Kusile Power Station, RSA

Delta Scan used as inspection consultant for Eskom Kusile Power station Assessments.

Delta Scan was appointed as the lead inspection team for the flue collapse at Eskoms Kusile power station. Kusile Units 1, 2, and 3 were offline for nearly a year after a flue-gas duct (FGD) collapsed in October 2022.

Their absence from Eskom’s grid left a 2,400MW hole in the utility’s generating capacity. This increased the required level of load-shedding by roughly two and a half stages for much of 2023.

Delta Scan initially assessed and established the cause of the collapse. Utilizing our specialized confined space inspection drone, the ELIOS 3, equipped with combined SLAM LiDAR technology, we successfully determined the cause. Excessive ash accumulation on the internal face of the flue led to the collapse through dislodgement. We accurately calculated the volumes of these ash deposits and assessed the unplanned load and forces exerted on the structure. It’s important to note that the structure was deemed unsafe for human access and at risk of further collapse. Our contribution was pivotal in achieving these insights.

The Aftermath:

After the initial investigation and verification of damages, our team took on the responsibility of conducting weekly assessments on the structure. These assessments aimed to determine the stability and structural integrity of the structure over time. To accomplish this, our team deployed the ELIOS 3 once again. For each deployment, the ELIOS 3 was piloted 180m up the chimney stack. The team then assessed the integrity of the supporting structure, bolts, nuts, and welds. Subsequently, post-operation assessments of the LIDAR data were conducted to understand the deflection behavior on major structural components.

Fortunately, it was determined that the structure had retained its integrity, allowing Eskom to finally devise a plan to recommission the structure. With a workaround solution in place, Eskom successfully returned Unit 3 to the grid through a temporary stack solution on 30th September 2023, followed by Unit 1 on the 16th October 2023.

These two units combined, add around 1,600MW of capacity to Eskom’s grid. This significantly improves the state of the system and reduces load-shedding.

Kusile’s Unit 2 is slated for a return to service with the temporary stacks before the end of November 2023.

Delta Scan was pivotal in this project. We are proud to have contributed into establishing a way forward to eventually alleviate the burden of load shedding on South Africa in some way or another.