Use of PRA in the nuclear regulatory field in South Africa

The nuclear regulatory authority in South Africa (since 1988 the Council for Nuclear Safety (CNS)), established in 1973 nuclear safety criteria against which to assess the level of safety of any facility using radioactive material. It is a regulatory requirement in South Africa to develop and maintain a living PRA for each facility and thereby to provide the necessary information to demonstrate compliance against these criteria. All safety submissions to the CNS must include at least a risk statement based on an accepted PRA study. The function of the CNS is to regulate all activities in South Africa involving the use of radioactive material and posing a significant risk to the public or plant personnel. This includes most aspects of the nuclear fuel cycle and the Koeberg NPS (two 2775 MW(th) PWRs). A PRA study including source terms for the two Koeberg units was presented by the contractor in 1979. This included the risk due to power and shutdown states and non reactor related accidents involving spent fuel storage, fuel handling and waste treatment related activities. At least 20 PRA studies have been performed for other nuclear facilities in the country. The CNS maintains an in-house PRA capability to perform independent assessments of licensee submission, to participate in developments of PRA methodology in the regulatory field, to perform pro-active safety work and to assist in regulatory decision making. Present ongoing work includes the development of a risk monitor, a risk management system, improvement in PRA codes, models, data collection and analysis, off-site risk assessment methodology and associated regulatory policy. (author). 1 fig