Our Vacancy

Senior System Engineer

  • Nuclear
  • Permanent /
  • Bristol
  • 12/11/23
  • On site

Assystem is an international company with one mission: accelerate the energy transition around the world.

Every day, our 6,500 switchers located in 12 countries (Europe, Middle East, Pacific Asia & Africa) connect their six thousand billion neurons to tackle the task of the century: switching to low-carbon energy.

We are a collective committed to the actors who are making the energy switch. Sharing our knowledge, expertise and values allows us to innovate and think differently about the energy transition.

Drawing on more than 55 years’ experience in highly regulated sectors subject to strict security and safety requirements, we provide our customers with engineering and project management services, as well as digital services and solutions to optimize the performance of complex infrastructure projects throughout their life cycle. The Group is currently ranked second in the world for nuclear engineering.

To ensure a viable, efficient, and reliable energy future for all.

Job Description

Performing the necessary engineering analysis, including the supporting calculations, for a specific system(s) in order to produce the system documentation required for the HPC project working from either the client office or later on-site as part of site engineering.

Responsible for system design and system integration into overall HPC design:

  • Produce, Review and update the system documentation for the mechanical and thermo-hydraulic design, electrical, operator instructions, human machine interface, safety and environmental, control logic design, as well as periodic testing in compliance with the engineering rules, methodologies, quality processes, and tools
  • Particularly for Instrumentation and Control, performing the analysis for defining the I&C Functional Requirements of the system and production of the

I&C logic :

  • Writing of the Instrumentation and Control Functional Requirements
  • Writing of Detailed Functional Diagram
  • Writing of the Functional Test Procedure
  • Testing the I&C logic and feeding results back into specification
  • Definition and description of human machine interface (alarm sheets, operating images, operating procedures)

Particularly for mechanical design:

  • Sizing of components e.g. pumps, pipework, pressure relief valves,
  • tanks etc.
  • Perform thermal-hydraulic calculation and modelling with in house or
  • commercial tools
  • Ensuring the 3D model is consistent with the intended system design
  • Formulate equipment specification and provide the data in respective
  • database or data sheet
  • Support to procurement team in formulation of technical specification for contract documentation
  • Support to procurement team in technical surveillance of supplier
  • documentation


  • Analysis and verification of input data, requirements, and lessons learnt from
  • other stations
  • Engage proactively with all stakeholders around the system to
  • ensure the delivery of a product meeting the requirements set by all disciplines
  • (layout, civil, hazard, nuclear safety, environment, configuration management,
  • Contribute to topics around good practises, innovation, improvement ofprocesses, and quality
  • Participate in experience sharing activities within the discipline

Management of configuration related to the system including:

  • Managing requests for modifications to system(s) issued by various external parties by producing specifications and following engineering cycle (I&C and/or mechanical design changes specifications)
  • Analysis and verification of the applicability of these modifications and challenging them as appropriate (support design stability approach)
  • Developing technical solutions and presenting them to internal or external stakeholders / the client to help resolve technical issues (technico-economic optimisation approach)

My profile


  • Chemical, Process or Mechanical Engineering degree or equivalent qualification
  • 5+ years experience of process engineering or relevant experience
  • Relevant experience in the nuclear industry
  • Experience of producing design documentation and Test Specifications
  • Ability to effectively manage own and team’s workload in order to respect deadlines and KPI requirements
  • Excellent interpersonal skills
  • Ability to communicate clearly and accurately, both written and orally, in English
  • Proactive and confident in communicating with others, particularly those based in remote offices including France and Germany.
  • Proactive in developing positive working relations with others within the project
  • Ability to prioritise, manage numerous tasks with other stakeholders


  • Knowledge of EPR system design principles and nuclear safety classification
  • Experience of working on an EPR project, operating plant or on an industrial site
  • Knowledge of UK licensing requirements and its application within the HPC project
  • Knowledge of effluent treatment systems scope of EPR or other BNI systems’ design

Due to the nature of work to be undertaken applicants will be required to meet certain residency criteria in order to attain a minimum level of UK security clearance if not already security cleared to a minimum SC level.

We are committed to equal treatment of candidates and promote, as well as foster all forms of diversity within our company. We believe that bringing together people with different backgrounds and perspectives is essential for creating innovative and impactful solutions. Skills, talent, and our people’s ability to dare are the only things that matter !. Bring your unique contributions and help us shape the future.

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