Re: Remember "Bit-Slice" Chips ?

The Natural Philosopher <tnp@invalid.invalid> wrote:

On 12/12/2024 20:42, Computer Nerd Kev wrote:

D <nospam@example.net> wrote:

On Thu, 12 Dec 2024, The Natural Philosopher wrote:
>

But by the mid 1970s they had become competitive with the rise in fuel
prices, and today's level of computer systems and long range networking would
probably result in just a couple of people to manage any routine issues on
the power plant and satellite comms back to the nuclear power plant builder
to tell them what to do if anything went outside operational norms

>
I wonder if they could use the model from some SMR startup for ships? A reactor
that is preloaded and welded shut.

 
Yes, and the reactor model for ships is basically the model for SMR
start-ups, except with the vague idea that they're suddenly going
to be much cheaper somehow (I'll believe it when they "hit the
shelves").
 

 
Its not a vague idea, its a completely sound business model
 
Over 85% of the cots of a new conventional reactor is in getting it
certified to be safe at every single stage of the construction.  Capital
lies idle ad does the workforce  in half finished constructions waiting
to be signed off fort the next stage, and woe betide you if some trivial
aspect of it isn't to the specification - you need to re-certify it all
over again.
SMRs cut the Gordian knot, By making the reactors in a factory to
identical specifications and having them small enough to trailer them to
the site, 90% of the certification is only done once. For as many units
as you care to make.

Hmm, but then earlier small reactor designs should have taken over
from large nuclear power plants already years ago. Unless there's
some new way to make them more cheaply now and therefore make the
cost per MW more competitive, which doesn't look to have been
proven.

Also, below a certain size, the scale effect swings towards you: the
reactor does not need active cooling to dissipate the decay heat after a
SCRAM shutdown. So no Fukushima or 3MI accident is possible. Convection
is enough to do the job.

Well the SL-1 reactor explosion happened to one of the USA's small
transportable nuclear power plant designs, before they were
rebranded SMRs. Granted that was probably due to operator error in
a way that a better design might have made impossible - withdrawing
a control rod too far causing power levels to instantly surge. On
the other hand it highlights that you do have to get as far as the
SCRAM shutdown state - SL-1 and Chernobyl blew up before that.

If fluid cooling is used during reactor operation then you still
have the potential for leaks, which has been a well documented
obstacle in old small reactor designs (eg. the Lenin Icebreaker,
and some of the US military's other portable reactor projects).

The only downside to SMRs is that at smaller sizes they need more highly
enriched uranium (or Plutonium/Uranium mixes) to get to critical. The
supply chain for that is not yet established at scale.
 
Most of the designs that seem likely to reach production first are
simply scaled down pressurised water reactors, as used in nuclear
submarines etc. with probably extra shelding and safety to meet
commercial safety standards.

Like the Americans already did in the 60s:
https://en.wikipedia.org/wiki/Army_Nuclear_Power_Program

The Russians even put them in a vehicle and made nuclear power
plants you could drive down the road!
https://sovietologist.blogspot.com/2008/08/pamir-nuclear-power-goes-on-road.html
https://ofis-7sandotherthings.blogspot.com/2015/03/the-tes-3-nuclear-tank.html

So I have zero doubt that SMRs are possible. My question is how
they've suddenly jumped from having military grade price tags to
something that makes commercial sense. Until companies are actually
selling the things profitably, or explain exactly how they intend
to make them cheaply, I'm skeptical. There are about as many
companies promising to make commercial fusion reactors by around
2030 or earlier. Cheap SMR designs seem to be in the same category
of crossed-fingers investment. But still, I'm glad someone's
trying, even if I wouldn't bet on their success myself.

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