Another option is to simply breed He3 with pure deuterium fusion; the output of the D-D reaction is He3 half the time, and otherwise tritium, which decays into He3 with a 12-year half-life. D-D produces neutrons but at normal fission energies, not the really high energy of D-T neutrons.

Fusion startup Helion, which is funded by YCombinator, is attempting a hybrid D-D/D-He3 reactor, saying the combined reaction would produce only 6% of its energy in the form of neutron radiation.