Nuclear MHD Converter

This work originates from the proposal MHD Compressor-Expander Conversion System Integrated with a GCR Inside a Deployable Reflector submitted by ANSALDO under PRDA RA-22-87PC90271, January 1987. The proposal concerned an innovative concept of nuclear, closed-cycle MHD converter for power generation on space-based systems in the multi-megawatt range. The basic element of this converter is the Power Conversion Unit PCU consisting of a gas core reactor directly coupled to an MHD expansion channel. Integrated with the PCU, a deployable reflector provides reactivity control. The working fluid could be either uranium hexafluoride or a mixture of uranium hexafluoride and helium, added to enhance the heat transfer properties. The original Statement of Work, which concerned the whole conversion system, was subsequently redirected and focused on the basic mechanisms of neutronics, reactivity control, ionization and electrical conductivity in the PCU. Furthermore, the study was required to be inherently generic such that the analysis and results can be applied to various nuclear reactor andor MHD channel designs. Specific goals of the project were 1 To evaluate the performance of the external reflector. 2 To determine the influence of additional, fission-induced mechanisms on the ionization levels of the working fluid. 3 To estimate the electrical conductivity levels that can be attained in the MHD channel, taking into account the effects of F- or other negative ions.