Mechanical Equipment Engineer - Energy

ALTEN UK is seeking a Mechanical Equipment Engineer to join our engineering team at Harwell. This role will support the detailed design, commissioning and testing of mechanical equipment for active nuclear facilities, ensuring safety, compliance and operational excellence. This is a unique opportunity to work on complex, safety‑critical systems including pumps, valves, HVAC systems, pipework and ancillary plant equipment, supporting post‑operational testing and cleanout activities.

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• Take responsibility for the design, installation, and testing of mechanical plant systems, working collaboratively with multidisciplinary engineering teams.
  
• Lead detailed mechanical design activities, producing high‑quality drawings, calculations and specifications.
  
• Support works testing, commissioning and verification of installed equipment performance.
  
• Troubleshoot and resolve mechanical system issues as they arise.
  
• Interface with electrical, instrumentation, process and civil engineering teams.
  
• Ensure compliance with nuclear regulations, safety standards and quality assurance requirements.
  
• Support post‑operational activities, including plant cleanout and preparation for maintenance or decommissioning operations.
  
• Contribute to risk assessments, method statements and safety documentation.
  
• Mentor junior engineers and support team development.
  

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• Degree in Mechanical Engineering or equivalent professional qualification.
  
• 5+ years’ experience in detailed mechanical design, ideally in nuclear, defence or other regulated safety‑critical industries.
  
• Hands‑on experience with mechanical plant equipment, including pumps, valves, HVAC systems, pipework and ancillary plant.
  
• Familiarity with works testing, commissioning and post‑operational cleanout procedures.
  
• Strong understanding of mechanical design standards and industry regulations (ASME, BS, EN).
  
• Proficiency in CAD/design software (AutoCAD, Inventor, SolidWorks or equivalent).
  
• Excellent communication skills and experience producing technical documentation.
  
• Ability to work both independently and collaboratively in multidisciplinary teams.
  

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• Previous experience in nuclear or regulated environments.
  
• Knowledge of plant maintenance, lifecycle management or decommissioning.
  
• Experience delivering projects in a hybrid working environment.
  

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• A personalised career path and a rewarding management style.
  
• A chance to work on the most exciting engineering projects and technologies with premium customers.
  
• Diverse range of engineering projects and industries.
  
• Competitive salary.
  
• Private medical and travel insurance.
  
• Pension scheme.
  
• Cycle‑to‑work scheme and other benefits.
  
• Social atmosphere, regular gatherings and team building.
  

Security Clearance: This role requires you to have or be willing to go through Security Clearance. Candidates will be asked to complete a Baseline Personnel Security Standard. If you are unable to meet this or the associated criteria, your employment may be delayed or rejected.

Seniority Level: Associate | Employment Type: Full‑time | Job Function: Consulting.