Explosion put Medupi’s unit 4 out of service for at least a year, says Eskom

Power utility Eskom says it anticipates that Medupi Power Station’s unit 4 will not return to service anytime soon.

This comes as Eskom’s executive management on Monday shared an update on the power utility’s operational performance.

Explosion

The Medupi coal-fired power plant in Limpopo experienced an explosion at its unit 4 generator on 8 August.

While the explosion caused severe damage to the generator, seven employees were treated for shock, but no injuries or fatalities were reported.

Eskom acting group executive for generation, Philip Dukashe, indicated that a detailed investigation into the incident was progressing.

“We had the unfortunate incident of unit 4 at the Medupi Power Station. The detailed investigation is underway, and we have started the process to replace it,” he said.

The Department of Public Enterprises (DPE) had previously confirmed that preliminary investigations into the explosion pointed out that the incident was a result of standard procedures not being followed.

ALSO READ: Medupi explosion may not mean more load shedding, but will cost Eskom billions

Meanwhile, Dukashe said the extent of the damage to the generator was still yet to be confirmed.

“Extent of plant damage to be established, including opening and inspections of the four main turbine cylinders, structural integrity of adjacent plant,” he said.

The executive further said Eskom would get a like-for-like replacement for the damaged equipment.

He added that the unit would not return to service within a year or more.

“[The] Schedule which will inform unit 4 return to service date to be compiled. The unit is not expected to be returned within the next 12 to 18 months,” Dukashe continued to say.

Eskom CEO André de Ruyter in late August told News24 that the explosion could add up to R2 billion to the extensive power plant’s bill, and could take up to two years to mend. 

Purging

The explosion took place at the coal-fired power plant near Lephalale in Limpopo just before 11pm on 7 August while hydrogen was being displaced with carbon dioxide and air, in order to find an external leak. 

This procedure of displacing hydrogen with carbon dioxide and air is called purging.

After the explosion, which took place while the unit was on a short-term outage, it was found that while employees were finding the leak, there was still hydrogen in the generator, which created “an explosive mixture”.

This ignited and resulted in the explosion. The explosion resulted in extensive damage to the generator and other components within close proximity.

READ MORE: Medupi: ‘Paper milestone’ doesn’t address cost, tech, environmental failures

Eskom’s operating department was tasked with the purging of hydrogen from the generator prior to the leak search.

The power utility previously confirmed the suspension of eight employees after the explosion, pending finalisation of the investigation.

The employees include an operating manager, an outage manager, two shift managers and four senior plant operators.

The incident took place just one week after Eskom declared that the contentious Medupi plant had finally reached commercial operation status.

Inside Eskom’s Medupi hydrogen explosion

Additional reporting by Sipho Mabena and Nica Richards