Around a dozen people are self-isolating at HM Naval Base Clyde in Scotland.
The naval base, also known as Faslane, is home to Britain’s nuclear deterrent.
There have been no confirmed cases of COVID-19 at the site, with those self-isolating doing so as a precaution on the basis of their symptoms, in accordance with NHS guidance.
Some cabins have been set aside for people who may need to self-isolate but live in multiple-occupancy accommodation.
It is understood there is no impact on the operational output of the base.
A Royal Navy spokesman said: "The Ministry of Defence has put in place robust plans to ensure the delivery of key operations in the UK and overseas and we are confident that essential defence tasks will be maintained during this time.
"Any serving personnel who are showing symptoms will follow the advice and guidance issued by Public Health England.
"Whilst sensible precautions are being taken, all required outputs are being maintained at HM Naval Base Clyde."
Cover image: PA.