What is "Database for Radioactive Substance Monitoring Data"?


The Japan Atomic Energy Agency (JAEA) is collecting monitoring data (published by various organizations including the Secretariat of the Nuclear Regulation Authority and Fukushima Prefecture) related to the Tokyo Electric Power Company (TEPCO) Fukushima Daiichi Nuclear Power Plant accident, including air dose rate, and radioactive concentration (ground surface, soil, seawater, marine soil, river water, river sediment, groundwater, and food). JAEA visualized these data and publicly released in this website so that users can comprehend information intuitively.

What does this Database provide?


  • Based on the results from radioactive substance surveys, the database displays distribution maps of radioactivity concentration or dose rate.
  • Based on the results from radioactive substance surveys, the database displays graphs of time change of radioactivity concentration or dose rate.
  • Download of survey results of radioactive substances is available with various file formats including CSV, XML, and KML

  • How to view distribution maps Page Top


    1. Database top page

    The top page displays category of surveys

    • (a) Choose the survey you want to see

    2. Registered Data Catalogue

    This page displays a list of surveys, with survey title, conductor, survey period, and brief a explanation for each survey.

    • (b) Choose the survey that shows ”Map” and click the title.

    3. Portal page

    This page shows a thumbnail, brief explanation, files for download, and reference links for each survey.

    • (c) Using the pulldown selector, (d)filter thumbnails.
    • (e) Drag and slide thumbnails
    • (f) Click the thumbnail of the survey you are interested in.

    4. Distribution map

    An enlarged distribution map is displayed.

    • (g) Click right or left arrow to see next map.

    How to view time change graphs Page Top


    1. Database top page

    The top page displays category of surveys

    • (a) Choose the survey you want to see

    2. Registered Data Catalogue

    This page displays a list of surveys, with survey title, conductor, survey period, and brief a explanation for each survey.

    • (b) Choose the survey that shows "Graph" and click the title.

    3. Portal page

    This page shows a thumbnail, brief explanation, files for download, and reference links for each survey.

    • (c) Using the pulldown selector, (d)filter thumbnails.
    • (e) Drag and slide thumbnails
    • (f) Click the thumbnail of the survey you are interested in.

    4. Time change graph

    Initially, only the map is displayed and graph section says “Select a marker on the map”.

    • (g) Select markers on the map that you would like to plot time change data for in the graph. The color of the map markers will match the colors used in the graph.
    • (i) Adjust the displayed time period using the slider.
    • (j) Zoom display period (1m: Last one month, 3m: Last three month, 6m: Last six month, YTD: Year-to-date, and 1y: Last one year).
    • (k) Using the selector, choose the item to draw a graph for (for example, Height in air dose rate measurement, or Nuclide in radioactivity substance analysis).
    • (l) Click the 'Map' or 'Satellite' button to change the display mode of the map.
    • (m) Choose dot size in the graph by clicking S (small), M (medium), or L (large). Clear chart by clicking “Clear chart”.

    How to download files. Page Top


    1. Download file

    The section of download files shows up under both distribution maps and time change graphs

    • (a) Click the link of the file you are interested to download.
    • (b) Coordinates described in the data were derived based on the Japanese World Geodetic System JGD2000 (essentially identical to the World Geodetic System WGS84). In cases where the data released from the original source organization were described using the Former Japanese Geodetic System, the coordinates were converted to the Japanese World Geodetic System JGD2000.

    2. Unified Format

    In order to facilitate comparative analysis between different survey items, we prepared CSV files with common headers. The header structure is as follows.

    Unified format for air dose rate measurement data

    Field No. Header Name
    1 Grid Code
    2 Latitude
    3 Longitude
    4 Prefecture
    5 City
    6 Measurement Date and Time
    7 Air dose rate at a height of 1 m

    Unified format for radionuclide concentration measurement data

    Field No. Header Name
    1 Grid Code
    2 Latitude
    3 Longitude
    4 Prefecture
    5 City
    6 Measurement Date and Time
    7 137Cs Deposition density
    8 137Cs Detection limit
    9 137Cs Measurement Error
    10 134Cs Deposition density
    11 134Cs Detection limit
    12 134Cs Measurement Error

    3. Reference

    The reference section shows up under the download section

    • (c) Click the link of the reference you would like to see.