For those not familiar, here's the wikipedia page on hybrid fusion-fission [1]. The idea is to use a sub-break-even fusion reactor as a source of very high ener

For those not familiar, here's the wikipedia page on hybrid fusion-fission [1]. The idea is to use a sub-break-even fusion reactor as a source of very high energy neutrons that would trigger fission in uranium or thorium isotopes that are otherwise non-fissile. For example U-238, which constitutes 99% of all uranium on earth, and which is currently the dead weight as far as uranium is concerned (worse, you spend a lot, a lot of money to separate U-235 from U-238). U-238 can undergo fission when targeted by fast neutrons, but can't sustain a chain-reaction, so fusion-fission hybrid reactors can't lead to a Chernobyl event (but a Fukushima is possible). Not clear why we don't hear more about fusion-fission hybrids on HN. It sounds like such a promising technology. [1] https://en.wikipedia.org/wiki/Nuclear_fusion%E2%80%93fission_hybrid https://en.wikipedia.org/wiki/Nuclear_fusion%E2%80%93fission...