Just before seven on the morning of Monday 28 April 1986, the day shift arriving at the Forsmark nuclear plant in Sweden set off the radiation alarms at the gate. The staff assumed Forsmark was leaking. It was not: the radiation was on their shoes. Two days earlier, at 1:23 in the morning, a reactor had exploded at Chernobyl in Ukraine, and Moscow was still denying that anything had happened. In August the Soviet Union told the world's nuclear experts in Vienna who was to blame: the men on the night shift. The experts largely accepted it.

Six years later, the same experts published a second report. It said the 1986 account had "laid blame almost entirely on actions of the operating staff", that some of what had been called violations "were in fact not violations", and that the reactor's emergency shutdown had a flaw found years before and never fixed. It still called some of the crew's decisions "most ill judged". This film follows the evidence from the shoes at Forsmark in to the control room, then back to the night itself, to Vienna, to the second report, and to the television series most of us remember, checked against the record: what the night shift did, what the reactor did, and what the emergency button really did when it was pressed.

About two hours long, narrated slowly enough to fall asleep to or listen to closely.

A note on sensitive content: two people died within hours and 28 more of radiation sickness within months, and the long-term toll is debated. Deaths are stated plainly and are never shown.

Chapters
0:00 Cold Open: Shoes at Forsmark
4:06 Four Sentences
12:17 Three Days
20:36 Fourteen Men
27:54 The Machine
35:10 Two Warnings
42:01 The Grid Controller
48:51 Thirty Megawatts
56:43 Thirty-Six Seconds
1:04:34 Five Thousand Tons
1:11:15 The Shelter
1:17:31 Vienna
1:25:11 The Second Report
1:33:57 On Television
1:44:29 Two Kinds of Number
1:54:42 The Arch

Watch the illustrated version, with real archive photographs: https://youtu.be/HI4v77LvpdI

Sources are listed in the YouTube description. Narration uses an AI voice.