Re: The Physics Behind the Spanish Blackout

On 11/06/2025 11:21 pm, David Brown wrote:

On 11/06/2025 13:41, Bill Sloman wrote:

On 11/06/2025 5:38 pm, David Brown wrote:

On 10/06/2025 19:23, Bill Sloman wrote:

On 11/06/2025 2:32 am, David Brown wrote:

On 10/06/2025 16:16, Bill Sloman wrote:

On 10/06/2025 5:21 pm, David Brown wrote:

On 10/06/2025 07:01, Bill Sloman wrote:

On 10/06/2025 6:44 am, Liz Tuddenham wrote:

Carlos E.R. <robin_listas@es.invalid> wrote:
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On 2025-06-09 21:54, Don Y wrote:

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OTOH, we're sticking with other technologies (fossil fuels -- coal -- and
nukes) despite obvious and yet to be solved problems INHERENT in their
technology.  Adding "inertia" synthetically to a network is a considerably
more realistic goal than sorting out how to deal with nuclear waste or
the consequences of burning carbon.

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Technically and economically, dealing with nuclear waste is many orders of magnitude easier than dealing with the consequences of burning carbon.

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Nuclear fission waste is mixture of isotopes. Some of them are very radioactive and decay fast, and keeping them safe until they've mostly decayed is technically demanding. The less radioactive isotopes are easier to handle, but some of them stay dangerously radioactive for upwards of 100,000 years, and keeping them safely isolated for that length of time is an as yet unsolved problem
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We all know that, I believe.  There are two ways to handle the waste - bury it deep enough, or use reprocessing/recycling to reduce the worst of the waste.  (Of course a better idea is to use more advanced nuclear reactors that produce more electricity for less waste.)

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There aren't any. If you fission U-233 (which is what thorium reactors do) you get slightly different proportions of exactly the same isotopes as you get from U-235 which pose essentially the same problems.

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Estimates by proponents of molten salt thorium reactors are between a hundredth and a thousandth of the levels of the more problematic waste materials for the same generated electricity.

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

 Oh, thanks for that!  I'd never heard of Wikipedia before.  I have also heard rumours that there is a newfangled way to search for information - "goggle", or something like that.  Perhaps you could explain that to us too?
 

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  No doubt they are overly optimistic, but they are still massively more efficient.

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The claim appears to be total nonsense.
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 Ah, well, if you say so it must be true.  You can no doubt refer to some comic book as a reference.
 

For the  long-lived transuranic radioactive isotopes,

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Nuclear fission doesn't produce any long-lived transuranic radioactive isotopes.

 Try reading the Wikipedia article you linked - perhaps also the page <https://en.wikipedia.org/wiki/Long-lived_fission_product>.

Nuclear reactors do produce them, but not by nuclear fission as I explained in the section below, which you clearly hadn't read when you produced your response.

The neutron flux in a nuclear reactor can be captured and promote some of the uranium and plutonium around into even heavier isotopes, but it is very minor component in nuclear waste.
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the thorium cycle in a  molten salt reactor gives about 5% of the quantities you get from standard light-water uranium reactors, and the waste is in a form that is easier to separate and recycle.

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Since the transuranic radioactive isotopes are a very minor problem anyway, who cares?

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It is the long-lived ones that are the problem.  Short-lived isotopes are only an issue if you let them escape before they have decayed.

What makes you think that transuranic radioactive isotopes are particularly long-lived? Heavier nuclei do tend to be less stable - technicium is the lightest element that doesn't have a stable isotope.

 Conventional uranium reactors use less than 1% of the uranium for useful energy production - the rest is wasted.  With molten salt thorium reactors, close to 100% of the thorium is used.

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Eventually. You have to take the spent fuel out of the reactor, take out the fission product and the U-233 that has been generated by neutron capture, and put the purified residue back into the reactor

 If only there were a way to do that...

There is. It involves doing chemistry on very nasty radioactive spent fuel rods so it's difficult and expensive, but perfectly practicable, if mostly economicaly impractical

Even with uranium fuel rather than thorium, breeder reactors and higher temperature molten salt reactors can greatly reduce the worst parts of the waste while generating power.

