The research results for radial cracking cases indicate that a better agreement for KIH can be achieved; the negative axial thermal stresses can lessen KIH and enlarge the critical hydride length, so its effect should be considered in the safety evaluation and constraint design for fuel rods; the critical hydride length lC changes slightly in a certain range of stress intensity factors, which interprets the phenomenon that the DHC velocity varies slowly in the steady crack growth stage. | Theoretical models of threshold stress intensity factor and critical hydride length for delayed hydride cracking considering thermal stresses