Senior Mechanical Design Engineer

Are you a Mechanical Design Engineer who is passionate about creating innovative engineering solutions that make a positive difference? Do you enjoy working collaboratively to solve complex challenges and supporting projects that contribute to a more sustainable future? Are you looking for a role that offers flexibility, professional growth and the opportunity to work on some of the UK's most significant engineering programmes? If so, we'd love to hear from you.

We are looking for Senior and Principal Mechanical Design Engineers to join our growing team and help meet increasing client demand across the region. This is an exciting opportunity to take a leading role on diverse and technically challenging projects while working alongside talented colleagues and clients who are shaping the future of the nuclear sector. Whether your experience has been gained within the UK nuclear industry or a comparable engineering environment, you will have the opportunity to work across projects spanning concept development through to detailed design and delivery. Our work supports critical programmes including nuclear new build, nuclear defence, life extension and decommissioning projects.

As part of AtkinsRéalis, you'll join a team that values curiosity, collaboration, courage and care. We are committed to creating an environment where people can thrive, develop their careers and contribute meaningfully to projects that matter.

Your role

As a Senior or Principal Mechanical Design Engineer, you will play a key role in leading design activities, bringing technical expertise, structure and clarity to complex engineering challenges.

You will have the opportunity to:

• Lead and mentor engineering teams working on a diverse range of complex projects.
• Support the design and development of mechanical equipment to the highest standards of safety, quality and efficiency.
• Deliver projects across the full design lifecycle, from concept and feasibility studies through to detailed design and implementation.
• Apply your expertise in advanced 3D CAD tools and machinery design to develop practical, innovative and fit-for-purpose solutions.
• Provide guidance on manufacturing, assembly and installation approaches while ensuring compliance with relevant regulations, standards and industry requirements.
• Work closely with multidisciplinary teams, clients and project stakeholders to develop engineering solutions that address complex challenges.
• Contribute technical input to proposals, budgets and project schedules, helping shape successful project outcomes.
• Support feasibility studies, optioneering and design reviews, providing clear technical insight and recommendations.
• Build trusted relationships with clients and colleagues, influencing decision-making through effective communication and collaboration.
• Support the development of junior engineers through coaching, mentoring and the sharing of knowledge and best practice.
• Whether working within AtkinsRéalis project teams or embedded within client programmes, you will play an important role in delivering outstanding outcomes and helping shape the future of the nuclear industry.

About you

We're looking for someone who enjoys solving complex problems, working collaboratively and helping others succeed.

You are likely to bring:

• Significant experience in Mechanical Design Engineering within nuclear, defence or other highly regulated engineering environments.
• Strong capability in Autodesk Inventor and/or Siemens NX.
• Experience using a range of engineering tools to design mechanical equipment such as mechanical handling systems, machinery, tooling, test rigs or mechanical components.
• A structured approach to engineering design and an understanding of how design decisions contribute to successful project delivery throughout the asset lifecycle.
• The ability to balance technical excellence with practical delivery, ensuring high-quality, right-first-time solutions.
• Confidence in engaging with stakeholders at all levels and building strong, lasting relationships both internally and externally.
• A collaborative mindset, with the ability to bring teams together, communicate effectively and create clarity within fast-paced environments.
• Strong problem-solving and organisational skills, with the ability to manage competing priorities and support successful project outcomes.
• Experience contributing to bids, planning activities, feasibility studies and engineering decision-making.
• A passion for continuous learning and professional development, with a commitment to sharing knowledge and supporting others.
• Experience working within the UK nuclear or defence sector and a desire to contribute to nationally important programmes.
• Most importantly, you'll be someone who is motivated by delivering meaningful engineering solutions, supporting others to succeed and helping create a safer, more sustainable future through engineering excellence.

Rewards & benefits

Explore the rewards and benefits that help you thrive – at every stage of your life and your career. Enjoy competitive salaries, employee rewards and a brilliant range of benefits you can tailor to suit your own health, wellbeing, financial and lifestyle choices. Make the most of a myriad of opportunities for training and professional development to grow your skills and expertise. And combine our hybrid working culture and flexible holiday allowances to balance a great job and fulfilling personal life.

Be rewarded. Find out more.

About AtkinsRéalis

We're AtkinsRéalis, a world-class engineering services and nuclear organization. We connect people, data and technology to transform the world's infrastructure and energy systems. Together, with our industry partners and clients, and our global team of consultants, designers, engineers and project managers, we can change the world. We're committed to leading our clients across our various end markets to engineer a better future for our planet and its people.

Find out more.

Additional information

Security clearance

This role may require security clearance and offers of employment will be dependent on obtaining the relevant level of clearance. If this is necessary, it will be discussed with you at interview. The vetting process is delivered by United Kingdom Security Vetting (UKSV) and may require candidates to provide proof of residency in the UK of 5 years or longer. If applying to this role please do not make reference to (in conversation) or include in your application or CV, details of any current or previously held security clearance.

We are committed to creating a culture where everyone feels that they belong - a place where we can all be ourselves, thrive and develop to be the best we can be. So, we offer a range of family friendly, inclusive employment policies, flexible working arrangements and employee resource groups to support all employees. As an Equal Opportunities Employer, we value applications from all backgrounds, cultures and ability. As a Disability Confident Leader, we are committed to offering an interview to all applicants who have a disability and meet the essential criteria. If you would like to be considered under this commitment, please let us know at the application stage.