Sizewell C - HR Monitoring (CRX & Building) Package

Overview of Scope Supply and installation of the HR Monitoring System to the to CRX and Nuclear Island Building The EAU (containment monitoring) system is required to continuously monitor and assess the mechanical behaviour and integrity of the Reactor Building and integrity of the Reactor Building and associated at nuclear island at Sizewell C (SZC) throughout construction, testing, and operation.

The system scope covers the design, supply, installation, commissioning, and documentation of: • Monitoring sensors (including extensometers, temperature probes, hydraulic levelling pots, pendulums, invar wires, inclinometers, hygrometers, and pressure sensors) • Associated cabling, connection/grouping boxes, and acquisition/data logger cabinets • All necessary software interfaces and data collection/reporting tools More than 200 sensors will be embedded and installed in both the inner containment wall and the common raft of the nuclear island.

The EAU monitoring system must provide real-time and periodic data on: • Settlements and deformations of the nuclear island raft (topographical markers, hydraulic levelling pots, extensometers, and temperature sensors) • Overall containment distortions (pendulums and invar wires) • Localized deformations and tendon failure detection (embedded extensometers, local monitoring devices) • Tension in prestressed cables (dynamometers) • Environmental parameters (temperature, humidity, internal and external pressure) All EAU system components must comply with the Book of Technical Specifications (BTS) Chapter 9.04 and associated referenced as well as client installation and interface requirements.

Instruments must be delivered with calibration certificates and installed in accordance with manufacturer and project-specific procedures.

The EAU system contractor will also provide: • Installation studies and execution drawings for all phases (temporary/erection and permanent/operational) • Material Approval Forms, Inspection and Test Plans, Quality Release Certificates, and Lifetime Quality Records (LTQR) • Data collection, reporting formats, and periodic analysis files as required by the client (monthly/bi-monthly during construction; weekly/daily during key phases; and as specified during operation)