Hacker News Reader

Comment by danenania | Hacker News Reader

"In the end, even with Chernobyl, nuclear power is still one of the safest per unit of energy produced."

I'm not anti-nuclear at all, but I see this argument used a lot and I don't think it's a good one. The concerns with nuclear are all about tail risk. Comparing past results to other forms of energy doesn't address this since neither Chernobyl nor Fukushima were worst case scenarios for nuclear.

An effective pro-nuclear argument should address the tail risk concern head-on rather than talking past it.

View on HN

Isn’t this like comparing the safety of a motorcycle to that of an A380? The “tail risk” of the latter is 800+ dead versus a single rider, but the expected value is way lower in the plane’s case.

In that case, there's plenty of data that shows the plane is safer mile-for-mile. There have been enough flights (of all jet models, not just the A380) and enough crashes to provide a reasonable estimate for the odds of a crash. From there, it's basic math to prove that the motorcycle is far more dangerous.

The challenge with nuclear energy is we don't have a big enough sample to say with certainty, just from the data, what the odds are of a disaster 1000x worse than Chernobyl.

My understanding is Chernobyl itself could have been 1000x worse and rendered much of Eastern Europe uninhabitable if the appropriate steps weren't taken in time, so to a neutral, non-expert observer, that would seem to indicate the odds are greater than zero.

This is what many anti-nuclear people are concerned about, so if you want to get them on your side, you need to explain in detail why that kind of event is no longer possible. Just stating that it hasn't happened, as if that were proof it can't happen, isn't convincing.

I see what you’re saying, but it seems impossible to prove it literally cannot happen if you just assume every safety system we put in place all fail at once, which is _possible_ I guess.

We live with worse tail risks daily though: we have nuclear weapons in the center of Europe (could be misused, there could be an accident, etc.), we have labs that handle or create deadly pathogens (there could be a leak, etc.), we live near volcanoes or in earthquake/tsunami prone areas, and of course we are living through climate change with unknown tail risk (to crops, to temperatures, etc.).

If you accept that sort of question with no real probability of happening (“what if 5G renders us all infertile because we misunderstand high frequency radio waves?”, “what if the flu vaccine produced this year kills us all?”), you can’t really do anything. It’s impossible to prove a negative, we have to deal with expected values given our knowledge.

That’s a very fair argument.

One consideration that comes to mind is if the scale necessary for operating nuclear is much greater than the examples you cited?

Thinking out loud, without taking a stance on either side, it seems we would need to scale nuclear power to the hands of many lesser qualified people than in the cases you mentioned, which would push the tail risk much harder.

That said, I haven’t thought deeply about the comparison here. If we need heavy magnitude of power, then we are bound to have to accept the risk of disaster as such concentrated power centers inevitably become unstable.

Scaling nuclear to power the world would also likely require extensive use of breeder reactors.

There clearly is a line where we don't do projects if the tail risk is too high, just like you wouldn't build a house next to a volcano that is known to violently erupt every year or decade--if it's every 1,000 years, it may be a different story. The question is which side of the line nuclear energy is on.

I basically agree that it's on the "worth doing" side given the right conditions are met. These conditions plainly weren't present in the USSR in the Chernobyl days, and probably aren't present everywhere nuclear plants are operating today either, but that's not a reason for a blanket anti-nuclear stance given its many benefits.

My point is simply that comparing historical results isn't relevant to the tail risk discussion. Pro-nuclear people should stop using this argument imo--it makes it seem as though they don't understand the position they're arguing against.

Sidenote on nuclear weapons: my sense is almost everyone does agree that the tail risk of a disaster is unacceptably high, but because game theory makes a drawdown extremely difficult, they're considered a grim necessity. If we could somehow destroy all nukes simultaneously and make it impossible to build new ones, we'd increase humanity's odds of survival quite a bit by doing that.

Reply on news.ycombinator.com