The 1.86GW Koeberg nuclear power station (KNPS), located near Cape Town, is the only commercial nuclear power plant (NPP) operating in South Africa as well as in the entire African continent.
Owned and operated by South Africa’s state-owned electricity utility Eskom, the Koeberg NPP comprises two pressurised water reactors (PWRs) supplied by French nuclear reactor manufacturer Framatome.
Construction on both the reactor units was started in 1976, while commissioning took place in April 1984 and July 1985, respectively.
The Koeberg nuclear power station supplied 11,616 gigawatt-hours (GWh) of electricity in 2020, accounting for 5.9% of South Africa’s total electricity production during the year.
Eskom is undertaking a steam turbine retrofit project worth £866m ($1.2bn) to extend the design life and safety of the two units of the Koeberg NPP for an additional 20 years until 2044 and 2045, respectively. The new steam turbines are planned to be installed within two years starting from January 2022.
Koeberg nuclear power station location
The Koeberg nuclear power station is located at Duynefontein, on the Atlantic coast of the Western Cape province of South Africa, approximately 27km north of Cape Town.
Koeberg nuclear power plant make-up
The Koeberg nuclear power station comprises two nuclear power islands, each equipped with a three-loop PWR and three 51B-type steam generators from Framatome. Each generating unit has a net power output of 930MW and a gross electrical capacity of 970MW.
The Koeberg NPP uses seawater for cooling, which is sourced from South Atlantic Benguela Current. The facility features double-walled, titanium-tubed condensers to condense and recover the steam passing through the turbines.
Management of spent fuel and waste from the Koeberg NPP
The spent fuel of the Koeberg NPP is stored in high-density storage racks in spent fuel pools on-site, while the low and intermediate level waste from the facility is transported in steel containers to a remote disposal site at Vaalputs in the Kalahari Desert, located approximately 600km north of Cape Town.
The Vaalputs waste repository is operated by the South African Nuclear Energy Corporation (Necsa), on behalf of the National Radioactive Waste Disposal Institute (NRWDI).
Power transmission from Koeberg
The electricity generated by the Koeberg nuclear power station is evacuated into the South African grid through a 400kV transmission line.
Koeberg nuclear power station refurbishment details
The Eskom Board approved a comprehensive refurbishment plan to extend the operational life of the Koeberg NPP in 2010, while the key contracts were awarded in 2014 and 2015.
The existing six steam generators of the power plant are being replaced with new steam generators as part of the refurbishment project. Each new steam generator will weigh approximately 380 tonnes (t) and measure 20m long.
The steam turbine retrofit project will also involve modifications and replacement of the existing piping systems and the replacement of forced air cooler units, along with necessary modifications to pressure vessels.
The first of six replacement steam generators arrived at the site in September 2020.
Contractors involved in the Koeberg nuclear power plant refurbishment
Areva (now Framatome) received a contract worth £237m ($388m) to design, manufacture and install six new steam generators for the Koeberg NPP in September 2014.
Tractebel was engaged to provide owner’s engineering support services for the replacement of steam generators on both units of the Koeberg nuclear power station in 2015. The contractual scope includes review and verification of engineering studies, quality assurance and control, licensing and engineering support, site management, as well as supervision during commissioning and start-up.
Jacobs, an engineering and construction company based in the US, was contracted to provide construction management services related to the plant’s secondary turbine system modifications in August 2021.
The scope of services will include piping prefabrication, pipe supports, piping modification and replacement, and installation of on-site scaffolding, rigging and lagging, apart from vessel modifications and strengthening, and replacement of forced air cooler units.
Contractors involved in the Koeberg nuclear power project
Framatome designed and supplied the reactors and steam generators, while Westinghouse provided the fuel assembly design and technology for the Koeberg NPP.
Framatome, in consortium with Framateg, was also responsible for the construction of the power plant.
PRDW, an international consulting engineering group based in South Africa, was engaged in site investigation, feasibility studies, and detailed design of breakwaters, pump house structures, and cooling water outfall for the Koeberg nuclear power project.
Averda, a waste management company based in Dubai, delivered the groundwater desalination plant for the Koeberg nuclear power station.
GECI International provided engineering services for licensing and start-up activities of the nuclear power facility.
DENSO Corporation, an automotive supplier based in Japan, provided corrosion prevention solutions for the steel structures of the plant.
Lloyd & Hill, a land survey company based in South Africa, provided regular deformation monitoring and associated engineering surveys for the Koeberg NPP.
Alstom was contracted to retrofit two steam turbines of the plant in March 2009, while Holtec International was contracted for the supply of HI-STAR 100 dual-purpose metal casks for the storage and transportation of spent fuel assemblies of the Koeberg nuclear power station in May 2015.