Enabling Safe, Compliant Integration of a New GAM System at Heysham 1

At Heysham 1, the GAM system plays a critical role in monitoring gaseous activity and identifying failed fuel, ensuring reactor conditions remain within defined safety limits.

As part of a fleet-wide modernisation programme, EDF Energy initiated the replacement of legacy GAM systems with a new solution developed by Canberra/Mirion. The new system was to be installed alongside the existing infrastructure, operating in parallel for a defined soak period to validate performance under live conditions.

This created a complex integration scenario – requiring careful coordination between new and existing systems without disrupting ongoing operations or compromising compliance.

Managing Integration Risk Without Disrupting Operations

The key challenge was not simply installing new equipment but ensuring seamless integration with existing plant systems.

The project required:

• Compatibility between legacy electrical supplies, control signals, and the new GAM system
• Modification of existing sample gas interfaces to enable dual system operation
• Assurance that all changes aligned with nuclear safety case requirements and quality standards

At the same time, the solution needed to support uninterrupted station operations, with both systems functioning reliably during the transition period.

AMS Nuclear approached the challenge through a structured, evidence-based engineering methodology focused on early risk reduction and design clarity.

Key activities included:

• A detailed site survey of the existing GAM installation and supporting infrastructure
• Comprehensive review of legacy and new system drawings, including electrical power and control interfaces
• Assessment of EDF’s proposed power supply solution for the new system
• Evaluation of modifications required to the sample gas isolation cubicle to enable parallel operation
• Development of a feasibility and design report defining interface requirements and implementation considerations

The scope covered both electrical integration and process interfaces, including small-bore sample gas pipework and plant signal connections.

All engineering outputs were delivered to QA Grade 2 and verified in accordance with EDF’s Company Technical Standards, ensuring suitability for nuclear safety-related applications.

AMS Nuclear delivered the project through a coordinated engineering and project management approach, ensuring alignment with site requirements and stakeholder expectations.

Engineering Delivery

• Deployment of SQEP C&I engineers to conduct surveys and technical assessments
• Production of a detailed feasibility/design report and marked-up drawings to support implementation

Quality & Compliance

• Formal verification of all documentation in line with QA2 standards
• Provision of verification records and supporting quality documentation
• Submission for client review by EDF SQEP personnel

Project Coordination

• Dedicated project management to oversee delivery and maintain the project quality plan
• Alignment with EDF framework agreement requirements and documentation processes

This project demonstrates how early-stage interface engineering can significantly de-risk complex system upgrades in operational nuclear facilities.

By combining detailed site knowledge with structured design assessment, AMS Nuclear established a repeatable approach that can be applied across the wider fleet, particularly where legacy systems must be integrated with modern technologies under live operating conditions.

The outcome is more than a single project success. It is a proven methodology for enabling safe, compliant and efficient modernisation of safety-critical systems across the UK nuclear sector.