A Royal Navy submarine is making a five-day official visit to the city of Southampton, giving hundreds of sea cadets, scouts and other youngsters a rare opportunity to sample life on board.

HMS Trafalgar is due to arrive at Associated British Ports’ Port of Southampton at around 12 midday on Friday (December 5), berthing at Eastern Docks.

The nuclear-powered submarine is hosting 18 visits by cadet and scout units – plus college students on public service courses - from across the city and Hampshire. Civic dignitaries and senior city council officers will also visit the vessel and meet her crew.

The Royal Navy has been working closely with Southampton City Council in advance of Trafalgar’s visit. It is the first visit to Southampton by a nuclear-powered submarine since HMS Tireless arrived for a five-day stopover in July 2006.

The 280ft Royal Navy sub is expected to be greeted by angry protesters as it berths at the docks’ risk area – Z Berth.

The arrival of the 5,000-tonne sub has sparked fears of a nuclear leak in the city after an incident in which it spilled 280 litres of radioactive waste water in Devonport, Plymouth, last month.

The spill – the largest since the 1980s – contained low levels of the radioactive element tritium which were picked up as the water was used to cool the reactor on board the submarine.

The water drained into the River Tamar at Devonport because a hose leaked as the contaminated water was being transferred.

Di McDonald, of Solent Coalition Against Ships, said: “We are shocked the Navy still insists on using Southampton docks for a PR exercise they want to carry out especially after what happened in Plymouth. There’s always a risk something could go wrong.”

However a Navy spokesman said there was no risk of a similar incident happening in the city.

He said: “The discharging of liquid from the submarine to the shore can only be done at Devonport and at Vaslane in Scotland.

“There is no way it could happen in Southampton because those procedures are not undertaken in Southampton.”

A spokesman for Southampton City Council said potassium iodate tablets had been handed out to anyone within a 2km zone of Eastern Docks, including to 12 schools and two nurseries in Southampton and two schools and a nursery in Hythe.