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Twaddle.
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You don't get any Pu-239 from neutron capture in U-238, but that's a feature rather than a bug.

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The problem with the nuclear industry is that it was viewed as a bug, not a feature.

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Nobody liked admitting that U-235/U238 nuclear reactor were plutonium breeders, and that processing spent fuel involved recovering the Pu-239 that had been bred, but there's no way they can avoid breeding plutonium

 If it was a secret, it was a badly kept secret.

It was never any kind of secret, but nobody liked talking about it.

 That is why thorium reactors where pretty much abandoned in the race to build bigger bombs.

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U-233 makes perfectly satisfactory bombs. Bigger bombs were actually hydrogen bombs, and the even bigger bombs that followed them used an outer layer of U-238 to capture lots of the neutron produced by hydrogen fusion, turning it into Pu-239 which fissioned immediately.
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https://en.wikipedia.org/wiki/Nuclear_weapon

 I know the basics of nuclear weapons, and I know how to read Wikipedia.

But you don't seem to bother. I got taught most of this stuff long before Google got going, but getting at the contents of the Melbourne University libraries isn't all that easy from Sydney and finding the information with google is pretty straightforward.

To the bomb makers, there is no such thing as a "satisfactory" bomb - they always want bigger.

Not always. You can fit small atomic bombs into big artillery shells, and fire them far enough away to survive the blast.

Priorities have changed since then, and lots of countries are working on thorium and molten salt breeder reactors.
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Nuclear fusion is more promising and hydrogen-boron fusion doesn't produce any neutrons at all - or wouldn't if anybody could get it to work.

https://hb11.energy/

Don't believe the hype.  Wait another 50 years until it is working.

HB11 hopes that they can get their scheme working rather earlier than that. I heard about it at tolerably sober Royal Society of NSW presentation. Nobody is promising that it is going to work, but the early studies they have done look promising. There's still a long way to go, but it might pan out.

Nuclear fusion has /always/ been promising.  I am sure it will be achieved eventually, but if we wait for it to be a commercially realistic source of a substantial proportion of the world's energy production, we will already have lost the ice on Antarctica, flooding the homes of about a quarter of the world's population, and raised the temperature of the homes of another quarter to uninhabitable levels.

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The guys at HB11 would beg to differ.

 Of course they would.  After all, they are financed by venture capitalists - begging is the name of the game.  They will keep releasing news about things /almost/ working in order to keep the cash flowing in.

Not my impression. They do small chunks of work when they get the money to do them, and report the results.

  /Eventually/ they might get it working - or someone else will - but it will be decades longer than any media release suggests.  The same goes for the dozen other private fusion research companies around the world.
 

They are currently financed by venture capitalist - which implies a 5% chance that their approach can be made to work, though I suspect that the odds are rather worse because the pay-off would be remarkably generous. You snipped the link without marking the snip.

 I snipped the link because I don't post links to random sites.

There's nothing random about the site. It has been there for years, and I've posted that link in the past - it's been around since 2017 and I referred to it here in 2019.

Asserting that some technology will take a long time to mature is a standard conservative tactic, but it is pure guess work.

 Fusion energy has been 50 years in the future for the last 80 years.  I have not seen anything to suggest that has changed much - and I make a point of keeping up with scientific and technical news.

But you haven't heard of hydrogen-boron fusion? And you haven't noticed that the current generation of hydrogen fusion machines have got pretty close to the Lawson criterion (and I did work with John D. Lawson's youngest son, who wasn't remotely in  the same league).

I believe that eventually, we will have workable fusion power (though it will probably be deuterium / tritium fusion first), and that will be a big step up from fission nuclear power.  For the next 50 years at least, however, thorium fission is the way to go for bulk power production, with solar and other renewables helping out as it takes a long time to get nuclear plants up and running.
 But you have done something unique here - I can't remember anyone else being so confused as to suggest that I am a conservative!

You've copied a conservative tactic. That doesn't make you a conservative, but it does suggest that you don't think too hard about what you post.
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Bill Sloman, Nijmegen