What is the present status of controlled “hot” fusion?
Scientists the world over have spent more than five decades and billions of dollars (an estimated $17 billion in the U.S. alone) to investigate the possibility of mimicking with devices here on Earth the fusion reactions of the stars. These are complex and large machines that rely on high magnetic fields or powerful lasers to compress and heat fusion fuel, typically the isotopes of hydrogen, deuterium, and tritium. The output of these hot fusion reactors is deadly neutron radiation, which must first be converted to heat in molten metal flowing around the core of the reactor. This heat must then be used to make steam to generate electricity. The process is fraught with exceedingly difficult engineering problems, and at best it would become another kind of power generation that leaves much radioactive waste in irradiated components. The controlled hot fusion program has made enormous strides since the 1950s when it began, but unlike cold fusion it is far below what is called healthy “bre