Former Soviet General Nikolai Tarakanov (Ralph Ineson), gave several interviews about the series, which fascinated the Russian public upon its release. Tarakanov took issue with a few small details but otherwise praised the series and its depiction of the events, and stated he was portrayed accurately. Tarakanov, 85 in 2019, suffers from chronic disease related to radiation exposure from his time in Chernobyl.
Initial filming started on May 13, 2018, in Fabijoniskes, a residential district in Vilnius, Lithuania, which was used to portray the Ukrainian city of Pripyat, since the district maintained an authentic Soviet atmosphere. At the end of March, production moved to Visaginas, Lithuania, to shoot both the exterior and interior of the Ignalina Nuclear Power Plant, a decommissioned nuclear power station that is sometimes referred to as "Chernobyl's sister" due to its visual resemblance and the nuclear reactor design used at both Chernobyl and Ignalina (RBMK nuclear power reactor).
Parallel to the show, after each episode's release, HBO released a podcast for each episode, "The Chernobyl Podcast," in which creator/writer Craig Mazin talks with Peter Sagal about many behind-the-scenes details about the writing and the production, and explained more about the history and real events behind the episode's storyline and the characters. Because of the series' underlying theme of lies, Mazin decided to do the podcast specifically to address discrepancies between historical fact and fiction, and which elements depicted were fictional and why.
Creator/writer Craig Mazin originally intended for the characters to speak with Russian accents, but quickly abandoned this idea after the interview process began, as the accents became a distraction for the actors.
Astonishingly, the three remaining reactors at Chernobyl remained operational and manned after the 1986 explosion of Reactor No. 4. Chernobyl Reactor No. 2 was shut down after a fire in 1991, Reactor No. 1 was shut down in 1996 after pressure from foreign governments, and Reactor No. 3 was closed in 2000. The decommissioning process, whereby the facility is dismantled to the point that it no longer requires radiation protection, is ongoing as of 2024. It is estimated that decommissioning will not be completed until 2065, 79 years after the disaster.