Article révisé par les pairs
Résumé : We apply the generator coordinate method (GCM) in a fully microscopic calculation of the E2 decay lifetime of the isomeric states of 238U,230Thand 232Th. The basis states have been generated by constrained HFBCS calculations with the potential SkM*. Triaxial quadrupole deformations have been included. Comparison is made with experiment in the case of 238U and experimenters are urged to search for the predicted decays in the thorium isotopes.