Simon Barber

About Simon Barber

Simon Barber is the UK Managing Director of Assystem. He joined the Group in 2020 after nearly a decade leading ARUP’s nuclear business. At Assystem, he oversees the company’s UK operations at a time when the country’s nuclear and low-carbon infrastructure agenda is expanding rapidly. His remit is strategically significant: the UK is a core market for Assystem, and Barber’s leadership has helped strengthen the firm’s position as a tier-one supplier in the British nuclear sector. He has also been closely associated with Assystem’s role in supporting both public and private developers of next-generation nuclear technologies, including small modular reactors (SMRs). Barber’s career reflects deep experience across the UK nuclear and energy engineering landscape. Before joining Assystem, he led ARUP’s nuclear business, and earlier in his career he held positions at Mace Group, Atkins, and British Energy. Those roles gave him broad exposure to nuclear operations, safety, engineering, project delivery, and business development in highly regulated environments. He is described as having over two decades of experience in the sector, with a track record spanning new build, defence, and power networks. His academic background in physics, along with postgraduate training in radiation and environmental protection, complements a technically grounded leadership profile. Since taking the helm of Assystem UK, Barber has been instrumental in driving growth and in positioning the business around the UK’s energy transition priorities. Under his leadership, Assystem has expanded its footprint, deepened its role in major nuclear programmes, and aligned more closely with the country’s decarbonisation ambitions. He has also helped reinforce the company’s value proposition as an engineering, project management, and digital services partner to complex industrial clients. In short, Simon Barber combines sector expertise, operational leadership, and commercial credibility, making him one of the key figures in Assystem’s UK strategy and in the broader nuclear supply chain ecosystem.