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Comment by PaulHoule | Hacker News Reader

LWR coolant is not that bad. They keep the water very clean with ion exchange resins because otherwise you can have problems with corrosion. Workers sometimes float in the water during refueling where they flood the area about the reactor and spent fuel pond and open the lid of the reactor vessel.

Leaks in liquid metal fast reactors are much more obnoxious but still manageable. Sodium catching on fire when it hits air frequently isn't as bad as it sounds (a "pool fire" isn't particularly hot or dangerous but a "spray fire" can be) but it is important to catch sodium leaks quickly without false alarms and many development projects had trouble with that.

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https://en.wikipedia.org/wiki/Monju_Nuclear_Power_Plant

I always enjoy the handwaving by nuclear enthusiasts. These are some of the most difficult engineering systems routinely built and operated by mankind, where a coolant loss accident doesn't just destroy the reactor but can turn the facility into a multi-billion dollar cleanup effort in minutes.

Monju was a poorly designed machine which was particularly badly run. I recently found a book they wrote about it and when I looked at the plans I thought "I can't believe they built that in an earthquake zone". I don't know if anyone is ever going to build another loop-type LMFBR as many of the problems you can have with a loop-type can't happen in pool-type reactors.

What was most shocking about the fire at Monju wasn't that it happened but that they tried to cover it up. Neither that nor the incident where they dropped the refueling machine into the reactor vessel were dangerous to people off site but the latter sure convinced everyone they didn't know what they were doing.

Contrast that to Superphenix where the fuel transfer drum failed and they struggled with a steam turbine system that was procured under corrupt contracts but overall had a good operational record. Or the three pre-1970s cases where there was significant fuel damage in the US but they found that a core melt in a LFMBR isn't as bad as it sounds because the iodine (most dangerous radioactive element in the fission products) reacts with the sodium and the NaI dissolves in the sodium so it doesn't go anywhere. Or EBR-II and the FFTF which performed flawlessly, or the highly successful fast reactors in Russia.

I would liken this to airplanes. They are similarly difficult to engineer and maintain, they can also go very very badly in mere minutes if operated incorrectly, they also have very costly recovery procedures if they crash somewhere populated.

For both systems there have been catastrophic accidents that were national tragedies, from which we learned a lot. "The rules of aviation are written in blood," and that is also true for reactors. Past failures like the one you linked don't mean that reactors are unsafe; if anything, because we had that failure to learn from, reactors are now much safer. If we had a volatile technology like nuclear reactors and none of them had ever had any accidents, then I would be very hesitant to have one in my home town since it could very well be the first to ever blow up.

I think the reason they have seen a lot of success where nuclear reactors haven't is simply up to the fact that they are both cheaper to build and that the public can very directly see where the benefit to them comes from, whereas nuclear power is abstract and indistinguishable from coal to the average person.

I agree with your analogy to an extent, but I think it's got a very significant flaw.

The consequences of aeroplane disaster are localised in space (to the immediate vicinity of the vehicle and whatever it crashes into) and time (once the crash has happened, it is more or less over).

Nuclear disasters can have global effects, and can last for decades.

I'm cautiously pro-nuclear in theory, but am awestruck by the incredible forces unleashed and the extreme impact they can have when mishandled. It's far more potent than anything merely mechanical.

"Construction started in 1986". Is this an example of an accident that would not occur today due to eg better technologies and practices, or an example of something inherent to nuclear technology that can never be made safe?

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