04-13U

On the basis of Griffith modified theory we carried out a description of the microcracks nucleation and growth in solids. Using Frenkel approach we obtained a value of critical strength for the microcracks with interacting edges, exceeding of which leads to fast destroying of a material. We performed numerical estimations of the time to destruction for matrixes of lava--like fuel-containing materials due to microcracks formation under irradiation and thermal activated processes influence.