Successful Recovery and Decommissioning of Russian RTGs – A Cooperative International Effort

From the 1970s into the early 1990s the Soviet Union and subsequently the Russian Federation actively used Radioisotope Thermoelectric Generators (RTGs) as sources of energy for lighthouses, navigation beacons, and other remote monitoring sites requiring autonomous power. By the end of the century over a thousand RTGs had been deployed. An RTG transforms heat through thermoelectric conversion into electric power, where the source of heat is generated through natural linear decay of radioactive isotopes (strontium-90). Most of these RTGs were installed at unguarded remote sites, but others were deployed near population centers. Recognizing the risk posed by the theft of unattended RTGs and their radioactive sources, Russia, the United States, and others within the international community agreed that something needed to be done to reduce the threat in the near term; while ultimately planning to fully recover and dispose of all RTGs, most of which had already exceeded their service life. The DOE/NNSA, Lawrence Livermore National Laboratory, Rosatom, and the NRC Kurchatov Institute led the effort, with expertise provided by other scientific U.S. and Russian organizations, as well as assistance from Norway, Canada, Finland, and France. In 2007 a Master Plan was developed and approved by Rosatom to address the overall complex task of recovering RTGs from largely remote geographical locations, transporting them to temporary storage, or directly to disassembly facilities; while remote security monitoring was recommended for those RTGs that posed even a higher risk (e.g. near population centers). Equally complex was the disassembly process, given the age of the RTGs and unforeseen issues when extracting RHSs (Radioactive Heat Sources), as well as the security risks when transporting sources to a long- term storage location for final disposition. In 2008, an Action Plan was initiated to carry out the Master Plan directives to best allocate resources and avoid duplication of effort. The results of the international effort have been hugely successful, where over the past decade 98% of the RTGs have been recovered, and alternative power sources (APS) based on solar energy replaced many of the active RTGs.