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Comment by onlyrealcuzzo | Hacker News Reader

So why don't they just build a ton of un-safe nuclear reactors where they used to test nukes and use long-distance high-voltage lines to transfer the power?

If you can test Tsar Bomba somewhere - why can't you build a nuclear reactor there that might melt down?

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They can't even get people to put nuclear waste in Yucca Mountain which just so happens to be adjacent to the Nevada Test Site. That's one of the most contaminated locations in the entire United States. The US government detonated 928 nuclear weapons there between 1951 and present.

There's a difference of dropping a bomb in the desert vs hauling nuclear waste across federal highways through people's "land" to get to Yucca Mountain. It's not exactly apples to apples of a comparison you're making here.

While it is definitely full of NIMBYism, there is a bit more complexity to the Yucca Mountain decision.

I don't know to what extent the public is aware of it but another problem with Yucca Mountain is that used LWR fuel is by no means waste and it doesn't make sense at all to dispose of it in its current form.

At best the LWR gets 2% of the energy out of natural uranium. A fuel cycle that removes the small fraction of fission products and feeds plutonium and uranium can extract vast amounts of energy from today's "nuclear waste". It is the plutonium that is radioactive for tens of thousands of years, if you use it as fuel the remaining fission products decay quickly and are less radioactive than the original ore in less than 1000 years.

So Yucca Mountain makes no sense from the viewpoint of the nuclear industry (it isn't going to fight for it) so if some people don't like it there is no point in pursuing it.

Yucca Mountain is irrelevant to the nuclear industry the US government has already agreed to deal with the fuel it’s quite literally not a problem for the industry.

The Act established a Nuclear Waste Fund composed of fees levied against electric utilities to pay for the costs of constructing and operating a permanent repository, and set the fee at one mill per kilowatt-hour of nuclear electricity generated. Utilities were charged a one-time fee for storage of spent fuel created before enactment of the law. … The Nuclear Waste Fund previously received $750 million in fee revenues each year and had an unspent balance of $44.5 billion as of the end of FY2017. … In late 2013, a federal court ruled that the Department of Energy must stop collecting fees for nuclear waste disposal until provisions are made to collect nuclear waste.[12]

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

Anyway, LWR can extract more than 2% of the energy in the fuel it mostly comes down to how enriched the uranium you feed them is because the ratio of U235:U238 in reactor grade fuel is different than the ratio LWR are burning. They can extract far more energy from weapons grade uranium, but using it would be a bad idea.

Agreed - in one case you're irradiating the land and air. In the other case you're safely trucking low-risk spent fuel in safe, secure enclosures and likely retaining the ability to reprocess and re-use that fuel in the future.

This is currently a big problem with renewable energy in the UK and other places. One reason you see negative wholesale costs for electricity in some places is you have a lot of generating capacity but no power lines to get it to demand.

It turns out the lead time to build long power lines is long and it is a politically difficult proposition because you have to get permits for a whole line from Point A to Point B.

One of the ways where the sticker price of renewables is higher than what is quoted is the cost of transporting it and one advantage of nuclear is it could be sited closer to demand in some cases.

I believe a compounding factor in this problem was a 2015 decision to ban onshore wind farms in England.

Leading to the somewhat perverse situation where it's now necessary to build new or bigger lines from Scotland all the way down to the south of England where most of that generated energy is needed.

Nuclear weapons use and nuclear meltdown don't have comparable radiation fallout. It's not even remotely similar. Nuclear bombs release radiation in a bang (usually disappearing in a couple days, IIRC), but nuclear melt downs release materials that continue to be radioactive (for an eternity).

Think about Chernobyl vs Hiroshima. Chernobyl is uninhabitable and will remain so for a very long time. Hiroshima was rebuilt in the exact same spot that was destroyed and is a healthy, thriving city, by all accounts.

Even in some far out place, nuclear fallout in some far out place will eventually make its way into the air and water of the world, count on it.

Could you expand on why the disappearance time is so much faster for a bomb than for a power plant? If 1kg of uranium undergoes fission, I would expect there to be a little less then 1kg of fission products resulting from it. No matter if it were a bomb or a power plant, the amount and lifetime of the fission products would be the same. There would have to be something else going on, like the bomb only splitting a tiny fraction of its uranium, or maybe something about the environment of the explosion destroying fission products?

At a very high level bombs are trying to convert as much of their fuel into energy as possible. The ideal bomb consumes most of the fuel and produces a lot of very nasty extremely short lived nuclear waste thus making a big detonation over a small fraction of a second. Waste products should be short lived isotopes to make them even more deadly weapons.

Meltdowns aren’t controlled reactions the waste includes perfectly useful fuel, short and long lived waste products, plus a mix of things such as control rods and the walls of the reactor etc. https://en.wikipedia.org/wiki/Corium_(nuclear_reactor)

There’s a few other effects such as mushroom clouds moving material away from the blast location, and reactors containing more nuclear fuel.

Do we actually have that much control over what the fission products are? My impression was that you hit U-235 with a neutron, and you get the same kinds of fission products out whether it's a bomb or a reactor. It's just determined by physics what kinds of isotopes are likely to come out, and my impression was that we don't know how to influence it so that only the shorter-lived kinds are created. Bombs may be designed to consume a very high fraction of the fuel, but that would tend to make them worse, since the fission products are more radioactive than the starting Uranium, and there will be more of them. The mushroom cloud thing does make sense as an explanation for why Hiroshima is still inhabited, though. And it's clear that Corium wouldn't be able form in the middle of a nuclear bomb explosion.

We don’t have direct control over the specific products, but as I understand it the extreme amounts of neurons in a nuclear bomb destabilize large atoms.

https://en.wikipedia.org/wiki/Radioactive_waste#Transmutatio...

I don’t understand all the details but apparently this is why some types of H-Bombs can be relatively “clean.”

Even if you don’t care about public safety, worker safety is going to be expensive. You can’t pay someone enough to handle fresh from the core fuel rods by hands because it will quickly kill them.

Similarly, you need a design that’s likely to last long enough to pay back construction costs.

Finally there’s logistic issues in locating power plants in the middle of nowhere. You need massive quantities of water and large massive workforce plus dedicated power transmission to someone in need of power etc.

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