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Comment by jarvist | Hacker News Reader

> using reactors designed to use the waste as fuel

What do you mean? The waste is full of nuclear poisons (a technical term, isotopes that stop fission by neutron capture). Reusing it means reprocessing to extract the Plutonium, which is burnable in a reactor (particularly as MOX). The chemistry required for this is pretty messy, and the radioactive environment (fuel from a power station is very 'hot' radioactively speaking) so horrific that you need a fully robotic plant.

This hasn't gone great for the UK, https://en.wikipedia.org/wiki/Thermal_Oxide_Reprocessing_Pla...

But we do now have 112 tonnes of Plutonium as a result of our half a century of reprocessing. Which no one knows what to do with, and is an enormous liability.

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The main problem with reprocessing is fears of weapons proliferation, which is an odd fear when it happens in countries that already have large piles of nuclear weapons, but there we are. The waste is mostly still full of fuel. Advanced designs like the Waste Annihilating Molten Salt Reactor could make this simpler and cheaper.

What to do with the UK's plutonium seems obvious to me: use it as nuclear fuel. If this isn't being done it's presumably because of political opposition, not technical problems.

Hardly an odd fear when adding new systematic components to the material supply chain massively increases the chance of some of that supply leaking.

Not doing that route makes you less exposed to risk.

In an extremely complex world where risk needs to be minimized as much as possible, it's totally reasonable for society to decide not to extract plutonium at mass scale in a free market way.

Sure if the military controlled the whole thing (as they do via their own supply chain) that could perhaps feel more secure... but who controls outflows of waste between governments, etc?

Hardly an odd fear when adding new systematic components to the material supply chain massively increases the chance of some of that supply leaking.

Not doing that route makes you less exposed to risk.

In an extremely complex world where risk needs to be minimized as much as possible, it's totally reasonable for society to decide not to extract plutonium at mass scale in a free market way.

Sure if the military controlled the whole thing (as they do via their own supply chain) that could perhaps feel more secure... but who controls outflows of waste between governments, etc?

Oh and the mind-boggling cost. Who pays?

Nuclear is one of the most expensive forms of energy when you cost in the full price of making it safe, including dealing with waste and ensuring absolutely no proliferation of weapons.

There are various reactor design proposals (such as molten-salt), which can be used to burn a variety of fissionable materials. There hasn't been nearly enough investment to put that sort of thing into production yet.

There's a lot of energy in those 112 tonnes, but you really need a fast reactor to burn it. Plutonium is a lot easier to tackle in a fast reactor than a thermal reactor.

Also, UPower can use the waste without putting it through a chemical separations process. In fact you can just take the SNF grind it up, and dump it into the UPower reactor alongside the rest of the fuel. It actually makes a pretty good fuel that way.

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