Hundreds of security-vetted BBC staff and a select band of unnamed radio artistes were to be clandestinely dispatched to transmission sites across the country at the first signs of international tension.

Just before the first missiles had reached Britain, the BBC was to use regional centres in Birmingham, Sheffield, Bristol and Middlesbrough to broadcast a national service that the Government hoped would create "a diversion to relieve strain and stress".

By 1960 the BBC had stockpiled thousands of recordings of "war" programmes and records for possible broadcast at the height of an attack.

How much of a boost to Britain's morale these programmes would have really been is highly questionable. Another set of secret documents detailing the horrors of nuclear warfare reinforces the huge challenge facing the BBC.

In a military briefing held at the BBC on 18 February 1955, senior staff were told by a General Kirkman of the War Office that, if a BBC building took a direct hit, "even those within a distance of about 30 miles downwind who escaped the blast would die from radiation effects."

Staff who lived within a 50-mile radius from the burst would develop serious radiation sickness.

General Kirkman concluded: "If one were to envisage half a dozen hydrogen bombs falling on the United Kingdom, very large numbers of people might be infected by radiation and it would be essential for those who had escaped to keep themselves free from contamination, in order both to rescue the victims of the fall-out ... and to restore life to the country."

With these survivors in mind the BBC and the government set out a strategy for broadcasting programmes that would boost morale and help the public cope with nuclear catastrophe. A BBC briefing paper written in 1957 declares the objectives of the broadcasts were to provide "instruction, information and encouragement".

The paper adds: "The only practicable means of providing programmes in war for the purpose of 'diversion to relieve strain and stress' would be by records and recorded programmes. To enable such programmes to be added to during the course of the war, the necessary artistes, facilities and staff should be dispersed to ... [existing] BBC premises [outside of London]."

Long before war was declared the BBC hoped to have dispersed 1,500 staff and artistes around the country. The remainder of the corporation's employees would be evacuated just before the first bombs fell, leaving a small nucleus in London "until it becomes untenable, or the seat of government leaves London". Preparations were begun on building fall-out bunkers in BBC buildings such as Broadcasting House.

The advent of television brought a new means of communication with the public during a nuclear war. But memos and letters, written in the early 1960s and originally deemed too sensitive for publication until 2015, indicate tensions between the BBC and War Office over who should have control of these facilities.

The military wanted to take over as soon as a nuclear threat became imminent, a plan resisted by the BBC. This issue was drawn to the attention of the Home Office and led to one minister observing: "An abrupt discontinuance of the television service in the preparatory period would have considerable effect on public morale and it would be desirable that the television service should continue, as far as possible, up to the outbreak of the war."

1955: The BBC's scenario

* THE KILLING ZONE: Staff living within a distance of about 30 miles downwind who escaped an initial blast would die from radiation effects.

* RADIATION SICKNESS: Gamma rays would gradually destroy individuals' white corpuscles. Cuts or bruises would become septic and colds would not get better. The only cure was careful nursing.

* BUILDINGS: Full protection would be provided by two to three feet of earth or equivalent screening by bricks, concrete or sandbags. A well-built house would provide only 20 to 40 per cent protection as rays would penetrate roofs.

* LENGTH OF TIME IN HIDING: BBC staff were told to stay in shelters for 14 days before it was safe to leave. It was estimated that it took this long for radioactive particles to decompose.

* EVACUATION: It was doubted whether evacuation before fallout arrived would have been possible.