Hydraulics in Nuclear: Reliability and Compliance Considerations

Hydraulic systems are used across a range of applications within the nuclear industry, including lifting systems, doors, containment systems, waste storage facilities and mechanical handling equipment.

In these environments, hydraulic equipment must be designed with reliability, safety, maintainability and project-specific requirements in mind.

For hydraulic engineering companies working within the nuclear sector, the challenge is not simply to produce a system that works. Equipment may need to operate reliably within highly controlled environments while satisfying demanding design, manufacturing, testing and documentation requirements.

Where Are Hydraulics Used in the Nuclear Industry?

Hydraulic systems can provide high force and controlled movement from relatively compact equipment, making them suitable for applications where precise mechanical movement is required.

Hydraulic solutions can be used in various nuclear-sector applications, including:

• Hydraulic lifting systems
• Door opening and closing systems
• Containment systems
• Waste storage facilities
• Pick-and-place mechanical systems

At Hedley, we supply hydraulic power units, pumps, motors and cylinders for nuclear-industry applications.

Why Reliability Matters in Nuclear Hydraulic Systems

Reliability is important in any industrial hydraulic system, but the consequences of failure can be particularly significant in safety-critical environments.

A hydraulic system may control movement, positioning, access, lifting or containment-related equipment. The consequences of unexpected movement or loss of hydraulic pressure therefore need to be considered during system design.

Reliability begins with understanding the application.

Engineers need to consider:

• Required operating pressure
• Required flow rate
• Duty cycle
• Load requirements
• Environmental conditions
• Failure modes
• Hydraulic fluid
• Component compatibility
• Maintenance requirements
• Testing requirements
• Emergency or fail-safe arrangements

These considerations should form part of the engineering design process rather than being addressed after the equipment has been manufactured.

Design for the Application

There is no universal hydraulic system suitable for every nuclear application.

A bespoke design may be required where equipment has unusual load requirements, restricted installation space, specific control requirements or demanding environmental conditions.

Hedley uses 2D hydraulic circuit design and 3D SolidWorks modelling to develop hydraulic systems and hydraulic power units around individual project requirements.

This approach can help identify potential installation and maintenance issues before manufacture.

Component Selection and Quality

Component selection is another important consideration for nuclear hydraulic systems.

Pumps, valves, cylinders, filtration equipment, hoses and fittings need to be selected according to the system’s operating conditions and relevant project specifications.

For safety-critical applications, component traceability, documentation and quality assurance may also form an important part of the procurement and manufacturing process.

Hedley works with established hydraulic manufacturers and has experience providing bespoke solutions for customers operating within the nuclear industry.

Pressure Equipment Compliance

Hydraulic systems can incorporate pressure equipment that falls within the scope of UK pressure equipment legislation.

In Great Britain, the Pressure Equipment (Safety) Regulations 2016 apply to pressure equipment and assemblies with a maximum allowable pressure above 0.5 bar, subject to the regulations’ exclusions and requirements. They cover areas including design, manufacture and conformity assessment.

The specific requirements depend on the equipment, fluid, pressure and classification.

For equipment intended for use on relevant nuclear sites, the Office for Nuclear Regulation is identified as the enforcing authority for the Pressure Equipment (Safety) Regulations in Great Britain.

This is why compliance requirements should be established at the beginning of a project rather than treated as an administrative exercise at the end.

Testing and Verification

Testing is a key part of ensuring that a hydraulic system performs as intended.

Depending on the application, testing can include:

• Pressure testing
• Functional testing
• Leak testing
• Control-system testing
• Cylinder testing
• Flow verification
• Hydraulic cleanliness checks

Hedley’s hydraulic design and manufacturing service includes testing and commissioning, while our hydraulic power units can be fully tested before installation.

Testing before delivery can also provide an opportunity to identify and resolve problems before equipment reaches site.

Hydraulic Cleanliness

Contamination can have a significant effect on hydraulic system reliability.

Particles and other contaminants can damage precision hydraulic components, accelerate wear and contribute to valve, pump and actuator failures.

For this reason, hydraulic cleanliness should be considered throughout manufacture, installation, flushing and commissioning.

At Hedley, we provide hydraulic pipework installation and flushing services, using hydraulic fluid monitoring and cleaning techniques as part of the installation approach.

Designing for Maintenance

Reliability is not only about preventing failure.

The system should also be designed so that inspection, servicing and component replacement can be carried out safely and efficiently.

This may involve:

• Accessible filtration
• Pressure gauges and test points
• Isolation valves
• Suitable inspection access
• Clear pipework routing
• Accessible components
• Monitoring equipment
• Appropriate documentation

Good maintainability can reduce the time required for planned servicing and fault diagnosis.

ALARP and Nuclear Engineering

Nuclear projects also operate within a broader regulatory and safety framework.

UK government guidance published in 2025 sets out principles for applying As Low As Reasonably Practicable (ALARP) and Best Available Techniques (BAT) in the nuclear industry. The guidance is intended to support consistent and proportionate application of these principles and does not change the underlying legal duties.

For hydraulic engineering projects, this reinforces the importance of considering risks and appropriate engineering controls throughout the design and project lifecycle.

The exact requirements will depend on the project, site, equipment and applicable regulatory arrangements.

Choosing a Hydraulic Engineering Partner for Nuclear Projects

When selecting a hydraulic engineering supplier for nuclear applications, it is important to consider more than product availability.

Relevant factors can include:

• Experience within the nuclear sector
• Engineering capability
• Quality management
• Design capability
• Manufacturing facilities
• Testing arrangements
• Documentation
• Component sourcing
• Installation capability
• Service and maintenance support

A Complete Hydraulic Engineering Approach

For demanding applications, having design, manufacture, testing and installation managed by an experienced hydraulic engineering company can simplify project delivery.

At Hedley, we can provide hydraulic system design, hydraulic power units, cylinders, manifolds, pipework, installation, testing and commissioning.

This allows the hydraulic system to be considered as a complete engineered solution rather than a collection of individual components.

Hydraulic Engineering for the Nuclear Industry

Hydraulic systems used within the nuclear sector must be designed around the requirements of the specific application, with reliability, safety, testing, maintainability and applicable compliance requirements considered from the outset.

Hedley Hydraulics has experience providing bespoke hydraulic solutions for nuclear applications and can support projects from hydraulic design through to manufacture, testing and installation.