“…[150] In the early stages, mercury was employed but found to be encumbered with several issues, namely, mercury oxidation in air, deposition of the mercury oxide on the heat exchanger, and its well-known toxicity. [150] Though, in the beginning, only the U.S.A. and the USSR scrutinized the potential of liquid metals for nuclear reactors, over the years, other countries, such as Japan, South Korea, and China, participated in this research field. The application of liquid metals in cooling system management of small modular reactors (S.M.R.s) is characterized by the following advantages: higher boiling temperature -the possibility to work with higher temperature; high efficiency of cooling compared to low mass; higher thermal conductivity, which implies greater heat transfer coefficients, higher heat inertia, and, most desirable, good electrical conductivity, enabling efficient activation of non-moving electromagnetic pumps.…”