Eskom 'up to the challenge' as Koeberg outages approach
Koeberg unit 1 is expected to shut down for an extended outage - to include refuelling and the replacement of three steam generators - by mid-December. It is expected to remain out of service until June 2023, meaning 920 MWe of capacity will be unavailable to meet South African generation needs, Oberholzer said at during Eskom's State of the System briefing on 15 November. Koeberg 2 will then undergo a similar outage for refuelling, maintenance and steam generator replacement starting in September 2023. This is expected to last for up to 200 days, he said.
The work being done at Koeberg is part of activities to enable the plant to operate for another 20 years beyond its current licence which expires in 2024-2025. The formal application to extend the operating licence was submitted to South Africa's National Nuclear Regulator in 2021, and Eskom submitted the safety case for long-term operation in support of the application earlier this year. The regulator has two years to conclude the review and provide an outcome, but no safety concerns have been identified that would preclude long term operation, and the company anticipates receiving the licence to operate beyond 2024.
Oberholzer said the anticipated timescale for the outages has now increased from earlier estimates of 120-150 days to 180-200 days after Framatome shared experience from steam generator replacement at Watts Bar in the USA, carried out earlier this year. Based on Framatome's experience at Watts Bar and from other steam generator replacements, he said, Eskom has now set more "realistic" targets.
"They've done it many times before so I asked them what is a realistic period to replace steam generators and they asked me what was in our plan … and they said there's no way you can do it [in that time frame]," he said.
In total, a budget of ZAR20 billion (USD1.15 billion) has been approved for the costs of extending the operating life of Koeberg, he confirmed.
Whatever it takes
South Africa's electricity generation is dominated by coal - Koeberg supplies about 5%. However state-owned utility Eskom's company-wide energy availability factor - or EAF - for 2022 has been 58.53% which is far below the targeted performance level of 75%, and load-shedding has been occurring on a regular basis. A key contributor to the low EAF has been high levels of planned maintenance over the summer months, the company said. Oberholzer said Eskom is determined to turn this around, but added that South Africa needs additional generating capacity in addition to improving outage times.
"Where we find ourselves now, it looks like a very steep hill … however we have accepted the challenge to improve the energy availability of [our coal and nuclear fleet], make no mistake. And we will do whatever is necessary to turn it around and to ensure available capacity to the country," he said.
"However I need to emphasise that we need additional capacity in the country 'the day before yesterday', in order for generation colleagues to properly maintain and look after the plant. And again I want to emphasise and that then means [we have to] make sure that when we execute work, whatever is required, that we do it properly, and that we don't [then] have trips and challenges after we've invested the money and the time to get the units to perform."
