Radiation exposure and oxidative stress status of wild Japanese macaques in the ex-evacuation zone of the Fukushima Daiichi Nuclear Power Plant accident

Ishikawa, Ryoya*; Suzuki, Masatoshi*; Kino, Yasushi*; Endo, Satoru*; Nakajima, Hiroo*; Oka, Toshitaka; Takahashi, Atsushi*; Shimizu, Yoshinaka*; Suzuki, Toshihiko*; Shinoda, Hisashi*; et al.

KEK Proceedings 2022-2, p.61 - 66, 2022/11

The balance between oxidative stress and antioxidant activity, which is a defense mechanism against oxidative stress, was investigated in the liver and bladder of wild Japanese macaques captured in Fukushima Prefecture. No significant induction of oxidative stress by exposure to environmental radionuclides after the Fukushima nuclear accident was observed, suggesting that the stress defense mechanism of the organism is activated in some organs.

scattering length from photoproduction on the proton near the reaction threshold

Ishikawa, Takatsugu*; Fujimura, Hisako*; Fukasawa, Hiroshi*; Hashimoto, Ryo*; He, Q.*; Honda, Yuki*; Hosaka, Atsushi; Iwata, Takahiro*; Kaida, Shun*; Kasagi, Jirota*; et al.

Physical Review C, 101(5), p.052201_1 - 052201_6, 2020/05

https://doi.org/10.1103/PhysRevC.101.052201

Zeolitic vanadomolybdates as high-performance cathode-active materials for sodium-ion batteries

Zhang, Z,*; Wang, H.*; Yoshikawa, Hirofumi*; Matsumura, Daiju; Hatao, Shuya*; Ishikawa, Satoshi*; Ueda, Wataru*

ACS Applied Materials & Interfaces, 12(5), p.6056 - 6063, 2020/02

https://doi.org/10.1021/acsami.9b19808

Guidance for gamma spectrometry intercomparison based on the information obtained through five intercomparisons during the Fukushima mapping project

Mikami, Satoshi; Ishikawa, Daisuke*; Matsuda, Hideo*; Hoshide, Yoshifumi*; Okuda, Naotoshi*; Sakamoto, Ryuichi*; Saito, Kimiaki

Journal of Environmental Radioactivity, 210, p.105938_1 - 105938_7, 2019/12

https://doi.org/10.1016/j.jenvrad.2019.03.014

Five intercomparisons of in situ spectrometry by 6-7 participating teams have been conducted between December 2011 and August 2015 at sites in Fukushima prefecture which affected by the fallout of FDNPS accident occurred in March 2011. The evaluated deposition densities agreed within 5-6% in terms of coefficient of variation (CV) for radiocesium (Cs and Cs), by our best achievement, and the ratio of Cs/Cs in deposition density agreed within 1-2% in CV, through five intercomparisons. These results guarantee the accuracy of the measurements of the mapping project. Two different methods for intercomparison were conducted: (1) sequential measurements at an identical point; and (2) simultaneous measurements in a narrow area within 3 m radius. In a comparison between the two methods at a site, no significant difference was observed between the results. The standard protocols for the two different intercomparison methods were proposed based on our experience.

Oxidation characteristics of lead-alloy coolants in air ingress accident

Kondo, Masatoshi*; Okubo, Nariaki; Irisawa, Eriko; Komatsu, Atsushi; Ishikawa, Norito; Tanaka, Teruya*

Energy Procedia, 131, p.386 - 394, 2017/12

https://doi.org/10.1016/j.egypro.2017.09.473

The chemical behaviors of lead (Pb) based coolants in the air ingress accident of fast reactors were investigated by means of the thermodynamic considerations and the static oxidation experiments for Pb alloys at various chemical compositions. The results of the static oxidation tests for lead-bismuth (Pb-Bi) alloys indicated that Pb was depleted from the alloy due to the preferential formation of PbO in air at 773K. Pb-Bi oxide and BiO were formed after the enrichment of Bi in the alloys due to the Pb depletion. The oxidation rates of the alloys were much larger than that of the steels, and became larger with higher Pb concentration in the alloys. The compatibility of Pb-Bi alloys with stainless steel was worse when the Pb concentration in the alloys became low, since the dissolution type corrosion was promoted by the Bi composition in the alloy. The Pb-Li alloys were oxidized as they formed LiPbO and LiCO. Then, Li was depleted from the alloy.

The CIELO collaboration; Progress in international evaluations of neutron reactions on Oxygen, Iron, Uranium and Plutonium

Chadwick, M. B.*; Capote, R.*; Trkov, A.*; Kahler, A. C.*; Herman, M. W.*; Brown, D. A.*; Hale, G. M.*; Pigni, M.*; Dunn, M.*; Leal, L.*; et al.

