

Scale has always been a problem with nuclear.
Fission is far from dead. It still the most compact power source with the lowest environmental impact.
The problems come in is that they all seem to be treated as one-off projects, which is costly and less safe than an approach at scale.
The cost of a reactor on a nuclear submarine is actually cheaper than a terrestrial one, despite being more complex, because when they build them, they build 20 at a time.
Also, if you look at recent construction of fossil fuel power plants, they are also largely overbudget and late. For the same reasons as with nuclear.
The best solution has always been a mix of renewables and nuclear due to their different strengths.











I think you might be right. A caltrop on the ground will tend to get picked up and stuck to the tires, so they will only impede one vehicle. One attached to a board will pull back out and remain in place.
That and it also makes the caltrops removable if you need to pass through it.