  Explosions of type Ic supernovae (SNe Ic) are investigated using a
relativistic hydrodynamic code to study roles of their outermost layers of the
ejecta in light element nucleosynthesis through spallation reactions as a
possible mechanism of the "primary" process. We have confirmed that the energy
distribution of the outermost layers with a mass fraction of only 0.001 %
follows the empirical formula proposed by previous work when the explosion is
furious. In such explosions, a significant fraction of the ejecta ($>$0.1 % in
mass) have the energy greater than the threshold energy for spallation
reactions. On the other hand, it is found that the outermost layers of ejecta
become more energetic than the empirical formula would predict when the
explosion energy per unit ejecta mass is smaller than $\sim 1.3\times
10^{51}{ergs/}\Msun$. As a consequence, it is necessary to numerically
calculate explosions to estimate light element yields from SNe Ic. The usage of
the empirical formula would overestimate the yields by a factor of $\gtsim 3$
for energetic explosions such as SN 1998bw and underestimate the yields by a
similar factor for less energetic explosions like SN 1994I. The yields of light
elements Li, Be, and B (LiBeB) from SNe Ic are estimated by solving the
transfer equation of cosmic rays originated from ejecta of SNe Ic and compared
with observations.
