[pdonis]

Newer reactor designs with entirely passive safety features remove the need for operators to take particular actions in the event of a problem, so "loss of brain accidents" are no longer possible. (Whether those designs can support the requirements for military use, which are quite different from those for civilian power generation, is a different question.)

That said, civilian nuclear power, at least in the US, was never operated with the same attention to detail and the same intolerance for f[oul]ups as Navy nuclear power; the kinds of mistakes that operators made at TMI (don't even start about Chernobyl, that's a whole other level of insanity) would have gotten Navy nuclear trainees kicked out of the program long before they were allowed to do anything with an actual reactor. (When I was an Engineering Duty Officer working at Norfolk Naval Shipyard, I saw a reactor officer get fired for an administrative error that probably would not even have been on the radar in a civilian plant.) So that can't be a significant part of the explanation of why civilian nuclear power is so costly in the US.

The high cost of civilian nuclear power in the US has always been primarily due to politics: things like unreasonable waste storage requirements imposed by the government (you don't need to store waste for 10,000 years if you reprocess it, like every other nuclear energy using country does) and endless lawsuits delaying plant construction being allowed to proceed even though they were based on no valid technical data whatever.

[dctoedt]

> Newer reactor designs with entirely passive safety features remove the need for operators to take particular actions in the event of a problem, so "loss of brain accidents" are no longer possible.

That would be excellent — although color me doubtful; people always seem to find new and innovative ways to f[oul] up ....

[pdonis]

> people always seem to find new and innovative ways to f[oul] up

That's why the passive safety features I referred to don't depend on people at all; they depend on the laws of physics, which are certainly more reliable than people. :-)

[bluejekyll]

I assume people are still building [those things](edit: these new reactors), and I also bet they require some regular amount of maintenance.

[pdonis]

> I assume people are still building those things

If you mean older reactor designs without the passive safety features I mentioned, I don't think the US is building much of anything.

> and I also bet they require some regular amount of maintenance.

Nuclear reactors of course require regular maintenance, like any large industrial plant, but those costs alone are not a significant impact. To the extent there are increased maintenance costs for nuclear, they are more than offset by lower fuel costs.

Operating costs in general for nuclear reactors are a significantly smaller fraction of total life cycle costs than for fossil fuels. The largest ongoing cost for a nuclear plant is usually the amortization of the initial capital investment, which is larger for nuclear because the plant has extra requirements like secondary containment and radiation shielding that aren't present in fossil fuel plants.

[bluejekyll]

>> I assume people are still building those things

> If you mean older reactor designs without the passive safety features I mentioned, I don't think the US is building much of anything.

No, I mean the new ones you mention, people will make mistakes building the new ones, including the failsafes, regardless of the physics.

> Nuclear reactors of course require regular maintenance, like any large industrial plant, but those costs alone are not a significant impact.

It's not the cost I'm responding to, but more the idea that human error will be entirely removed. People will be responsible for that maintenance, they will screw it up.

[pdonis]

> people will make mistakes building the new ones, including the failsafes

Mistakes during building can be caught and corrected by appropriate quality assurance procedures before the plant is put into operation. That is standard procedure on any construction job. That's very different from human error during the actual operation of the plant.

> People will be responsible for that maintenance, they will screw it up.

And such mistakes can also be caught and corrected by appropriate checking procedures before they cause a problem in actual operation. That is standard procedure for maintenance on any industrial plant.

> the idea that human error will be entirely removed

Nobody is claiming that human error can be entirely removed. But it is certainly possible to design systems so that the unavoidable human errors can be caught and corrected before they cause more serious problems.

[Arnt]

Digressing, perhaps… do you know anything about why the passive designs weren't built? There are something like 500 nuclear reactors, of which approximately zero use entirely passive safety features. Not 250, not even 50.

[pdonis]

> do you know anything about why the passive designs weren't built?

Because they're too recent. By the time these designs were developed, the nuclear industry in the US was basically dead, so there has been no real opportunity for them to be commercially deployed.

[Arnt]

I seem to recall reading about them in the earlyish nineties. Specifically a fine article about a Swedish gravity-based design, which used electric power to keep things running and many, many failures should result in things being pulled down by gravity and failing safely.