> Manufacturers are also experimenting with “fourth generation” models that use liquid sodium or molten salt instead of water to transfer heat from fission, removing the possibility of dangerous hydrogen production.
Yup. One of those few areas where the capital required is so massive it can bankrupt even big dogs if they fuck up. See Westinghouse. Need some more gov joint investment or it will be the same state in 20 years as it is now.
It's easier to secure a massive plant than a thousand small ones.
Imagine the outcome of some underpaid and overworked cable runner digging into a buried mini-reactor with a JCB digger. Or a trucker falls asleep at the wheel and drives their Mack truck through an above-ground reactor.
The difference is between the media coverage being "Idiot drives truck into nuclear facility, is arrested, no damage" and "Idiot digs into mini-reactor, irradiates neighbourhood".
And that's before people start yelling "Not in my back yard!"
There are already thousands of medical and industrial sites which contain material arguably scarier and more susceptible to accidents than what would be in a small reactor. The most recent was several months ago at UW Harborview: https://www.kiro7.com/news/local/hazmat-response-for-radioac...
I think your last reasons are probably more influential. Nobody knows or seems to care much about sites like where the above incident occurred. And so far such incidents have been fairly contained, at least in the U.S. In some other parts of the world neighborhoods do become contaminated on rare occasion.
Reactors can be small and (relatively) cheap, but those aren't cost effective for power production. Producing power for sale on the grid requires huge economies of scale to compete with other sources.
Tiny, safe, low-cost reactors are a better fit for off-grid power and heat in remote areas.
That's supposed to be the promise / fix of SMR: plop down a fully self-contained reactor of a few tens~hundreds MWe in a shaft, plug it to the grid and leave it there for a few decades, when it's out of fuel swap it out and go recycle it in a dedicated facility.
Though of course aside from not quite existing yet and probably needing a smart grid to coordinate properly these will take full-bore hits from NIMBY.
The predominant NIMBY strategy is to request a new impact study every 6 months so as to insert delays and restarts into the capital-intensive, highly coordinated construction process, bringing it from merely arduous to nearly impossible. Pre-fabbed reactors would reduce both the attack surface and the per-hit damage considerably.
There are plenty of sites that would be happy to host nuclear, if it were possible to build. Vogtle and Summer are our recent examples, and NuScale is deploying soon too.
NIMBYs have not held back nuclear as much as the industry itself.
The nuclear power plant at Shoreham on Long Island is possibly the most famous example of NIMBYism killing nuclear. The reactor was built and operated at test levels, but the NIMBYs demanded for full operation to include a disaster plan to evacuate all of Long Island (5+ million people) in a completely impossible time span of a few hours.
One issue was that small-package reactor designs of the 50s and 60s required highly enriched uranium... which doesn't seem like the best idea to leave lying around at (by definition) remote outposts.
My understanding from a friend who worked on nuclear subs was that transmutation due to radiation is what makes working with reactors so complicated and error prone. You can't assume anything about common tools and materials since the metallurgy becomes quite important in ways that we're not used to.
Well, tools better not be exposed to much neutron radiation, or else the person holding the tools will be in trouble. :)
What he may have been talking about is activation of troublesome elements that cause contamination that interferes with access. A prime example of this is the wear resistant alloy Stellite, used in valve seats. It's an alloy of cobalt. Some cobalt does wear off, gets circulated through the reactor, and is transmuted to 60Co, which increases the radiation field around all the piping.
All the materials in your reactor that are exposed to neutrons need to be purged of troublesome trace elements that can cause this sort of activation.
Doesn't SpaceX sidestep a bunch of this stuff by achieving reliability via redundancy instead? Like, put three valves in series when it needs to fail closed, and three in parallel when it need to fail open, that kind of thing.
I wonder if there's potential for a similar approach here?
Whether actual reactors get built is another matter.