At a very rapid superfluid transition in 3He, follows after a reaction
with single neutron, the creation of topological defects (vortices) has
recently been demonstrated in accordance with the Kibble-Zurek scenario for the
cosmological analogue. We discuss here the extension of the Kibble-Zurek
scenario to the case when alternative symmetries may be broken and different
states nucleated independently. We have calculated the nucleation probability
of the various states of superfluid 3He during a superfluid transition. Our
results can explain the transition from supercooled A phase to the B phase,
triggered by nuclear reaction. The new scenario is an alternative to the
well-known ``baked Alaska'' scenario.Comment: RevTex file, 4 pages, 3 figures, submitted to Phys. Rev. Let