This is not a film, but due to its brevity and low number of chapters (5) it could be considered a film as it can be watched in one afternoon.
This is a miniseries directed by American Craig Mazin.
It has won numerous awards: Golden Globe for Best Miniseries and Best Supporting Actor (Skarsgård); BAFTA Television Award 9 awards; Emmy Award 10 awards, etc.
It tells the story of the most important nuclear accident on European soil.
On 26 April 1986, reactor 4 at the Chernobyl nuclear power plant in Ukraine (then part of the Soviet Union) exploded in mid-air, releasing an unprecedented amount of radioactive material into the open air.
The play tells the story of many Soviet citizen "liquidators" who sacrificed their lives or their health to return the radioactive waste from the reactors to the nuclear power plants.
(There may be disagreements about whether this account is true or not, but that is another debate, it is about enjoying this masterpiece).
Of particular note is the music by the great Hildur Gudnadóttir, an Icelandic cellist, who also scored The Joker. The music keeps you in tension during all the chapters.