I am not an expert, but it’s worth noting that the kp index has a maximum value of 9. So though the Carrington event had a kp of 9, its intensity on the related (but not capped) HP30/HP60 scale [1] would likely have been higher.
[1] https://kp.gfz.de/en/hp30-hp60
Casting (who played who), acting, costumes and scenography (where did they get all these '80 soviet cars), and choice of scenes to film.
I had my hair rising when the guy cleaning roof of a building neighboring the reactor got stuck in deadly radiation zone for 4x the allowed 13 seconds. "You're dead comrade."
