In this contribution we considered different aspect of brittle fracture of solids under the action of irradiation by powerful pulsed beams of relativistic electrons and neutrons. The fracture of aluminum plates consists of several stages including formation of blisters, craters and laminations; and is accompanied by appearance of a complex system of stresses in the surface layer. Computer simulation by Monte Carlo method revealed that the loose zone containing the main quantity of Frenkel’s pairs does not overlap with the maximum of absorbed energy. Computer simulation by Molecular Dynamics revealed that vacancy clusters can transform into dislocation loops, voids or microcracks in dependence on strain state. A model of brittle fracture of metals suggested incorporates Coulomb’s explosion that generate shock waves. The fracture in the form of chunks induced by neutrons is simulated by Monte Carlo method. It is found that crack interaction can be different, i.e. cracks can attract, repel, and lead to breaking off parts of a material.