From the quote(having not watched the vid) it doesn't say 200k people died ,it says 200k people took part, 600k liquidators in total were used, (some say 800k but 200k apparently cleaned up an essentially non radiactive site). It says 200k people were involved and the radiation was at a lethal level, not that it killed them, earlier guys often wore no protection later guys DID wear protection.
Keep in mind this was 24 years ago so roughly the oldest people would be 50years old now. 60k of those 600k are dead, 1 in 10 way to young, thats FAR beyond normal levels of cancer deaths and this will be skewed as a much lower number were at Chernobyl and the worst effected sites, lots were much further away, probably meaning 1 in 5, maybe less, died from being in the highest radiation area. Another 165k of them or so, are disabled now, so you've got basically 1/3rd of them dead or disabled, and a lot of them didn't really that close.