Sm synchrotron-radiation-based Mssbauer spectroscopy of Sm-based heavy fermion compounds

Tsutsui, Satoshi; Higashinaka, Ryuji*; Mizumaki, Masaichiro*; Kobayashi, Yoshio*; Nakamura, Jin*; Ito, Takashi; Yoda, Yoshitaka*; Matsuda, Tatsuma*; Aoki, Yuji*; Sato, Hideyuki*

Interactions (Internet), 245(1), p.9_1 - 9_10, 2024/12

https://doi.org/10.1007/s10751-024-01851-y

Analysis of the relationship between operational quantity used for area monitoring and protection quantity for external exposure

Endo, Akira

JAEA-Research 2024-002, 90 Pages, 2024/05

JAEA-Research-2024-002.pdf:4.22MB

This report presents a comprehensive analysis of the relationship between three quantities used for area monitoring - ambient dose equivalent , maximum dose equivalent , and ambient dose - and effective dose for external irradiation by photons, neutrons, electrons, positrons, protons, muons, pions, and helium ions. For the analysis, calculations were performed using PHITS (Particle and Heavy Ion Transport code System) and the ICRU sphere. The analysis result shows that and can induce large differences in the estimation of effective dose over a wide energy range for various particle types covered by ICRP Publication 116 while can conservatively estimate effective dose within the acceptable range for area monitoring. In other words, and have limitations in estimating effective dose, and using is recommended as a more appropriate quantity for the purpose. This conclusion supports the proposal of ICRU Report 95 to use for estimating effective dose in various external exposure situations. The use of ambient dose is particularly important in situations where various types of radiation are encountered, such as the use of radiation in the medical and academic fields and exposure in aviation and can meet the evolving requirements of radiation monitoring for the expansion of the field of radiological protection.

Statistical optimization of nZVI chemical synthesis approach towards P and NO removal from aqueous solutions; Cost-effectiveness & parametric effects

Maamoun, I.; Eljamal, R.*; Eljamal, O.*

Chemosphere, 312, Part 1, p.137176_1 - 137176_11, 2023/01

https://doi.org/10.1016/j.chemosphere.2022.137176

Chloramphenicol removal from water by various precursors to enhance graphene oxide-iron nanocomposites

Idham, M. F.*; Falyouna, O.*; Eljamal, R.*; Maamoun, I.; Eljamal, O.*

Journal of Water Process Engineering (Internet), 50, p.103289_1 - 103289_16, 2022/12

https://doi.org/10.1016/j.jwpe.2022.103289

Basic study on seismic respnse of soil-structure interaction system using equivalent linear three-dimensional FEM analysis of reactor building

Ichihara, Yoshitaka*; Nakamura, Naohiro*; Nabeshima, Kunihiko*; Choi, B.; Nishida, Akemi

Kozo Kogaku Rombunshu, B, 68B, p.271 - 283, 2022/04

https://doi.org/10.3130/aijjse.68B.0_271

This paper aims to evaluate the applicability of the equivalent linear analysis method for reinforced concrete, which uses frequency-independent hysteretic damping, to the seismic design of reactor building of the nuclear power plant. To achieve this, we performed three-dimensional FEM analyses of the soil-structure interaction system, focusing on the nonlinear and equivalent linear seismic behavior of a reactor building under an ideal soil condition. From these results, the method of equivalent analysis showed generally good correspondence with the method of the nonlinear analysis, confirming the effectiveness. Moreover, the method tended to lower the structural stiffness compared to the nonlinear analysis model. Therefore, in the evaluation of the maximum shear strain, we consider that the results were more likely to be higher than the results of nonlinear analysis.

Applicability of equivalent linear analysis to reinforced concrete shear walls; 3D FEM simulation of experiment results of seismic wall ultimate behavior

Ichihara, Yoshitaka*; Nakamura, Naohiro*; Moritani, Hiroshi*; Horiguchi, Tomohiro*; Choi, B.

Nihon Genshiryoku Gakkai Wabun Rombunshi, 21(1), p.1 - 14, 2022/03

AA2020-0911.pdf:8.99MB

https://doi.org/10.3327/taesj.J20.038

In this study, we aim to approximately evaluate the effect of nonlinearity of reinforced concrete structures through seismic response analysis using the equivalent linear analysis method. A simulation analysis was performed for the ultimate response test of the shear wall of the reactor building used in an international competition by OECD/NEA in 1996. The equivalent stiffness and damping of the shear wall were obtained from the trilinear skeleton curves proposed by the Japan Electric Association and the hysteresis curves proposed by Cheng et al. The dominant frequency, maximum acceleration response, maximum displacement response, inertia force-displacement relationship, and acceleration response spectra of the top slab could be simulated well up to a shear strain of approximately =2.010. The equivalent linear analysis used herein underestimates the maximum displacement response at the time of ultimate fracture of approximately =4.010. Moreover, the maximum shear strain of the shear wall could not capture the locally occurring shear strain compared with that of the nonlinear analysis. Therefore, when employing this method to evaluate the maximum shear strain and test results, including those during the sudden increase in displacement immediately before the fracture, sufficient attention must be paid to its applicability.

