The phase transition from a superfluid system to a normal fluid system in nuclei under the influence of a strong Coriolis field is investigated by the generator coordinate method (GCM). The strange behavior of the experimental moments of inertia in the nucleus WYHf is well reproduced in this theory. The pairing collapse of the neutrons, however, is completely washed out by the fluctuations. It is found that the fluctuations of the orientation in gauge space, taken into account by number projection before the variation play the most important role. Fluctuations connected with the virtual admixture of pairing vibrations add only small corrections. (orig.).