Other mistake: Legasov is told that a 30km zone will be evacuated, shown as an ill-founded cabinet decision. Legasov himself proposes a 200km zone. At the end of the episode, Legasov appeals to Gorbachev (General Secretary) and asks him to evacuate 2600 square kilometers. It's easy to check that this is a 29km radius circle, nothing like the 200km he proposed.
Chernobyl (2019)
1 mistake in Open Wide, O Earth
Starring: Jared Harris, Jessie Buckley, Paul Ritter
Genres: Drama
Trivia: Despite the overall level of accuracy in the show, one deliberate choice was to use "comrade [surname]", rather than the full name as is typical in formal Russian address. It was felt it would be too distracting for viewers.