Environmentalists warn against new nuclear energy expansion after Koeberg’s unit one shutdown

The unexpected shutdown of unit one at the Koeberg Nuclear Power Station earlier this month has given ammunition to environmental activists who have been campaigning against the addition of further nuclear power to South Africa’s energy mix, and those opposed to the extension of Koeberg’s life span. 

According to Eskom, the unit was shut down on 11 September to restore redundancy of the steam pressure relief system in line with the operating technical specifications after one of the isolation/block valves failed its three-monthly routine test.  

“This latest outage indicates what we should expect from nuclear power in South Africa’s repeated unexpected outages in addition to constantly shifting completion dates and ongoing deception of the public of the actual costs involved,” the Koeberg Alert Alliance’s spokesperson, Lydia Petersen, said in a statement. 

The alliance is a group of organisations and individuals opposed to the building of further nuclear reactors at the station.

Over its lifetime Koeberg has not been able to deliver power to the grid about 28% of the time. Its unit one was set to reach end of life by July, but a few days before that the nuclear regulator extended the licence by 20 years. 

Environment groups have launched appeals against this decision, which they say was shrouded in secrecy. 

Electricity and Energy Minister Kgosientsho Ramokgopa recently withdrew the gazetting of a ministerial determination to proceed with nuclear power after environmentalists challenged it based on fairness and legality.

Earlier this month Ramokgopa said South Africa would “follow the science” to develop nuclear power capacity as part of the country’s just transition to cleaner renewable energy, including wind, solar and hydropower, despite opposition by what he called “emotionally charged lobbyists” who cite the dangers of nuclear power and radioactive waste disposal. 

He said the country still has plans to pursue 2 500 megawatts of energy from nuclear, as set out in the Integrated Resource Plan  2019.

The latest shutdown of Koeberg — which is generating about 405 megawatts, according to Eskom spokesperson Daphne Mokwena — is concerning, the alliance said.

“This unexpected shutdown raises important questions about the sustainability of relying on ageing nuclear infrastructure,” Petersen said.

“This situation, so soon after the new licence, raises questions about whether the necessary upgrades and safety improvements for long-term operation were fully addressed.”

Eskom said all protocol was observed when the unit was shut down. 

“Koeberg Unit 1 was conservatively and safely shut down on Wednesday 11 September 2024 … At no point was the safety of the plant, staff, public or environment at risk. The intervention has been completed and the unit is in the process of being safely returned to service and will be returned to service by the end of this week. All stakeholders who were required to notify were informed as per the stringent protocols,” Mokwena said. 

But Hartmut Winkler, of the University of Johannesburg’s department of physics, remains unconvinced. 

“Shutdowns happen on occasion at all power plants, including nuclear plants. That in itself is not remarkable, and Koeberg typically has a couple of such shutdowns each year. What however raised eyebrows now was that this one was slightly long and happened after a major refurbishment completed less than a year ago,” he said.

“What also worried many is that Eskom never announced it until the information was leaked to the press, suggesting that the matter was potentially embarrassing and led to greater public scrutiny. Eskom needs to be open with the public about its Koeberg operations and admit to problems when they occur. Statements about the plant being ‘switched off safely’ don’t cut it.”

Both Winkler and the alliance raised concerns about the costs associated with a nuclear build, with the former arguing that it would be better for the country to pursue renewable sources of energy such as solar and wind. 

“I see no place for new nuclear in South Africa’s energy future. Nuclear can no longer compete financially with solar and wind, and with improved storage technologies the intermittency of renewables is no longer the major problem it once was,” Winkler said.

“New nuclear builds also typically take 10 years, and often vastly exceed initially projected costs and completion times. I would not have a problem with extending the life of Koeberg if the process and the associated construction work was done properly and within the projected budget.”

Environment groups have also pointed to the Western Cape’s stable electricity supply despite Koeberg being down to back the argument that it is not needed.

Eskom has said the “successful implementation of the generation operational recovery plan continues to ensure that we have sufficient generation capacity. Additionally, we have sufficient emergency reserves to handle any sudden changes in demand during peak periods.”

Winkler said science and cost modelling should dictate whether Koeberg should be extended and whether nuclear power should even be considered for the country’s energy path.

“Instead of promoting the virtues of nuclear and making premature supportive moves he [Ramokgopa] should allow a proper, professional scientific and cost evaluation of future energy scenarios that would provide the basis of a completely revised Integrated Resource Plan for Electricity,” he said.

“He has already rejected the previous draft plan released about a year ago that was shown to be seriously flawed due to incorrect assumptions and dubious model calculations. Any decisions on the future of nuclear builds or the Koeberg life extension should be guided by the outcome of professional modelling and studies.”