  The beta decay of $^{192,190}$Pb has been studied using the total absorption
technique at the ISOLDE(CERN) facility. The beta-decay strength deduced from
the measurements, combined with QRPA theoretical calculations, allow us to
infer that the ground states of the $^{192,190}$Pb isotopes are spherical.
These results represent the first application of the shape determination method
using the total absorption technique for heavy nuclei and in a region where
there is considerable interest in nuclear shapes and shape effects.
