But consider this analogous situation. I was working in a government physics lab when Star Wars (excuse me—SDI) was still a program that you could get money from for all kinds of projects. Nobody—I mean nobody—actually doing research believed in the program. That we would actually build a Star Wars defense shield to make Ronald Reagan proud. But they happily sent off grant proposals and were glad to accept money to work on various things. You can spin lots of pet projects so it sounds like they are all about missile defense. But the algorithms I worked on, during my brief involvement, would have been more useful for game design.
…or any other juicy bits you got for us?
You've lost me :S
Fusion is likely the energy source of the future and that’s ok. It’s ok to dream of far future deep space colonization, and take just one tiny step closer to that dream.
Places with existing gas and oil, and maybe even coal, power stations aren’t going to tear them down when fusion becomes do-able or even economically viable. Not just due to the sunk-cost fallacy but because they don’t want 10,000+ newly unemployed workers who honestly probably won’t retrain for fusion. And more reasons like that.
I personally doubt Fusion will be significantly cheaper than Fission let alone coal any time soon. But, if it happens their not going to care about their workforce. That said, fission > fusion isn’t going to require more training for most of the workers. In many locations they would both have identical cooling towers for example.
If we had cheap Fusion tomorrow we could replace much of fossil fuels with synth fuels with neutral CO2 cycle. We get to reuse existing infrastructure but without massive co2.
D-T requires extracting tritium from a breeder blanket which will likely be very expensive. But the ratio of T:D can be lowered the more efficient the design, with pure D-D designs avoiding that issue entirely.
- neutron bombardment, the unavoidable consequence of the only realistic fusion reaction, deuterium + tritium, turns every known material brittle and radioactive; and can be trivially used for uranium enrichment
- tritium is almost impossible to contain, and requires fission plants to create - the fusion plants could theoretically create a surplus, but they would have to recapture essentially 100% of a very hard to capture gas (today they normally leak about 10% of the injected tritium)
- fusion plants need to be massive to be even close to break-even - the energy drain of the facility consumes a sizeable portion of the generated energy; most of this power drain is still required while the facility is not operating the reactor, increasing projected costs of running a facility
- ICF tech is very close to fusion weapon tech, so there is a massive risk for proliferation from there as well; MCF tech is not, thankfully
[0] https://thebulletin.org/2017/04/fusion-reactors-not-what-the...
All this volume will have to be hermetically sealed from the outside world, since it will become permeated with tritium. Keeping that tritium from escaping the building will be a major headache (polymer seals cannot be used on penetrations, as tritium permeates through polymers). This will be true in any fuel cycle using deuterium, not just DT, since D+D -> T+p reactions will be occurring.
JET already had robust procedures for handling Tritium. It wasn’t that difficult because we are talking about such small amounts and the T is lighter than air so minute releases aren’t a major public hazard. Don’t forget Fission reactors actually produce Tritium.
As to the Mississippi River flow estimate that’s something like 6 orders of magnitude larger than what I am referring to. Still, the other way of looking at that statistic is if half of the Tritium used per day was dumped into the Missisippi every day it would be considered safe to drink when well mixed.
Realize also that what has to be constrained is the cumulative leakage from all fusion power plants, not just a single one. The world would need on the order of 10,000 1GW power plants, to displace fossil fuels.
Globally, I do think fission or potentially fusion has a minor role because it could be important for a few countries locally even if it’s not cost effective in most areas. But realistically their only really competing with each other.
Nuclear fission looks unable to compete with renewables at current prices in almost all the world. There's a zone around Poland where it does the best. But even those zones go away as renewables and storage proceed down their experience curves. If there are very minor niche uses, fission would work just fine vs. fusion, particularly in high latitude countries that are already members of the nuclear club.
Circling back to my original post, it’s clearly not needed any time soon. I think it’s worth doing in much the same way building the ISS was worth doing. That said, I was trying to avoid being dismissive of possible upsides which seem unlikely but still possible.
Whatever the opposite of devils advocate is.
The tragedy of engineering is that in any market niche, generally only one technology can win. The others are driven to extinction. It's like ecology's "one niche, one species" rule. As Freeman Dyson pointed out, this is not like science, where multiple complementary theories may coexist. We build chips from silicon, not GaAs or superconducting niobium or any of the other possible technologies that were considered over the decades.
An engineer, if he's old enough, will have seen many technologies come up then fail and die. There are more ways to solve problems than there are sufficiently distinct problems, so this is inevitable. When fusion competes with fission, and wind, and solar, and geothermal, and..., it's a fight to the death. The notion that fusion is inevitable is a stacking of the mental deck to just assume fusion will win this competition.
But what about projects like Iter? There's a lot going on in fusion that has no alternative government justification. Surely those provide little to no value for weapons programs.
If fusion for grid-scale energy is really accepted to be non-viable (and if we're honest... it is) then that has some pretty far-reaching consequences.
I don't think that fusion is categorically non-viable, but the approaches of the currently funded megaprojects all seem to be. More creative and compact approaches could still have potential. Of course, there's always PACER, which illustrates our cognitive dissonance.