Paper 11: Progress towards the identification of safety requirements for advanced reactors

SYNOPSIS Any reactor in a populated community must have a low risk of releasing large quantities of fission products (10 curies 1-131 and associated fission products), and the risk of even greater releases must be progressively reduced. Very high releases must essentially be linked with overheated or molten fuel when retention in the fuel lattice becomes ineffective. In addition, there are many uncertainties in the effectiveness of containment of a molten core and the ability to recool overheated cores becomes progressively more difficult with increase in core power and rating.

Safety then lies in the prevention of fuel melting and this places even greater emphasis on the need for a good primary envelope, reliable means for shutdown and for the provision of auxiliary power.