EPJ Web of Conferences, 146, p.02001_1 - 02001_9, 2017/09

https://doi.org/10.1051/epjconf/201714602001

The CIELO collaboration has studied neutron cross sections on nuclides (O, Fe, U and Pu) that significantly impact criticality in nuclear technologies with the aim of improving the accuracy of the data and resolving previous discrepancies in our understanding. This multi-laboratory pilot project, coordinated via the OECD/NEA Working Party on Evaluation Cooperation (WPEC) Subgroup 40 with support also from the IAEA, has motivated experimental and theoretical work and led to suites of new evaluated libraries that accurately reflect measured data and also perform well in integral simulations of criticality.

Ion species/energy dependence of irradiation-induced lattice structure transformation and surface hardness of NiNb and NiTa intermetallic compounds

Kojima, Hiroshi*; Kaneno, Yasuyuki*; Ochi, Masaaki*; Semboshi, Satoshi*; Hori, Fuminobu*; Saito, Yuichi*; Ishikawa, Norito; Okamoto, Yoshihiro; Iwase, Akihiro*

Materials Transactions, 58(5), p.739 - 748, 2017/05

https://doi.org/10.2320/matertrans.MBW201612

Bulk samples of NiNb and NiTa intermetallic compounds were irradiated with 16 MeV Au, 4.5 MeV Ni, 4.5 MeV Al, 200 MeV Xe and 1.0 MeV He ions, and the change in near-surface lattice structure was investigated by means of the grazing incidence X-ray diffraction (GIXD)and EXAFS. The NiNb and NiTa lattice structures transform from the ordered structures (orthorhombic and monoclinic structures for NiNb and NiTa, respectively) to the amorphous state by the Au, Ni, Al and Xe ion irradiations. Irrespective of such heavy ion species or energies, the lattice structure transformation to the amorphous state almost correlate with the density of energy deposited through elastic collisions.

Effect of magnetism on lattice dynamics in SrFeAs using high-resolution inelastic X-ray scattering

Murai, Naoki*; Fukuda, Tatsuo; Kobayashi, Tatsuya*; Nakajima, Masamichi*; Uchiyama, Hiroshi*; Ishikawa, Daisuke*; Tsutsui, Satoshi*; Nakamura, Hiroki; Machida, Masahiko; Miyasaka, Shigeki*; et al.

Physical Review B, 93(2), p.020301_1 - 020301_5, 2016/01

https://doi.org/10.1103/PhysRevB.93.020301

Status of decommissioning of the Plutonium Fuel Fabrication Facility and R&Ds of dismantling technologies for gloveboxes

Kimura, Yasuhisa; Hirano, Hiroshi; Watahiki, Masatoshi; Kuba, Meiji; Ishikawa, Shinichiro

Dekomisshoningu Giho, (52), p.45 - 54, 2015/09

http://ci.nii.ac.jp/naid/40020624160

The Plutonium Fuel Fabrication Facility (PFFF) of the Japan Atomic Energy Agency is now in its decommissioning phase. In the PFFF, terminated gloveboxes have been dismantled. Gloveboxes to be dismantled are surrounded by a plastic enclosure to prevent contamination from being spread into process room. Dismantling operations for gloveboxes are performed manually by workers, each wearing an air-feed suit. However, the mental and physical loads placed on workers wearing the air-feed suits are intensively high. Therefore, R&Ds on new dismantling technologies including utilization of heavy machines covered with plastic enclosure for anti-contamination have been started to reduce the potential risks associated with workers and decommissioning costs. In this paper, the status of decommissioning of the PFFF and the overview of developed dismantling technologies for -tight gloveboxes are described.

Probing strongly correlated 4-orbital symmetry of the ground state in Yb compounds by linear dichroism in core-level photoemission

Mori, Takeo*; Kitayama, Satoshi*; Kanai, Yuina*; Naimen, Sho*; Fujiwara, Hidenori*; Higashiya, Atsushi*; Tamasaku, Kenji*; Tanaka, Arata*; Terashima, Kensei*; Imada, Shin*; et al.

Journal of the Physical Society of Japan, 83(12), p.123702_1 - 123702_5, 2014/12

https://doi.org/10.7566/JPSJ.83.123702

We show that the strongly correlated 4-orbital symmetry of the ground state is revealed by linear dichroism in core-level photoemission spectra, as we have discovered for YbRhSi and YbCuSi. Theoretical analysis shows us that the linear dichroism reflects the anisotropic charge distributions resulting from a crystalline electric field. We have successfully determined the ground-state 4 symmetry for both compounds from the polarization-dependent angle resolved core-level spectra at a temperature well below the first excitation energy. The excited-state symmetry is also probed by temperature dependence of the linear dichroism where the high measurement temperatures are on the order of the crystal-field-splitting energies.