  We analyze $pA$ interactions at ultra-high energies within the semiclassical
approximation for high energy processes accounting for the diffractive
processes and a rapid increase with the incident energy of the coherence
length. The fluctuations of the strength of interaction expected in QCD and
momentum conservation are taken into account also. We evaluate the number of
wounded nucleons in soft and hard processes, the multiplicity of jets in the
proton fragmentation region as a function of the variance of the distribution
over the interaction strengths directly measured in forward diffractive $pN$
scattering for RHIC and LHC energies. We argue that these results could be used
to test whether parton configurations containing a parton carrying the $x\ge
0.5$ fraction of the projectile momentum interact significantly weaker than on
average. We also study leading twist shadowing and the EMC effect for
superdense nuclear matter configurations probed in the events with larger than
average number of wounded nucleons.
