Redefining Reliability: Replacing Obsolete Reactor Pressure Test Systems at EDF’s Heysham 1 and Hartlepool Power Stations

Project Overview

Client: EDF Energy - Heysham 1 & Hartlepool

Market Sector: Generating

Modernising Critical Test Equipment to Support Safe Reactor Operations

EDF Energy selected AMS Nuclear Engineering to replace their ageing pressure test trolleys with a modern, dual-range solution that enhances safety, precision and long-term reliability. With decades of experience delivering safety-critical EC&I systems for the UK’s nuclear fleet, AMS brought a combination of technical attention to detail, deep regulatory understanding and hands-on engineering expertise.

The project’s goal was to ensure precision, safety and operational continuity during a critical stage in the station lifecycle – the transition from generation to defueling. AMS’s proven ability to design bespoke, compliant and practical nuclear systems made the team ideally positioned to engineer a modern solution tailored to EDF’s evolving operational needs.

The Challenge. Maintaining Operational Confidence During System Obsolescence.

Heysham 1 and Hartlepool power stations relied on portable “POP” test trolleys to set and verify RPV Safety Relief Valves: equipment operating at pressures up to 45 bar g. However, as EDF prepared for defueling operations, set pressures were to be de-rated to approximately 15 bar g.

The original trolleys, though proven in service, were built for an earlier operating regime. They incorporated legacy instrumentation and were configured for higher-pressure testing. As operational requirements evolved, EDF sought a refreshed solution capable of delivering the same dependable performance at lower pressures, supported by modern digital systems and improved calibration control.

Our Solution. Engineering a Compliant, Dual-Range Test Solution.

AMS Nuclear Engineering responded with a bespoke dual-range test trolley, capable of supporting both the existing (≈45 bar g) and defueling (≈15 bar g) pressure settings. The system was designed from the ground up to deliver accuracy, safety and full regulatory compliance.

Each unit featured:

Dual-range operation, enabling seamless transition between standard and reduced pressures.
Modern digital instrumentation, including 4–20 mA pressure transducers, precision indicators and paperless data recording.
Enhanced operator safety, through robust isolation, vent and regulating valves, plus ergonomic layout for ease of use.
Full compliance with the Pressure Systems Safety Regulations (PSSR 2000), BS EN 61010-1, and ISO 9001:2015 QA standards

AMS delivered the full package – detailed design, documentation, manufacturing and testing, supported by comprehensive Operation and Maintenance manuals.

Many thanks to the AMS Nuclear team, a great job all around by you. It looks the business. 10 out of 10.

Boiler Lead Technologist, EDF Energy

Our Delivery. Delivering Long-Term Reliability and Measurable Value.

The new test trolleys provided EDF with a future-ready, fully traceable solution that enhanced both operational performance and maintainability.

Key outcomes included:

Seamless continuity in pressure testing through dual-range flexibility.
Improved data integrity with modern digital recording and calibration.
Simplified maintenance, using modular design and accessible components.
Reduced downtime through ergonomic design and operator-friendly controls.

The project was completed under QA Grade 2, verified through Factory Acceptance Testing and fully aligned with EDF’s Central Technical Organisation procedures.

Many thanks to the AMS team for a very professional and high-quality job.

Boiler Lead Technologist, EDF Energy

Measurable Results. Safeguarding the Future of Nuclear Operations.

Through this project, AMS demonstrated their ability to translate complex technical challenges into safe, efficient and enduring engineering solutions. The upgraded trolleys are not only maintaining pressure testing capability today, they’re underpinning the long-term reliability of EDF’s defueling operations, ensuring continued safety and compliance across the UK’s nuclear fleet.

Replacing Obsolete Reactor Pressure Test Systems at EDF’s Heysham 1 and Hartlepool Power Stations