The boundaries of what documentary filmmakers can do seem to expand all the time and this year the 45 or so documentaries shown at the Berlinale gave a taste of where the format is going.

As might be expected of this most political of major European film festivals, documentaries about the war in Ukraine loomed large, with at least a half dozen focusing on Ukrainians or the conflict.

Other noteworthy offerings included a main competition movie, “Sur l’Adamant” (On the Adamant), an intimate look at mentally ill people who use the eponymous floating mental-health clinic moored on the Seine river in Paris.

“Nomades du Nucleaires” (Nuclear Nomads), also French, followed itinerant workers who do maintenance in radioactive areas of French nuclear plants. They are well paid by blue-collar standards — up to 7,000 euros ($7,400) a month, one of them says — but the riskiness of the job, the worries about getting the next one, separation from their families — if they’re not divorced — and their nomadic lifestyle in caravans take a toll.

Lest recent events be forgotten, the Italian “Le Mura di Bergamo” (The Walls of Bergamo) examined the devastating impact of Covid on the northern Italian city of 120,000. An astounding 6,000 people died in the first two months of the pandemic, making it perhaps the worst per-capita Covid death toll in the world. Half the film is devoted to therapeutic discussion groups survivors hold on grassy knolls in the city’s 16^th-century walls.

Documentaries on less portentous topics were on offer, too, including a biopic about the disco diva Donna Summer, and a career-retrospective on American folk singer Joan Baez. For name recognition, there was Sean Penn’s “Superpower”, the actor’s personalised take on the Ukraine war, and “Kiss the Future”, a lookback at a fabled 1997 concert by Irish supergroup U2 in Sarajevo.

The bulk of the films, though, had strong social or political themes — often both.

Nicolas Philibert, the French director of “Sur l’Adamant”, who had an art-house hit two decades ago with “Etre et Avoir” about an elementary school in rural France, said documentaries sometimes allow people who appear in them to open up more than they otherwise would. He also said the subjects who were filmed, talking about themselves or doing their daily routines, knew what was happening.

“These people on the Adamant I filmed talked to us…they are very aware of what they’re talking about and their presence in connection with the filmmaker who’s there,” Philibert said.

The film opens with an on-board musical event where François, a middle-aged man with a gravely voice, sings the French rock song “The Human Bomb”. It could be any cafe’s karaoke night, until Philibert’s camera catches up with François later on and he says: “Only strong meds keep me talking to you…otherwise I think I’m Jesus.”

Another man with musical talent, probably in his 70s, sings a song he has composed and accompanies himself on a keyboard. He seems the perfect French intellectual, until he asserts that he and his brother had a strong affinity with Vincent van Gogh and his brother Theo, and that German filmmaker Wim Wenders made a movie about them but won’t release it.

Philibert said that neither the workers nor the patients wear identifying badges or clothing, leaving it up to the viewer to figure out who is who. As the patients talk about art work they make as therapy, play music or participate in a mock accounting exercise to test math skills, the distinctions become more and more blurred.

“Nomades du Nucleaire” opens with Vincent, one of the workers, showing off a piece of land he has bought and talking about the plans for living there. Pretty much all of the dozen or so people featured want a stable life, but meanwhile they crisscross France, which generates half of the EU’s nuclear power, in search of the next gig.

All of them dread the experience of being assigned a task, as one has, where a single day’s dose of radiation is so high that it puts them off the job for a month. “I don’t want to die right away,” the worker says.

Meanwhile their lifestyle, moving from place to place and living in caravans that sometimes are parked in guarded parking lots, spurs many of them to smoke and drink to excess.

Co-directors Killian Friedrich of Germany and Tizian Zargari of France said their intention was to portray “workers in the shadows” whose existence is little known to the general public.

They also wanted it to be the workers’ movie, not their own, so only briefly do we hear one of them ask a question.

“We like invisible narration,” Friedrich said. “Let them give us their story.”

By Michael Roddy