Database for Radioactive Substance Monitoring Data
Japan Atomic Energy Agency (JAEA) collects and discloses the results of measurement of air dose rates in Fukushima Prefecture and neighboring prefectures due to the accident at TEPCO's Fukushima Daiichi NPP, which are disclosed by the Nuclear Regulation Authority and Fukushima Prefecture, etc., as well as the results of analysis of radioactive materials in land soil (soil surface and in soil), sea area (sea water, sea bottom soil), rivers (river water, river bottom soil) and underground water, food (agricultural, forestry, livestock, marine products, etc.). The results are made public so that users can intuitively grasp the situation by visualizing the large volume of data.
Website Service Restoration Notice
Due to a system outage, the Japan Atomic Energy Agency website was temporarily unavailable from approximately 3:13 p.m. on Friday, February 6, 2026. Service was fully restored at 3:00 a.m. on Saturday, February 7, and the website is now operating normally.
We apologize for any inconvenience this outage may have caused and appreciate your patience and understanding.
Website Migration (February 3)
Thank you for using this website.
This database will be migrated to RAMDAS, operated by the Nuclear Regulation Authority, as outlined below.
- New website URL: To be announced at a later date
- New website launch date: Tuesday, March 3
On and after the launch date of the new website, the functions of this website at the current URL will no longer be available.
We apologize for any inconvenience this may cause and appreciate your understanding.
Contents
Measured air dose rate data, i.e. the amount of radiation per unit time in the air (Air absorbed dose rates[nGy/h], or ambient dose equivalent rate[μSv/h]). The air dose rate is continuously observed around the nuclear facilities to detect abnormality including radioactive substances leakage.
In order to confirm the condition in the depth distribution of radioactive cesium comprehensively mainly within a 80 km radius of the Fukushima Dai-ichi NPP, we collected soil samples at various depths using a scraper plate which is the standard method to measure radioactive nuclides in soil profiles employed at IAEA and researched the depth distribution of radioactive cesium.
Measured data of radioactive substances released to the environment by Fukushima Daiichi NPP accident in seawater.
Measured data of radioactive substances released to the environment by Fukushima Daiichi NPP accident in marine soil.
Measured data of radioactive concentration deposited on the surface soil after TEPCO's FDNPP accident.
Measured data of radioactive substances released to the environment by Fukushima Daiichi NPP accident including ground deposition, radioactive concentration of soil sample and environmental sample, and radioactive substance depth distribution.
Measured data of radioactive substances in the Atomosphere Dust (floating).
Measured data of radioactive substances in the Atmosphere Dust (fallout) and rainfall.
Measured data of radioactive substances in the water including river water and lake water.
Measured data of River Bottom Sediment Quality, Environment around the river, and Rivers Suspended Sediment.
Data of radioactive substances measured to maintain our safety and security of drinking water.
Data of radioactive substances measured to maintain our safety and security of Wild Birds and Animals.
Measured data of the radioactive cesium on the bottom of the sea by ship towing monitoring.
Data of radioactive substances measured to maintain our safety and security of food including agricultural products, livestock products, fishery products, and processed food.
Data of radioactive substances measured to waste, sewage sludge, etc. contaminated by radioactive materials.
Updates All Updates
The survey results have been added to the following measurement items.
・Radioactive Concentration-SeawaterーSeawaterーResults of Environmental Radioactivity Monitoring by Fukushima Prefecture (Ports and Sea Surface Fishing Ground) (Sea Water)
・Radioactive Concentration-SeawaterーSeawaterーResults of Environmental Radioactivity Monitoring by Fukushima Prefecture (Ports and Sea Surface Fishing Ground) (Sea Water)
・Radioactive Concentration-SeawaterーSeawaterーDistribution of Radioactivity Concentration in the Seawater around Fukushima Dai-ichi NPP by TEPCO
・Radioactive Concentration-SeawaterーSeawaterーReadings of Sea Area Monitoring (Seawater) by NRA
・Radioactive Concentration-SeawaterーSeawaterーMonitoring Results of Sea Area related to ALPS-treated water (Seawater) by MOE
・Radioactive Concentration-Marine SoilーMarine SoilーReadings of Sea Area Monitoring (Marine Soil) by NRA
・Aquatic organismーAquatic organismーMonitoring Results of Sea Area related to ALPS-treated water (Aquatic Organisms) by MOE
・Aquatic organismーAquatic organismーReadings of the Monitoring on Radioactivity Level in fish and shellfish by TEPCO
・Aquatic organismーAquatic organismーReadings of the Monitoring on Radioactivity Level in Fisheries Products by Fisheries Agency
The survey results have been added to the following measurement items.
・Radioactive Concentration-SeawaterーSeawaterーDistribution of Radioactivity Concentration in the Seawater around Fukushima Dai-ichi NPP by TEPCO
・Radioactive Concentration-Marine SoilーMarine SoilーDistribution of Radioactivity Concentration in the Marine Soil around Fukushima Dai-ichi NPP by TEPCO
・Aquatic organismーAquatic organismーReadings of the Monitoring on Radioactivity Level in Fisheries Products by Fisheries Agency
The survey results have been added to the following measurement items.
・Radioactive Concentration-SeawaterーSeawaterーResults of Environmental Radioactivity Monitoring by Fukushima Prefecture (Ports and Sea Surface Fishing Ground) (Sea Water)
・Radioactive Concentration-SeawaterーSeawaterーMonitoring Results of Radioactive Substances in Public Water Areas (Seawater) by MOE
・Radioactive Concentration-SeawaterーSeawaterーDistribution of Radioactivity Concentration in the Seawater around Fukushima Dai-ichi NPP by TEPCO
・Radioactive Concentration-SeawaterーSeawaterーResults of Environmental Radioactivity Monitoring by Fukushima Prefecture (Ports and Sea Surface Fishing Ground) (Sea Water)
・Radioactive Concentration-Marine SoilーMarine SoilーMonitoring Results of Radioactive Substances in Public Water Areas (Marine Soil) by MOE
・Radioactive Concentration-Marine SoilーMarine SoilーResults of Environmental Radioactivity Monitoring by Fukushima Prefecture (Ports and Sea Surface Fishing Ground) (Marine Soil)
・Radioactive Concentration-Marine SoilーMarine SoilーDistribution of Radioactivity Concentration in the Marine Soil around Fukushima Dai-ichi NPP by TEPCO
・Aquatic organismーAquatic organismーReadings of the Monitoring on Radioactivity Level in Fisheries Products by Fisheries Agency
・Radioactive Concentration-SeawaterーSeawaterーMonitoring Results of Seawater monitoring in Tokyo Bay by MLIT
・Radioactive Concentration-SeawaterーSeawaterーSeawaterーMeasurements of subdrain, groundwater drain, and groundwater bypass by Fukushima Prefecture
This is the Database for Radioactive Substance Monitoring Data renewed and released on October 1, 2021. Click here for the old site.