Extending Reactor Safety at Dungeness B: Engineering a Pneumatic Solution That Protects Performance

Project Overview

Client: EDF Energy - Dungeness B

Market Sector: Generating

Safeguarding Boiler Integrity for Long-Term Operation

EDF Energy’s Dungeness B power station, part of the UK’s advanced gas-cooled reactor fleet, required a robust, hazards-qualified system to support its Boiler Lifetime Project. The goal was clear: extend the safe operating life of the boilers and mitigate the impact of any tube leaks, protecting both plant performance and nuclear safety.

With a long-standing track record of delivering safety-critical EC&I systems across the UK nuclear fleet, AMS Nuclear was chosen to design, qualify, and supply the Automatic Boiler Depressurisation System (ABDS) air subsystem — a key part of EDF’s wider reactor protection strategy.

Our team’s combination of technical rigour, practical site experience, and ISO 9001-certified quality systems made AMS the natural partner for this complex modification. Working collaboratively with EDF, we applied our consult–design–build approach to deliver a right-first-time engineering solution that met the highest standards of reliability, compliance and maintainability.

The project demanded technical precision, full regulatory alignment and delivery timed precisely with statutory outage milestones.

The Challenge. Meeting a Critical Challenge Head-On.

The modification challenge centred on developing an air system that could rapidly and reliably depressurise the boiler during abnormal conditions, without disrupting ongoing operations.

The solution would need to:

Integrate seamlessly with existing reactor systems
Meet strict seismic, fire and environmental qualification requirements
Deliver full compliance with EDF’s QA Grade 2 and nuclear safety standards.

With the R22 statutory outage approaching, AMS was tasked with providing a system design ready for manufacture, testing and installation — ahead of schedule.

Every element had to meet Class 2 nuclear qualification and operate reliably under fire, flood and seismic conditions. It was a demanding brief, exactly the kind of challenge our team is built for.

Project Engineer, AMS Nuclear

Our Solution. Designing a System Built for Safety and Simplicity.

AMS delivered a complete consult–design–build solution, engineering a pneumatic subsystem capable of driving the ABDS actuators that depressurise the boilers.

Each air system included:

A solenoid valve panel controlling the air supply to the actuators
A 100 L air receiver providing hazards-qualified stored energy
Flexible hose assemblies and mounting frameworks designed for resilience and ease of maintenance.

The systems were designed for long-term operation through 2033, with all materials, welds, and components meeting EDF Energy, British and international standards (BS EN, ASME IX, IEEE 344).

Factory acceptance testing demonstrated airtight integrity, correct pressure responses and complete functional reliability, all documented through AMS’s Quality Management System and Lifetime Record Package.

Our Delivery. Delivering Results that Strengthen Reactor Safety.

By project completion, AMS had designed, manufactured and tested 16 fully qualified ABDS air systems, ready for integration into both Dungeness B reactors.

The outcomes were significant:

On-schedule delivery supporting EDF’s statutory outage programme for R21 and R22.
Improved safety resilience, with each system proven against fire, flood and seismic hazards.
Lifecycle efficiency, designed for minimal maintenance and complete component traceability.
Regulatory assurance, fully compliant with EDF Energy’s safety case and UK nuclear licensing conditions.

This project exemplifies how collaboration and engineering rigour can deliver dependable outcomes for safety-critical systems. It’s a strong example of AMS working hand-in-hand with EDF to support long-term generation.

Project Manager, AMS Nuclear

Measurable Results. A Proven Model for the Future.

The success of the Dungeness B ABDS project strengthened AMS’s position as a trusted partner in the UK nuclear fleet’s life-extension programme.

By combining engineering precision with a proactive, accountable delivery model, AMS helped EDF Energy achieve a key milestone in their commitment to safe, long-term reactor operation, as well as setting a repeatable standard for future safety-critical modifications across the fleet.

Engineering a Pneumatic Solution That Protects Performance