
Ultra Safe Nuclear - dongobongo
https://www.usnc.com/
======
hairytrog
Two interesting things to see here, of many. They are really planning the
sites to be temporary compared to the solar/wind/ and other industrial power
plants that have little or no plan for returning their sites to the original
virgin soil. And two, they seem to use a molten salt loop like in concentrated
solar to meet variable demand without changing the power level of the reactor,
which you can't really do because of Xenon poisoning. So it's like a natural
gas plant in its ability to deliver power, but clean and holds 20 years of
fuel inside the reactor.

~~~
ajross
And unlike a natural gas plant, it costs 3-10x what the equivalent generating
capacity in renewables would cost.

I come to post this Same Thing every time this discussion comes up. It's not
about safety. Everyone serious understand nuclear, even current technologies,
is "safe enough" to be useful to build out.

Nuclear is _outrageously expensive_ , though. And new reactor designs don't
seem to be making much progress on that.

Look, I think nuclear is fine. But as a numerate and earnest environmentalist,
I don't see where the case for it lies. Right now, we should be building out
solar and wind as fast as we can, because they're good and safe and CHEAP. And
when we get to that last 5-10% where we need buffering capacity that we're
currently getting via gas? Yeah, maybe then we can talk about nuclear.

But even then... meh. What's the case on trying to finish the job on
electrical generation vs. putting those same dollars into low hanging fruit in
other areas of the energy puzzle?

Nuclear needs to make its case on a balance sheet before it makes sense to
talk about.

~~~
Wowfunhappy
So, why did so many countries/companies originally build nuclear reactors, if
the economics inherently don’t make sense? Has something changed?

~~~
ajross
To make bombs. And what's changed now is we have enough bombs.

Seriously, even the reactors that aren't expressly breeding fuel were designed
with an eye to the technology and as part of programs in the 50's-70's to
build out expertise in this critical technology area of national security.

Countries wanted bombs. To make bombs you need a nuclear industry. Ergo,
everyone who wanted bombs built civilian reactors, without exception.

~~~
dirtyaura
This argument doesn’t hold. There are several countries such as Finland that
have operated nuclear power plants for decades and do not have ambitions for
nuclear bombs.

~~~
ajross
If you want to go with that argument: cite Japan, not Finland. But it doesn't
have to be 100% true to be largely true. The overwhelming majority of nuclear
capacity has been built out by nuclear powers or aspiring nuclear powers. And
with few exceptions the end of their warhead buildout happens to correlate
with the end of their megawatt buildout.

~~~
pfdietz
Japan has a stockpile of separated reactor grade plutonium sufficient to make
thousands of bombs. This is a deniable kind of proliferation. If push came to
shove they could weaponize that material without having to make new plutonium.

(And, yes, reactor grade Pu CAN be used in weapons, with proper design.)

------
grawprog
So why has nuclear waste become a thing that's not mentioned anymore? It was a
pretty big thing in the 90's, now it seems to get brushed under the rug for
all this 'safe' nuclear power marketing. It's mot just meltdowns and
containment breaches that are a problem with nuclear power. None of the
renewable alternatives produce radioactive waste that needs to be stored and
dealt with.

[https://en.m.wikipedia.org/wiki/Radioactive_waste](https://en.m.wikipedia.org/wiki/Radioactive_waste)

>Exposure to radioactive waste may cause health impacts due to ionizing
radiation exposure. In humans, a dose of 1 sievert carries a 5.5% risk of
developing cancer,[12] and regulatory agencies assume the risk is linearly
proportional to dose even for low doses. Ionizing radiation can cause
deletions in chromosomes.[13]

~~~
manfredo
Because it's not a problem. There's actually very little of it. It occupies a
volume the footprint of a football field and 10 yards high [1]. Storing it is
pretty foolproof: bury it in an area with no aquifer. The main risk of
contamination is getting into the groundwater. If there's no groundwater the
risk of contamination is eliminated even if the containers decay over time.
And lastly, it doesn't make sense to bury our waste right now because some of
the latest reactors being built can use this waste as fuel.

We hold nuclear to an incredible double standard with respect to the waste it
produces. Fossil fuels release substantially more radioactive waste [2], and
that waste is poorly contained. Usually put in an exposed pile next to the
plant, which occasionally spills into rivers nearby [3]. Not to mention a
whole other host of pollutants like heavy metals, and the carbon dioxide that
is th main driver of climate change.

1\. [https://www.energy.gov/ne/articles/5-fast-facts-about-
spent-...](https://www.energy.gov/ne/articles/5-fast-facts-about-spent-
nuclear-fuel)

2\. [https://www.scientificamerican.com/article/coal-ash-is-
more-...](https://www.scientificamerican.com/article/coal-ash-is-more-
radioactive-than-nuclear-waste/)

3\.
[https://en.m.wikipedia.org/wiki/Kingston_Fossil_Plant_coal_f...](https://en.m.wikipedia.org/wiki/Kingston_Fossil_Plant_coal_fly_ash_slurry_spill)

