Green Energy Plant Power Outage

In March Sutro Group was commissioned to undertake inspection and maintenance, asset integrity management and quality assurance as part of the 2021 outage of a Green Energy Plant located in South Wales.

The plant is a wood-fired power station, it generates 40MW of renewable electricity for businesses and up to 75,000 homes.

The project made use of the full range of Sutro Group’s services including rope access, drone inspection, NDT inspection and confined space rescue. This included:

Flue Stack Inspection

The purpose of this inspection is to determine the overall condition and fitness for purpose of the Stack and its associated support structure. The general visual inspection was carried out on the Flue Stack with access via rope access and drone inspection, allowing visual contact with the whole of the circumference of the stack. The stack was isolated and offline at the time of the inspection.

As part of the inspection, a percentage of bolts were removed from the stack flanges and underwent tensile stress testing (a form of NDT inspection) to outline their integrity. The UT inspection indicated there is no loss of plate thickness from the installed drawing. A UT Inspection Report was prepared and formed part of the report.

Internal Drone Inspection of the Boiler Furnace

The purpose of this inspection was to determine the overall condition and fitness for purpose of the boiler furnace and its associated support structure. The Elios 2 internal drone was commissioned to undertake the survey negating the need for man entry and associated costs such as scaffolding.

The whole inspection was achieved within 3 hours at a cost of around £3,000. This compares to a total of 5 days and a cost of circa £200,000 using traditional methods of scaffolding and rope access. These traditional methods would also have required 4 scaffolders to erect and disassemble the scaffolding and 4 rope access engineers to carry out the survey. This all adds up to a big cost saving and a massive reduction in health and safety risks.

Asset Integrity NDT Inspection of High-Pressure Steam Main Pipework

The purpose of this inspection was to determine the overall condition and fitness of the 91.5 main bar steam main and its associated welded sections.

As part of the WSE, a percentage of welds were identified for inspection.

A Sutro PCN trained technician undertook shear wave UT and MPI techniques on the following:

4 main steam welds
2 main steam nozzle branch welds

Whilst the majority of welds were found to be in good condition, 1 weld was noted as having wall loss/defects and a repair was initiated via the onsite pipework contractor. A technical report detailing all of the findings was submitted to the client and pipework contractor.

Confined Space Rescue Of All Site Works

As part of the Confined Space Regulations 1997; Regulation 5: Emergency Arrangement

‘Regulation 5 requires that no one should enter or work in a confined space unless there are emergency arrangements in place that are appropriate for the level of risk involved in the task/space.

These should include making provision for extracting workers from the confined space and making provision for first-aid equipment (including resuscitation equipment) where the need can be foreseen.’

To that end, Sutro provided a designated onsite confined space rescue team to facilitate rescue across all site confined space entries in the event of an emergency.

Our management and technicians are City & Guilds trained to ‘Level 5 Managing Confined Spaces’ and ‘High-Risk Rescue’ respectively and are IRATA Rope Access trained to the appropriate level to undertake such rescue techniques.

Sutro’s Power Plant Outage Services

Sutro’s power plant outage team has in-depth experience with planned and unplanned outages. We can help whether you are planning an outage to make your power plant more efficient for the future, or need support dealing with an unplanned plant shutdown.

Sutro Service Capabilities for power plant outages include: