Nuclear Mechanical Commissioning Engineer – Derby

Assystem UK Ltd; East Midlands; On-site; GBP 60,000 - 85,000; Full time

Job summary

Assystem is seeking a Mechanical Commissioning Engineer to join the on-site commissioning team at a Nuclear Licensed Site in Derby. The role starts with a 2-shift pattern (Mon–Fri) and may move to 3 shifts from February 2026, supporting commissioning of gas, fluid and vacuum systems and safety-related equipment.

Key tasks include authoring test procedures, recording results, conducting tests, and coordinating with vendors and internal teams to ensure safe, compliant commissioning across nuclear

Qualifications

• Experience with commissioning gas, fluid and vacuum systems and mechanical handling equipment.
• Familiar with Licence Condition 21 site arrangements, health and safety standards, permits, and safety case adherence.
• Able to perform initial operator duties during commissioning testing phases (i.e., non-active commissioning).
• Previous experience of witnessing, supervision, and acceptance of vendor and supplier testing on-site.
• Skilled in authoring test procedures and reports.
• Understanding of design, construction, and handover processes.

Responsibilities

• Author and manage commissioning test procedures and prepare safe systems of work.
• Maintain accurate records of test results.
• Conduct commissioning tests and analyze results.
• Communicate effectively and manage processes.
• Carry out commissioning duties on systems such as nuclear, conventional and environmental safety systems, wastewater tanks, nuclear qualified cranes.

Skills

Gas systems commissioning

Licence Condition 21 familiarity

Operator duties during commissioning

Vendor/supplier testing on-site

Test procedures & reports authoring

Design/construction handover knowledge

Job description

Assystem is seeking a Mechanical Commissioning Engineer to join the on-site commissioning team at a Nuclear Licensed Site in Derby. The role starts with a 2-shift pattern (Mon–Fri) and may move to 3 shifts from February 2026, supporting commissioning of gas, fluid and vacuum systems and safety-related equipment.

Key tasks include authoring test procedures, recording results, conducting tests, and coordinating with vendors and internal teams to ensure safe, compliant commissioning across nuclear