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Senior Nuclear Criticality Assessor


Warrington (Hydrock 3T)


Nuclear Management Consultancy

Employment type

Full time

Contract type


We have a fantastic opportunity for an experienced Senior Nuclear Criticality Assessment Specialist to join our thriving Nuclear team in our Warrington office.

The Team – Our Nuclear Division

Our Nuclear Division is well established but still very much a growing team, supporting a wide range of key nuclear projects across the UK, from new build through to decommissioning. We pride ourselves on being innovative and providing strategic and bespoke support to meet our clients’ needs, and have worked hard to build strong and mutually beneficial relationships with these clients. We recognise that the success of our business is underpinned and sustained by our people, and we always seek to ensure that we support, encourage and empower each member of our team to further build on what we have achieved.

We have a number of exciting projects, ongoing as well as future opportunities, with a wide range of high-profile nuclear clients. This includes delivery of work through large, long-term frameworks as well as through smaller, bespoke work packages. We are keen to welcome the right person into our team to support the successful delivery of this work and continued growth. 

The Role – Senior Nuclear Criticality Specialist

We are seeking a highly skilled and experienced Senior Nuclear Criticality Assessment Specialist to join our team. As a key member of our team, you will play a crucial role in supporting our clients to develop designs that will ensure the safe operation of nuclear facilities and the compliance with regulatory standards.

Key Responsibilities:

  • Conduct comprehensive nuclear criticality safety assessments for various nuclear systems, facilities, and operations.
  • Support our clients to develop and implement criticality safety programs, policies, and procedures in accordance with industry standards and regulatory requirements.
  • Perform complex calculations and analyses using specialized nuclear criticality codes and software tools.
  • Evaluate and mitigate potential risks associated with nuclear criticality events through effective safety controls and measures.
  • Provide technical expertise and guidance to multidisciplinary teams on criticality safety issues and solutions.
  • Produce, review and approve criticality safety documentation, reports, and procedures.
  • Collaborate with clients, regulatory authorities, stakeholders, and external consultants on criticality safety matters.


  • Bachelor’s degree in Nuclear Engineering, Physics, or a related field. Advanced degree (Masters or PhD) preferred.
  • Proven experience (at least 7-10 years) in nuclear criticality assessment and safety within the nuclear industry.
  • In-depth knowledge of nuclear criticality codes (e.g., MCNP, SCALE) and proficiency in performing criticality calculations.
  • Strong understanding of regulatory requirements and standards related to nuclear criticality safety (e.g., ONR, IAEA).
  • Excellent analytical and problem-solving skills, with the ability to assess complex technical issues and develop effective solutions.
  • Effective communication skills, with the ability to convey technical information clearly and concisely to both technical and non-technical stakeholders.
  • Leadership experience in managing criticality safety projects and guiding junior staff members.

What's great about Hydrock now Stantec

We are a multi-disciplinary engineering consultancy of over 900 staff in 21 offices across the UK. Our driving motivation is to be a ‘Force for Good’, as it is our aim to improve the quality of people’s lives from our employees to our clients, through to the communities we work in and our planet as a whole through the work we do.  

From the buildings that surround you, the roads and bridges you cross, all related to the infrastructure that we create, we aim to offer the most sustainable possibilities to shape the places, communities and society that we live in through meeting our client’s needs. Through the path we are on to delivering a green future, the result is something that everyone can be proud of. 

Named as Building’s Engineering Consultant of the Year in 2023, we’re known for delivering outstanding sustainable projects for our communities, planet, and society.

 Some of these projects have recently received industry accolades, including Cleveland Pools winning the Conservation and Regeneration category at the Construction Excellence South West Awards 2023; Bay Technology Centre named Commercial Project of the Year at the British Construction Industry Awards 2022; YGG Tan-y-Lan picked out in the Integration and Collaborative Working category at Construction Excellence Wales Awards 2022; The Deaf Academy singled out for its Universal Design at the Civic Trust Awards 2022; and Bristol’s iconic waterfront Wapping Wharf Living sweeping up at the Bristol Property Awards.

 Take a look at our 2023 end of year film and get a feel for what we’re all about. 

What we can offer you: 

Inspiring and supportive colleagues 

Reward for progression and hard work 

An opportunity to develop your soft skills, as well your technical skills

Competitive starting salary 

Excellent health benefits 25 days of holiday (buy/sell up to five days), accrue 1 day extra every 2 years, with bonus holidays too!

An earlier finish on Friday (4pm!) 

An opportunity to give back: “Day off for good cause” (on a workday) 

A huge range of flexible benefits, including climate perks and an EV car leasing scheme 

A place to feel included

We champion diversity, equity and inclusion. As an Equal Opportunities Employer, we commit to supporting our employees and ensure we create a safe environment that nurtures you to perform at your best. Offering our people flexibility is an important factor in achieving this aim.  

We consider all application individually with the required qualifications and knowledge without regard to any of the protected characteristics. We would like to provide everyone with a fair selection, assessment and employment experience so we ask with are made aware of any physical or neurodiverse condition within your application for which appropriate reasonable adjustments can be made by us. 

Looking for the next steps? 

Once you have completed your application through our careers site, we aim to review and respond to you as soon as your application’s been reviewed.

If shortlisted, a member of our Talent Acquisition Team will call you for an initial pre-screen by phone (typically 30 minutes) to help us assess your motivations and interest in the position and Hydrock now Stantec. 

If you progress following this telephone pre-screen, you will be invited to attend a formal interview by video conference (Microsoft Teams) or in our offices. 

For the latest updates and news, connect with us on our LinkedIn page!

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