[ExI] Fusion breakthrough

Rafal Smigrodzki rafal.smigrodzki at gmail.com
Fri Dec 16 07:46:02 UTC 2022

On Thu, Dec 15, 2022 at 10:14 PM Stuart LaForge via extropy-chat <
extropy-chat at lists.extropy.org> wrote:

> What nuclear waste is there in laser-primed fusion of deuterium fuel
> pellets?

### The tritium-deuterium reaction they are all working on produces an
insane neutron flux, so bad that e.g. the liner of a large
continuously running tokamak would need to be exchanged every two years and
would contain about 20 Chernobyls worth of radioisotopes. It's insane - the
fusion reactor would have to be rebuilt every two years and the liner would
be extremely high-level nuclear waste.

IMO, the only way fusion could ever become viable is with aneutronic
reactions - but this requires even higher temperatures, so probably won't
happen anytime soon.


> How much of that economic destruction by SWB is due to government
> interference and subsidization of solar and wind? And SWB would be far
> less useful on Mars or Europa. Whereas fusion is like carrying around
> your own shard of a star.

### Almost 100% of the money spent on fusion was government-provided,
including the lab work we are discussing, so there you go.

But what matters in the long term is not so much where the research grants
came from but rather the comparison of the prices of SWB vs fusion energy.
As I said, SWB is *now* cheaper than *running costs* of coal power
(excluding capital depreciation). This is the cheapest source of
high-quality (i.e. electric) energy ever invented. Fusion on the other hand
is maybe 30 years (at current speed of progress) away from barely producing
more energy than is used to keep the reactors running (engineering
break-even), and forget about the economic break-even.

Yes, when we start venturing off planet in a serious way, fusion would be
great to have available, so I am all in favor of continued basic research
but trying to commercialize it in the next 30 years is a waste of money.

> About 15-20 years ago people were just as skeptical and made the same
> arguments about SWB with respect to fossil. When something happens
> after 60-straight years of well-funded nothing, it IS unexpected.

###  Yes, this is true and in fact I did point out the economic
non-viability of solar about 12 years ago on this very list but the price
of solar went down by 85% since then, so now solar actually does make
sense. However, the situation is different if you apply the same reasoning
to fusion - while solar was a factor of 10 away from economic viability,
fusion is a factor of ??? 1000? 10,000? away from being economically viable
and at current rates of progress it just won't happen for a long time.


> Lithium is good. I agree we should mine more. If deserts tiled with
> solar panels is how we achieve the wattage to to ignite our fusion
> reactions, then so be it. How much energy is too much, Rafal? Why are
> you willing to leave energy on the table? This is a Promethean moment
> for all of humanity; it is tangible hope.

### Tony Seba has some great presentations about how much energy we would
have after the transition to SWB, you be the judge if it's too much:

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