Eskom’s Duvha
power station unit 4,
after the incident
 
Pretoria, South Africa — ESI-AFRICA.COM — 28 November 2011 – Workers who deviated from the rules earlier this year knocked unit four at Eskom’s Duvha power station “’ which meant 600MW of critical generation capacity “’ out of the generation system.

South Africa’s national power utility has disclosed the findings of a comprehensive investigation into an event that on February 9 resulted in massive damage to the steam turbine, electricity generator and components supporting the unit at Duvha. Sake24 reports that the loss of 600MW could topple the balance of South Africa’s extremely fragile electricity supply, again causing power cuts to ravage the country, particularly over the coming three months.

The mechanical damage at Duvha at the time caused a fire leading to structural damage to the adjacent walls and steel support structures.

The good news is that Eskom’s insurer will cover the claim for the damage. Eskom spokesperson Hilary Joffe declined to disclose the amount, but said that it was considerably less than the R3billion previously mentioned to Sake24. As in the case of any other insurance claim, an excess payment is required, said Joffe.

Last week Eskom chief executive Brian Dames said that Eskom itself, two groups of independent consultants from the insurer, as well as Eskom’s engineering consultants had come to the conclusion that deficient and ineffective management in several areas had led to the incident.

The underlying cause was modifications to the control system in 2004. The direct cause was that the operator had deviated from the prescribed procedure for the overspeed test.

Eskom said the modifications had since been replaced by modifications approved by the manufacturer. All other units at Duvha had been inspected and, where necessary, the same modifications had been done. New rules had been introduced to prevent a repetition.

Where staff members had deviated from prescribed procedures Eskom would take disciplinary action, if necessary, said Joffe. Monitoring requirements for similar testing and training materials have also been improved

Dames said the current focus was on repairing the unit. Eskom’s teams had already dismantled the damaged equipment, determined the precise extent of the damage, and started to buy new components.

The turbine and the foundations of the generator will be repaired early next year, after which the system will be assembled by mid-year. The unit is expected to return to operation by the third quarter of 2012.