ENSaF - Steps towards a European Space Nuclear Safety Framework
Summerer, Leopold Summerer
ESA

Nuclear power sources (NPS), including radioisotope thermo-electric generators, radioisotope heater units and nuclear reactors are been used in space missions during the last 40 years. ESA missions containing nuclear power sources have so far been cooperative missions with NASA, conducted under the US nuclear safety framework and launched from US territory. Therefore, ESA had not yet established its own nuclear safety framework. Space missions containing nuclear power sources involve hazards to ESA and contractor personnel as well as to the local and global populations not present in non-nuclear launches. As with all activities involving significant quantities of radioisotopes, space missions containing nuclear power sources require dedicated procedures, controls and processes in order to keep the associated risk as low as reasonably achievable (ALARA principle). Due to the potential cross-border risk these activities are subject to international conventions and recommendations agreed upon within the United Nations framework. The launch of spacecraft containing nuclear power sources requires furthermore the participation of organisations not involved in the regular launch safety framework and the assurance of launch nuclear safety requires additional activities, reviews and approvals throughout and integrated in the standard life-cycle of a mission’s development and implementation. Following a recommendation by the European Working Group on Nuclear Power Sources for Space in 2005 and in line with the effort within UN COPUOS to develop an international safety framework for the use NPS in space, ESA has initiated the development of a comprehensive space nuclear safety framework (ENSaF), focussing on radioisotope power sources. This paper describes the process for the drafting of such a framework as well as its preliminary conclusions and recommendations.