Role Overview: We are seeking an experienced Principal Mechanical Engineer to lead and support mechanical engineering activities on nuclear decommissioning projects. This role requires a strong background in mechanical engineering, with significant experience in the nuclear sector, particularly in high-hazard waste retrieval and storage systems. The successful candidate will provide technical leadership, mentoring to junior engineers, and assurance across the design lifecycle. Key Responsibilities: Lead the mechanical design and engineering effort on nuclear decommissioning projects from concept through to detailed design, installation, and commissioning. Develop fit-for-purpose, safe, and compliant engineering solutions for high-hazard environments, including waste retrieval and storage systems. Provide technical governance and assurance to ensure designs meet nuclear safety, quality, and regulatory requirements. Produce and review technical documentation, including specifications, design substantiations, calculations, and reports. Engage with multidiscipline engineering teams, safety case authors, operations personnel, and supply chain partners to ensure robust and integrated design outcomes. Act as the technical mentor to junior and developing engineers, promoting best practices and knowledge sharing. Participate in hazard and operability studies (HAZOPs), design reviews, and technical risk assessments. Support bid development and proposal writing for new projects where required. Essential Requirements: Degree-qualified in Mechanical Engineering or a related discipline. 10 years of mechanical engineering experience, with 5 years specifically in the nuclear sector. Demonstrable experience in nuclear decommissioning, preferably with involvement in high-hazard waste retrieval and storage systems. Strong understanding of design codes, standards, and safety regulations relevant to the nuclear industry (e.g., ASME, BS, PD 5500). Experience in mentoring or guiding junior engineers. Proficient in using engineering tools and software for mechanical design and analysis. Excellent written and verbal communication skills. Desirable: Chartered Engineer (CEng) or working toward professional registration. Familiarity with CDM regulations and engineering governance processes. Experience working in Sellafield, Magnox, or similar legacy nuclear environments. Understanding of glovebox design, remote handling, and shielding design considerations.