Nuclear and Radiological Safety
Tetra Tech delivers expert nuclear and radiological safety services, supporting clients with comprehensive safety case development, peer review, and Independent Nuclear Safety Assessment (INSA).
We help nuclear-licensed site operators implement robust strategies to manage risks effectively, meet legal requirements, and maintain high safety standards. We provide actionable advice at every project stage—from conceptual design to decommissioning. With over 30 years of experience in nuclear safety case preparation, management, and INSA, our clients trust us to work directly with regulators on their behalf.
Our team integrates science-based modelling with practical regulatory insight to deliver credible safety arguments, hazard management strategies and robust, proportionate independent peer reviews. Our team includes dedicated specialists in criticality safety, radiation shielding and dose assessment, fire engineering and human factors. We work collaboratively with design and operations teams to identify gaps, propose practical improvements, and deliver transparent, evidence-based safety solutions.
Nuclear Safety Case Production
We ensure nuclear safety cases meet legal and regulatory expectations with clarity and technical excellence.
- Hazard and fault identification using all industry-recognised techniques
- Hazard management strategies
- Hazard analyses covering conventional, radiological, chemotoxic, environmental, fire, transport, construction, and demolition safety
- Consequence assessments using analytical techniques and established computer codes
- Fault and event tree analysis and probabilistic safety assessment (PSA) using proprietary software packages
- Safety case development for all facility lifecycle stages, including design, commissioning, operation, periodic review, and decommissioning
- ALARP (As Low As Reasonably Practicable) assessments and judgements
Human Factors
Our human factors team enhances safety by systematically analysing the interaction between people, systems and environments. We ensure that tasks, equipment, and processes are compatible with users’ physical and psychological capabilities, minimising the potential for human error and supporting optimal performance.
- Human factors assessment reports
- Human factors integration plans (HFIPs)
- Human factors assumptions and issues register (HFAIR)
- Human error and type identification
- Quantitative and qualitative human reliability assessment (HRA), derivation of human error probabilities (HEPs)
- Assessment of performance shaping factors (PSFs)
- Human factors design input, including derivation of design requirements, validation and verification (V&V)
- Allocation of function between the operator and the system tasks
- Behavioural safety and safety culture assessments
- Human factors input to training programmes, competency, and processes
Nuclear Fire Safety and Engineering
Our fire engineering team deliver accurate, proportionate nuclear fire safety assessments that form part of a facility’s safety case and meet all legislative and regulatory requirements.
- Fire safety strategies (design and retrospective)
- Nuclear fire hazard analysis
- Fire engineering calculations and analysis
- Computational fire modelling
- Fire loading and passive fire resistance studies
- Means of escape analysis
- Fire hazard identification
- Selection of fire protection measures
Radiation Shielding and Dose Assessment
We help protect workers and the public through scientifically validated models and ALARP justifications.
- Scoping calculations for conceptual designs
- Bulk shielding assessments
- Penetration assessments
- Detailed neutron and gamma dose rate calculations using proprietary software packages
- Dose uptake assessments
- Shielding substantiation
Peer Review
We provide independent peer review services to ensure legal and regulatory expectations are met with clarity and technical excellence. Our experienced professionals have extensive knowledge of safety assessment, engineering, and operations. We conduct Independent Nuclear Safety Assessments (INSA) and Independent Technical Assessments (ITA) for a wide range of nuclear safety case and engineering documentation, across all facility operations and lifecycle stages.
