Unit Two of the Duvha power station, some 15 km from Witbank, in Mpumalanga, was in the process of being returned to service after an outage, when a fire broke out on the turbo-generator on the morning of January 8.
However, it seems that a month later, the investigation into the incident has not yielded any conclusive findings.
No one was injured in the fire and Eskom spokesperson Tony Stott said at the time that there was no interruption to the electricity supply.
The 600MW unit was said to be stable in shutdown conditions and Eskom authorities launched a technical investigation into the incident.
At the time of the fire, Stott said it would take about a week before investigators could determine the cause of the explosion and the extent of the damage.
Since then, numerous attempts to contact Stott have failed.
The Solidarity Trade Union, which presents some 7 000 Eskom employees, told Engineering News Online this week that it is involved in the Eskom probe, but that the cause of the explosion is still unknown.
“Nothing formal has yet emerged from the investigation, but there are two main issues that the union is querying at this stage,” said Solidarity spokesperson Dirk Hermann.
He said that the union is concerned about the fact that the maintenance of the power station had been outsourced by Eskom and, as a result, the regularity of inspections carried out at Duvha.
“Though the cause has not yet been established, we are arguing that a maintenance problem could have caused the fire. It is actually incredible that no one was hurt in the explosion, because it was big,” Hermann added.
“We are also concerned that the problem could also affect other units and we’ve asked Eskom to conduct thorough inspections at all their stations.
Last month, Solidarity also speculated that the repairs to the unit could run into some R2-billion and take between two and four years to complete.
No official confirmation of any of these allegations could be obtained from the power utility.
It is also not clear what action Eskom would take to prevent such incidents from recurring and it is also not known if any action would be taken against the company tasked with performing the maintenance.
The last unit at the Duvha power station, which cost some R1,6-billion to build, came into operation in 1984. The station employs 900 people and its mine boasts the largest open-cast colliery in the Southern Hemisphere.
Duvha became the first power station in the world to be retrofitted with pulse jet fabric filter plants on three of its six units in 1993. Eskom says these plants contribute largely to the reduction of air pollution by removing 99,99% of the fly ash which otherwise would be released into the air through the station's chimneys.