Abstract: Disclosure is made of a gripping mechanism which comprises a casing mounted on the housing of the gripping mechanism and displaceable with respect to the housing. One end face of the casing interacts with a spring arranged on the housing, whereas the other end face of the casing carries a cap whose shape corresponds to that of the contact surface of a fuel assembly's head. The length of the casing is selected so that when the head of a fuel assembly is gripped by gripping jaws pivotably mounted on a slider accommodated in the housing, the end face of the cap comes into contact, under the action of the spring, with the contact surface of the fuel assembly's head, thus forming a closed circuit for passage of the cooling medium through the cavity of the slider and casing and through the head of the fuel assembly into the fuel assembly.