Prince William jokingly told employees at BAE Systems in Barrow-in-Furness, Cumbria that they can "get back to work" after watching him unveil a plaque at the factory.
The occasion was to mark the opening of a new suite of offices where the next generation of Britain's nuclear submarines will be designed.
More top news
A cheap over-the-counter painkiller taken by millions of people in Britain every day could have the hidden benefit of slowing down ageing.
Some four million Brits are expected to fly out of the UK over the festive period, along with many more using roads and railways.
Scientists believe they may have found the key to fighting HIV - and it rests in the immune system of llamas.