Evaluation study of fault activity on Shionohira and Kuruma Faults located at the border of Fukushima and Ibaraki Prefecture, Japan

Aoki, Kazuhiro; Imai, Hirotaro; Seshimo, Kazuyoshi; Kimura, Megumi; Kirita, Fumio; Nakanishi, Ryuji

JAEA-Research 2024-005, 177 Pages, 2024/10

JAEA-Research-2024-005.pdf:12.02MB

This study presents a method for evaluating displacements on active faults that lack clear markers of fault offset. The method uses geological surveys, core studies, and chemical analyses along with hydraulic and mechanical tests. We applied this method to three test sites along the Shionohira Fault (Shionohira and Betto sites) and the Kuruma Fault (Minakamikita site). Laboratory friction tests on the fault gouge using a variable-speed, rotating shear friction apparatus were conducted. The samples from the Shionohira and Betto sites showed velocity weakening or strengthening, but no velocity dependence was observed at the Minakamikita site. A small-scale test to induce fault slip was conducted using the SIMFIP method. At the Shionohira site, fault slip can be modeled as a Coulomb rupture and shows a frictional dependence on slip velocity. On the other hand, at the Minakamikita site, a complex response using multiple fractures and slip planes was observed. Based on the water pressure response, the hydraulic properties of the area between the faults were evaluated. The transmissivity and specific storage are larger at Shionohira than at Minakamikita. Fault slip data such as shear plane attitude or shear sense were obtained from core samples and stress inversion analysis was performed. We attempted to elucidate the history of the movement and stress that formed the fracture zone. The results reconstructed five activity stages at Shionohira site and two stages at Minakamikita site. As shown in this report, the frictional properties, fault rupture mode, hydraulic properties and the history of fault motion were found to be different between the Shionohira and Kuruma sites. However, the results are based on a few locational data, so case studies at other sites and more applications to other faults should be considered to improve the reliability of the evaluation.

In-beam -ray spectroscopy of Mg via knockout reactions at intermediate energies

Momiyama, Satoru*; Doornenbal, P.*; Scheit, H.*; Takeuchi, Satoshi*; Niikura, Megumi*; Aoi, Nori*; Li, K.*; Matsushita, Masafumi*; Steppenbeck, D.*; Wang, H.*; et al.

Physical Review C, 96(3), p.034328_1 - 034328_8, 2017/09

https://doi.org/10.1103/PhysRevC.96.034328

no abstracts in English

Standard Gibbs free energies for transfer of actinyl ions at the aqueous/organic solution interface

Kitatsuji, Yoshihiro; Okugaki, Tomohiko*; Kasuno, Megumi*; Kubota, Hiroki*; Maeda, Koji*; Kimura, Takaumi; Yoshida, Zenko; Kihara, Sorin*

Journal of Chemical Thermodynamics, 43(6), p.844 - 851, 2011/06

https://doi.org/10.1016/j.jct.2010.12.023

Standard Gibbs energies for transfer (G) of actinyl ions (AnO; z = 2 or 1; An: U, Np or Pu) between an aqueous solution and an organic solution were determined based on distribution method combined with voltammetry for ion transfer at the interface of two immiscible electrolyte solutions. The organic solutions examined were nitrobenzene, 1,2-dichloroethane, benzonitrile, acetophenone and 2-nitrophenyl octyl ether. Irrespective of the type of organic solutions, G of UO, NpO and PuO were nearly equal to each other and slightly larger than that of Mg. The G of NpO was extraordinary large compared with those of ordinary monovalent cations. The dependence of G of AnO on the type of organic solutions was similar to that of H or Mg. The G of An and An were also discussed briefly.

Separation of actinide ion based on electrolytic extraction by flow electrolysis cell for rapid ion transfer

Kitatsuji, Yoshihiro; Okugaki, Tomohiko*; Kasuno, Megumi*; Maeda, Koji*; Kimura, Takaumi; Yoshida, Zenko; Kihara, Sorin*

no journal, , 

no abstracts in English