Employees working at Unit 4 of Medupi power plant and whose generator exploded at the weekend have been placed on precautionary suspension by Eskom pending the conclusion of an investigation.
Eskom said the explosion occurred during work to displace hydrogen with carbon dioxide and air respectively, in order to find an external leak.
“Following the power station’s preliminary investigation, it appears that while performing this activity air was introduced into the generator at a point where hydrogen was still present in the generator at sufficient quantities to create an explosive mixture, which ignited and resulted in the explosion,” the utility said.
“It also appears that there was a deviation from the procedure for carrying out this activity. As such Eskom has undertaken to place those employees who were responsible to manage and execute this work under precautionary suspension pending the conclusion of the major event investigation.”
The company said the explosion had resulted in extensive damage to the generator, but there were no injuries sustained by personnel on site.
Speaking on news channel Newzroom Afrika, Eskom spokesperson Sikonathi Mantshantsha said the incident was not likely to lead to rolling power blackouts because the unit had already been out for scheduled maintenance.
Energy analyst Chris Yelland posted images of the aftermath of the explosion on Twitter.
Since the start of the year, South Africa has experienced 650 hours of rolling blackouts by Eskom, which supplies about 95% of the country’s energy needs. The utility has struggled to meet demand for more than a decade, while its infrastructure has suffered frequent breakdowns, largely due to years of inadequate maintenance.
A Council for Scientific and Industrial Research (CSIR) report said that in the first half of this year alone, Eskom load shedded 963 gigawatts of power, translating to 76% of the total scheduled blackouts implemented during 2020. This means the country spent 15% of the time in darkness for the first part of 2021.
Last week, Eskom announced that Unit one, the last of six generation units at Medupi, had attained commercial operation status.
“This is an investment that will serve generations of the people of South Africa and power the economy for at least the next half-century,” the utility’s executive for group capital division Bheki Nxumalo said.