Liquid metal cooled reactor Clementine was the first liquid metal cooled nuclear reactor and used mercury coolant, thought to be the obvious choice since it is liquid at room temperature. However, because of disadvantages including high toxicity, high vapor pressure even at room temperature, low boiling point, producing noxious fumes when heated, relatively low thermal conductivity, and a high neutron cross-section, it has fallen out of favor. Sodium and NaK (a eutectic sodium-potassium alloy) do not corrode steel to any significant degree and are compatible with many nuclear fuels, allowing for a wide choice of structural materials. They do, however, ignite spontaneously on contact
XM Liquid Metal since the beginning of XM Satellite Radio's launch, but with the incoming of Major League Baseball and XM's MLB Home Plate talk station, XM Liquid Metal had to be removed from the satellites for extra bandwidth. On February 15, 2005, the switch was made. With the change, XMLM DJ Ward Cleaver moved to XM 48 SquiZZ to do mid-days. Unfortunately, unlike other XM Online channels, XM Liquid Metal was not carried of other services such as DirecTV or AOL Radio. For about a year, there were various complaints on XM online forums, and ones that were sent to XM themselves.