Utilization of polystyrene for floatation of decommissioned nuclear submarines in Russia

Over the past several years the Russian Federation (RF) has removed from service a large number of nuclear powered submarines (NPSs) from their Navy. The current RF concept of NPSs dismantlement typically involves the following steps: in-place floating storage, transporting (towing) to a dismantlement shipyard, removing the nuclear reactor fuel, and final dismantlement and disposal of the NPS. Appropriate technical systems and funding has not been allocated for their proper dismantlement. Therefore, long-term floating storage of the NPSs is required. To ensure that the NPSs remain afloat, a system has been developed for inserting polystyrene into the NPSs main ballast tanks (MBTs). The process has been successfully applied to a limited number of intact submarines. This system could also be applied to sections of decommissioned submarines, such as reactor compartments, currently floating in unstable conditions in bays in Northwest and Far East Russia.