Calculation and Experimental Study of the Interaction Between a KZh Steel Structure and RBMK-1000 Graphite Stack

For the possible operation of power units with the RBMK-1000 reactor during the period of the formation of a graphite stack, NIKIET performed a series of experiments to recreate the force action of the graphite stack on the sealed vessel of the reactor, represented by the KZh metal structure. The experiments justified the joint movement of the graphite stack and 50 mm metal structure with the assumption of up to 5% local plastic deformations of the metal structure at the contact with the graphite stack, which was beyond the limits of the strength calculations valid at the time of works. As a part of the performed study, the behavior of graphite blocks during their destruction under interaction with the metal barrier was determined. The experiments, which revealed the significant conservatism of previous calculations, showed that graphite blocks can be destroyed under interaction with the metal structure without damaging the safety barrier.