LSDスパイクの経時変化確認

芝野 幸也; 阿部 勝男; 政 和男*; 細金 達哉; 茅野 雅志; 角 美香; 藤原 英城*; 山口 和哉*; 本木 知佳*

第41回日本核物質管理学会年次大会会議論文集(インターネット), 4 Pages, 2020/11

LSDスパイクは、同位体希釈質量分析法によるU, Puの計量分析に使用する標準物質である。LSDスパイクはU, Puの混合溶液を調製後、バイアル瓶に分取し、乾固して調製される。LSDスパイクは、乾固直後、バイアル瓶の底に張付いた状態であるが、保管期間の経過に伴いバイアル瓶の底から剥がれるなど徐々に劣化し、分析結果に影響を与える恐れがある。本研究では、日本原燃から委託を受け調製したLSDスパイクを用いて、約2年間静置状態で保管し、LSDスパイクの経時変化を評価した。

Emergent spin-1 Haldane gap and ferroelectricity in a frustrated spin- ladder

上田 宏*; 小野田 繁樹*; 山口 泰弘*; 木村 剛*; 吉澤 大智*; 森岡 俊晶*; 萩原 政幸*; 萩原 雅人*; 左右田 稔*; 益田 隆嗣*; et al.

Physical Review B, 101(14), p.140408_1 - 140408_6, 2020/04

https://doi.org/10.1103/PhysRevB.101.140408

We report experimental and theoretical evidence that RbCuMoO has a nonmagnetic tetramer ground state of a two-leg ladder comprising antiferromagnetically coupled frustrated spin- chains and exhibits a Haldane spin gap of emergent spin-1 pairs. Three spin excitations split from the spin-1 triplet by a Dzyaloshinskii-Moriya interaction are identified in inelastic neutron-scattering and electron spin resonance spectra. A tiny magnetic field generates ferroelectricity without closing the spin gap, indicating a unique class of ferroelectricity induced by a vector spin chirality order.

A Consideration on the use of shear waves to improve the sensitivity of an optical ultrasonic sensor for under-sodium viewers

猿田 晃一; 白濱 卓馬*; 山口 智彦; 上田 雅司

E-Journal of Advanced Maintenance (Internet), 10(2), p.1 - 8, 2018/08

http://www.jsm.or.jp/ejam/Vol.10No.2/AA/AA148/AA148.html

The present work is intended to investigate shear waves induced on stainless steel diaphragms by the incidence of ultrasonic waves, with the main emphasis on the understanding of the generation mechanism of the resultant second wave, in order to explore the possible use of the shear waves for improvement of the sensitivity of an optical ultrasonic sensor used for under-sodium viewers. The response of the diaphragms exposed to ultrasonic waves with different pressure profiles is measured by a heterodyne interferometer to examine the location where the shear waves are excited. The generation of the second wave is interpreted on the basis of interference of these shear waves. The effectiveness of the use of the shear waves is demonstrated by an improved sensitivity of 0.26 nm/kPa for a 3-mm-diameter and 5-m-thick diaphragm. This sensitivity is approximately 7 times as high as the sensitivity achieved with the first wave, which is the displacement of the diaphragm caused by directly incident ultrasonic waves.

R&D of multi-frequency ECT algorithms for FBR SG tubes

Mihalache, O.; 山口 智彦; 白濱 卓馬; 上田 雅司

E-Journal of Advanced Maintenance (Internet), 9(2), p.60 - 65, 2017/08

The adherence of sodium on the external surface of steam generator tubes (SGs) of Fast Breeder Reactors (FBR) adds an additional level of complexity in the in-service inspection (ISI) of SGs using eddy current testing (ECT). The paper focusses on research and development (R&D) of novel multi-frequency (MF) algorithms, based on ECT signals, special developed and tuned to enhance the signal from defects located on external SG tube surface and to suppress electromagnetic noise from the conductive sodium and SG support plates. The application of the MF algorithm is investigated using both three-dimensional finite element (FEM) simulations and experimental measurements from SG tubes soaked and then drained of sodium, in a sodium tank mock-up.

R&D of multi-frequency ECT algorithms for FBR SG tubes

Mihalache, O.; 山口 智彦; 白濱 卓馬; 上田 雅司

Proceedings of 3rd International Conference on Maintenance Science and Technology (ICMST 2016) (Internet), 2 Pages, 2016/11

The adherence of sodium on the external surface of steam generator tubes of Fast Breeder Reactors (FBR) adds an additional level of complexity in the in-service inspection (ISI) of SGs using eddy current testing (ECT). The paper focusses on research and development of novel multi-frequency algorithms, based on ECT, special developed and tuned to enhance the signal from defects located on external SG tube surface and to suppress electromagnetic noise from the conductive sodium and SG support plates. The application of the method is investigated using both three-dimensional finite element (FEM) simulations and experimental measurements from SG tubes soaked and then drained of sodium, in a sodium tank mock-up.

