Radiation Fields and Safety Zones for Nuclear Systems on Planetary Surfaces

<ns3:p>There is increasing government and private sector interest in sending astronauts and advanced robotic equipment to the Moon for lunar exploration, space mining, and commerce. Space nuclear technologies, including both radioisotope and fission energy, are enabling technologies that could support such activities through lunar night survival and high-energy activities like space mining. Both NASA’s flagship Artemis program and China’s International Lunar Research Station aim to send astronauts to the lunar surface within a decade, and eventually establish a base. The potential for astronauts from multiple countries and companies to operate near space nuclear systems makes radiation safety an important technical and policy consideration for nuclear system developers and mission planners. However, there is relatively limited norms, standards, or guidance about how to safety site and operate space nuclear systems in proximity to astronauts on planetary surfaces. This paper proposes the development of the “radiation field” concept to represent the radiation emissions from space nuclear systems and facilitate their incorporation in lunar policy and mission planning. It reviews potential dose thresholds for different zones and proposes using the safety zone policy mechanism proposed by the international Artemis Accords to communicate radiation field information. Its findings provide the initial basis for developing radiation safety practices for astronauts on the surface of the Moon and Mars.</ns3:p>