Koeberg Nuclear Power Station Long-Term Operation, Melkbosstrand

Africa has one nuclear power station, and for most of 2023 and 2024 half of it was opened up for surgery. The Koeberg Nuclear Power Station long-term operation program, run by state utility Eskom, replaced all six steam generators at the twin-unit plant near Melkbosstrand, 30 kilometres north of Cape Town, so reactors that entered service in 1984 and 1985 could run another 20 years.

Koeberg’s two Framatome-designed pressurised water reactors each put about 930 MW net on the grid. Together they cover roughly 5% of South Africa’s electricity, which is why every outage there gets felt.

Project Scope

The steam generators were the critical path. The original U-tube units were prone to cracking, and replacing them was a precondition for licensing the plant past its 40-year design life. Eskom’s contract went to Areva, now Framatome, at ZAR 4.4 billion (about $240 million at the time), with the new generators built by Shanghai Electric Power Equipment. Each replacement unit weighs more than 320 tonnes and is 22 metres long.

Unit 1 came offline on 10 December 2022. Removal of the first old generator was announced in March 2023, and the unit returned to the grid on 18 November 2023 after an outage of almost a year, the longest in the plant’s history. Unit 2 went down on 11 December 2023 and was resynchronised on 30 December 2024.

The steam generators weren’t the only work. The wider program, which Nuclear Engineering International put at $1.2 billion, also takes in reactor pressure vessel head replacement, a new refuelling water storage tank completed in 2019, feed-train components and secondary steam system changes. Engineering News reported that General Electric handled balance-of-plant modifications on the secondary turbine system and that Jacobs carried balance-of-plant hardware changes. Jacobs’ scope also covered engineering and construction management on the secondary steam system, according to NEI.

Why It Matters

The licences are the payoff. The National Nuclear Regulator extended Unit 1 to 21 July 2044 in July 2024, and Unit 2 to 9 November 2045 in November 2025.

The schedule wasn’t cheap. Eskom pulled Unit 2’s replacement out of a planned 2022 outage over power-supply concerns, and Framatome treated the postponement as a compensation event under its NEC3 contract. In July 2025 the Western Cape High Court ordered Eskom to pay about €35.3 million plus ZAR 256.6 million, with interest, while arbitration between the two continues.

Eskom points out that more than 120 reactors worldwide now run beyond 40 years. Koeberg has joined them, and South Africa kept 1,860 MW of Western Cape baseload without pouring a new foundation.

Project Team & Details