
Pentagon awards contracts to design mobile nuclear reactor - spking
https://www.defensenews.com/smr/nuclear-arsenal/2020/03/09/pentagon-to-award-mobile-nuclear-reactor-contracts-this-week/
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davidu
There are a few startups pitching a "nuclear power station in a shipping
container" idea -- and having heard them and done a bunch of reading about the
state of nuclear, it's hard to not come away with a complete and strong belief
that:

1) It's a really good idea.

2) Nuclear power, more broadly, is probably our best bet to quickly the tide
against climate change.

~~~
jasoncartwright
Nuclear is much more expensive than wind in the UK, and plants take 10yrs+ to
build.

[https://www.reuters.com/article/us-energy-
nuclearpower/nucle...](https://www.reuters.com/article/us-energy-
nuclearpower/nuclear-energy-too-slow-too-expensive-to-save-climate-report-
idUSKBN1W909J) "Nuclear energy too slow, too expensive to save climate:
report"

[https://www.bbc.co.uk/news/business-41220948](https://www.bbc.co.uk/news/business-41220948)
"Two firms said they were willing to build offshore wind farms for a
guaranteed price of £57.50 per megawatt hour for 2022-23. This compares with
the new Hinkley Point C nuclear plant securing subsidies of £92.50 per
megawatt hour."

Perhaps reply addressing my point rather than blindly downvoting :(

~~~
jswizzy
Nuclear is expensive because of design costs and regulations. Mass production
would greatly lower prices. The fact is when I was a nuclear power plant
operator the same WOG value you could buy at Home Depot for 10 dollars costs
300 dollars with all the certifications and requirements for safety need in a
nuclear plant.

~~~
dajohnson89
don’t you welcome the spirit of all those pesky regulations?

~~~
bumby
Those regulations are buying down risk.

Sure, they could buy them from Home Depot without those regulations. But how
do they know they were manufactured to spec? How do they know the manufacturer
used the correct alloy?

You aren’t paying for “regulations” you’re paying for quality pedigree. This
is also why aerospace work is so expensive. The industry has determined the
supply risk is too great without a verifiable level of quality. Quality is
expensive, but not as expensive as failure in these industries.

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dfox
In fact US Army did design nuclear reactor that can be shipped in two 4TEU
intermodal containers (design of the thing is highly RBMK-ish) and then
managed to deploy that and cause nuclear accident with casualties(in the sense
of personnel being pinned to the roof by reactor control rods that were
somehow ejected out of the reactor)...

~~~
King-Aaron
Is that the Three Mile Island incident you're talking about? I'm genuinely
curious, though thought that was a full scale reactor

~~~
LaMarseillaise
I believe dfox is referring to this incident:
[https://en.wikipedia.org/wiki/SL-1#Accident_and_response](https://en.wikipedia.org/wiki/SL-1#Accident_and_response)

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ggm
Portable nuclear generators exist in many navies worldwide. Russia has ones on
barges. It feels like this is a design imperative we know works because we
have many working examples.

I never understood why the same people who make submarines cannot make
commercially viable seaborne reactors for power. Probably the cost benefit
didn't pan out but does the tech work? There is no question.

The whole "safe at any speed" thing is the problem, not the underlying
physics.

~~~
p_l
Russians have, in development, an upscaled version of the reactor tech from
Project 705 submarines.

Design goals include ability to just put a power/heating station reactor block
on single flat rail car and ship it to and back. Lead/bismuth coolant, passive
safeties, if the reactor fails it essentially entombs itself in lead
preventing fissile material leak and making it easy to cleanup. And since it's
a fast reactor, it burns fuel that typical light water reactors treat as
waste.

Remember containerized DCs? It's that, just for nuclear power plants. With
possibility to mass produce airliftable 100MW nuclear power plants.

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TheSpiceIsLife
This looks like a potentially great product, especially if it fits in a 40'
shipping container.

It'd enable isolated and remote sites to significantly reduce their dependence
on diesel generators.

And I'd guess the defence angle enables increased use of hybrid vehicles.

~~~
castratikron
How many times could you charge a Tesla with a nuclear reactor the size of a
40' shipping container before you needed more fuel?

~~~
tlb
With 1 MW you can fast-charge 10 at a time. Doing that for 10 years is on the
order of 100000 charges.

It'd be perfect for supercharger stations on the Alaska Highway.

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entee
The military may not have this problem but for civilian use I’d ask: how do
you secure this? For example: how do you ensure someone with a semi truck
doesn’t ram into it and spill massively radioactive stuff all over the place?

~~~
acidburnNSA
The nuclear fuel in these is almost always solid. It doesn't spill. All you
have to do is ensure it is coolable in all geometries. To do that in this kind
of scenario you generally down-rate it to powers that can be carried off by
natural circulation of air flowing by it while it lays in the ditch. It's a
tradeoff though because you generally want to get as much power as possible
out of your equipment. If you want to trade lower power for a longer lasting
core with more accident resilience you can do that.

