Eskom CEO Brian Dames has expressed his "disappointment" with industrial group Hitachi over the delay in the building of the boilers for the important Medupi power station.

Dames said that no assessment had been completed and so there was no definite answer on what impact the possibility of the delay may have.

"We are doing the initial assessment now and that should give us a good sense but we don't have a timeframe. The issue is around the boiler work that is being done and particularly around the steel erections being done by them and we are just not confident on their progress on that," he said.

Hitachi won the R38.5 billion tender in a controversial decision by Eskom in 2007 as it emerged that the Japanese industrial group had close ties to the ruling African National Congress' (ANC) investment arm Chancellor House.

Dames said Hitachi had won the contract through a "normal" commercial tender process and that the problems were not unique to SA or for a project of this size. He said that Eskom would take recourse through the normal contract provisions of penalties and that it would enforce its rights.

Dames said that there were no direct implications yet on the commissioning of the giant power station as Eskom always adopted a conservative approach and that the first unit was always planned to come on line in 2013.