What happens if the swimming pool leaks ?

I mean ... millions of people who barely maintain their homes avoid pool leaks, and when it does leak, it tends to be slow enough that they can call in a professional to fix the problem. Imagine a fastidiously maintained facility ... I think they can probably work it out

Yes, but the expected value of harm from my backyard pool leaking is, well, I can't swim and I need to resurface the pool liner. Multiply this issue by the probablity that it'll happen at all, and you get, well, a filled pool to swim in.

But the expected harm from a SNR like this having a leak is decidely not the same. Yes, the leaks may be rare, but the outcomes from such a leak occuring have Chernobyl-like outcomes in their failure trees. The probability calculus still may return that this design is quite fine, given the risk tables, but you MUST run the numbers. Hand waving is not ok here.

You have to consider stuff like terrorist attack and so on. Nobody is so incentivized in making your backyard pool leak.

What if a dam explodes? More people have died due to dam failures (both intentional and accidental) than have died to nuclear power, but there is nowhere near the freaking out over the safety of dams compared to nuclear power.

For comparison, the Banqiao Dam failure (the largest dam failure in history) killed as many people as the sum total of every nuclear power plant failure and every atomic bomb ever used, combined.

Nuclear has the lowest deaths per petawatt-hour of any generation method: https://en.wikipedia.org/wiki/Energy_accidents

Lower than wind and solar.

While dam break cost lives, there is crucial differences that are never mentioned by the pro-nuclear crowd on HN.

1.) Dam breaks devastate much smaller areas. So even if the human toll is the same, the amount of infrastructure lost is smaller.

2.) The area is unlivable (or even inaccessible) for a much smaller duration of month instead of millenia.

Maybe land lost "forever" (on the timescale of individual human lives) is not a big problem in some part of the world, but in densely populated areas (any they need the most power, so would have MORE reactors per area) you can not simply block off an area the size of Belgium because a reactor exploded. This makes nuclear power a lot less attractive in India, Europe or (coastal) China.

Chernobyl's exclusion zone was ~1000 mi^2, consisting of ~120,000 people. The Oroville dam evacuation zone is ~250mi^2 encompassing ~180,000 people. Floods are no laughing matters; the Chinese decision to break the levees of the Yellow River during the Second Sino-Japanese War is credited with killing 400,000 people or so and rendering millions homeless, and the land was unusable for the better part of a decade, not "a month."

> 2.) The area is unlivable (or even inaccessible) for a much smaller duration of month instead of millenia.

Millennia of uninhabitability is anti-nuclear propaganda. Most of the zone will be reinhabitable within a century of the accident, and much of it is already inhabitable again but still excluded out of safety margin concerns.

Strengthening your point on the persistent anti-nuclear "uninhabitable for millennia" myth, check this recent article out [1]. The wildlife at Chernobyl is thriving. There are far worse energy accidents in other industries that cause far more and widespread damage.

[1] https://thoughtscapism.com/2019/05/08/worlds-worst-energy-ac...

Chornobyl's exclusion zone covered small part of contaminated area only. My parent's home is in contaminated area, but nobody was evacuated. Cancer rate is 2.5x larger at average in four regions of Ukraine, which are near to Chornobyl. I saw 6m (20 foot) wide circle of dead grass at about 800m from my parents home, where a hot particle landed. Both my neighbors are died because of cancer. I live in clear region, but my lungs was very radioactive for few years, because of my visits to parents.

> Cancer rate is 2.5x larger at average in four regions of Ukraine, which are near to Chornobyl.

Citation needed. WHO says up to 4000 early cancer deaths total from Chernobyl. 2.5x larger cancer fatalities would be hundreds of thousands if not millions of people which is not seen by any credible study that I'm aware of.

My ex grew up in Gomel and didn't get cancer. Neither did her parents.

In Ukrainian. See graphic at page 235 (Thyroid cancer level growth since tragedy).

http://irbis-nbuv.gov.ua/cgi-bin/irbis_nbuv/cgiirbis_64.exe?...

My brothers were unable to escape. Younger brother had problems with thyroid, but survived. (I had problems with thyroid too, but at much smaller scale). Older brother had brain surgery about two months ago, but it's unknown is it helped or not yet.

Dams also protects people from floods, so they are net positive.

The pool, as far as I can tell, is built pretty sturdy. Breaking this amount of concrete takes a lot of high explosives, and breaking it underwater is an order of magnitude harder. The Allies at WWII had to go to a great length to damage German dams, while using multiple heavy bombers.

If terrorists were in possession of such amounts of powerful explosives, and a capacity to place them inside a highly guarded area, they could use that to blow up a city center to a much greater destructive effect.

It's not human action that would worry me, it's nature. Freezing cycles could easily erode a pool in a few decades and make micro-cracks that fester unnoticed for years. Rust is an ever present issue for re-inforced concrete and is the cause of countless civil engineering disasters.

Practical Engineering on Youtube is a great overview of the issues we humans have with water: https://www.youtube.com/user/gradyhillhouse/playlists

Of interest here are these videos:

https://www.youtube.com/watch?v=eImtYyuQCZ8&list=PLTZM4MrZKf...

https://www.youtube.com/watch?v=0EzoHXEzdwY&list=PLTZM4MrZKf...

https://www.youtube.com/watch?v=EACkiMRT0pc&list=PLTZM4MrZKf...

