- South Africa’s nuclear generation plant was shut down last week.
- Koeberg Unit 1 was shut down after one of the isolation/block valves failed its three-monthly routine test.
- At the time, the plants second unit, Unit 2, was also down on planned maintenance.
- The sudden deficit in generation was picked by government owned open cycle gas turbine plants.
- The news comes as the country’s new National Transmission Company secretly started to export 250MW to Zambia last month. Read more
Five days after the event, the country’s state-owned energy utility, Eskom, finally confirmed the failure.
“Koeberg Unit 1 was conservatively and safely shutdown on Wednesday 11 September 2024 after one of the isolation/block valves failed its three-monthly routine test. The unit was shut down to restore redundancy of the steam pressure relief system in line with the operating technical specifications. At no point was the safety of the plant, staff, public or environment at risk”, said Eskom is a brief statement.
“The intervention has been completed and the unit is in the process of being safely returned to service. All stakeholders who were required to notify were informed as per the stringent protocols,” the utility added.
The last week has seen a massive spike in deployment of Eskom’s open cycle gas turbine plants. Image credit: Eskom
Koeberg Units one and two started commercial operation in 1984 and 1985, respectively. Koeberg’s Unit 1 received a license to continue operating until 2044 in July this year after a life extension programme, and Eskom is planning to extend operation of Unit 2 until 2045.
On 15 July 2024, the National Nuclear Regulator (NNR) announced that its assessment of the Koeberg Long Term Operation (LTO) application concluded that the application is compliant with the technical provisions contained in “Regulations on the Long-Term Operation of Nuclear Installations (R.266)” together with the relevant documentation. The NNR Board granted approval for Koeberg Unit 1 with conditions but to date has not pubically stated the conditions.
The Board further noted that for Koeberg Unit 2, given that the evaluation process for the 20 year extension is still in progress and the current Unit 2 licence sustains until 9 November 2025, the decision is deferred to be made before November 2025.
The latest failure comes in the same month the International Atomic Energy Agency (IAEA) completed a review of long-term operational safety of the Koeberg Nuclear Power Plant (NPP) in South Africa. Concerns were raised over the ageing containment buildings which have degraded over the last 40 years. Read more
The IAEA inspection team noted that the plant needs to continue its work to ensure that:
- The plant programmes supporting Long Term Operation (LTO) are fully implemented for the LTO period.
- The containment monitoring system is fully refurbished and remains fully functional during the LTO period.
Author: Bryan Groenendaal
