  We calculate the light element production induced by the explosion of an
isolated supernova in the ISM. We use a time-dependent model and consider
energetic particles accelerated at the forward (process~1) and reverse
(process~2) shocks. Both processes are primary, but are shown to underproduce
Be and B. The reasons for this failure are analyzed and used to propose a
possible alternative, based on the acceleration of particles inside
superbubbles.
