It is possible director Setsurō Wakamatsu has taken the Hollywood route in portraying the staff as so infallibly courageous – though Fukushima 50 is adapted from journalist Ryusho Kadota’s book, which investigated the response to the earthquake and tsunami in more than 90 interviews. Possibly to avoid lawsuits from Tokyo Electric Power Company executives portrayed here as selfish and shamefully caught on a back foot, everyone in the film is fictionalised – except for prime minister Naoto Kan, though he is never referred to by name, and plant manager Masao Yoshida. Yoshida crucially defies orders and allows the reactors to be cooled with seawater – which prevented meltdown and the possible devastation of Japan’s entire eastern seaboard. The reactors also must be “vented” for pressure manually by workers agonisingly selected for the task. Played by Ken Watanabe as a man having the ultimate bad day at work, the simmering Yoshida looks in need of a similar intervention.

Wakamatsu treats his account of these critical hours – the first direct depiction of the disaster, though Sion Sono’s Himizu (2011) was a poetic first responder – like a machine to be kept running at all costs. Often it consists of little more than technicians pelting into crisis rooms, adhering to the Akira school of screaming, with shocking gas-pressure read-outs. The civilian backstories are token, and though the film is critical of the brass, it doesn’t let this anger break into climactic outrage. Yoshida died in 2013 of unrelated oesophageal cancer: Watanabe’s big-shouldered presence makes this an ample tribute to the man, but the film could have been more than an easy clap for his workers.

Fukushima 50 is available from 8 March on digital formats.