A nuclear reactor at Koeberg in Cape Town automatically shut down on Sunday night but risk of power interruption was minimal, Eskom said on Monday.
“The initial indication is that the fault is on the turbine control system, which is currently being investigated,” it said in a statement.
The reactor, Koeberg Unit 2, was being maintained in a safe condition.
The station’s other reactor, Koeberg Unit 1, was running at full power and supply of electricity to the Cape was being augmented by Eskom’s peaking stations.
“The supply of electricity to the Cape is currently stable and the risk of interruption of supply is minimal.”
If the fault was not discovered on Monday, he estimated that the unit would be completely shut down for two to three days. The unit was being held at 6% of its operating capacity while being investigated.
Stott said the incident was unusual as it had shut the whole system down.
The two units supply about 50% of the Western Cape’s electricity needs and together produce about 900 megawatts when running at full power.
Jacob Maroga, Eskom’s MD of transmission, said the situation was being given top priority and that Cape residents would be kept informed on the progress of returning Koeberg Unit 2 to service.
In August this year, Eskom said that in the case of power outages in the Western Cape earlier in the year, it accepted that there were oversights regarding some of its practices and procedures. However, this did not mean that it had been negligent.
Every technical fault did not amount to a breach of a licence condition or negligence, it added.
The power utility was responding to a probe by the National Electricity Regulator of South Africa into power outages in the Western Cape, which found Eskom guilty of transgressing its licensing conditions as well as negligence.
Eskom chief executive Thulani Gcabashe said in August that Eskom’s own investigations into the seven incidents had confirmed that its planned maintenance was properly implemented within the challenges and constraints of a complex operating environment.
“However, areas for improvements have been identified. These included recommendations regarding equipment and systems, procedures, plans and studies and organisation learning strategies.
“All of these have been prioritised and put into action plans that are being monitored at the highest levels of management. More than 50% of the recommendations have already been implemented while others can be regarded as work in progress,” Gcabashe said.