~~~
merb
1\. How long does it need to be kept safe?

2\. How to find a storage facility that can keep it safe that long?

3\. How to ensure that a facility does not contamine other stuff in X years?

4\. if it is recycable why does nobody do it?

5\. if it is so easy to store it safe, why does not country have a TRUE final
depot?

yeah coal is bad, but why compare it to coal in the first place when we want
to reduce such things anyway?!

~~~
manfredo
1\. Forever. Uranium is a heavy metal, it's toxic regardless of it's
radioactivity.

2\. The US already has one [1]. Congress stopped it's opening, but it's
sitting there built ready to be used. Europe also is constructing a disposal
site [2]

3\. Like I wrote in my comment, bury it in an area with no groundwater.

4\. France does recycle it's nuclear waste.

5\. We do, as I pointed out above. And for the second time, this waste is fuel
for some of the reactors currently being built.

The reality is that nuclear waste will have minimal if any impact on the rate
of uranium contamination. Naturally occurring uranium is responsible for
vastly more contamination than nuclear waste. Streams and rivers flowing down
from mountains pick up uranium in the sediment and bring it downstream:
[https://www.cbsnews.com/news/uranium-contaminates-
drinking-w...](https://www.cbsnews.com/news/uranium-contaminates-drinking-
water-in-us-west/)

1\.
[https://en.m.wikipedia.org/wiki/Yucca_Mountain_nuclear_waste...](https://en.m.wikipedia.org/wiki/Yucca_Mountain_nuclear_waste_repository)

2\.
[https://en.m.wikipedia.org/wiki/Onkalo_spent_nuclear_fuel_re...](https://en.m.wikipedia.org/wiki/Onkalo_spent_nuclear_fuel_repository)

~~~
noja
> Forever

How can anything with a cost that lasts forever be cheaper?

~~~
philipkglass
Most toxic elements last forever. That includes the toxic elements in coal
ash. Both coal ash and spent nuclear fuel need indefinite safe storage. It can
be cheaper to store spent nuclear fuel because it's so much more compact than
fossil fuel waste.

Remember that the status quo already has a large forever-waste cost of its
own. Nuclear waste is a trade off vs. other kinds of waste, and it is cheaper
than the status quo.

~~~
arawde
Wanted to leap in here to mention tailings from minings projects. The gold
that goes into a circuitboard comes from a mine which likely has a tailiings
facility and associated dam, which is essentially an open pit filled with
water into which tailings are dumped.

They're incredibly toxic materials. We had an engineer go out to the field and
take a sample of some tailings, and after 6 months of being left in a lab, the
materials had eaten through the stainless steel tube containing the sample.

It's not just power generation that has a negative externality in the form of
waste. ALL resource extraction has associated waste.

~~~
TeMPOraL
Not to mention, industrial chemical processes in general.

Toxic waste requiring indefinite safe storage is _the default state_. Spent
nuclear fuel is actually nice here in a way, because in some cases, it's a
self-solving problem (dangerous stuff decaying into less dangerous stuff over
time).

------
tyho
The walk away passive safety is a tradeoff with non-proliferation concerns.
This design requires 20% enrichment, much higher than traditional reactors.
This might be a smart tradeoff, but let's not pretend it's doesn't exist.

[https://www.aps.org/units/fps/newsletters/201810/reactors.cf...](https://www.aps.org/units/fps/newsletters/201810/reactors.cfm)

~~~
carry_bit
The countries in the nuclear club represent a significant fraction of the
world's energy consumption. Even if they were the only ones to eliminate the
use of carbon-based energy via nuclear, it would be a good start.

