Senior Contracts / Commercial Manager

About Assystem

Today, Assystem is among the top three independent nuclear engineering firms worldwide. With over 60 years of experience in highly regulated sectors, the group supports public and industrial stakeholders in the execution of complex and strategic infrastructure projects, subject to high safety and security requirements.

Assystem mobilizes 8,000 experts in 13 countries and intervenes across the entire project lifecycle, in engineering, project management and digital solutions.

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.

Your mission

• 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.

Benefits include

• 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

• Demonstrable experience in commercial management within nuclear new build, SMR, or any highly regulated infrastructure programmes.
• Experience of NEC contract forms (NEC3/NEC4) and contract management in complex environments.
• Proven experience managing high value contracts and Tier 1 supplier interfaces.
• Experience in cost management, forecasting, and commercial reporting.
• Experience working on large scale, complex programmes (e.g. power generation, infrastructure, defence)
• Ability to influence senior stakeholders and lead commercial decision making
• Highly analytical with a focus on risk management and value optimisation

We are committed to equal treatment of candidates and promote, as well as foster all forms of diversity within our company. We believe that bringing together people with different backgrounds and perspectives is essential for creating innovative and impactful solutions. Skills, talent, and our people’s ability to dare are the only things that matter !. Bring your unique contributions and help us shape the future.

NOTICE TO CANDIDATES ON RECRUITMENT FRAUD – We are committed to safeguarding candidates from fraudulent activity associated with our recruitment process. Please note that we will never offer specialist CV writing services, request payment or ask for sensitive personal information during the recruitment process.

We are committed to equal treatment of candidates and promote, as well as foster all forms of diversity within our company. We believe that bringing together people with different backgrounds and perspectives is essential for creating innovative and impactful solutions. Skills, talent, and our people’s ability to dare are the only things that matter !. Bring your unique contributions and help us shape the future.