Unit 1 of the Koeberg Nuclear Power Station was switched off on Saturday 10 December for planned refuelling and routine maintenance.
The previous date for the outage had been postponed more than once.
Koeberg Unit 1 has been online for 407 days since the last outage.
According to Eskom, the delay was to allow time to stabilise the system and recover some generation capacity.
“While Eskom is ready to commence with the outage, with the contractors and all the requisite resources on standby, grid stability is an important consideration prior to shutting down the Unit 1 reactor to commence the maintenance and refuelling outage,” said Sadika Touffie, Acting Chief Nuclear Officer.
“This is going to be a long but necessary outage – the first of its kind for Koeberg. Eskom has taken care to ensure no undue delays are experienced once the project gets under way.”
Outage duration
The outage will be for a duration of approximately six months.
The extended unavailability of the unit is due to the planned long outages meaning the electricity supply system may be under additional strain during the outage.
This will be the 26th refuelling outage on Unit 1 since commissioning.
“It will also see the replacement of the unit’s three steam generators as part of the long-term operation programme of the power station. The reactor pressure vessel head on this unit was replaced several years ago,” Eskom says in a statement.
However, the Koeberg Alert Alliance (KAA) group argues that this is a dangerous move given the current electricity shortage.
“Today (Thursday 8 December) Koeberg Unit 1 was planned to be taken offline for six plus months for refurbishment to extend its life beyond 2024, removing 920MW from the grid, equal to 1 loadshedding stage, costing the economy R311 bn,” the group says.
Protesting the ageing plant
Anti-nuclear demonstrations were held to highlight concerns of Capetonians about the implications of Eskom extending Koeberg’s lifespan next year. The nuclear plant reaches the end of its 40-year lifespan in 2024, but Eskom is trying to extend its operating life by another 20 years before any public consultation.
Earlier this year a small group of protesters representing civil society organisations gathered outside the National Nuclear Regulator (NNR) offices in Table View to protest the suspension and pending discharge of their representative on the NNR Board.
However, Eskom says that the Koeberg units, at 920MW each, are the largest generating units on the African continent. Their safe and reliable operation is a significant contributor to meeting the country’s electricity demand.
The Koeberg outages are planned at times of the year when the impact on the overall electricity supply is minimised as far as possible.
“Koeberg Nuclear Power Station is an important part of the Eskom generating fleet due to its reliable operation, low primary energy costs, its strategic location in the Western Cape to stabilise the national electricity grid and the fact that it is a clean source of energy.
“Unlike other types of power stations, where fuel can be added to continue generating power, the fuel at a nuclear power station is sealed inside a reactor vessel, which is opened for refuelling every 15 to 18 months. This is also a time when the station will perform certain required inspections on equipment and perform more intrusive maintenance that cannot be performed when the unit is online,” Eskom says.
