc2, which is also unconventional and different between the two compounds. This provides further evidence that the SC is mediated by the FM fluctuations in URhGe and UCoGe.
Higemoto, Wataru; Ito, Takashi; Yokoyama, Makoto*
no journal, ,
no abstracts in English
