New Reactor Cores for the Royal Navy Nuclear Submarines – the MoD has secured a supplier to produce new reactor cores for the Royal Navy's nuclear submarines and to upgrade the plant where they will be built.    The nuclear reactor cores will be used to power the seventh and final ASTUTE Class submarine and the first of the Royal Navy's next generation of nuclear deterrent submarines, known as the Successor Class.       The investment, awarded to Rolls-Royce in a £1.1bn contract, will also fund an eleven year refurbishment of Rolls-Royce's plant at Raynesway in Derby, extending its operating life by more than 40 years.      The contract, which secures 300 jobs at Rolls-Royce, will see construction of new buildings to replace existing facilities that have reached the end of their useful lives.   Replacing the existing infrastructure with the advanced nuclear reactor core production facilities will cost around £500m. A further £600m will be spent on producing new reactor cores for the ASTUTE and SUCCESSOR Class submarines.