The latest phase of the upgrade to Rolls-Royce's Raynesway factory in Derby will officially open later today.
The firm secured a £1 billion contract from the Ministry of Defence in June to build reactors for the next generation of nuclear submarines.
Atlantic House will be officially opened by HRH the Duke of Kent.
More top news
A minibus with 16 people on board has crashed into a garden in Lincolnshire, leaving several people injured.
Eloise Parry, 21, died after taking diet pills containing the poisonous Dinitrophenol (DNP).
Northampton Saints have been handed a tough draw in the European Challenge Cup.