Pebble bed modular reactor (PBMR). Programme status

ESKOM is the South African state electricity utility, with an installed capacity of 38,397 MW at the end of 1996 (98% of all national generating assets). It is largely coal based with a small proportion (5%) nuclear. The current nuclear power plant (Koeberg) has two PWR units of 965 MW (gross). As part of ESKOM's long term planning process investigations are made into new power generation options. The option of further LWR was investigated extensively in the late 1980s and rejected due to the cost penalty compared to ESKOM's coal fired options. In 1993 ESKOM reconsidered the nuclear option (specifically for load centres away from coal fields) and again discounted LWRs. Further investigation was done and two key nuclear issues where identified. These are cost and public acceptance. It was considered that both of these were driven by the safety issues related to potential accidents. It was seen that the only way to obtain competitive costs with nuclear power was to remove the potential (however remote) for accidents with significant offsite consequences. The only reactor type that was seen to have this was the small HTR, using coated particle fuel. This design was then investigated in much greater detail and the Pebble Bed Modular Reactor (PBMR) concept design was undertaken. The reason for the level of detail in the concept design was to ensure that the safety arguments were valid and that the costing could be effectively done. The key requirements for such a programme are seen to be: Adequate technology level in the local industry; Limited (compared to USA/EU/Japan) anti-nuclear movement; Large enough utility to provide backing for the project; Non-prescriptive Licensing regime; and Cost structure for power generation that excludes current nuclear technology. All these are seen to be met in the South African situation with ESKOM being well placed, both in terms of its size and legal position as well as the high regard it is held in