Members of the IAEA’s International Nuclear Safety Advisory Group (Insag) have recommended that there be a full review of the safety aspects of the Pebble Bed Modular Reactor (PBMR). They were concerned that current enthusiasm for the 110MWe reactor would lead to the safety evaluation being rushed.

The Swiss Insag chairman, Alec Baer, cited several safety issues, including the vertical axis turbine – never used before on a nuclear plant – and the quality of the reactor’s spherical graphite-clad fuel.

Baer said Insag is worried that some safety issues for the PBMR will be considered resolved using assumptions from earlier experience with pebble bed high-temperature gas-cooled reactors such as Germany’s Juelich research centre’s successful prototype AVR unit. Baer said that a full safety review should be developed, and that it will be a long time before the prototype will be built in South Africa.