How would cheap, accessible nuclear fusion realistically play out?

Question

Imagine that (1) easily manufacturable, cheap (~$1m USD startup/operating costs), non-portable nuclear fusion was announced and (2) plans for how to build and operate it were made freely available on the internet.What would its global impact realistically look like over the short (10 years), medium (25 year), and long (100+ years) term?Friends and I loved this thought experiment and I think HN might find it interesting/worthwhile to discuss too!

PaulHoule · Accepted Answer

I find it hard to believe.The easiest kind of fusion (D+T) by far uses Deuterium and Tritium and produces copious quantities of neutrons, more than either a thermal or fast fission reactor. There is a certain thickness of shielding you need to stop the neutrons and it's not small. Handling tritium is also a pain because it is an isotope of hydrogen that will go between the atoms of many metals, get incorporated into water supplies, etc. If somebody is handling tritium at energy-production scale you will always hear about leaks to the environment even if these are "mostly harmless."Other kinds of fusion are a lot harder. The difficulties that drive fusion reactors like ITER to be huge would drive them to be even larger. I'd imagine interstellar travelers somewhere have huge D+D reactors so they can "live off the land" on Oort cloud objects.

trinovantes · Answer

How advanced a civilization is is strongly correlated to energy consumption. If cheap fusion energy is possible, then I think we'll see the next "industrial revolution" as many activities that were previously deemed infeasible for mass consumption due to energy costs will be possible.e.g. Every household can have indoor greenhouses for home grown fruits/vegetables