Critique of the Board-Hall model for thermal detonations in UO2--Na systems

The Board--Hall model for detonating thermal explosions is reviewed and some criticisms are offered in terms of its application to UO2-Na systems. The basic concept of a detonation-like thermal explosion is probably valid provided certain fundamental conditions can be met; however, Board and Hall's arguments as to just how these conditions can be met in UO2-Na mixtures appear to contain serious flaws. Even as given, the model itself predicts that a very large triggering event is needed to initiate the process. More importantly, the model for shock-induced fragmentation greatly overestimates the tendency for such fragmentation to occur. The shock-dispersive effects of mixtures are ignored. Altogether, the model's deficiencies imply that, as given, it is not applicable to LMFBR accident analysis; nonetheless, one cannot completely rule out the possibility of meeting the fundamental conditions for detonation by other mechanisms