I have been looking for the same sensor as @norcis for the same reason - Astravets Nuclear Power plant
I found that the European Commission publishes this data for all European countries on their website here approximately every hour: https://remon.jrc.ec.europa.eu/
A little bit of tinkering and I found the API endpoint that returns the latest data (looks to be updated hourly) in JSON. Sadly the data isn’t fully real-time but it gives average and maximum values that I will be using for the automations.
It is possible to track a specific station or an area of stations. For instance, I am tracking max and avg value in Kalveliai station (nearest station to the nuclear plant) and also getting an average of all stations in Vilnius area.
- platform: rest
name: Radiation in Kalveliai station
resource: https://rewidget.jrc.ec.europa.eu/v3/objects/point?id=LT21042
scan_interval: 1800 # check every 30 minutes
unit_of_measurement: nSv/h
value_template: '{{ value_json.avg.val }}'
headers:
Content-Type: application/json
- platform: rest
name: Radiation in Kalveliai station Max
resource: https://rewidget.jrc.ec.europa.eu/v3/objects/point?id=LT21042
scan_interval: 1800 # check every 30 minutes
unit_of_measurement: nSv/h
value_template: '{{ value_json.max.val }}'
headers:
Content-Type: application/json
- platform: rest
name: Radiation in Vilnius Area
resource: https://remap.jrc.ec.europa.eu/api/maps/polygon?id=622_294&zoom=7
scan_interval: 1800 # check every 30 minutes
unit_of_measurement: nSv/h
value_template: '{{ value_json.avg }}'
headers:
Content-Type: application/json
- platform: rest
name: Radiation in Vilnius Area Max
resource: https://remap.jrc.ec.europa.eu/api/maps/polygon?id=622_294&zoom=7
scan_interval: 1800 # check every 30 minutes
unit_of_measurement: nSv/h
value_template: '{{ value_json.max }}'
headers:
Content-Type: application/json
To change a station, simply replace LT21042 with the station identifier that could be found by looking at the Advanced map: https://remap.jrc.ec.europa.eu/Advanced.aspx
For tracking a hexagon area you may want to look at the simple map (https://remap.jrc.ec.europa.eu/Simple.aspx) and watch what requests browser is making when clicked on a chosen hexagon and replace the
id and zoom values in the resource: