Senior Commercial Manager

Join the Fusion and Modular Nuclear Business Unit! We are seeking an experienced Commercial Manager to support the successful delivery of nuclear new build and SMR programmes. You will lead and manage pre- and post-contract commercial activities across high value, complex contracts, ensuring robust governance, effective risk management, and value optimisation throughout the project lifecycle. You will work within multi disciplinary project teams, interfacing with clients, regulators, Tier 1 contractors, and supply chain partners to deliver commercially robust solutions aligned to programme objectives and UK nuclear regulatory expectations.,

• Lead commercial delivery across the full contract lifecycle for nuclear new build / SMR projects, from early contractor involvement (ECI) and procurement through to execution and final account.
• Manage contract administration, compensation events, change control, and claims in accordance with NEC (or equivalent) forms of contract.
• Develop and implement claims avoidance and resolution strategies to protect project value.
• Lead or support development of procurement strategies aligned to programme delivery schedules.
• Manage interfaces with key suppliers and strategic partners across the nuclear supply chain.
• Ensure effective packaging, sourcing, and commercial structuring to optimise delivery and risk allocation.
• Manage commercial risk and opportunity, including risks linked to scope maturity, regulatory approvals, and contractor performance.
• Support monthly reporting, performance analysis, and corrective action planning.
• Support negotiation and resolution of commercial disputes with contractors and suppliers.
• Collaborate with engineering, project controls, legal, and procurement teams to ensure integrated delivery.
• Provide commercial input into bid development for nuclear new build and SMR opportunities, including pricing, risk allocation, and contract strategy.
Why Apply? Join Assystem and become a key player in delivering critical nuclear projects that shape the future of energy. Embrace this opportunity to excel in a dynamic environment where your expertise and leadership will drive global innovation.


• Pension scheme (8% company contribution / 4% personal contribution)
• 25 days' paid annual leave + bank holidays + option to buy or sell days
• Professional fees reimbursed
• Flexible working
• Employee referral scheme