A BBC documentary claiming to lift the lid on the “shocking state” of safety at Sellafield will be broadcast tonight (Monday).

The episode of Panorama – Sellafield’s Nuclear Safety Failings – sees an investigative reporter “uncover the truth” about the nuclear site, says the BBC.

Previewing the half-hour show, described as a “special investigation into the shocking state of Britain’s most hazardous nuclear plant”, the BBC says: “With a high-level whistle-blower, hundreds of leaked documents and exclusive access to former senior managers, reporter Richard Bilton uncovers the truth about Sellafield.

“He finds an ageing and run-down plant, where nuclear waste is stored in dangerous conditions and insiders fear a serious accident.”

A spokesman for Sellafield Ltd said: “Since being approached in February 2016, Sellafield Ltd and the Nuclear Decommissioning Authority have been co-operating with Panorama . As public bodies, we respond as openly and transparently as possible to public and media interest, whilst recognising that safety and security of the site remain the priority.

“We have met with Panorama on a number of occasions, given them access to the site, provided them with a substantial amount of written and verbal briefings and appeared in formal interviews on camera for the programme.

“We will continue to work closely with the producers to ensure they have a balanced view of the challenges and good progress being made at one of the world’s most complex nuclear sites.”

Panorama: Sellafield’s Nuclear Safety Failings will be broadcast on BBC1 at 8.30pm.