Helium-3 as a fusion source: Low-radioactive fuel and big opportunities

The deuterium - heliuum-3 (D-3He) fuel, so called low-radioactive cycle, is a compromise for the thermonuclear fusion, and it is considered to be much cleaner than the deuterium – tritium (D-T) reaction. Helium-3 mining issues are discussed. The paper also provides an estimate of the helium-3 isotope reserves on planet Earth.