Electricity Minister Dr Kgosientsho Ramokgopa has expressed deep concern that another delay to the return to service of Koeberg Unit 1 could result in both of the nuclear power station’s units being out of service simultaneously later this year.

The unit is currently undergoing a long-duration outage that includes the replacement of its three steam generators, which is one of the preconditions for extending the plant’s life for 20 years.

Speaking during his weekly update on the implementation of the Energy Action Plan, which followed a recent period of intense Stage 6 loadshedding, the Minister revealed that he was growing increasingly concerned that there could be an outage “overlap”, which would result in a period where there would be no production from Koeberg.

“That would represent a net loss of 920 MW from where we are currently [with Unit 1 being out of service]. That’s a huge dent on our generating capacity.”

Ramokgopa indicated he had planned to meet with the leadership of Koeberg last week for a report on the outage, but he had been unable to do so and that the meeting would take place this week instead.

“I've asked for a more detailed report, and the more we get an indication of what the issues are, the more we are getting very, very, very worried. It is something that requires urgent attention.”

The Unit 1 outage began on December 10 and was initially scheduled to continue for about 180 days and returned to service in June.

In March, however, the State-owned utility confirmed that the early June return to service date was “no longer achievable”, but that it would be reintroduced before Unit 2 was shut in September for a similar outage. This, after a previous attempt to replace the Unit 2 steam generators was postponed when it emerged that Eskom’s storage facilities had not been completed in time.

It is understood that Unit 1 may now only be returned in October, but this has not yet been confirmed by Eskom despite several Engineering News enquiries in recent days.

Eskom indicated to Engineering News last week that it was planning to issue a formal statement on developments at Koeberg, but no statement had yet been released by the time Ramokgopa held his briefing.

Eskom did confirm, however, that all three Unit 1 steam generators had been successfully replaced and welding in these generators had commenced.

“We would also like to assure the public that it is our commitment to ensure that we prioritise safe working standards on this project,” the utility added in a written response to questions posed.

No answers were provided regarding the effect of the outage slips on Eskom’s efforts to secure a Long-Term Operation (LTO) licence.

Unit 1’s 40-year licence expires on July 21, 2024, and it is currently uncertain whether Eskom has received confirmation of a separate licence validity date for Unit 2, to reflect the fact that the unit came into operation a year-and-a-half after Unit 1 in November 1985.

Securing the licence change request for Unit 2 has been identified as a key priority and risk for the operation of Koeberg for a further 20 years.