The exciting story of the splitting of the atom, a scientific breakthrough of incalculable importance that ushered in the nuclear age, has a dark side: the many events in which people were exposed to radiation, both intentionally and by accident.
| Actor | Role |
|---|---|
 Emmanuelle YacoubiSelf - Narrator (voice) | Self - Narrator (voice) |
| MMasami YoshizawaSelf | Self |
| SSumio KonnoSelf | Self |
| OOscar GonzalesSelf | Self |
| AAlexander MartinSelf | Self |
| DDaniel HarrenSelf | Self |
| HHisako SakiyamaSelf | Self |
| RRoberto RequenaSelf | Self |
| SShigeru FukayaSelf | Self |
| MMasatoshi YamashitaSelf | Self |
| TToshikazu TaniwakiSelf | Self |
| KKazuma MasumotoSelf | Self |
| JJean-Marc CossetSelf | Self |
| LLeo FeurtSelf | Self |
| YYves LenoirSelf | Self |
| RRuiko MutoSelf | Self |
 Lewis StraussSelf (archive footage) | Self (archive footage) |
 Marie CurieSelf (archive footage) | Self (archive footage) |