Advanced Compact Power System: An Overview

Abstract

The renewed interest in very small modular reactors for power generation of space exploration missions focuses on the power systems in kilo-power range that has minimum moving parts such as turbines and pumps. Because of their small size, mobility, simple maintenance requirements and safety, these reactors are also attractive for meeting the off-grid energy requirements. In design of these reactors, there are number of options for extracting the heat from the core and power conversion systems. For heat removal, two-phase heat pipes with liquid metals such as potassium, lithium, or sodium as the working fluid are suitable candidates, while conventional Stirling engine and solid-state thermoelectric generation are the available options for power conversion. Thermoelectric generation has a direct thermal-to-electricity route with no moving parts while the Stirling engine goes through the thermal to mechanical to electrical conversion route through a crankshaft.
For the neutronics analysis, Monte Carlo simulations can be used to establish the criticality of the design, and heat removal capability can be estimated using empirical relations. The control and automation in a kilo-power micronuclear reactor, based on the timely operation of sensors and actuators is necessary for steady-state power generation. Reactor control is achieved by boron carbide layers on rotating drums in a beryllium oxide reflector surrounding the core. The control system can actuate the control drum mechanism which controls the production of heat flux to keep the power at constant level. Thus, for a coupled state-space model to determine the time-dependent response, dynamic modeling can be carried out in the MATLAB Simulink environment. This study presents a brief overview of the advanced compact power system design that is suitable for space applications and off-grid installation.