Perhaps they should have included a nuclear engineer on the team, who could have told them to use a breeder reactor to process the 'waste' into useful energy so

Perhaps they should have included a nuclear engineer on the team, who could have told them to use a breeder reactor to process the 'waste' into useful energy so that the remainder would only be dangerous for a few hundred years instead of 10,000. That would make storing it safely a much easier problem.