Determination of parameters for an equation to obtain natural background radiation using KURAMA-II loaded with C12137-01 type CsI(Tl) detector

Ando, Masaki; Matsuda, Norihiro; Saito, Kimiaki

Nihon Genshiryoku Gakkai Wabun Rombunshi, 20(1), p.34 - 39, 2021/03

https://doi.org/10.3327/taesj.J20.007

We measured count rates and air dose rates at 11 measurement points where the influence of the Fukushima Dai-ichi Nuclear Power Plant accident could be ignored to obtain parameters for a background equation applying to KURAMA-II loaded with the high sensitivity CsI(Tl) detector, C12137-01. It was found that the sensitivity of KURAMA-II (C12137-01) was about 10 times or more for background measurement, compared with KURAMA-II loaded with the standard type CsI(Tl) detector, C12137. A background equation for the energy range of 1400-2000 keV was determined as, y (Sv/h)=0.062 x (cps). We evaluated background air dose rates using KURAMA-II (C12137-01) for 71 municipalities and compared them with the previous study using KURAMA-II (C12137). Evaluated background air dose rates in this study were almost equal to those in the previous study. We confirmed that the background equation evaluated in this study was applicable for the KURAMA-II (C12137-01).

Calculations for ambient dose equivalent rates in nine forests in eastern Japan from Cs and Cs radioactivity measurements

Malins, A.; Imamura, Naohiro*; Niizato, Tadafumi; Takahashi, Junko*; Kim, M.; Sakuma, Kazuyuki; Shinomiya, Yoshiki*; Miura, Satoru*; Machida, Masahiko

Journal of Environmental Radioactivity, 226, p.106456_1 - 106456_12, 2021/01

https://doi.org/10.1016/j.jenvrad.2020.106456

Decreasing trend of ambient dose equivalent rates over a wide area in eastern Japan until 2016 evaluated by car-borne surveys using KURAMA systems

Ando, Masaki; Mikami, Satoshi; Tsuda, Shuichi; Yoshida, Tadayoshi; Matsuda, Norihiro; Saito, Kimiaki

Journal of Environmental Radioactivity, 192, p.385 - 398, 2018/12

https://doi.org/10.1016/j.jenvrad.2018.07.009

Car-borne surveys using KURAMA systems have been conducted over a wide area in eastern Japan since 2011. The measurement data collected until 2016 was analyzed, and decreasing trend of the dose rates in regions within 80 km of Fukushima Dai-ichi Nuclear Power Plant were examined. The averaged dose rates tended to decrease considerably with respect to the physical decay of radiocaesium, and the ecological half-lives of the fast and slow decay components were estimated. The decrease of the dose rate in the forest was slower than its decrease in other regions, and the decrease of the dose rate in urban area was the fastest. The decrease in the dose rates obtained via the car-borne survey was larger than that obtained on flat ground with few disturbances using survey meters approximately 1.5 y after the accident; hereafter, the decrease in the dose rates obtained via the car-borne survey was same as the latter measurement.

Measurement of ambient dose equivalent rates by walk survey around Fukushima Dai-ichi Nuclear Power Plant using KURAMA-II until 2016

Ando, Masaki; Yamamoto, Hideaki*; Kanno, Takashi*; Saito, Kimiaki

Journal of Environmental Radioactivity, 190-191, p.111 - 121, 2018/10

https://doi.org/10.1016/j.jenvrad.2018.04.025

Ambient dose equivalent rates in various environments related to human lives were measured by walk surveys using the KURAMA-II systems from 2013 to 2016 around the Fukushima Dai-ichi Nuclear Power Plant. The dose rate of the locations where the walk survey was performed decreased to about 38% of its initial value in the 42 months, which was beyond that attributable to the physical decay. The air dose rates decreased depending on the level of the evacuation areas, and the decrease was slightly larger in populated areas where humans are active. The comparison of walk survey data with car-borne survey data indicated that the air dose rate varies largely even within a 100 m square area. The dose rates measured by the walk surveys were estimated to be medial of those along roads and those of undisturbed flat ground. The air dose rates measured by the walk surveys decreased quickly compared with the air dose rate from the flat ground measurement.