National Governmental Agencies
- Japan Atomic Energy Commission
- Nuclear Regulation Authority
- Nuclear Regulation Authority: Emergency information
- Monitoring information of environmental radioactivity level (Nuclear Regulation Authority)
- National Institute for Environmental Studies
- Ministry of Economy, Trade and Industry
- Meteorological Research Institute, Japan Meteorological Agency
- Hydrographic and Oceanographic Department, Japan Coast Guard
- Ministry of the Environment
Educational
Research Institutes, Universities, Public Interest Corporations
- Japan Science and Technology Agency
- National Institute for Fusion Science
- High Energy Accelerator Research Organization (KEK)
- Japan Atomic Energy Agency
- Quantum Life and Medical Science Directorate, National Institutes for Quantum Science and Technology (formerly National Institute of Radiological Sciences)
- National Institute of Public Health
- National Institute for Agro-Environmental Sciences
- Japan Fisheries Research and Education Agency
- National Institute of Advanced Industrial Science and Technology
- Low Level Radioactivity Laboratory, Institute of Nature and Environmental Technology, Kanazawa University
- National Institute for Environmental Studies
- Institute for Integrated Radiation and Nuclear Science, Kyoto University
- Department of Nuclear Engineering and Management, School of Engineering, The University of Tokyo
- Research Institute for Radiation Biology and Medicine, Hiroshima University
- Marine Ecology Research Institute
- Nuclear Safety Technology Center
- Nuclear Safety Research Association
- Central Research Institute of Electric Power Industry
- Japan Atomic Energy Relations Organization
- Japan Chemical Analysis Center
- Radiation Effects Research Foundation
- Institute of Radiation Measurements
Local Governments
Aomori
Miyagi
Fukushima
Ibaraki
Kanagawa
Niigata
Ishikawa
Fukui
Shizuoka
Kyoto
Shimane
Okayama
Ehime
Electric Power Companies
- The Federation of Electric Power Companies of Japan
- Hokkaido Electric Power Co., Inc.
- Tohoku Electric Power Co., Inc.
- Tokyo Electric Power Company Holdings
- Chubu Electric Power Co., Inc.
- Hokuriku Electric Power Company
- Kansai Electric Power Co., Inc.
- The Chugoku Electric Power Co., Inc.
- Shikoku Electric Power Co., Inc.
- Kyushu Electric Power Co., Inc.
- The Japan Atomic Power Company
- J-POWER
- Japan Nuclear Fuel Limited
- Nuclear Safety Network (NSnet)
Other
- Sapporo Association of Radiological Technologists
- Panel for Study of Radiation and Health
- Japan Nuclear Technology Institute