At the heart of the Trafalgar Class is a powerful pressurised water reactor Type PWR1 supplied by the Reactor Machinery Contractor Rolls Royce Marine Power. Its core only requires refuelling once in every 9-10 years. Refit and refuelling is undertaken by Devonport Management Limited (DML) at Devonport Royal Dockyard. A full refit normally takes between 2 and 3 years to complete including refuelling. Two boats of the Class are normally under refit at any one time.
Safety in operation is paramount in all RN nuclear submarines and the entire SSN flotilla was temporarily withdrawn from service during year 2000 when a fault was detected in the primary coolant circuit of HMS Tireless.
The Trafalgar Class submarines can remain submerged for