MA燃料遠隔取扱試験設備の製作及び試験結果,1; 燃料冷却試験装置

西原 健司; 田澤 勇次郎; 井上 昭; 菅原 隆徳; 辻本 和文; 佐々 敏信; 大林 寛生; 山口 和司; 菊地 将司*

JAEA-Technology 2015-051, 47 Pages, 2016/03

JAEA-Technology-2015-051.pdf:3.6MB

J-PARCに建設が計画されている核変換物理実験施設(TEF-P)で用いる高線量のMA含有燃料の取扱い設備の設計製作に必要なデータを取得する試験装置群(MA燃料遠隔取扱試験設備)の内、燃料冷却試験装置の製作及び試験結果についてとりまとめる。試験によりTEF-Pの設計に用いる圧力損失及び温度上昇の評価式が妥当であることが確認され、冷却概念の成立性が示された。

Effects of metallic diaphragm on sensitivity characteristics of optical ultrasonic sensor for under-sodium inspection

猿田 晃一; 山口 智彦; 上田 雅司

EUR-27790-EN, p.209 - 214, 2016/00

https://doi.org/10.2790/13215

We report the effects of the metallic diaphragm on the sensitivity characteristics of the optical ultrasonic sensor used in under-sodium inspection. The diaphragm is set on the wall of a tank filled with water in place of sodium to have direct contact with water on one side and air on the other side. A heterodyne interferometer is employed to detect the wave on the diaphragm induced by the ultrasonic wave emitted from a piezoelectric transducer placed in the water tank. Two kinds of waves appear on the diaphragm: the first corresponds to the incident ultrasonic wave and the second is surface wave arising from the peripheral of the diaphragm. We found that the first wave increases with decreasing thickness of the diaphragm, while the second wave is dependent on both the thickness and diameter. Moreover the second wave has larger amplitude than the first wave due to interference effect at the center of the diaphragm. This result suggests that the small amplitude of the incident ultrasonic wave can be detected with a higher sensitivity by using the second wave on the diaphragm.

Experimental measurements and simulations of ect signal for ferromagnetic SG tubes covered by a sodium layer

山口 智彦; Mihalache, O.; 上田 雅司

Electromagnetic Nondestructive Evaluation (XVII), p.144 - 154, 2014/00

https://doi.org/10.3233/978-1-61499-407-7-144

強磁性体の蒸気発生器伝熱管の外表面に導電性物質であるナトリウムが付着すると渦電流探傷試験において欠陥の検出性能に影響を与えることから、著者らはナトリウム浸漬試験と電磁場解析を行い、伝熱管や構造物支持板や溶接部にナトリウムが付着した場合の試験結果を確認したので、本会議にて発表する。

「もんじゅ」1次主冷却系配管検査装置の機能試験

前田 幸宏; 山口 智彦; 上田 雅司; 藤木 一成*

日本保全学会第10回学術講演会要旨集, p.599 - 601, 2013/07

高速増殖原型炉「もんじゅ」では、1次主冷却系配管の供用期間中検査として、ナトリウム漏えい検出器による連続漏えい監視や目視試験に加え、代表部位に対する体積試験を行う計画であり、高温構造設計の妥当性を確認する観点から、代表部位として原子炉容器出口から中間熱交換器入口に至る高温配管のエルボ部を選定し、応力集中部(横腹部)及び両端の周方向溶接部に対し、配管外表面から超音波探傷を行う。検査時における作業員の被ばく低減のため、遠隔・自動で検査するための装置が開発され、供用前検査での使用経験と関連技術の進歩を踏まえ、装置の更新と改良が行われた。本稿では、改良後の検査装置について、モックアップを用いて実施した機能試験の結果及び実際に「もんじゅ」の配管に取り付けて動作確認を実施した結果について報告する。

Large scale 3D FEM electromagnetic simulations and validations for FBR steam generator tubes

Mihalache, O.; 山口 智彦; 上田 雅司

Abstracts of Electromagnetic Nondestructive Evaluation Series, p.42 - 43, 2012/07

The present paper focuses on electromagnetic simulations of ECT for helical SG tubes and large SP models. Large scale 3D simulations are validated by comparison with experimental measurements conducted in a mock-up test in our laboratory. State of the art parallel numerical simulations using an electromagnetic code developed with a hybrid OpenMP-MPI approach for very large FEM models are conducted using up to 1024 CPUs in Fujitsu BX900 supercomputer. The availability of large models offers new insights into ECT for large structures in FBR, where electromagnetic interference can appear due to close proximity of multiple tubes.