------
yabones
For a more dense read, see the whitepaper[1] from Oak Ridge National
Laboratory about FCM fuels, which seems to be one of the key innovations of
this reactor type. Instead of using pellets of Uranium oxide directly inside
the reactor, this method encapsulates the fuel in a high temperature ceramic
material which makes it very unlikely for the reactor to 'melt down' the way
that mainstream reactors can.

[1]
[https://info.ornl.gov/sites/publications/Files/Pub42476.pdf](https://info.ornl.gov/sites/publications/Files/Pub42476.pdf)

------
hairytrog
Seems like their claim to "Ultra Safe" is actually merited based on a first
principles look at the power density. They claim 1.24 W/cm^3 versus 20-40
W/cm^3 in normal reactors. The high power densities mean you have to be able
to cool the reactor, even when you shut down the reactor because reactors take
a long time to actually turn off. With such low power density, it should be no
problem to cool down the reactor. It'll just cool down naturally, like a hot
pot. In fact the metric to look at would be power per core surface area.

~~~
cbmuser
There are reactor types like the Integral Fast Reactor that will safely shut
itself down even if the cooling systems fail.

In fact, the engineers at Argonne deliberately tried to overheat the reactor
by shutting off its pumps and they failed.

~~~
dongobongo
But they don’t lose the liquid coolant - which seems like a pretty reasonable
scenario.

~~~
jabl
Especially considering the IFR (and it's predecessor EBR II where the
experiment the parent refers to was done) are pool type reactors, meaning the
reactor sits in a big pool filled with the primary coolant, there are no pipes
where the primary coolant leaves the tank.

------
xibalba
Assuming nuclear truly can be ultra safe, how do you convince a public that
has seen Chernobyl, Three Mile Island, and Fukushima to get on board?
Particularly when the "competition" (solar, wind, etc) has such a strong
tailwind.

~~~
3pt14159
Deaths per joule are the lowest out of any major fuel source except for maybe
wind, which is debatable depending on your assumptions about the future.

~~~
TheOtherHobbes
That's deaths per joule _so far._ How would nuclear compete if far more
renewables were installed, producing far more joules?

How about clean-up costs? Estimates for Fukushima vary from $76bn to $660bn
depending who you ask.

[https://www.scientificamerican.com/article/clearing-the-
radi...](https://www.scientificamerican.com/article/clearing-the-radioactive-
rubble-heap-that-was-fukushima-daiichi-7-years-on/)

How about general carelessness?

[https://www.scientificamerican.com/article/nuclear-
weapons-s...](https://www.scientificamerican.com/article/nuclear-weapons-site-
alarms-shut-off-scientists-inhale-uranium/)

This is not unusual for the nuke industry, both civil and military.

Which is the problem. This is primarily a managerial issue, not a
technological one. And the quality of executive and managerial decision-making
of all kinds across the entire industry is nowhere near the standard required
for future confidence. Especially given increasing risks from extreme climate
change events.

~~~
evgen
Since deaths from renewables scale linearly with installations I think that
nuclear will continue to win that particular argument. Building more wind
turbines and solar installations is not going to reduce the deaths from
installation and maintenance.

I wonder what the clean-up costs are long-term for the groundwater
contamination from solar panel production and for the dismantling and junking
of wind turbines when they reach their EOL? Maybe not as much as nuclear but
definitely not free -- right now they are a hidden negative externality just
like coal plant fly ash, but eventually someone is going to have to pay the
bill.

~~~
flor1s
The type of renewable matters though, it seems like retrofitting existing
houses with solar panels is relatively more dangerous than building utility
scale solar farms (no roof to fall off from, higher yield).

------
bl0b
Random renewable energy-related question that I've been thinking about:

Specifically wrt solar, a big argument against is that it can't provide power
during the night and we don't have a good way to store energy. What I'm
wondering is why it's so imperative that residential/commercial properties are
able to get full power from the grid 24/7? What if prices for power go way up
during the night (because it can't come from solar), and people could just
learn to get most of their power from the grid during the day? And have a
relatively small per-house battery that charges during the day and can be used
at night.

~~~
sparkie
> What if prices for power go way up during the night

Individual energy providers do not control prices. The market does.

