Analysis of beyond design basis accident with hydrogen explosion in the at-reactor spent fuel storage pool of NPP with RBMK-1000

Abstract

The article evaluates the consequences of a hydrogen explosion in an at-reactor spent fuel storage pool due to the development of a beyond design basis accident with a complete long-term blackout. Two scenarios of hydrogen generation in a spent fuel storage pool with a subsequent hydrogen explosion are considered. In the first scenario, the formation of radiolytic hydrogen occurs in the undried storage pool. In the second scenario, hydrogen is formed as a result of the steam-zirconium reaction in the dried storage pool when the cooling water is supplied to the walls of the emergency storage pool. The maximum explosion pressure is calculated using the shock Hugoniot adiabat. The calculations of initial static load taking into consideration hydrogen explosion exposure for each scenario were performed using the equivalent static load method. This method consists in the switch from a dynamic task to a static one, in which the maximum deflections are equivalent. The calculation of the stress-strain state of spatial structures is carried out in the ZENIT-95 program. It is shown in the work that not in all cases of hydrogen explosion, destruction of structures occurs.