"Invisible" radioactive cesium atoms revealed; Pollucite inclusion in cesium-rich microparticles (CsMPs) from the Fukushima Daiichi Nuclear Power Plant

Miyazaki, Kanako*; Takehara, Masato*; Minomo, Kenta*; Horie, Kenji*; Takehara, Mami*; Yamasaki, Shinya*; Saito, Takumi*; Onuki, Toshihiko*; Takano, Masahide; Shiotsu, Hiroyuki; et al.

Journal of Hazardous Materials, 470(15), p.134104_1 - 134104_11, 2024/05

https://doi.org/10.1016/j.jhazmat.2024.134104

A Systematic approach for the adequacy analysis of a set of experimental databases; Application in the framework of the ATRIUM activity

Baccou, J.*; Glantz, T.*; Ghione, A.*; Sargentini, L.*; Fillion, P.*; Damblin, G.*; Sueur, R.*; Iooss, B.*; Fang, J.*; Liu, J.*; et al.

Nuclear Engineering and Design, 421, p.113035_1 - 113035_16, 2024/05

https://doi.org/10.1016/j.nucengdes.2024.113035

Simulation of predicted effects of decontamination and cultivation activities on reduction of air dose rates using Monte Carlo method

Kim, M.; Yoshimura, Kazuya; Sakuma, Kazuyuki; Malins, A.*; Abe, Tomohisa; Nakama, Shigeo; Machida, Masahiko; Saito, Kimiaki

Kankyo Hoshano Josen Gakkai-Shi, 12(2), p.39 - 53, 2024/04

More than ten years have passed since the accident at TEPCO's Fukushima Daiichi Nuclear Power Station. But with the progress of decontamination, the evacuation order has been lifted and the return of residents is still ongoing. Under these circumstances, in order to quantitatively evaluate the effect of decontamination activities and cultivation on air dose rate reduction, a detailed environmental model was constructed using 3D-ADRES for a real area located in the Okuma town, Fukushima prefecture. Monte Carlo simulations were performed using the model to calculate realistic distributions of radioactive Cs based on measurement results and air dose rates reflecting changes over time. As a result, the distribution of air dose rates at 100 cm above ground level in the target area according to decontamination and cultivation activities was calculated. The calculated air dose rates reproduced the measured values well, and were confirmed to be appropriate as a method for evaluating the effects of decontamination and cultivation activities. This method is expected to serve as a reference for further decontamination management measures to reduce the air dose rate in the difficult-to-return zone, where entry is still restricted.

Survey of air dose rate distribution inside and outside of wooden houses in Fukushima Prefecture; Actual condition of dose reduction factor

Kim, M.; Malins, A.*; Machida, Masahiko; Yoshimura, Kazuya; Saito, Kimiaki; Yoshida, Hiroko*

Nihon Genshiryoku Gakkai Wabun Rombunshi (Internet), 22(4), p.156 - 169, 2023/11

https://doi.org/10.3327/taesj.J23.001

Dose reduction factor of a Japanese house is important information in the external exposure estimation of returning residents. In 2019, a total of 19 wooden houses were surveyed in Iitate Village and Namie Town using a gamma plotter that can continuously measure the air dose rate. In addition, the characteristics of the reduction factor were investigated from the measured air dose rate. In the vicinity of houses, uncontaminated areas exist underneath houses and, the ratio of paved surfaces such as asphalt roads is relatively high; furthermore, the pavement has a tendency for the radiation source to decay quickly. Therefore, the air dose rate near the house showed a relatively low value in common at all sites. Air dose rates above unpaved surfaces showed higher values and larger variations than those above paved surfaces within a radius of 50 m form the center of a house. The reduction factor was widely distributed even for one house, if the ratio of every air dose rate observed inside and outside the house is considered. It is suggested that a realistic reduction factor may not be obtained when the reduction factor is obtained based on the measured values at a small number of points that do not have the representativeness of the radiation field to be measured.

