South Africa’s nuclear installations are able to withstand all external events considered in the original design, National Nuclear Regulator (NNR) CEO Boyce Mkhize said on Thursday.
External events include seismic activity, tsunamis, flooding, fire, aircraft crashes, tornados, loss of offsite power and station blackout.
“There were no findings to warrant curtailing operations or to question the design margins of these facilities,” Mkhize said at a media briefing, discussing assessment reports submitted by Eskom and the South African Nuclear Energy Corporation (Necsa), following the March 2011 nuclear disaster in Japan.
The NRR last year directed the operators of nuclear installations in South Africa to perform safety reassessments on the Koeberg and Safari-1 nuclear reactors, considering the lessons learnt from the Fukushima nuclear disaster.
“The aims of the safety reassessments were to identify vulnerabilities in the design and basis of the facilities, evaluate the safety margins for beyond design events and identify necessary modifications, measures and technical features to be implemented where there is a need to strengthen defence-in-depth and improve the safety of operating facilities,” Mkhize said.
The safety reassessments identified a number of potential improvements to further reduce risk beyond the design requirements, he said.
The NNR also identified areas for strengthening the regulatory regime, which would be addressed as part of the current review of the regulatory standards and practices.
“These areas of improvement relate to the inclusion of specific requirements on common mode external events and the combination of events for beyond design basis events; the revision of the nuclear authorisation for Safari-1 to include provisions relating to accident management measures; the inclusion of specific provisions relating to testing and maintenance of all equipment included in the respective severe accident management measures; and the inclusion of specific requirements related to the robustness of accident management measures and emergency planning arrangements considering beyond design basis,” he added.
It also recommended that South Africa should perform a full self-assessment of all emergency planning and response infrastructures using the International Atomic Energy Agency’s emergency preparedness review.
Meanwhile, NNR special project manager Pieter Bester highlighted that precautionary measures such as upgrading onsite and offsite communications, strengthening key equipment to improve seismic robustness and constructing a robust portable equipment storage facility would further enhance the safety of the country’s nuclear properties.
“The NNR is confident that the recommendations stemming from the stress tests would enhance principles of defence-in-depth when it comes to the safety of the nuclear power generation in South Africa and further reduce the associated risks to as low as reasonably achievable,” Mkhize concluded.