State-owned power utility Eskom insists that it remains committed to ensuring that first power flows from the first Medupi unit in December 2013. However, it has become increasingly forthright about the risks posed to the schedule and has also shared these risks with the National Energy Regulator of South Africa (Nersa).
In a written response to a Nersa question posed during the recent public hearings into Eskom’s third multiyear price determination application, Eskom indicated that the commercial operation of Medupi Unit 6, the first unit, might only start on February 28, 2014. However, it stressed that it was still targeting December 2013 for first power.
The note indicated that commercial operations might be affected by the emergence of quality assurance issues that had been discovered, relating to boiler welds. Output from the second unit, Unit 5, should begin in July 2014, the response added.
Nersa full-time regulatory member for electricity Thembani Bukula confirmed with Engineering News Online that the alternative date had been provided by Eskom.
However, he stressed that this response had been framed in such a way as to reinforce Eskom’s stated commitment to the December 2013 schedule – a schedule from which Public Enterprises Minister Malusi Gigaba has insisted there should be no deviation.
Nevertheless, Eskom indicated this week that it would need to assess whether commitments it had received from its key contractors, Hitachi Power Africa and Alstom, could in fact be met.
Speaking on Radio 702 on Tuesday, CEO Brian Dames indicated that, despite assurances from leading officials at the two companies, there was a risk that the commitments would not be fulfilled.
“I have commitment from both Alstom and Hitachi that, on the two issues that they have, they will correct all of that and not impact our schedule.
“Now they have let us down a few times. Do I trust them? We will have to see,” Dames said, adding that he was “concerned”.
Public Enterprises Ministry spokesperson Mayihlome Tshwete, told Engineering News Online that he was unaware of any alternative commercial operations date for the first Medupi unit.
He said Eskom, as well as the contractors and the unions at the Medupi project site, had all made public commitments to the December start-up schedule.
However, he said an assessment was under way in a bid to understand whether or not the seven-week strike and the problem contracts could have an effect on the project’s schedule.
Besides a protracted strike and site closure, reports in the Business Day newspaper suggested that there were also boiler-weld problems and that a key control software contract was running well behind schedule.
Alstom confirmed with Engineering News Online that one of the information technology subsystems, namely the boiler protection system, had suffered some delays.
The company also confirmed that it had requested an extension of time under the contract provision to cater for delays in site access.
“Alstom has mobilised resources to meet the December deadline requested by Eskom management,” spokesperson Kobie Hyman said.
Hitachi Power Africa told Engineering News Online that there were two welding-related issues with which it was currently dealing: a site weld problem and a manufacturing workshop weld problem.
Spokesperson Pamella Radebe explained that a problem was identified with the post-weld heat treatment being carried out by an on-site subcontractor. The problem came to light during a routine Hitachi auditing process and was “immediately brought to Eskom’s attention”.
On Unit 6, about 9 000 suspicious welds were identified and were being subjected to hardness testing and verification.
“Based on preliminary results to date we anticipate that the repair rate for these welds will be less than 10%,” Radebe said.
Remedial action would involve re-heat treatment and replacement where necessary, and the repair process would be conducted in parallel with the daily work programme to ensure it was “accommodated within the overall project time schedule”.
Hitachi also discovered that one of its manufacturing subcontractors had failed to adhere to the code processes stipulated by the Welding Procedure Qualification Records codes and standards for the production of boiler pressure parts.
“A requalification process, which is now in its final stages, is being successfully carried out,” she explained, adding that some welds would be replaced.
Repairs would comprise less than 1% of all welds and Hitachi would conduct quality assurance tests to ensure compliance with the codes.
Business Day also reported that outgoing Eskom finance director Paul O’Flaherty would move on to the Medupi site in the coming days to “unlock” any remaining issues with the contracts. He would do so with the support of Balfour Beatty, a leading infrastructure services company from the UK.