This is after portions of the station were destroyed after an accident caused by a crack at the root of the low-pressure two (LP2) cylinder blade.
This resulted in 15 other blades breaking off and severe turbine movement and vibration.
Pieces of equipment were catapulted through the roof and an explosion led to a severe fire which raged for more than two hours.
Eskom generation MD Ehud Matya did not put a figure on the refurbishment of the power station.
He said that press estimates of R2-billion probably included the rebuilding of the unit from scratch.
These figures are much higher than what will actually be spent, since Eskom will be salvaging some equipment from the plant and using some spare equipment from sister power plants, noted Matya.
As the company is going into a commercial pro-cess to buy new and like-new equipment, he did not want to give a breakdown of costs.
The commercial preparation and award process is 60% complete, Engineering News was informed.
Prinsloo confirmed that a stripdown and damage assessment had been completed and that a compilation and review of the scope of work was 95% complete.
He noted that the exciter, generator and LP2 shaft would have to be replaced, while the high-pressure and interim-pressure shafts would have to be repaired.
Unit two of the power station is expected to be back on load by the end of this year, Prinsloo reported.
However, the biggest challenge to the repair process remains having to replace the more-than-200-t turbine generator.
This will have to be lifted using a special crane, and the foundations modified for this purpose.
The replacement generator, due to its size, is also expected to take several weeks to be moved from the coast to the power station.
It is proposed that a second-hand, or as-new, unit be bought from the UK.
Prinsloo indicated that staff are enthusiastic about being involved in the maintenance project, which is on a scale greater than has ever been undertaken before.
Matya, in turn, commented that, due to the accident, the company had had to readjust its plans to cater for demand, and had experienced a financial impact.
However, it was able to draw on excess capacity within the group to cater for a sixth of the power plant’s capacity, or 600 MW, not being available.
There had also been no negative effect on customers since the unit was not producing electricity at the time of the accident.
In addition, since power generated at a particular power station is not earmarked for a specific customer, but fed into the power grid, specific customers were not affected.
Matya confirmed that Duvha remains one of the cash cows of the company’s power station group since it was built at the mouth of a mine and is provided with a steady, reliable source of coal.