Possibilities for increasing efficiency, simplifying the design of the energy conversion system, and reducing the probability of sodium/water interaction in liquid-metal reactors (LMRs) using liquid-metal magnetohydrodynamic (LMMHD) energy conversion technology are investigated. Of the six different LMMHD power conversion systems considered, the LMMHD Rankine steam cycle offers the highest efficiency—up to 15% greater than a conventional LMR. The LMMHD Ericsson gas cycles, on the other hand, offer a significantly simplified and compact LMR plant design. All the LMMHD power conversion systems eliminate the sodium/water interaction problem. In addition to commercial applications, LMMHD energy conversion technology opens interesting new possibilities for special terrestrial as well as space applications of LMRs.