The x-energy gas cooled reactor behind this particular concept has
astoundingly robust fuel pebbles called triso. They conduct their heat to the
vessel and it passes it to passive airflow in all accidents.

~~~
entee
Thanks this helps a lot. One other Q: if the pellets spill, how dangerous are
they from a radioactivity perspective?

~~~
acidburnNSA
Unshielded but intact pebbles would emit extraordinarily high amounts of
radiation that falls off with 1/r^2 by geometric attenuation. Picking them up
and putting them back in a shield would require remote handling (long tools
and/or robots).

But once they're all picked up and re-shielded, the radiation would be gone.
Much different from spilling a vat of radioactive liquid which is much harder
to clean.

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perfunctory
Awarding military contracts is how fundamental R&D is being funded in the US.
Because direct R&D funding is not popular with the general public you have to
go in a roundabout way and pretend it’s for military use. There is no
guarantee anything practical will come out of this.

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siliconunit
I would rather spend some pennies to make sure the fellas at General Fusion
complete the first full scale demo MTF reactor...fission is an extremely
appealing tech for many reasons, the problem seems to always boil down to the
general population reaction when a massive disposal factory and relative
multi-millennia deep cave gets built next door...GF MTF tech looks like a very
good compromise between fully fledged self sustaining plasma tokamaks a la
ITER, and experimental pulsed solutions that still do not produce valuable
output..

~~~
ttul
Fellas and ladies... just saying.

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6nf
How would these reactors compare to nuclear submarine reactors for example? I
imagine those are fairly compact but probably not really suitable for general
user power supply?

~~~
battery_cowboy
A submarine reactor uses very, very highly enriched uranium not suitable for
keeping outside a military installation and onboard a moving tank (with
several inches of steel wall) due to security concerns, and the design of the
reactor is pretty safe, but it's still using 60's reactor designs running 80's
electrical control systems with 2000's PCs running those controls. Lesser
enrichment would require a much larger reactor to get the same power, and we
have newer gen reactors that are much safer, too.

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lwansbrough
Is there a theoretical minimum size for a nuclear reactor (based on current or
viable near-future technology)? If so, what kind of dimensions are we talking?

~~~
amelius
I guess the problem is mostly weight, which you need to shield the thing off
from its environment.

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gandalfian
Well in 2014 I read here that Lockheed will have a prototype fusion reactor on
a truck within five years. And its now 2020 sooooo....

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IXxXI
Where's that clean thorium reactor that never appears to manifest itself
beyond vaporware.

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lebuffon
Is it pre-requisite that it use uranium? Are these Thorium ideas you find on
the web real?

~~~
acidburnNSA
Thorium requires breeder reactors. Breeder reactors are more complicated.
That's why we don't have thorium reactors today.

[https://whatisnuclear.com/thorium-
myths.html](https://whatisnuclear.com/thorium-myths.html)

~~~
lebuffon
Great material. Thanks

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dear
If we can miniaturize nuclear reactors to the point that they can be drop-in
replacements for batteries, then we can potentially run our electronics,
appliances, machinery, vehicles standalone for decades without
refuel/recharge.

~~~
wmf
RTGs and betavoltaic cells scale down to that size but the powers that be
don't want nuclear material so widely distributed.

~~~
fsh
Betavoltaic cells get outperformed by coin cells and RTGs by solar panels in
most applications. There are some niche space applications, but not much else.

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intpx
[https://en.wikipedia.org/wiki/SL-1](https://en.wikipedia.org/wiki/SL-1)

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andrewpk
Wonder if they’ll finally start looking into thorium salt reactors again
(which were originally designed for civilian use).

~~~
chadcmulligan
It seems thorium isn't quite up to the hype -
[https://whatisnuclear.com/thorium-
myths.html](https://whatisnuclear.com/thorium-myths.html)

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JoeAltmaier
Makes sense - half of the Trillion-dollar budgets for middle-east wars was
'fuel to air-condition tents'.

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anovikov
It's a good idea because it will greatly cut the amount of fuel to be carried
and thus speed up deployment of large scale expeditionary forces.

Think of days when electricity-to-fuel will be able to also produce liquid
fuel for tanks, jets etc. to operate, then moving large masses of armor deeply
into the enemy territory will become a no-brainer to such a point that
territorial depth will cease to be a viable protection!

~~~
pjc50
Until someone brings the other kind of nuclear to the battlefield.

~~~
anovikov
Logistic chain suffers a lot under the threat of WMD, because many things it
depends on such as ports, airfields, and bridges, are stationary and a no-
brainer to be nuked. If enemy starts using nukes, not having to carry too much
liquid fuel all the way will help a lot. And it makes the most of the supplies
army has to transport, with proportion increasing because say, need for
ammunition decreases as shells get smarter, but better protected tanks and
APCs weight more and thus need more fuel.

