Engineering a Future-Proof Safety-Critical Monitoring System for Hinkley Point B

The Moisture in Reactor Gas Monitoring System plays an important role in monitoring the condition of reactor circulation gases during station operation. As safety case requirements evolved and equipment approached the latter stages of its operational life, an upgrade was required to ensure continued compliance with the Boiler Tube Safety Case, Vessel Overpressure Protection Equipment (VOPE) requirements and EDF’s standards for Control & Instrumentation modifications.

Rather than simply replacing ageing equipment, the project presented an opportunity to modernise the overall system architecture. The objective was to improve maintainability, simplify future equipment replacement, strengthen system monitoring and establish a Through Life Management Strategy capable of supporting future operational requirements.

From the outset, AMS Nuclear approached the project as a complete systems engineering challenge rather than a straightforward equipment replacement.

Working collaboratively with EDF engineers, the project progressed through concept design, detailed engineering and multiple design reviews as operational requirements continued to evolve. Regular technical workshops, clarification meetings and formal design reviews ensured that new safety case requirements, alarm philosophy updates and operational improvements could be incorporated while maintaining programme progress. Throughout the design phase, project risks, technical queries and implementation strategies were actively managed to provide a controlled and fully substantiated engineering solution.

The engineering solution extended well beyond instrumentation selection. Human Factors considerations influenced the design of the operator interface, while close engagement with specialist partners ensured the developing design satisfied seismic qualification, electromagnetic compatibility (EMC) and safety case requirements. This collaborative approach allowed the system architecture to mature alongside the evolving project specification whilst maintaining confidence in the final solution.

AMS Nuclear delivered a complete engineering package covering every stage of the project lifecycle, from initial concept development through to commissioning and operational handover.

The upgraded MIRG systems introduced significant improvements across both instrumentation and system functionality. Enhanced sample conditioning arrangements improved gas measurement performance, while redesigned sample gas paths optimised flow characteristics and simplified maintenance activities. The system architecture was deliberately developed to remove the restrictive nature of the original design, allowing future analyser technologies to be incorporated without fundamental system redesign.

A comprehensive redesign of the alarm philosophy aligned system operation with EDF standards whilst introducing new control logic capable of supporting VOPE requirements. The revised architecture ensured that individual analyser alarms could initiate the required voting logic whilst maintaining the integrity expected of a Category B safety significant system.

Behind the physical installation sat an extensive programme of engineering substantiation. AMS Nuclear produced detailed design reports, calculations, specifications, risk registers and implementation strategies alongside complete drawing packages covering instrumentation, electrical systems, process pipework, control logic, operator interfaces and equipment layouts. Reliability assessments, component compliance reviews, alarm analysis, FMEA preparation, FAT and SAT planning, obsolescence planning and software registers formed part of the overall engineering deliverable, ensuring the final solution was fully justified and ready for long-term operational service.

The project also required extensive equipment qualification activities. Seismic qualification by design and testing, EMC gap analysis and EMC qualification against BS EN 61326-3-1 ensured the upgraded systems could operate reliably within the demanding nuclear environment while supporting the station’s safety case obligations.

Following completion of the engineering phase, AMS Nuclear manufactured, tested, installed and commissioned eight Moisture in Reactor Gas Monitoring Systems for Hinkley Point B.

The project demanded close coordination between AMS Nuclear, EDF and specialist suppliers throughout manufacture, installation and commissioning to ensure programme objectives were maintained while supporting station operational requirements. Working as an integrated engineering team, AMS Nuclear successfully managed technical interfaces across multiple disciplines to deliver the complete system into operational service.

The finished installation incorporated improved operator interfaces, enhanced maintenance facilities, optimised sample pipe routing, modern alarm and interlock arrangements and a flexible system architecture designed to support future lifecycle requirements without extensive redesign.

The successful completion of the project provided Hinkley Point B with more than replacement monitoring equipment, it delivered a fully modernised moisture measurement and sampling system designed to support the station throughout its remaining operational life.

All eight MIRG systems were delivered, commissioned and placed into operational service, providing enhanced monitoring capability, improved maintainability and greater flexibility for future equipment upgrades. The project also established a robust engineering baseline through comprehensive design substantiation, equipment qualification and lifecycle planning, ensuring the upgraded systems could continue to support evolving operational and safety case requirements.

As one of AMS Nuclear’s most significant safety-critical engineering programmes, the project demonstrates the company’s capability to deliver complete EC&I solutions for complex nuclear applications – from concept development and systems engineering through to manufacture, qualification, installation and commissioning.

• Complete design, substantiation, manufacture, testing, installation and commissioning of eight Moisture in Reactor Gas Monitoring Systems.
• Category B, Class 2 safety significant Control & Instrumentation system.
• Comprehensive design substantiation supporting evolving safety case requirements.
• Modern alarm philosophy and voting logic supporting VOPE functionality.
• Through Life Management Strategy (TLMS) incorporated into the system architecture.
• Full seismic qualification by design and testing.
• EMC gap analysis and qualification against BS EN 61326-3-1.
• Human Factors integration to improve operator usability and maintainability.
• Comprehensive reliability assessments, FMEA preparation, FAT/SAT planning and obsolescence management.