Saying that coal ash is "more radioactive than nuclear waste" is too ambiguous. There are many kinds of nuclear waste with varying degrees of radioactivity. I assume there are also variations in the degree of radioactivity in coal ash. It might be meaningful to say that a particular kind of coal ash is more radioactive than a particular kind of nuclear waste, but without that context it's a meaningless comparison.

At the point where it's already waste, you don't really care about the energy that was produced from it, possibly years or thousands of years ago.

If one power plant creates 1000t of waste, and another creates 10000t of waste while providing the same amount of electricity, I think we can reasonably say that the second generates 10x more waste.

"Well, if you pick just one ton of waste from either plant it's the same waste!" is technically true, but it's neither here nor there.

(Of course in case of nuclear vs. coal it's a bit more complicated because the waste products are not the same, but I still think we can reasonably compare waste per energy.)

If the 1000t is radioactive at 5Bq/Kg and the 10000t is radioactive at 2Bq/Kg, it's at best confusing to say the second plant's waste is "more radioactive".

If bill gates venture into power pans out there won’t be nuclear waste at all it seems.

There are already plants that can do what he's proposing, like the CANDU reactor. It looks like they've taken some ideas directly from that reactor, so it looks pretty conspicuous that they never mention it.

Wait, what, no!

CANDU is a thermal water moderated reactor, albeit moderated with heavy water rather than light water, allowing it to use natural uranium instead of enriched (as Canada didn't have enrichment capability and didn't want to depend on other nations). And it's a pressure tube design, meaning the high pressure water is kept in a bunch of tubes rather than having one big pressure vessel like most light water reactors (again, because Canada didn't have heavy forges required to produce traditional reactor vessels).

What Bill Gates funded is a company called Terrapower that is making a sodium cooled fast breeder. Very different from CANDU. Fast breeders are a pretty cool concept, but they and the reprocessing technology for closing the fuel cycle isn't as mature as light water reactors.

I wasn't saying that they're the same, I was saying that they solve many of the issues that they were talking about with nuclear power (ie: need to use enriched uranium, no waste etc.). Candu reactors currently produce "waste", but they were designed not to since Canada thought they had little uranium to work with. Once it was found it was abundant in Canada, they stopped the reprocessing step, and just used newly mined uranium.

I don't know much about this stuff. Just watched that doco on Netflix, inside bills brain. It was the first I had heard of Nuclear power using depleted uranium, and that America apparently has enough depleted uranium to power the US for ~140 years or something.

I don't know why this isn't being pushed harder if it's safer and cleans up some of this waste.

Yeah, I watched the whole thing too. They leave out so much stuff, like that Paul Allen left the company because Bill & Steve Ballmer tried to dilute his shares when he had cancer, or that they actually bought DOS (the doco makes it look like they were working their ass off to build it).

CANDU reactors are Canadian, they use heavy water. They've been around for 50 years, people don't use them because they can't be used to make nuclear weapons. All the reators in Canada are these style.

We just need to find a way, way cheaper source of heavy water.

Sure there will. What do you think will happen to all the maintenance items and discarded scrap?

Surely you usually do care, because usually the discussion is about the best way to generate a given amount of energy.

The coal is as radioactive as the ash, thus these power plants are not creating any new radioactive waste.

Does that apply also to nuclear fuel? The byproducts of fission with uranium is less radioactive, or has a shorter half life, if I recall.

Short half lives are what make something radioactive. It's not 1:1 but basically take the amount of material / half life > how much radiation is being released.

Uranium 238 is extremely stable with a half life of 4.468 billion years, and the more active uranium 235 still has a half life of 0.7 billion years. Which is why they survived geologic timescales from earths formation.

Strontium-90 by comparison is produced in a nuclear reactor and has a half life of 28.8 years making it vastly more nasty. Further, while nuclear waste is incredibly nasty stuff, high neutron fluxes also turn the walls etc radioactive though to a less extreme extent.