Probabilistic risk assessment for sodium-cooled fast reactors by the CMMC method; Consideration of operator's recognition probability for accident managements

Koike, Akari*; Nemoto, Masaya*; Nakashima, Risako*; Sakai, Takaaki*; Doda, Norihiro; Tanaka, Masaaki

Proceedings of 2023 International Congress on Advanced in Nuclear Power Plants (ICAPP 2023) (Internet), 2 Pages, 2023/04

To evaluate the effect of the operator's recognition of the accident management (AM) necessity on plant safety, the operator's recognition of the AM necessity was modeled as a function of time-dependent success probability, and dynamic PRA analyses were performed for a sodium-cooled fast reactor during abnormal snowfall. The analysis results showed that the operator's recognition of the snowfall can avoid the core damage at an earlier stage after the accident.

Quantitative risk assessment with CMMC method on abnormal snowfall incident for a sodium-cooled fast reactor

Nakashima, Risako*; Koike, Akari*; Sakai, Takaaki*; Doda, Norihiro; Tanaka, Masaaki

Proceedings of 29th International Conference on Nuclear Engineering (ICONE 29) (Internet), 6 Pages, 2022/08

In development of a quantitative risk assessment method to the external hazards for a sodium-cooled fast reactor, a dynamic PRA using the Continuous Markov chain Monte Carlo (CMMC) method was performed to evaluate the effect of global warming on the probability of exceeding the temperature limit as a core damage factor. There is a possibility that the amount of snowfall in abnormal snowfall events will increase due to global warming in the future. A hazard curve of snowfall considering global warming was developed. The results show that the probability of exceeding the temperature limit is increased by the abnormal snowfall events due to global warming.

Intrinsic torques emerging from anomalous velocity in magnetic textures

Araki, Yasufumi; Ieda, Junichi

Physical Review Letters, 127(21), p.277205_1 - 277205_7, 2021/12

https://doi.org/10.1103/PhysRevLett.127.277205

Momentum-space topology of electrons under strong spin-orbit coupling contributes to the electrically induced torques exerting on magnetic textures insensitively to disorder or thermal fluctuation. We present a direct connection between band topology and the torques by classifying the whole torques phenomenologically. As well as the intrinsic anomalous Hall effect, the torques also emerge intrinsically from the anomalous velocity of electrons regardless of a nonequilibrium transport current. We especially point out the intrinsic contribution arising exclusively in magnetic textures, which we call the "topological Hall torque (THT)". The THT emerges in bulk crystals without any interface or surface structures. We numerically demonstrate the enhancement of the THT in comparison with the conventional spin-transfer torque in the bulk metallic ferromagnet, which accounts for the giant current-induced torque measured in ferromagnetic .

Correlation of anomalous Hall effect with structural parameters and magnetic ordering in MnSn thin films

Yoon, J.-Y.*; Takeuchi, Yutaro*; DuttaGupta, S.*; Yamane, Yuta*; Kanai, Shun*; Ieda, Junichi; Ohno, Hideo*; Fukami, Shunsuke*

AIP Advances (Internet), 11(6), p.065318_1 - 065318_6, 2021/06

https://doi.org/10.1063/5.0043192

Structure of a highly acidic -lactamase from the moderate halophile sp.560 and the discovery of a Cs-selective binding site

Arai, Shigeki; Yonezawa, Yasushi*; Okazaki, Nobuo*; Matsumoto, Fumiko*; Shibazaki, Chie; Shimizu, Rumi; Yamada, Mitsugu*; Adachi, Motoyasu; Tamada, Taro; Kawamoto, Masahide*; et al.