Relationship between the contact angle of pure Cu and its alloys owing to liquid Na and electronic states at the interface

Saito, Junichi; Monbernier, M.*

Surfaces and Interfaces (Internet), 41, p.103248_1 - 103248_8, 2023/10

https://doi.org/10.1016/j.surfin.2023.103248

Intruder configurations in Ne at the transition into the island of inversion; Detailed structure study of Ne

Wang, H.*; Yasuda, Masahiro*; Kondo, Yosuke*; Nakamura, Takashi*; Tostevin, J. A.*; Ogata, Kazuyuki*; Otsuka, Takaharu*; Poves, A.*; Shimizu, Noritaka*; Yoshida, Kazuki; et al.

Physics Letters B, 843, p.138038_1 - 138038_9, 2023/08

https://doi.org/10.1016/j.physletb.2023.138038

Detailed -ray spectroscopy of the exotic neon isotope Ne has been performed using the one-neutron removal reaction from Ne. Based on an analysis of parallel momentum distributions, a level scheme with spin-parity assignments has been constructed for Ne and the negative-parity states are identified for the first time. The measured partial cross sections and momentum distributions reveal a significant intruder p-wave strength providing evidence of the breakdown of the N = 20 and N = 28 shell gaps. Only a weak, possible f-wave strength was observed to bound final states. Large-scale shell-model calculations with different effective interactions do not reproduce the large p-wave and small f-wave strength observed experimentally, indicating an ongoing challenge for a complete theoretical description of the transition into the island of inversion along the Ne isotopic chain.

One-pot synthesis of superparamagnetically modified zeolite chabazite for removal of Cs from radioactively contaminated water

Ito, Azusa; Karmaoui, M.*; Thirunavukkarasu, G.*; Hriljac, J. A.*

APL Materials (Internet), 11(4), p.041105_1 - 041105_9, 2023/04

https://doi.org/10.1063/5.0139282

Nonlinear magnon polaritons

Lee, O.*; Yamamoto, Kei; Umeda, Maki; Zollitsch, C. W.*; Elyasi, M.*; Kikkawa, Takashi*; Saito, Eiji; Bauer, G. E. W.*; Kurebayashi, Hidekazu*

Physical Review Letters, 130(4), p.046703_1 - 046703_6, 2023/01

https://doi.org/10.1103/PhysRevLett.130.046703

High-temperature gaseous reaction of cesium with siliceous thermal insulation; The Potential implication to the provenance of enigmatic Fukushima cesium-bearing material

Rizaal, M.; Nakajima, Kunihisa; Saito, Takumi*; Osaka, Masahiko; Okamoto, Koji*

ACS Omega (Internet), 7(33), p.29326 - 29336, 2022/08

https://doi.org/10.1021/acsomega.2c03525

Modelling of the LTDE-SD radionuclide diffusion experiment in crystalline rock at the sp Hard Rock Laboratory (Sweden)

Soler, J. M.*; Meng, S.*; Moreno, L.*; Neretnieks, I.*; Liu, L.*; Keklinen, P.*; Hokr, M.*; ha, J.*; Vetenk, A.*; Reimitz, D.*; et al.

Geologica Acta, 20(7), 32 Pages, 2022/07

https://doi.org/10.1344/GeologicaActa2022.20.7

Task 9B of the SKB Task Force on Modelling of Groundwater Flow and Transport of Solutes in fractured rock focused on the modelling of experimental results from the LTDE-SD in situ tracer test performed at the sp Hard Rock Laboratory in Sweden. Ten different modelling teams provided results for this exercise, using different concepts and codes. Three main types of modelling approaches were used: (1) analytical solutions to the transport-retention equations, (2) continuum-porous-medium numerical models, and (3) microstructure-based models accounting for small-scale heterogeneity (i.e. mineral grains and microfracture distributions). The modelling by the different teams allowed the comparison of many different model concepts, especially in terms of potential zonations of rock properties (porosity, diffusion, sorption), such as the presence of a disturbed zone at the rock and fracture surface, the potential effects of micro- and cm-scale fractures.