I hear what you're saying, but I think the point I tried to make in my OP is getting lost here ... in a (well run) facility such as this, nothing would fester unnoticed for years. Actually, I love that you posted some of Grady's videos ... it shows just how much knowledge we have around these problems. And yes, they're not easy, and they're not necessarily cheap to deal with ... but we can deal with them. It's a known problem.

The pool only needs to function for a few days during/after an accident until heat energy from fission product decay reduces to lower levels. The pool's function is as an accident mitigation measure - and when any accident occurs the reactor enters a "shut down" state. The decay heat energy that needs to be dissipated is much lower than normal reactor operational power output.

The pool won't normally be radioactive if I'm reading things right, so... nothing will happen. It's the backup for if the pods fail, not a primary line of defence.

What happens if a windmill explodes?

I'm not too sure but I can say for certain that it doesn't spew radioactive material into the environment.

There would be some trace amounts of radioactivity in the materials used. Probably not enough to harm the public.

Similarly, most fission reactor failure modes don't release harmful amounts of contamination to the public.

Some exotic runaway condition - not sure if generators can do that - electric motors if wired incorrectly self destruct in amusing ways.

More likely you have an over speed failure and the it runs out of control and self destructs flinging the blades and other heavy objects about.

"Having passive decay heat removal usually decreases the probability of core damage by about 100x."

100x isn't 100% though.

100 of these small reactors has the same risk as one large reactor. Perhaps higher, because like you, everyone goes around saying the risk has been designed out.

Though obviously one small reactor going boom is preferable to a big one doing the same.

100% safe is never the metric. Nothing is 100% safe. Every form of energy generation has risks that have to balance the good the energy source brings. Nuclear is nearly unique in that it can produce carbon-free energy (unlike fossil and biomass), continuously for 2 years on end between reloads (unlike wind/solar/coal), and it can be deployed in a wide variety of geographic locations (unlike hydro and geothermal).

The risk is that there are occasionally nuclear accidents: Three mile island and fermi 1 meltdowns, both of which killed zero people. Chernobyl, which killed ~50 from ARS and up to 4,000 early deaths over the next several decades (on top of a few million cancers that would have happened anyway in the population). Fukushima, which killed up to one person. Can anyone name any fatal natural gas explosions? Any hydro dam failures that killed 100,000? How many people per year does coal kill by operating normally (~200,000). We as a society accept certain risks from our energy infrastructure because of all the good we get from it.

Here is a plot of how many thousands of days of life are lost by various things [1]. Note that nuclear is almost ridiculously low. This chart doesn't include the impact of climate change on human lives. Nuclear fission is a climate superpower, and we cannot be justified in neglecting this natural resource because we're afraid of something going boom.

TLDR: A factor of 100x improvement in nuclear safety goes from tiny risk to supertiny. Current plants are already safer than almost everything else we know. Some studies have more people dying from installing solar on their roofs than getting killed by radiation from nuclear fission plants.

[1] https://i.imgur.com/ClgbpA4.png

A 1% failure rate is not acceptable.

Nice try downplaying the actual consequences of a reactor incident like Chernobyl.

Do I have to mention radioactive boars roaming in Bavarian forests again?

The billions in costs to an economy?

The only part I agree with you is that coal is a not an acceptable way to generate power.

There's now sufficiently cheap power generators that don't devastate whole areas for centuries to come. Let's use those instead of this old nuclear tech.

Core damage frequency of modern plants is in the 1e-6 to 1e-8 range/year. That's 4-6 orders of magnitude lower than 1%.

I highly recommend you read some recent info regarding Chernobyl [1]. I'm not downplaying it at all. I'm using quantitative numbers produced by teams of UN and WHO scientists.

RE cost: climate change will cost trillions. Nuclear power plants can prevent that cost.

"Centuries" is a persistent anti-nuclear myth. Again, see [1]. I don't think you're well justified in saying I'm downplaying Chernobyl when you're going on and saying stuff like this!

[1] https://thoughtscapism.com/2019/05/08/worlds-worst-energy-ac...

Yeah, even Sun will blow and destroy our Solar system, so solar energy is not safe too.

BTW: Will you move to Chornobyl to demonstrate that radioactivity is safe? Land is cheap here.

Sure, if my family and job were there. Its a thriving wildlife refuge now. Check it out.

https://thoughtscapism.com/2019/05/08/worlds-worst-energy-ac...

I can drive to Chornobyl by bicycle. I just don't want that.

Wildlife is thriving in my area too, because people abandon homes and move to cities instead.

However, if you like it, you can create similar exclusion zone near to you. Just vote for nuclear power and wait until next nuclear disaster.

Come on. You can drive nearly to the reactor itself and not even get a yearly background radiation dose now. There are a few hot spots where contaminated gear from decommissioning is stored, that's it.

People got cancers at increased rate, which is limited to less than two generations of damage. The range had expired a bunch of years ago.

Going into high mountains is a bigger radiation risk today.

As a bonus, you can just drive to Fukushima on a bike today and not even get a daily dose of some inhabited places in the US.

Cancer rate continue to grow here at steady rate. My neighbors died because of cancer, my brother has tumor. Tell your nice story to someone else, please.

> However, if you like it, you can create similar exclusion zone near to you. Just vote for nuclear power and wait until next nuclear disaster.

Reminder that coal has more radioactive waste over a decade than a nuclear plant does in its worst failure mode; and that worst failure mode is very unlikely with modern reactor designs (unlike Chernobyl and Fukushima)

1) We are out of coal now.

2) All coal plants in the world combined cannot make land inhabitable for millennia.