Acta Crystallographica Section D, 71(3), p.541 - 554, 2015/03

https://doi.org/10.1107/S1399004714027734

The crystal structure of halophilic -lactamase from sp.560 (HaBLA) was determined using X-ray crystallography. Moreover, the locations of bound Sr and Cs ions were identified by anomalous X-ray diffraction. The location of one Cs specific binding site was identified on HaBLA even in the presence of 9-fold molar excess of Na (90 mM Na /10 mM Cs). This Cs binding site is formed by two main-chain O atoms and an aromatic ring of a side chain of Trp. An aromatic ring of Trp interacts with Cs by the cation- interaction. The observation of a selective and high-affinity Cs binding site provides important information that is useful for designing artificial Cs binding sites useful in bioremediation of radioactive isotopes.

Relationship between particle and heat transport in JT-60U plasmas with internal transport barrier

Takenaga, Hidenobu; Higashijima, Satoru; Oyama, Naoyuki; Bruskin, L. G.; Koide, Yoshihiko; Ide, Shunsuke; Shirai, Hiroshi; Sakamoto, Yoshiteru; Suzuki, Takahiro; Hill, K. W.*; et al.

Nuclear Fusion, 43(10), p.1235 - 1245, 2003/10

https://doi.org/10.1088/0029-5515/43/10/026

no abstracts in English

Catalyst for auotomotive emissions control in next generation; Relation of the intelligent property to its structure

Mizuki, Junichiro; Nishihata, Yasuo; Tanaka, Hirohisa*

Genshiryoku eye, 49(3), p.36 - 39, 2003/03

http://ci.nii.ac.jp/naid/80015773116

We use X-ray diffraction and absorption to show that the perovskite-based Pd catalyst retains its high metal dispersion owing to structural responses to the fluctuations in exhaust-gas composition that occur in state-of-the-art petrol engines. We find that as the catalyst is cycled between oxidative and reductive atmospheres typically encounttered in exhaust gas, Pd reversibly moves into and out of the perovskite lattice. This movement appears to suppress the growth of metallic Pd particles, and hence explains the retention of high catalytic activity.

Magnetic structure and the hall resistivity of CuZnCrSe

Iikubo, Satoshi*; Yasui, Yukio*; Oda, Keisuke*; Ono, Yohei*; Kobayashi, Yoshiaki*; Sato, Masatoshi*; Kakurai, Kazuhisa

Journal of the Physical Society of Japan, 71(11), p.2792 - 2799, 2002/11

https://doi.org/10.1143/JPSJ.71.2792

no abstracts in English

Power dependence of ion thermal diffusivity at the internal transport barrier in JT-60U

Sakamoto, Yoshiteru; Suzuki, Takahiro; Ide, Shunsuke; Koide, Yoshihiko; Takenaga, Hidenobu; Kamada, Yutaka; Fujita, Takaaki; Takizuka, Tomonori; Shirai, Hiroshi; Fukuda, Takeshi

Purazuma, Kaku Yugo Gakkai-Shi, 78(9), p.941 - 948, 2002/09

http://ci.nii.ac.jp/naid/10009630025

no abstracts in English

Mercury flow experiments, 3; Simulation test plan under abnormal condition

Kaminaga, Masanori; Kinoshita, Hidetaka; Haga, Katsuhiro; Hino, Ryutaro

JAERI-Tech 2002-002, 22 Pages, 2002/02

JAERI-Tech-2002-002.pdf:5.37MB

The Neutron Scattering Facility will be utilized for advanced fields of Material and Life science using high intensity neutron generated by spallation reaction of 1MW pulsed proton beam and mercury target. Design of spallation mercury target system is in progress to obtain high neutron performance with high reliability and safety. The target system is using mercury and contains large amount of radioactive spallation products, therefore to establish the safety of the target system, transient behaviors of the system during anticipated events should be well understood. The safety protection system and an instrumentation system for detecting abnormal conditions must be designed based on the transient behaviors in order to terminate the transient events safely. Transient behaviors of the mercury system have been analyzed by using RELAP5 code. This report presents a test plan of mercury system transient phenomena during abnormal events using a mercury experimental loop and modification of the mercury experimental loop for abnormal transient simulation tests.