Britain's nuclear submarine fleet played a vital part in maintaining peace in Europe during the Cold War. But now former submariners and dockyard workers are falling ill with cancer and leukaemia - illnesses they claim were caused by exposure to radiation while serving their country.
Panorama reports on the men's battle to establish exactly what risks were taken to maintain the nuclear deterrent.

(Note: as Panorama is topical and likely to react to events in the news, its subject matter may change)