The purpose of the NNR is: to focus on the safety of Koeberg, to address its recent developments and their safety impact, and to concentrate on the refuelling of Unit 2 and its implications.

The NNR Regulatory Process describes the requirements that ESKOM has to adhere to: Safety Standards, Licensing Directives, Licensing Guides, Nuclear Licence, demanding a Safety Analysis Report from ESKOM. Furthermore, NNR performs technical assessments and Compliance Assurance Programmes to ensure that ESKOM programmes, management and procedures are up to standard through in-service inspection and maintenance assessment. ESKOM must be in accordance with the NNR ACT. It is required that its standards and practices are internationally competent and that it applies international experience and feedback. The Regulatory Process assures nuclear safety through in depth defence of multiple barriers of protection with numerous means to protect each barrier, as well as provisions of prevention, control, mitigation, containment and emergency response. There exist two trains of each safety system, including heat removal systems. Power supplies off-site are: the National grid (400kV and 132 kV), Acacia (3 generators) and a dedicated line to Koeberg, whereas on-site power supplies are diesel generators, two for each unit and an additional generator for either unit. A house-load operation is also available.

The inspection on maintenance 18-24 January entailed the evaluation of possible serious issues with regard to the maintenance of Koeberg in the light of events involving unscheduled shutdowns of both units from December 2005 to February 2006. Both the SAPS and NIA was in agreement with the NNR that the current security arrangements are adequate. The assessment of the grid reliability focused on the identification of causes of failure, corrective actions and risk implications. The conclusion was reached that Acacia’s dedication to Koeberg and N-1 mode of operation of grid is now a prerequisite. Grid insulators must be modified for better adaptability to weather conditions.

On 25 December Unit 1 at Koeberg was shutdown for generator repairs due to a loose bolt (8 cm) left in the generator. After maintenance inspection, no safety issues were identified although minor issues were raised. The unit will remain shutdown while repairs on the generator are being done.

Between 25 December and 19 January power outages led to grid failures and the NNR agrees with the response of Acacia and Koeberg. On 19 February heavy "mist and residual pollution from fires", led to grid power supply problems that also affected the power supply from Acacia to Koeberg. Within 10 seconds emergency power was drawn from internal diesel generators. ESKOM was directed to keep the plant shutdown until safety assurance was provided, which was granted by the NNR on 22 February. The plant was synchronized to the national grid by 23 February.

One of the 400kV lines, supplying the Western Cape with Power from the north, experienced a fault. Unit 2 at Koeberg underwent a turbine trip and shut down completely. The 132kV line from Acacia also experienced a problem due to a switching error at the Acacia power station, which tripped the generator sets at Acacia. Units thus drew power from the diesel generator. The connection to the 400 kV network and the 132kV dedicated line from the Acacia power station were re-established. ESKOM was directed to keep the plant shutdown until: the 400kV and 132kV lines were completely operative, and no possibility of security threat remained that would put the safety of the unit in jeopardy. On 2 March, these assurances were provided to the NNR. The plant was synchronized to the national grid by 23 February. Unit 2 is subsequently returned to power.

Unit 2 refuelling outage is due soon. On 3 March ESKOM informed the NNR that they intend on operating 66% of unit 2 capacity until the end of May, because of a concern of: an overlap with unavailability of unit 1, and winter months power supply. This operating mode has been approved by the NNR. Unit 2 fuelling outage and safety modifications are delayed to May/June. Unit 1 replacement rotor is being transported from France for fitment into the stator to bring Unit 1 on line in mid-May. Its damaged stator and rotor is currently being repaired. Both units will run together for about a week until end of May.

The NNR is contented that safety was never compromised, and that the corrective actions address the causes of the recent events insofar as power supply to Koeberg is concerned. However the NNR is apprehensive of the frequency of grid problems, they will continue to follow up on this matter.