A Consolidation Process for Spent Burnable Poison Rod Assemblies

A new consolidation system for the spent burnable poison assembly utilizing a sequence control robot operated under water was proposed. A credible accident in the system was analyzed mainly from the viewpoint of tritium release, based on the diffusion analysis of tritium in borosilicate glass. It was found that the amount of tritium released would be small even after the rupture of burnable poison rods. An experiment on a new consolidation system was performed using spent burnable poison assemblies. The volume of burnable poison assemblies was reduced safely and securely by a factor of 7 to 14 for burnable poison rods and by 22 for hold-down portions. It was proved that the consolidation system is collectively feasible.