Reactor System Design Engineer - Nuclear at ALTEN

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What will you be doing?

ALTEN UK is seeking a Reactor System Design Engineer to support the design and integration of advanced reactor systems for major nuclear and clean energy programmes.
You will combine your chemical engineering expertise with systems-level thinking to develop efficient, safe, and innovative system architectures for next-generation power stations.

Your main responsibilities will be:

• Lead and support system design and optioneering studies, assessing and comparing design options through structured decision-making methods (e.g. PUGH matrices).
• Develop optimised chemical and fluid system concepts balancing performance, safety, and maintainability.
• Integrate lessons learned and best practices from industry to deliver robust, innovative solutions.
• Define and manage system requirements to ensure alignment with overall reactor architecture and project objectives.
• Use and maintain requirements management tools such as IBM DOORS.
• Bring together multidisciplinary inputs — including mechanical, control, and safety engineering — to deliver a fully functional, safe, and efficient system design.
• Apply expertise in fluid flow, heat exchangers, and service condition control to optimise performance and safety.
• Support detailed analysis and design of fluid handling systems, ensuring correct operation under various process and environmental conditions.
• Execute practical design tasks, such as relocating and optimising heat exchangers and defining service integration and control measures.
• Understand and assess both internal and external hazards, ensuring that design solutions meet safety and operational requirements.
• Evaluate how operating conditions affect system performance and interactions across the reactor architecture.
• Contribute to hazard reviews, risk assessments, and design substantiation activities.

You are...

• A chemical, system or  process design engineer with a systems mindset and strong analytical approach.
• Collaborative, able to work across engineering disciplines to deliver integrated design solutions.
• Curious and innovative, driven to improve performance, safety, and sustainability.
• Confident using structured decision-making methods to guide complex design development.

Qualifications

Experience, skills and qualifications required:

• Degree (or higher) in Chemical Engineering, Process Engineering, mechanical engineering, system engineering  or related discipline.
• Proven experience in chemical process design, system optioneering, and system integration.
• Strong understanding of fluid systems, heat exchangers, and hazard management.
• Experience in requirements management and use of IBM DOORS (desirable).
• Excellent analytical and problem-solving skills, capable of applying structured engineering methods.
• Knowledge of system architecture, safety integration, and multi-discipline coordination.

Desirable:

• Experience within nuclear, energy, or process industry environments.
• Familiarity with systems engineering standards and requirements traceability.
• Exposure to hazard analysis, HAZOP, or risk assessment processes.

Why join us? 

We foster a community of dually talented individuals who are both entrepreneurs and technology specialists. Our teams embody the spirit of innovation and entrepreneurship, enabling us to develop solutions most efficiently. 

Our commitment to sustainable growth is unwavering, and we continuously strive for accelerated transformation and continuous improvement. Through ALTEN labs, mentoring programs, internal universities, and more, we are always pushing boundaries and embracing new possibilities. 

We offer incredible opportunities to join inspiring projects in the most innovative companies. 

We prioritise your career development with personalised support plans tailored to your own aspirations. We're here to empower you and help you reach your full potential. 

Join our passionate team and start building tomorrow, today! 

In short you get: 

• A personalised career path and a rewarding management style 
• A chance to work on the most exciting engineering projects and technologies along with Premium Customers
• A huge diversity of engineering projects and industries
• A competitive salary
• Private Medical & Travel Insurance
• Pension Scheme
• Cycle-to-work Scheme among many additional benefits
• Social atmosphere, regular gatherings, and team buildings
• Flexible way of working (role dependent)