  Radioisotopes are natural clocks which can be used to estimate the age of the
solar system. They also influence the shape of supernova light curves. In
addition, the diffuse emission at 1.8 MeV from the decay of 26Al may provide a
measure of the present day nucleosynthetic activity in the Galaxy. Therefore,
even if radionuclides represent only a tiny fraction of the cosmic matter, they
carry a unique piece of information. A large number of radioisotopes are
produced by massive stars at the time of their supernova explosion. A more or
less substantial fraction of them are also synthesized during the previous
hydrostatic burning phases. These nuclides are then ejected either at the time
of the supernova event, or through stellar winds during their hydrostatic
burning phases. This paper focusses of the non explosive ejection of
radionuclides by non-rotating or rotating Wolf-Rayet stars.
