Eskom said all procedures were followed when shutting down the unit. (David Harrison/M&G)
The sudden shutdown of Koeberg 1 earlier this month has provided ammunition for environmental activists who have campaigned against adding any more nuclear power to South Africa's energy mix, as well as activists opposed to extending the plant's lifespan.
According to Eskom, the unit was shut down on September 11 to restore redundancy in the steam pressure relief system in line with the operational technical specifications after one of the isolation/block valves failed its three-monthly routine inspection.
“This outage shows what we should expect from South Africa's nuclear plants, given the repeated unexpected shutdowns, constant changes to completion dates and continued misleading of the public about true costs,” Cobourg Alert Alliance spokeswoman Lydia Petersen said in a statement.
The alliance is a group of organisations and individuals who oppose the construction of further reactors at nuclear power plants.
The Koeberg nuclear power plant has been unable to feed into the grid for about 28% of its lifespan. Unit 1 was due to end its life in July, but the nuclear regulator extended its operating licence for another 20 years just days before.
Environmental groups have appealed the decision, arguing it was shrouded in secrecy.
Power and Energy Minister Gosientosho Ramokgopa recently withdrew the gazette of his decision to go ahead with nuclear power after environmentalists challenged it on grounds of fairness and legality.
Ramokgopa said earlier this month that South Africa would “follow the science” to develop nuclear power capacity as part of a just transition to cleaner renewable energy sources, including wind, solar and hydropower, despite opposition from “emotional lobbyists” who argue about the dangers of nuclear power and radioactive waste disposal.
He said the country still plans to secure 2,500 megawatts of energy from nuclear power, as set out in the 2019 Integrated Resource Plan.
The coalition said the recent closure of the Koeberg thermal power station, which generates about 405 megawatts, was cause for concern, according to Eskom spokesperson Daphne Mokwena.
“This unexpected outage raises important questions about the sustainability of our reliance on our aging nuclear infrastructure,” Petersen said.
“This situation so soon after the new licence was issued raises questions about whether sufficient upgrades and safety improvements have been made to ensure long-term operation.”
Eskom said all procedures were followed when shutting down the unit.
“Koeberg 1 was carefully and safely shut down on Wednesday 11 September 2024…The safety of the plant, staff, the public or the environment was not put at risk. Interventions have been completed and the unit is in the process of safely restarting and is expected to be restarted by the end of this week. All parties that needed to be notified have been notified in accordance with strict procedures,” Mokwena said.
But Hartmut Winkler from the University of Johannesburg's physics department isn't convinced.
“All power plants, including nuclear plants, have outages from time to time. That in itself is nothing remarkable and Koeberg has two or three such outages every year. But what is surprising now is that this outage was a bit longer and came after major refurbishment works had been completed less than a year ago,” he said.
“Also, what concerns many is that Eskom did not announce the matter until information was leaked to the press, suggesting that the matter may become embarrassing and lead to further public scrutiny. Eskom needs to be open with the public about Koeberg's operations and admit problems when they arise. A statement that the plant has been 'safely shut down' is not enough.”
Both Winkler and his coalition have expressed concerns about the costs associated with building nuclear plants, and Winkler has argued the country would be better off pursuing renewable energy sources such as solar and wind.
“I don't see any room for new nuclear power in South Africa's energy future. Nuclear can no longer compete economically with solar and wind, and improvements in storage technology mean that the intermittency of renewables is not as big an issue as it once was,” Winkler said.
“Building a new nuclear power plant typically takes 10 years and often significantly exceeds the original planned costs and completion times. If the process and associated construction works are done properly and within budget, there is no problem with extending the life of the Koeberg.”
Environmental groups also point out that the Western Cape has a stable electricity supply, despite Koeberg standing by his argument that it is not needed.
“The successful implementation of our generation recovery plan ensures that we continue to have sufficient generating capacity, with sufficient emergency reserves to meet any sudden changes in peak demand,” Eskom said.
Winkler said science and cost models should determine whether the Koeberg plant should be extended and whether nuclear power should be considered as a national energy source.
“Instead of touting the benefits of nuclear power and prematurely providing support, [Ramokgopa] “The report will enable a proper and expert scientific evaluation and cost assessment of future energy scenarios and should form the basis of a fully revised comprehensive resource plan for electricity,” he said.
“He has already rejected the previous draft plan, presented almost a year ago, which was found to be seriously flawed by erroneous assumptions and questionable model calculations. Any decisions regarding the future of nuclear power plant construction or the life extension of the Koeberg nuclear power plant must be made based on the results of expert modelling and research.”
