CEFAS23-44 Contract for BEEMS Tidal Monitoring System - Sizewell B Power Station

The BEEMS (British EDF Estuarine and Marine Studies) programme is funded by NNB Generating Company HPC (NNB GenCo). Through this programme, Cefas provide authoritative scientific information on the marine and transitional waters in the vicinity of potential new build nuclear power stations and require a competent Supplier to deliver the element described below.

The initial objective of this work was to install a tide gauge to provide a precise, robust and reliable system for continuous monitoring, and subsequent transmission of data for tide level at the offshore intake screen marker beacon approximately 1000m from the Sizewell power station.

OTT Hydrometry Ltd (OHL) were commissioned by CEFAS to upgrade the existing tidal monitoring system to include the following aspects:

• Accurate monitoring of tidal levels at the offshore marker to OAD
• Levels recorded on site and transmitted on a 5 minute frequency to the onshore system
• Sufficient power source to maintain service all year round
• Data to be transmitted to the onshore system via radio link
• Data to be sent daily to CEFAS FTP site
• Data to be logged on the onshore system
• A 4-20mA data feed from the onshore system into the Sizewell power station SCADA system
• Ensure vessel used for servicing complies with Cefas' VSAID processes.

In order to ensure the system continues to function correctly and record accurate data it is strongly advised that both the onshore and offshore systems are regularly serviced at 6 monthly intervals. Service would need to cover the following:

Onshore service

• Assessment on battery condition
• Assessment on external antenna and cable run
• Download and assessment of stored data
• Upgrade data logger firmware if required
• Check on all wiring and component condition

Offshore service

• Assessment on wind generator condition
• Clean and report on solar panels
• Assessment of all external wires
• Assessment of radio antenna
• Assessment of level sensor and mount
• Download and assessment of stored data
• Upgrade data logger firmware if required
• Check on all wiring and component condition
• Assessment on battery condition and replacement if required
• Level check
• General assessment on structure condition, particularly mounting points
• Complete previous works (replacement of solar panels and timer switch) from October 2022 service.