Advanced shield development for a fission surface power system for the lunar surface

摘要

A nuclear reactor power system such as the affordable fission surface power system enables a potential outpost on the moon. A radiation shield must be included in the reactor system to reduce the otherwise excessive dose to the astronauts and other vital system components. The radiation shield is typically the most massive component of a space reactor system, and thus must be optimized to reduce mass as much as possible while still providing the required protection. Various shield options for an on-lander reactor system are examined for outpost distances of 400 m and 1 km from the reactor. Also investigated is the resulting mass savings from the use of a high-performance cermet fuel. A thermal analysis is performed to determine the thermal behaviours of radiation shields using borated water. For an outpost located 1000 m from the core, a tetram-ethylammonium borohydride shield is the lightest (5148.4 kg), followed by a trilayer shield (boron carbide-tungsten-borated water; 5832.3 kg), and finally a borated water shield (6020.7 kg). In all of the final design cases, the temperature of the borated water remains below 400 K.