There is video footage of nearby villages in Pripyat, in the first week after the Chernobyl disaster. When I watch it there are villagers leading normal lives in normal clothing. Some Russian nuclear scientists pass by in full radioactive suits. Then there these clearly visible "flashes" in the air; I have looked on youtube but haven't found the video that I watched a long time ago. My layperson understanding is that these flashes are caused by an extreme amount of radiation.

Here's footage that shows the flashes in the air. They are subtle orangish flashes that are quick. But there's one for instance just after 3 minutes. This isn't the original one that showed the flashes better. Anyway: Chernobyl

From Wikipedia "Ionized-air glow":

Within minutes after the steam explosion that caused the Chernobyl accident at 01:23 local time, a number of employees at the power station went outside to get a clearer view of the extent of the damage. One such survivor, Alexander Yuvchenko, recounts that once he stopped outside and looked up towards the reactor hall he saw a "very beautiful" LASER-like beam of light bluish light, caused by the ionization of air, that appeared to flood up into infinity.

My questions are:

  • What amount of radioactive material is needed to make those flashes in the air happen?

  • Is radiation alone enough?

  • Are other factors such as weather, temperature or other prior chemical elements in the air needed to allow this flashing to happen?

  • $\begingroup$ Comments are not for extended discussion; this conversation has been moved to chat. $\endgroup$ – Loong Jun 30 '19 at 10:32
  • 3
    $\begingroup$ I worked in the nuclear industry for many years. As with anyone else who works with radiation (scientists, x-ray personnel etc) , we wear film badges which basically were just pieces of photographic film in a lightproof envelope and in a plastic holder. Radiation partials cloud show up as tiny spots on the film so they just develop the film out your badge every few weeks and see how many spots are on it to guess how much exposure you have had. The blue glow and flashes though, are normally associated with very high levels of radiation and atoms which have been 'excited' glow as they return to $\endgroup$ – Paul Jul 1 '19 at 14:12

The white flashes seen in the video are the result of radioactive contamination of the original film. Airborne radioactive particles were deposited onto the film and caused a local overexposure of the negative, quite similar to the historic experiment of Antoine Henri Becquerel. That's why the flashes only appear in individual spots in individual frames of the film. (This is also explained in the documentary The Battle of Chernobyl, which also contains these film excerpts.)

enter image description here

There was no corresponding visual phenomenon in the air that could be directly observed by people in Pripyat.

The ambient dose rates measured in 26 locations in Pripyat on 26 April 1986 at noon (i.e. about the time when the film was recorded) were about 0.038–1.9 R/h (i.e. about 0.38–19 mGy/h; with a geometric mean of 2.4 mGy/h). Such dose rates cannot cause any directly visible effects in air.

The flashes on the film are not related to any visual phenomenon that was caused by nuclear reactions, radiation, fire or other chemical reactions at the open reactor during the night of the accident.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.