Eskom initiated studies to identify sites suitable for the location of nuclear installations in the 1980s. Among the sites identified is the Thyspunt site, located on the coast in the Eastern Cape Province about 90km west of Port Elizabeth. As part of the characterisation of the site, Eskom commissioned the Council for Geoscience (CGS) in 2010 to conduct a probabilistic seismic hazard analysis (PSHA) for the site. The focus of the PSHA is exclusively on vibratory ground motions due to tectonic earthquakes.
The project consisted of two phases, the first of which was investigations to collect additional geological information, while the second phase was the assessment of seismic hazard through the application of the Senior Seismic Hazard Analysis Committee (SSHAC) Level 3 approach. The project commenced with the start of geological investigations in September 2010, and culminated in the delivery of the SSHAC Final report and Participatory Peer Review Panel (PPRP) acceptance letter in June 2013.
The study was conducted using the SSHAC Study Level 3 assessment process, following the guidelines in NUREG-2117, which are viewed as being the current best international practice. The SSHAC process ensures consideration of the knowledge and uncertainties of the larger technical community within a robust and transparent framework. The final PSHA study report provides comprehensive documentation of the seismic characterisation of the Thyspunt site in terms of the hazard of earthquake-induced vibratory motion.