Most people wouldn’t expect that a miniseries about a 1980s disaster in the Soviet Union would become the highest-rated TV show on IMDb, but the HBO miniseries Chernobyl managed to make it happen. And it’s one of the rare instances where the hype surrounding it is completely warranted. Chernobyl creates an atmosphere that flawlessly blends the banal bureaucracy of Soviet life with the apocalyptic horror of the Chernobyl nuclear reactor disaster.

Writing a five-episode series covering an event that affected the world and involved thousands of people is no easy feat, but writer Craig Mazin (in case you didn’t know, he’s the guy who wrote The Hangover and used to be Ted Cruz’s roommate, what a resume!) did a spectacular job of creating a story out of that mountain of experiences. However, like most TV shows that are a fictionalized version of real events, there are some aspects of the story that are literally fiction. And here are 10 of the most important details about the real disaster that the show leaves out.

The Real Acute Radiation Deaths Took Longer

It’s not surprising that the show and its writers changed the impression of how long acute radiation poisoning would take to kill someone, because obviously speeding it up speeds up the story itself. But the realities of acute radiation poisoning would have been somewhat different. The show was correct in that it would appear that a patient was getting better for a while before they start deteriorating, but the show made it seem like this happened over the course of a few hours or days. It took the real firefighter Vasily Ignatenko two weeks to succumb to his poisoning (which sadly was slightly different but just as gruesome as it was portrayed).

Valery Legasov Wasn’t Actually An Expert On RBMK Reactors

The real Valery Legasov was definitely an expert on nuclear physics and he was one of the highest-ranking Soviet scientists in the field, however, Legasov was actually pretty uninformed when it came to the actual construction and function of the RBMK nuclear reactors.

The miniseries itself actually does hint at this occasionally when Ulana Khomyuk informs Legasov that his assumptions are incorrect, however, the story overall presents him as the most qualified and informed person to do the job. And just like with many other Soviet crises, Legasov was an expert in his own field but not necessarily the ideal person for this particular job.

Many Of The Firefighters Didn’t Have Gear At All

The show definitely portrays the firefighters in Pripyat as being woefully unprepared for the horrors they were about to face when they went to put out the fire at the Chernobyl reactor, but the reality of the situation was actually even worse. Not that any proper firefighting gear would have protected them from the brutality of the broken reactor’s radiation, but in many cases, the firefighters fighting that fire didn’t even have that. Yes, some of them were properly outfitted in firefighting gear, but some of them had to fight the fire in their own clothes, some of them were on the scene wearing only tee shirts.

The System Of Propaganda Was Even Better Than They Made It Seem

The control over the media and information in the Soviet Union was far beyond what most of us can even imagine in our own lives. And the politicians in the upper echelons of the government who are portrayed in the Chernobyl miniseries make it very clear that this information is to be controlled at all costs. And although they couldn’t avoid the literal nuclear fallout getting out of the country, they did an excellent job of obfuscating all of the information about what actually went on when Chernobyl exploded, even now many former Soviet citizens are unsure of exactly what happened.

The Three Divers Weren’t Volunteers

Every form of fiction seeks out to find a hero for the story to inspire others and keep the audience engaged and compelled, and although Chernobyl was based on real events the writers did fuss with the reality of the situation to give accolades to the people involved in the situation.

It was undoubtedly a heroic act for those three divers to go drain the tanks beneath reactor four, they weren’t asked to volunteer and they weren’t even given any reward for doing the job. They simply worked at the plant and knew the area, so they were assigned the task and completed it.

Threats Weren’t Necessary To Get People To Do What They Were Told

The real-life Anatoly Dyatlov already makes for an excellent TV villain, and he does deserve to shoulder a fair bit of the blame for the absolute train wreck that Chernobyl became. But the writers of the Chernobyl miniseries leaned into that villainy even more than necessary. The threat of doing something or else being shot is actually a bit of a recurring theme throughout Chernobyl, but the reality of the situation is that it wasn’t actually necessary to do so. The show itself acknowledges that people in the Soviet Union are socialized to do whatever they’re told, and the same attitude applied to the entire Chernobyl disaster.

Communism Still Had Its Hierarchies

Chernobyl has been rightfully praised for everything that it does right, and it does do a lot of things right. People who were alive in the Soviet Union during that era have been astonished to see how accurately the production has managed to reproduce the settings and overall visual style of that time. However, there are some details that the show gets wrong, namely that every single person is treated exactly the same. Yes, they’re living under communist rule, but someone like Valery Legasov would have a very different living space than most of the other characters that we see in the miniseries.

Ulana Khomyuk Wasn’t Real

The character of Ulana was completely made up by the writers of the miniseries, and she was intended to serve as a stand-in for the thousands of Soviet scientists who actually did do all of the work trying to fix Chernobyl.

It’s an understandable move, because including every single person who played a part would be impossible, and it’s more narratively convenient to narrow things down. However, Ulana is clearly meant to serve a more heroic role in the story as well, which makes for a more satisfying tale but is unfortunately an inaccurate representation of how nearly everyone involved in the crisis behaved.

Chernobyl Was In Some Ways Inevitable

In his dramatic (and fictionalized) presentation at the trial at the end of Chernobyl, Valery Legasov explains that the entire design of the RBMK reactors are faulty and that this kind of result was bound to happen at some point, which is absolutely true. But the overall structure of the Soviet society and government also ensured that some level of disaster was pretty much inevitable as well. The Soviet system always prioritized productivity over humanity, and in a system like that, it is a near guarantee that there will be a serious loss of life as a result of those priorities.

The Truth Of Chernobyl Is Still Buried

The Soviet control over the media in their country and the spread of information was extraordinary. As Zharkov dramatically explains after the disaster, if it means cutting the phone lines and trapping people in the city, then that’s what must be done to protect the country. And because the cover-up of Chernobyl was so great, even now the full story is not something that has come together. There are still mysteries that are left to be uncovered, and even the people who were face to face with the disaster only know their experiences of the story, they don’t even know a fraction of what really happened.