The only real danger is that of a tritium leak, but the short half-life makes the prospect of a leak less concerning.
It’s difficult to be sure of safety in complicated systems when the only people with enough technical expertise to fully vet the systems have an interest in their success. I’m not saying it can’t be done, but I think it slows policy down significantly.
For the record the HBO series on Chernobyl, while a good show, greatly exaggerated parts of the story. There was no threat of a megaton-level thermonuclear explosion that would destroy Kiev or make huge parts of Europe uninhabitable from the melted core coming in contact with water. The soviets did know about the RBMK's propensity to have a runaway reaction, and the rest of the world never allowed those types of reactors to be built.
[1] https://www.statista.com/statistics/494425/death-rate-worldw...
[2] https://ourworldindata.org/grapher/death-rates-from-energy-p...
Low probabilities, but man they would suck.
Here's an example from Argonne National Laboratory:
> In the first test, with the normal safety systems intentionally disabled and the reactor operating at full power, Planchon's team cut all electricity to the pumps that drive coolant through the core, the heart of the reactor where the nuclear chain reaction takes place. In the second test, they cut the power to the secondary coolant pump, so no heat was removed from the primary system.
"In both tests," Planchon says, "the temperature went up briefly, then the passive safety mechanisms kicked in, and it began to cool naturally. Within ten minutes, the temperature had stabilized near normal operating levels, and the reactor had shut itself down without intervention by human operators or emergency safety systems."
- There are many passive systems that work in concert to prevent the fission material from having a runaway chain reaction that continues on its own,
and
- It is literally impossible within our understanding of physics for the reaction to continue without the continued application of power to the reaction chamber.
No matter how 'safe' the former gets, it's just asymptotically approaching the latter. There will always be more assumptions and caveats involved in preventing a self-sustaining reaction from continuing.
In particular, re. that article, a lot seems to be resting on the sodium cooling pool being present while there's something else going wrong. So what if an earthquake breaks it open and dumps it out. Or a bomb.
Of course you never have zero risk. That literally impossible and not a standard you would use for literally anything else in human existence.
The fact is, you can design nuclear power plants that are so safe that the chain of events you had to come up with to get any radiation outside of the reactor safety boundary is so ridiculous that the probability of them happening is barley measurable.
Sure if you have human error and 3 black swan events on the same day, the risk is not zero.
But even if you come up with these crazy events the damage from those events would be a far smaller then Chernobyl and Chernobyl was also far less damaging then in popular imagination.
The risk that somebody dies during the construction of the reactor confinement building is probably 100000x higher, but nobody seeks to prevent ever building large structures.
> Chernobyl operators thought their reactor design had zero risk of exploding, current reactors are much safer but I'm pretty sure the risk isn't zero.
This is where we are with nuclear. Any debate goes back to Chernobyl. Again, in no other area do we go and say 'well the soviet thought this in the 60s so therefore we can never moved past it'.
There is fundamental physics and chemistry involved and just because some soviet operators didn't know that does mean its unknowable.
Humanity should be living in the nuclear age. Climate change would not even be a thing if everybody had done what the French have done in the 70s. And we would be much better in terms of space exploration if the whole world were not so reluctant about using anything nuclear.
It also doesn't matter that no specific nuclear reactor will have a lifetime of 10,000 years. The problem is that per megawatt of energy generated, fission theoretically creates (much) longer-lived waste than fusion. Over a longer-than-one-hundred-year timeframe, equivalent amounts of energy generation result in vastly different waste carrying costs. Fusion's waste carrying costs are much lower.
And obviously that number is even more in favor of fusion if it only takes 10 years. (ITER claims 100 years though: https://www.iter.org/sci/Fusion)
Firstly, 10 years worth of energy is inside a fission reactor and is capable of releasing most of that energy in an instant if not properly controlled. This cannot happen in a fusion reactor. A year's worth of fuel is in a gas tank on the wall and needs absurd conditions to ignite. It cannot happen spontaneously.
Secondly, the exhaust is helium-4: a stable isotape of a valuable element.
Thirdly, the neutron bombardment in a fusion reactor activate the materials they hit. If they hit lithium then they make tritium: a much needed isotape for fuel in first generation fusion reactors. The other materials they hit are chosen to have half-lives of less than 100 years. So you have a nuclear site that no one's allowed to touch for a while then you can recycle the materials. It's nothing like the transuranium nuclear waste from fission plants.
10 years isn't 5 minutes, but it means you just need to keep it secure for a few decades before burying and forgetting it rather than many human lifetimes.
Any leaks will be (to some extent) self-cleaning, insofar as they'll decay substantially within a human lifetime, so if you stop the leak you can wait a couple decades and it will have cleaned itself up. That's much better than the long-life stuff fission produces.