About us

The Environmental Dynamics Research Group develops and refines models, prediction systems, and analytical methods to assess the environmental impacts of radioactive material releases and contamination events across the atmosphere, land, and oceans.
To ensure model accuracy, we collect and analyze environmental samples through targeted surveys and fieldwork.
Our research also investigates material cycling using both radioactive and stable isotopes, further validating our models and contributing to solutions for pressing global challenges, including climate change.

News

Research

Environmental science
digital twins

We are engaged in research and development to understand the environmental behavior of environmentally hazardous substances, including radioactive substances. We have developed models and systems to simulate the transfer process of various substances in the atmosphere, land, hydrosphere, and biosphere, and aim to understand the material circulation in each sphere. In recent years, we have been working on research and development of environmental behavior digital twins that can comprehensively evaluate the environmental behavior of substances in each sphere by combining these multiple models.

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For other related research, please check JOPSS and researchmap of our group members.

Environmental material
circulation using
radioactive materials
and stable isotopes

Armed with analytical techniques for radioisotopes and stable isotopes in the environment, we are using a unique approach that uses them as tracers to understand the actual state of material circulation, elucidate mechanisms, and predict responses to climate change. We aim to evaluate the impact of substances released by human activities on the environment based on new knowledge gained from not only observations in real environments but also from laboratory experiments that simulate environmental changes, targeting a wide range of fields from forests and farmland to coastal oceans.

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Carbon cycle research in forests and farmlands using radiocarbon (14C) as a tracer

Ocean circulation structure and material circulation using artificial and natural radioisotopes as tracers

  • Evaluation for carbon storage capacity of coastal sediments using radioisotopes
  • Food web analysis in freshwater ecosystems using radiocarbon

Environmental dynamics of radionuclides from nuclear facilities

  • Developing a highly sensitive analytical method for iodine-129 in environmental samples
  • Dynamics of stable and radioactive iodine in marine and inland waters

For other related research, please check JOPSS and researchmap of our group members.

Fukushima Daiichi
Nuclear Power Plant
Accident

We have conducted surveys and research on the radioactive materials released during the Fukushima Daiichi Nuclear Power Plant accident. How did the radioactive materials spread into the environment immediately after the accident? And what will become of these radioactive materials in the future? To answer such as questions, we have been working to understand the current state of the radioactive materials resulting from the accident and predict their behavior through surveys of forests, oceans, and rivers, as well as laboratory experiments and computer simulations.

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For other related research, please check JOPSS and researchmap of our group members.

Fukushima Daiichi Nuclear Power Plant Accident Archives

Instruments

Member

Group reader

Hideyuki Kawamura

Field of expertise

Marine environment simulation, Oceanography

Degree

Doctor of Science

Topics

  • Development of the marine radionuclide migration model SEA-GEARN
  • Simulation of ocean diffusion of radioactive materials from the Fukushima nuclear accident
  • Simulation of drifting debris from the Great East Japan Earthquake
  • Development of an emergency marine environment radioactivity assessment system
  • Development of a material circulation prediction model for the Sea of Japan
Manager

Hiroaki Terada

Field of expertise

Atmospheric dispersion simulation, Meteorology

Degree

Doctor of Engineering

Topics

  • Improvement of the worldwide version of system for prediction of environmental emergency dose Information WSPEEDI
  • Development and application of the atmospheric dispersion database system WSPEEDI-DB
  • Reconstruction of Atmospheric Release and Dispersion of Radioactive Materials by Computer Simulation－Contribution to the Refinement of Dose Assessment in the Early Stage of the Accident by Improving the Dispersion Calculation Optimization Method－
  • Improved Capability for Atmospheric Dispersion Simulation－Enhancement of Prediction Performance of WSPEEDI-II for Middle- Range Scale Dispersion using Krypton-85 Measurement Data－

Mariko Andoh

Field of expertise

Environmental radioactivity, Isotope biogeochemistry

Degree

Doctor of Science

Topics

  • Research into the behavior of substances in the environment using radiocarbon and stable isotopes
  • Spatial Variation in Radioactive-Cesium Deposition Caused by Topographical Factors－Detailed Examination of the Air-Dose Rate in a Mountainous Forest Catchment－

