A5065844623- Radioactive contamination and transfer
- Radioactivity and Radon Measurements
- Radioactive element chemistry and processing
- Nuclear and radioactivity studies
- Nuclear Physics and Applications
- Geology and Paleoclimatology Research
- Isotope Analysis in Ecology
- Atmospheric chemistry and aerosols
- Chemical Synthesis and Characterization
- Radiation Dose and Imaging
- Geochemistry and Elemental Analysis
- Heavy metals in environment
- Radiation Detection and Scintillator Technologies
- Geochemistry and Geologic Mapping
- Methane Hydrates and Related Phenomena
- Radiation Therapy and Dosimetry
- Air Quality and Health Impacts
- Geological Studies and Exploration
- Geological and Geochemical Analysis
- Analytical chemistry methods development
- Concrete and Cement Materials Research
- Marine and coastal ecosystems
- Groundwater and Isotope Geochemistry
- Graphite, nuclear technology, radiation studies
- Helicobacter pylori-related gastroenterology studies
University of Tsukuba
2016-2025
Yokohama National University
2023
Gunma Prefectural College of Health Sciences
2022
Osaka City University
2019-2021
University of Toyama
2019
Hiroshima University
2009-2018
Planetary Systems (United States)
2012-2018
Fukushima University
2017
Fukushima Medical University
2017
Applied Science University
2017
Previous studies have shown that radiocesium (mainly 137Cs) was retained at the very surface of soils in Fukushima Prefecture. Clay minerals and micas are assumed as main sorbents for cesium (Cs) Fukushima, but direct evidence is lacking this hypothesis. In study, natural sample (soil sediment) from Prefecture investigated through sequential extraction experiment (modified BCR method), which showed more than 94% 137Cs fixed residual phase. The results indicated most Cs occurred interlayer...
Vertical profiles of iodine-131 and cesium-137 emitted from the Fukushima Daiichi Nuclear Power Station were determined in soil core samples collected prefecture. The showed that more than 76% radionuclides retained within 5 cm surface. Leaching experiments cesium was strongly bound to particles which could not be leached with 2 M HCl, while 40% iodine incorporated into humic substances.
Concentrations of the radionuclides, U, Pu, and Cs were measured in water samples (10-20 L) to study analyte dispersion migration following Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. A total 8 including oceanic paddy-field collected vicinity plant. Determinations Pu isotopes performed by accelerator mass spectrometry (AMS), inductively coupled plasma (ICP-MS), γ-ray spectrometry. The 236U/238U atom ratio was range 1.83-8.20 × 10-9 for fresh around 0.57 seawater while...
We present a feasibility study for using 236U as an oceanic circulation tracer based on depth profiles of and 137Cs in the Japan/East Sea. The concentration predominantly anthropogenic 236U, measured with Accelerator Mass Spectrometry (AMS), decreased from (13±3)×106 atom/kg surface water to (1.6±0.3)×106 close sea floor (2800 m). profile has smooth trend values are generally proportional that same samples, but slightly lower ratio 137Cs/236U below 2000 m. cumulative inventory dissolved...
Black-colored road dusts were collected in high-radiation areas Fukushima Prefecture. Measurement of (236)U and Pu isotopes (134,137)Cs samples was performed to confirm whether refractory elements, such as U Pu, from the fuel core discharged ascertain extent fractionation between volatile elements. The concentrations all exceptionally high, ranging 0.43 17.7 MBq/kg, respectively. (239+240)Pu detected at low levels, 0.15 1.14 Bq/kg, with high (238)Pu/(239+240)Pu activity ratios 1.64-2.64....
We found four radiocesium-bearing microparticles (CsMPs) with high cesium (Cs) radioactivity in suspended particles collected from the Kuchibuto River Fukushima by filtering water during 2011–2016. The CsMPs were identified autoradiography and subsequently separated other "multiple wet separation method" using a NaI scintillation counter. present contained 0.426–2.827 Bq of 137Cs had chemical composition similar to that released accident at Daiichi Nuclear Power Plant (FDNPP). activity ratio...
Abstract Isotopic ratios of radioactive releases into the environment are useful signatures for contamination source assessment. Uranium is known to behave conservatively in sea water so that a ratio uranium trace isotopes may serve as superior oceanographic tracer. Here we present data on atomic $$^{233}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mrow/><mml:mrow><mml:mn>233</mml:mn></mml:mrow></mml:msup></mml:math> U/ $$^{236}$$...
A field survey was carried out soon after the Fukushima Dai-ichi Nuclear Power Plant accident. Gamma-ray emitting radionuclides and plutonium isotopes in a series of soil samples collected from heavily contaminated areas outside 20-km exclusion zone, as well Okuma Town adjacent to plant, were measured. Volatile such 131I, 134Cs, 137Cs contributed largely released radioactivity. Higher depositions these nuclides observed northwestern—including Iitate Village, which is at distance 25-45 km...
Abstract. Atmospheric deposition is one of the main sources dissolved iron (Fe) in ocean surfaces. processes are recognized as controlling fractional Fe solubility (Fesol%) marine aerosol particles. However, impact these on Fesol% remains unclear. One reasons for this lack field observations focusing relationship between and species In particular, effects organic ligands have not been thoroughly investigated observational studies. study, size-fractionated particles Pacific Ocean were...
Adsorption of radiocesium (RCs) on particulate matters in aquatic environment is important to understand its mobility and bioavailability. We here focused factors controlling partition RCs sediments Kuchibuto (Fukushima) Pripyat (Chernobyl) Rivers, though level water was much smaller than WHO guideline. Moreover, Cs speciation organic matter-clay mineral interaction were studied: (i) extended X-ray absorption fine structure showed that the contribution outer-sphere complex larger Chernobyl...
The quantification of long-lived radiocesium, 135 Cs, is essential for assessing the long-term safety high-level radioactive waste repositories.