Job Description ALTEN UK is seeking a Mechanical Equipment Engineer to join our engineering team at Harwell. In this role, you 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. Your main responsibilities will be: As a Mechanical Equipment Engineer, you will take responsibility for the design, installation, and testing of mechanical plant systems, working collaboratively with multidisciplinary engineering teams. Your main responsibilities will include: 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. You are… Passionate about mechanical engineering in safety-critical applications Detail-oriented and methodical in design and verification activities Confident in communicating with multidisciplinary teams Able to manage multiple priorities and workstreams independently Committed to maintaining compliance and safety standards