Maureen Kearney’s story is unbelievable. It is a story of unbelief, in fact — of denial, cover-ups, corruption and injustice directed at a small woman who was just doing her job. She’s played with an electric stillness by the great Isabelle Huppert in Jean-Paul Salome’s Venice Film Festival Horizons title The Sitting Duck (La Syndicaliste). There are still plenty of people who openly doubt her story, including people on her own side of politics. Perhaps it would be easier all round if it weren’t true.

Kearney was a union officer working within the partly French government-owned energy company Areva, which included a significant nuclear reactor business with projects all over the world. Kearney was no Karen Silkwood; she posed no threat to the concept of nuclear power. She maintains she was targeted when...