Katsunori Tsuduki

Field of expertise

Computer system administration

Degree

Doctor of Engineering

Topics

  • Computer Management

Takashi Suzuki

Field of expertise

Ocean survey, Iodine-129, Accelarator Mass Spectrometry

Degree

Doctor of Science

Topics

  • Elucidation of factors affecting the concentration of iodine-129 in seawater discharged from nuclear facilities
  • Elucidation of transport for radioactive iodine in the global-scale transport and coastal marine environments
  • Development of a highly sensitive analytical method for iodine-129 in environmental samples

Takahiro Nakanishi

Field of expertise

Geochemistry, Environmental radioactivity, Oceanography

Degree

Doctor of Environmental Earth Science

Topics

  • Research into the behavior of substances in the environment using radionuclides and stable isotopes
  • Research into the environmental behavior of radionuclides originating from the Fukushima Daiichi Nuclear Power Plant accident

Hiromasa Nakayama

Field of expertise

Local scale atmospheric dispersion simulation

Degree

Doctor of Engineering

Topics

  • Development of a local area high resolution atmospheric dispersion and dose assessment system
  • Radiological and nuclear terrorism

Masakazu Ota

Field of expertise

Material transports in land surface system

Degree

Doctor of Engineering

Topics

  • Development of a land surface model
  • Model simulation for transports of tritium, carbon-14, radioiodine, and radiocesium in atmosphere-vegetation-soil system
  • Carbon cycling in land surface ecosystems (e.g. forests)

Masanao Kadowaki

Field of expertise

Atmospheric dispersion modeling, Atmospheric chemistry

Degree

Doctor of Science

Topics

  • Radioactive iodine cycle in the environment using a chemical transport model
  • Development of a multi-scale atmospheric dispersion model

Tsubasa Ikenoue

Field of expertise

Environmental Engineering, Hydrology, Simulation of environmental fate

Degree

Doctor of Engineering

Topics

  • Prediction of radioactive cesium behavior in land and rivers for 30 years after the TEPCO Fukushima Daiichi Nuclear Power Plant accident
  • Evaluation of the impact of radiocesium supply through rivers to coastal waters off Fukushima on radiocesium behavior in seabed sediment

Rongwei Sun

Field of expertise

Environmental chemistry, Inorganic chemistry

Degree

Doctor of Engineering

Topics

  • Mineral function in facilitating soil carbon sequestration

Kenta Irie

Field of expertise

Meteorology, Tropical cyclone, Urban precipitation

Degree

Doctor of Science

Kanako Miyazaki

Field of expertise

Inorganic chemistry

Degree

Master of Science

Visiting Researcher

Toru Tanimori

Field of expertise

γ-Ray Astrophysics, High energy physics

Degree

Doctor of Science

Topics

  • Establishment of a 3D dose diffusion prediction method and development of a method for investigating inside structures using differences in gamma-ray transmittance
Collaborating Engineer

Hiromi Nemoto

Topics

  • Development of the atmospheric dispersion prediction system WSPEEDI
Collaborating Engineer

Hiroaki Suda

Topics

  • Environmental Sample Analysis
Research Assistant

Mutsumi Shimizu

Topics

  • Environmental Sample Analysis
Research Assistant

Misuzu Kaminaga

Topics

  • Environmental Sample Analysis
Research Assistant

Kikuko Yoshigaki

Topics

  • Environmental Sample Analysis
Secretary

Eiko Nishimura

Jun Koarashi

Field of expertise

Isotope biogeochemistry, Radioecology

Degree

Doctor of Engineering

Topics

  • Terrestrial carbon cycle and its feedback to climate change
  • Behavior of radionuclides in the environment

Azusa Nagakubo

Field of expertise

Environmental science simulation

Degree

Doctor of Engineering

Publications

Access・Contact

Japan Atomic Energy Agency
Nuclear Science Research Institute
Nuclear Science and Engineering Center
Research Group for Environmental Science
2-4 Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195, Japan
Tel: (+81)-29-282-5100