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.
As a Nuclear Design Engineer, you’ll be responsible for designing components, assemblies, and systems that meet stringent requirements for safety, cost, availability, and longevity. From early concept through to in-service support, you’ll ensure every design is resilient, efficient, and built to perform under real-world conditions.
You’ll work across nuclear plant systems and supporting equipment—including tooling, assembly/disassembly systems, and maintenance solutions—contributing to every stage from design to deployment and beyond.
🧠 What You’ll Be Doing
🎯 Key Responsibilities
🎓Key Experiences and Qualifications
🚀 Why Join Assystem?
✨ Work on nationally significant, technically complex projects
📈 Strong career development and progression opportunities
🤝 25 days annual leave (buy and sell leave scheme)
🌍 Opportunity to make a real impact in energy, defence and infrastructure
**Security clearance**
This role requires the successful candidate to hold a minimum of a Security Check (SC) clearance without any caveats to that clearance.
Due to the nature of work this role will be delivering and for the protection of certain assets, the successful candidate has to be a UK national or in MoD approved cases a Dual National from a non-ITAR country.
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.

Assystem, one of the world's leading independent nuclear engineering companies, is committed to accelerating the energy transition. We see ourselves as an activist in the development of nuclear energy, convinced that it is an essential part of the fight against climate change.
8,000 switchers, spread in 13 countries in Europe, Asia, Africa and the Middle East are working every day to make the energy switch by accelerating the development of nuclear and renewable energies, power grids, clean hydrogen projects and low-carbon transport.
We design and supervise major projects through our engineering activities and accelerate our customers' digital transformation. We also develop new solutions to build faster and improve the performance of complex infrastructures.
59 years of experience have made Assystem a key partner of the world's largest industrial groups: CEA, EDF, ENEC, Enedis, Engie, Framatome, ITER, K.A. CARE, Naval Group, NICDC, Orano, RATP, Rolls Royce, Royal Commission, Sellafield, SNCF...
Assystem is ranked in the Top 3 companies in the nuclear energy sector.