Bernd Doppler was the father of Helge Doppler. He was the director of the nuclear plant until he was replaced by Claudia Tiedemann in 1986.
Bernd is a promoter of the idea of building a nuclear power plant in Winden and on at least one occasion he speaks passionately in favour of this project at a meeting with journalists. He even goes as far as having himself, his wife and son shown on a poster promoting nuclear energy.
Although Bernd visibly limps and is forced to use a stick to walk, this doesn't hamper his mobility.
In her conversation with Noah, Greta states she is uncertain if Helge is really Bernd's son, but Bernd seems much more caring to the boy than herself. However, upon hearing about dead bodies at the construction site (presumably Erik and Yassin), Bernd leaves Helge, as he is more concerned about the future of the power plant.
Bernd, who has apparently served as the director of the plant from its launch, retires from his position. He strongly supports Claudia Tiedemann as his successor. Confronted by Claudia over reports, he declares that he believes Claudia to be the right person to cover up for the plant's problem in the post-Chernobyl era. He later admits to Claudia that there was an incident in the power plant.
When moving out of his office, Bernd collects his private belongings, including photos of himself, Greta and Helge and another one of adult Helge. This suggests his lasting affection for his family. Strikingly, his alleged grandson, Peter is absent from the photos.
In 1986, Bernd is disabled and in a wheelchair, however the reason of his disability is unknown. Bernd lives in the Doppler household in 1986, seemingly alone (suggesting that Helge lived in the cabin by that time). It is unknown when and how the house is transferred to the Tiedemanns to become the hotel owned by Regina.