Idea:
A Block that emits a redstone signal proportional to the radiation per s of the chunk.
Connected comparators show the total recieved amount of radation of the sensor in the chunk.
This internal counter for the total radiation recieved can be reset by applying a redstone signal to the bottom of the sensor.

Possible uses:
Radiation alarm when connected to a siren.
Automatic shutdown protokol when connected to vault doors.
Automatic counterstrike when connected to lauchpad and an enemy nuke hits nearby.
Trigger emergency measures of reactors or other important equipment.
Can be used to subject entities like animals to specific doses of radiation for "science" when connected to togglable radiation souce.

just use ambience radioation generator energy detector and redstone lamp

OR just use the fucking geiger counter block, it does exactly that

yes

The geiger counter block is compatible with OpenComputers, just use that, or you could use an Ambience Radiation Generator and just put a Power Detector by it.