An analytical study on the irradiation-induced stresses in nuclear graphite moderator bricks

An analytical model for analyzing the stresses of a hypothetical nuclear graphite moderator brick is presented, considering dimensional change and other property changes due to fast neutron irradiation. The relationship between the stresses and the dimensional change of the material was studied, together with the sensitivity of the stresses to other factors such as the brick geometry, irradiation-induced creep, and Poisson’s ratio. The analytical results agree well with those predicted by the finite element method. The analytical model can therefore provide a useful means for validating more sophisticated numerical tools and performing quick sensitivity analysis.