Principal Nuclear Security Engineer
Confirmed on the employer's own hiring board on Nov 2, 2026. First seen by Alion on Oct 29, 2026. Assystem scores B on the Alion truth index.
Today, Assystem is among the top three independent nuclear engineering firms worldwide. With over 60 years of experience in highly regulated sectors, the group supports public and industrial stakeholders in the execution of complex and strategic infrastructure projects, subject to high safety and security requirements.
Assystem mobilizes 8,000 experts in 13 countries and intervenes across the entire project lifecycle, in engineering, project management and digital solutions.
The role will provide experienced engineering support to the Design Authority responsible for security-related infrastructure and assets. It will support the development and maintenance of engineering evidence, governance and assurance, helping ensure assets continue to meet their required performance throughout their lifecycle.
The position will work alongside engineering teams, projects and other stakeholders, providing technical advice, challenge and knowledge transfer while supporting ownership of the function.
TASKS
- Develop, review and maintain engineering justification and supporting evidence for security-related assets.
- Assess engineering information and provide proportionate technical advice, challenge and assurance.
- Support the assessment and control of design changes, modifications and concessions.
- Define and maintain appropriate inspection, maintenance and testing requirements, including review of results.
- Provide engineering support and assurance to projects through design, commissioning and acceptance.
- Support periodic review of assets and engineering evidence to identify and manage emerging issues.
- Develop and improve engineering processes, procedures, standards and guidance.
- Undertake or support independent technical and peer reviews.
- Work collaboratively with client, contractors and other stakeholders across engineering, operations, maintenance and assurance.
- Support client capability through technical advice, coaching and knowledge transfer.
EXPERIENCE
Essential:
- Engineering experience in a high-hazard regulated environment.
- Engineering substantiation or design justification for nuclear structures, systems and components.
- A good understanding of security engineering principles and good practice, such as ONR's Security Assessment Principles (SyAPs) and Technical Assessment Guides, or IAEA guidance.
- A working knowledge of nuclear safety cases and how they relate to security.
- Experience of developing management arrangements or engineering processes.
Desirable:
- Experience of working with the Ministry of Defence or on defence nuclear programmes.
- Experience of security regulation or assessment.
- Experience of working in a nuclear design authority.
QUALIFICATIONS & TRAINING
Essential:
- Engineering degree or equivalent experience.
- Relevant qualification in Security or equivalent experience.
Desirable:
- Chartered Engineer (CEng) or working towards it.
- Chartered Security Professional (CSyP).
Why join the community of Switchers?:
The Group is currently ranked Third in the world for nuclear engineering.
A dynamic career management policy to enable our employees to progress through our five business lines: operations, project, technical, sales and support functions
Provide opportunities to work on exciting, global projects
Access to an employee assistance programme with free mindfulness, health, wellbeing resources and a confidential support line available 24/7 via phone or text
Discount vouchers for days out and restaurants, eye test and glasses vouchers, cycle to work scheme, free flu jabs
Security clearance:
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.
This role would also require you to be able to gain Developed Vetting.
Travel to the client site will be required for this role - Our team would be happy to discuss further.
NOTICE TO CANDIDATES ON RECRUITMENT FRAUD - We are committed to safeguarding candidates from fraudulent activity associated with our recruitment process. Please note that we will never offer specialist CV writing services, request payment or ask for sensitive personal information during the recruitment process.
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.