Eskom shuts down Kusile unit after system failure

Ailing state-owned entity Eskom’s shutdown of a unit of the Kusile power station due to a system failure has increased the prospect of exacerbated load shedding.

Eskom said it anticipated that the Kusile unit may be offline for a few months.

Household chimney

The power utility explains that the duct is similar to a chimney, providing a channel for exhausting gases from the power station.

It said on 23 October exiting of the sulphur dioxide absorber failed on the horizontal rubber expansion joint as well as the compensator.

A compensator directs flue gas up the chimney and allows for thermal expansion of the chimney.

This occurred while the unit was on forced shutdown for flue gas de-sulphuration (FDG) recirculating pump repairs.

The duct that connects Kusile Unit 1 to the smoke stack has failed.

Unit 1, 2 and 3 connect to one smoke stack.
Unit 1 now down.
Unit 2 was off, and remains off as precautionary measure.
Unit 3 was generating, and remains generating. https://t.co/51uuIHvu3z

— Chris Yelland (@chrisyelland) November 2, 2022

Probe

Eskom spokesperson Sikonathi Mantshantsha said investigations and assessments are underway to determine the cause of failure of the Kusile unit, and to ascertain the extent of the damage, as well as the recovery scope of work.

“While it is uncertain at this point, it is anticipated the unit may remain offline for a few months and this duration shall become clearer over the next few weeks.

“Access to the area has also been restricted as part of precautionary measures.

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“Consultations with various specialist stakeholders, including the original equipment manufacturer, are in progress to determine best course of action to restore the plant as quickly as possible,” Mantshantsha said.

Return to service

He explained that the failed section of unit 1’s flue gas duct is located inside the flue chimney.

“The ducts are made from steel sections welded together and surrounded by a windshield, which is made of reinforced concrete that also houses the unit 2 and unit 3 flue gas ducts.”

Mantshatsha added that Kusile Unit 2 was off load at the time, while Unit 3 was generating electricity.

“Unit 4, whose FGD duct is housed on a separate flue chimney, is currently on load generating full load to the national grid.

“As part of precautionary measures put in place, the return to service of Unit 2 has been put on hold while Unit 3 continues to run at stable load,” Mantshantsha said.

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