Photo Jay Caboz.
Koeberg Power Plant. Photo Jay Caboz.
  • Following a trip at the Koeberg nuclear power station, just outside of Cape Town, South Africa was once again plunged into stage four load shedding on Tuesday.
  • The state utility said it was in the process of gaining regulatory approval to synchronise back onto the grid, which could be by Sunday.
  • While South African’s gripe in their dark offices, Business Insider gathered some surprising facts about Koeberg.
  • For more stories, go to www.BusinessInsider.co.za. 

Following a trip at the Koeberg nuclear power station, just outside of Cape Town, South Africa was once again plunged into stage four load shedding on Tuesday.

The trip which resulted in Unit 1 having to be disconnected from the grid.  It has since been fixed, said Eskom. The state utility said it was in the process of gaining regulatory approval to synchronise back onto the grid, which could be by Sunday. 

Eskom assured the country that the nuclear reactor section of the plant was not affected.

While South African’s gripe in their dark offices, Business Insider gathered some surprising facts about Koeberg:


Koeberg power station has been running since 1984 and is the only nuclear reactor in Africa.

It boasts the largest turbine generators in the Southern Hemisphere and is the most southerly-situated nuclear power station in the world.


It is situated at Duynefontein, 27 kilometres  north of Cape Town on the Atlantic coast.

Source Google Maps.
Koeberg power station. Source Google Maps.

Koeberg is surrounded by 3 000 hectares of nature reserve owned by Eskom, containing more than 150 different species of birds and half a dozen small mammal species. The reserve is open to the public and a great place for hikes.

Using imagery, we can show you how it looked before it was built (1974) to now. 

The land where Koeberg was built in 1976 was little more than dunes and fynbos. We hunted down National Geo-spatial Information imagery to show how it looked in 1974 and compared it to 2018. The impact is striking.

Images across the country are free on the Department of Rural Development and Land Reform website, which has the largest repository of historical aerial photography dating back to 1926.

Koeberg has an installed capacity of 1 940 MW, which powers roughly 3.6% of South Africa’s electricity.

Compiled by Jay Caboz.
Eskom's energy bread basket in percentage. Data source IRP2019, IPP website, Eskom statement updates. Compiled by Jay Caboz.

Unit 1 holds a record of running for 400 days without being interrupted, a milestone that was achieved in December 2017. Koeberg, Africa’s only nuclear power station, has an installed capacity of 1 940 MW.

It provides approximately 3.6% of South Africa’s energy needs.


It consists of two 970 MW units.

On 4 April 1984 Unit 1 came online, with Unit 2 following suit on 25 July 1985.


Unit 1 was just recently serviced and came back onto the grid on 6 January.

Every 15 to 18 months a unit is shut down for refuelling, maintenance and statutory inspections. Outages are scheduled to avoid having both units out of service at the same time.

During these routine outages, one third of the used nuclear fuel is replaced with new fuel. Maintenance, plant modifications, inspections and statutory work is done to ensure that international safety standards continue to be met and that reliable plant performance continues. 


Spent fuel is stored on site on Keoberg in special pools equipped with high-density racking. 

The low and intermediate level waste from Koeberg is transported by road in steel and concrete containers to a remote disposal site at Vaalputs, 600 km away in the Kalahari Desert.

Source Google Maps.
From Koeberg to Vaalputs. Source Google Maps.

The Vaalputs trenches are eight metres deep and are therefore surrounded by clay and 50 metres above the water-table. When the trenches are full they are back-filled and capped with two metres of compacted clay to exclude rainwater before being covered with sand and replanted with the original vegetation.

Source Google Earth.
VaalputsRadioactive Waste Disposal Facility. Source Google Earth.


Koeberg operates on three separate water systems: a primary loop, secondary loop, and a tertiary loop.

Source Eskom.
Source Eskom.

Each system is separate because it means that the water in the reactor, which is radioactive but is in a closed system, does not come into contact with the other two systems. This system is kept under pressure, hence the name Pressurised Water Reactor (PWR).

After the steam has been used to drive the Turbine, it is sucked down into the condenser where a third circuit, utilising seawater, pumps in at a rate of 40 tons per second.


In April 2019 Eskom announced that it was overhauling Koeberg with the aim of extending its lifespan by at least 20 years, reported fin24

Nuclear plants in other countries with similar designs to Koeberg, which operate pressurised water reactors, have secured approval to operate for 60 years and some are considering applying for a further 20 year extension, according to Eskom.


Here’s a video explaining how Koeberg generates power.

Ever wondered how Koeberg makes its electricity? Learn about it in just five minutes. 


The cooling water system for the condensers uses seawater – at the rate of 80 tons every second to cool the steam in the condensers.

Source Google Maps.
Source Google Maps.

Once it has cooled the steam, it is returned to the sea. 


In 2016, a drone crashed into the Koeberg Power Station site.           

The drone was returned to the owner, which resulted in the company suspending its safety officer for not reporting the violation. Drone laws prohibit the flying of drones near  national key points and nuclear power plants


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