If there is market demand for energy at night, then people will fill in the
gap to provide it. Anyone pushing up prices at night will have competition
from someone else who will undercut them. They'll be forced to drop prices or
lose customers.

Batteries are inefficient, expensive, and do not provide an adequate amount of
electricity for most purposes. Consider a UPS, they're about 90% efficient at
most, and for all that 10% of wasted energy, you get to power your computer
for about 15-60 minutes if the power is lost. The batteries only last a few
years.

Also, a bigger argument against solar (at least, photovoltaics) is that they
use up rare earth metals, have limited lifetimes (<25 years), and then become
non-recyclable toxic waste.

Concentrating solar energy is more promising as a sustainable solution, but
requires large infrastructure and the right climate to be cost effective.

~~~
pfdietz
"Inefficient" = 90%? I think you need to think more about what you've written
there.

~~~
sparkie
As stated, that is "at most". A usual UPS is 80-89% efficient.

Even still, assuming they were 90% efficient, is it worth the extra 10% energy
consumption just so you can run your computer for 1 hour at night when the
solar energy provider ups their rate? You still need to consume the additional
energy in the day to charge the battery.

For me to label it efficient, I'd be looking for 95%+, but 99% would be
preferable.

Remember, this efficiency declines as the battery ages. You only get a few
years of efficient use before it declines significantly. Then you have a
disposal problem. A typical UPS uses lead-acid batteries, the same type used
in cars. They're not environmentally friendly.

~~~
pfdietz
Of course it's worth it. Losing 10% of the energy in storage is close to
trivial, particularly if that energy is otherwise curtailed excess production.
It would be worthwhile to use far less efficient storage for long term load
leveling, if the capital cost were low enough. Hydrogen with cheap
electrolysers and combined cycle turbines might have a round trip efficiency
of 33% -- and that would be GREAT as a last component for getting to a fossil-
fuel free grid, particularly at high latitude.

~~~
sparkie
But this is missing the elephant in the living room (this thread), which is
nuclear.

One of the main issues with nuclear is that it isn't cost effective to turn
on/off to meet demand changes in day and night. Nuclear power stations usually
only generate energy for the baseload. If we were to cut energy consumption
down at night (by increasing costs), the baseload would also drop, and leave
an even larger gap to meet for peak, which must be met by other means like
solar or fossil fuels.

If anything, we want to shift some energy consumption to off-peak times like
early hours, so that the baseload is higher and can be met by cheaper nuclear,
along with other solutions like tidal. If this happens, the gap between peak
and baseload during the day/evening will be smaller, and can be met with
solutions like (concentrating) solar which are more environmentally friendly
than photovoltaics + batteries.

~~~
pfdietz
No, it's not missing nuclear. Hydrogen is the stake through the heart that
kills the last argument for nuclear (that batteries can't handle long term
load leveling). With reasonable projections of where the costs of renewables
and storage are going, nuclear gets optimized right out of the picture.

~~~
sparkie
Yeah, I can't take you seriously. GL with your blackouts and energy quotas,
oh, and reliance of fossil fuels. Where do you think the energy is going to
come from to perform electrolysis for hydrogen? solar? You are _nowhere near_
meeting basic needs yet with solar, wind, tidal, geothermal combined. (3 out
of the 4 can be intermittent/dependant on environmental conditions and are not
reliable). Remember, energy demand is going to continue increasing. By the
time your renewable utopia exists, you're going to need to double or triple
its capacity.

Perhaps I'm unaware of some technological breakthrough which can produce
hydrogen using little energy?

Nuclear is great once up-front costs are paid. Most future energy demand will
be met by nuclear. Cleaner renewables will be there to provide additional
capacity above baseload, but I wouldn't depend on them to meet basic needs.

