Software jobs in United Kingdom

Assystem is a global leader committed to accelerating the energy transition. With 7,850 employees across 12 countries, we tackle the monumental task of switching to low‑carbon energy. Our 55+ years of experience in highly regulated sectors ensure we deliver top‑notch engineering, project management, and digital solutions.

🚀Join the Fusion and Modular Nuclear Business Unit!🚀Assystem has an exciting opportunity for a Control SystemsEngineer to join our expanding Fusion and Modular Nuclear (FMN) business unit. As leaders in the design and development of new technologies, you will have the opportunity to work across multiple cutting‑edge projects developing technical solutions making net‑zero power generation a reality.

Provide engineering expertise in the design, development and verification of control systems used in nuclear facilities. The role covers programmable logic controllers (PLCs), distributed control systems (DCS), safety‑related I&C functions and supporting systems such as SCADA/HMI. The engineer ensures that control system implementations are safe, compliant and fully traceable to nuclear requirements throughout the project lifecycle.

Your Mission:

• 🌐 Design robust control system architectures that seamlessly support plant operations, automated sequences, interlocks, and vital protection functions.
• 📄 Create high‑quality technical documentation—including control philosophies, functional requirements, logic descriptions, cause‑and‑effect diagrams, and interface specifications.
• 🧠 Configure and program PLC, DCS, and specialised control platforms in line with nuclear lifecycle standards and industry expectations.
• 🤝 Collaborate closely with EC&I, process, mechanical, safety, and human‑factors engineers to ensure unified and consistent system performance across all interfaces.
• 💻 Integrate intelligent control logic with SCADA/HMI systems, historians, networks, and field instrumentation for smooth and reliable operations.
• 🚨 Apply best‑practice alarm management aligned with EEMUA 191 and site strategies to ensure clarity, efficiency, and safety.
• 🔍 Execute rigorous verification and validation activities—including peer reviews, simulations, software testing, FAT, SAT, and commissioning support.
• 🧪 Develop comprehensive test specifications ensuring alignment with requirements, functional hazards, and safety classifications for full assurance.
• 📑 Maintain strong configuration control and software governance, managing versions, coding standards, and baselines within nuclear‑grade quality frameworks.

Why Join the Community of Switchers?

• 🌟 Over 55 years in nuclear engineering.
• 🏆 Ranked among the top 3 largest nuclear engineering companies.
• 💼 Attractive social benefits, including an engaging Employee Committee and holiday bonuses.
• 📚 Ongoing training with numerous career opportunities.
• 📈 70% of our managers are promoted internally!
• 🏠 Hybrid work: 1‑2 days remote per week.

Skills and Experience:

• 🔧 Hands‑on control systems engineering experience in regulated sectors—ideally nuclear, defence, energy, or similarly high‑integrity environments.
• 📊 Proven ability to produce detailed control deliverables such as control philosophies, logic diagrams, and sequence descriptions.
• 🧾 Skilled in interpreting P&IDs, process narratives, safety requirements, and mechanical schematics to inform accurate and efficient design.
• 💡 Strong understanding of PLC/DCS programming techniques including structured text, ladder logic, function block, and sequential function charts.
• 🧪 Experienced in verification, testing, simulation, or model‑based methods for validating control logic with precision.
• 📚 Knowledgeable in nuclear I&C lifecycle requirements and safety classifications, including industry standards like IEC 61513, IEC 60880, IEC 61508, and IEC 61226.
• 🚨 Familiar with alarm management best practices and experienced in applying EEMUA 191 to improve operational clarity and performance.
• 🏭 Insight into nuclear new build control architectures, including reactor island and balance of plant systems.
• 🌐 Experience with digital twin concepts, advanced simulation, or MBSE methodologies to enhance system development.
• 🔐 Awareness of cybersecurity requirements for nuclear I&C systems to support secure and resilient operations.
• 🎓 Chartered Engineer status or actively working toward chartership, demonstrating professional commitment and credibility.

• BPSS and SC required
• Ability to travel Assystem offices and customer sites within UK.
• To undertake work packages supporting major UK and international Nuclear Clients.

Due to the nature of work to be undertaken applicants will be required to meet certain residency criteria in order to attain a minimum level of UK security clearance if not already security cleared to a minimum SC level.

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.