Neutron induced hydrogen ion propagation into zircaloy cladding and material degradation due to hydride/dislocation formation

There is a direct relationship between the integrity of the fuel cladding and the integrity of the nuclear reactor. Fuel claddings are faced with various impacts in reactor normal operation conditions. One of the most important of those effects that is responsible from the operational lifetime of the claddings is zirconium hydride (ZrH2) formation. In current researches it is assumed that in ZrH2 formation, the propagation of H ions in Zr metal is done mostly by the effect of material diffusion under the stress, temperature and concentration gradients. In a reactor where dense nᵒ fluxes and radioactive interactions are observed, the role of the nᵒ-H ion collisions in the formation of ZrH2 where H ions are bombarded into Zr material, is not considered much. Even if the distance taken by the H ions induced by the nᵒ collisions propagating into the Zr material, is smaller than the distances where the hydride and zirconia are formed, the ranges of H ions into the Zr where hydride loops are formed may still be worth to analyse in order to determine the negative impacts on the cladding more precisely. In order to calculate the effects and make the propper analysis, the energy values of H ions produced by the neutrons during moderation in water are calculated first by the help of a nuclear code, say FLUKA and the outputs of it will be inputs to another code for example the SRIM code and as a result the H ions at various energies bombarded to zircaloy-4 cladding will be traced and analysed thus making the scope of herein this research.