I have pondered whether it would be possible to generate hydrogen more cheaply
via concentrating solar or geothermal. The hotter you can get water before
performing electrolysis, the less electricity will be required. Above 3k
Celsius, the atoms in water will dissociate without electricity. You might
have a reasonable argument against nuclear if you don't need to spend 3x the
electricity creating the hydrogen than you'll get back from it.

~~~
pfdietz
> You are nowhere near meeting basic needs yet with solar, wind, tidal,
> geothermal combined.

Ah, the old "it hasn't happened yet, therefore it can't happen" argument. I'm
sure if you honestly think about it you can realize why that argument is
nonsense.

> (3 out of the 4 can be intermittent/dependant on environmental conditions
> and are not reliable).

We're talking here about power for hydrogen production. Intermittency doesn't
matter much for that (it requires the electrolysers be cheap, but their costs
have plummeted recently, so that's no longer an obstacle.)

> Perhaps I'm unaware of some technological breakthrough which can produce
> hydrogen using little energy?

Perhaps you could stop using strawman arguments? Hydrogen doesn't have to be
produced with little energy in order for hydrogen storage to be viable. The
energy that is used just needs to be sufficiently cheap. You know, like that
$0.013/kWh power from large scale PV in the UAE? And that's only the latest in
a constant string of record low bids.

> Nuclear is great once up-front costs are paid.

Yes, if you can get the Nuclear Fairy to wave a magic wand and make the power
plant appear for free, it's much less expensive (but even then, the operating
costs will be much higher than renewables). In the real world where real money
has to be paid to build nuclear power plants, not so much.

> I have pondered whether it would be possible to generate hydrogen more
> cheaply via concentrating solar or geothermal.

Neither of these are competitive with PV now. Hell, it's now cheaper to make
domestic solar hot water with PV and a resistive heater than it would be to
use solar thermal collectors (although a heat pump water heater would be
cheaper still). PV has gotten THAT cheap.

------
Lazare
Eh. In my view, nuclear is very clearly safe enough, and has been for some
time.

What's more interesting to me is whether it's _cheap_ enough.

~~~
dongobongo
1% of commercial reactors Have failed catastrophically. Seems like terrible
track record.

~~~
Lazare
> 1% of commercial reactors Have failed catastrophically.

That seems a bit high to me. There have been a _lot_ of commercial reactors.

> Seems like terrible track record.

Even if true, everything fails sometimes. Rooftop solar has a surprisingly
high death rate from _people falling off of roofs while installing it_.

Ultimately it's a question how safe nuclear is relative to other power
methods, probably in terms of deaths per terawatt hour. And even counting
those catastrophic failures, it turns out it's actually extremely safe.
(...which really underscores just how horribly dangerous some of the
alternatives are...)

None of which means nuclear power is _economic_.

------
nimish
Safety is no longer the reason Nuclear is not worth it.

The sun is a giant, free nuclear fusion plant in the sky. We can capture 1/5th
of its output per square meter. For free!

The wind -- caused by solar heating -- also generates free power.

The cost of harvesting it is now so low, and will always continue to decline
as any technology will, that any fuel-based generation mechanism is going to
be rendered uneconomic with time alone. They depreciate faster as time goes
on!

Investing in any such generator needs to be for other reasons like land
scarcity.

~~~
gruez
>We can capture 1/5th of its output per square meter. For free!

except you know, the solar panels. by the same logic you can you can capture
fission power for free, all you need is set up the reactor.

~~~
semi-extrinsic
There was a comment here about cleanup costs of nuclear vs. solar, that was
deleted while I was typing my response to that. I'm just gonna copy in my
response here, because I think it's an interesting topic:

Are we really sure solar panels are much easier to dismantle on a euro-per-kWh
basis though? That is, if you divide the total cost of dismantling and
recycling a solar power plant, divided by the total amount of energy produced
over the lifetime, does solar power do much better than nuclear?

Nuclear power in Germany (17 powerplants) has produced well over 5 million
gigawatthours over the lifetime so far. It's hard to put good numbers on the
cleanup costs, but somewhere in the ballpark of 50 billion euros is probably
correct. (Keep in mind that some cost is the government paying the powerplant
owners compensation because they are forcing them to shut down long before
end-of-life).

So that gives you around 0.01 euros per kWh. A solar panel with 20% efficiency
placed close to the equator produces 500 kWh/m2/yr. Over 30 years of lifetime
that would produce 15 000 kWh/m2.

Are you sure you would spend significantly less than 150 euros per square
meter of panel to dismantle, transport and recycle the solar panels?

~~~
jbob2000
Solar panels aren't the only way to generate energy using the sun. You can
build a concentrated solar farm (see:
[https://edition.cnn.com/2019/02/06/motorsport/morocco-
solar-...](https://edition.cnn.com/2019/02/06/motorsport/morocco-solar-farm-
formula-e-spt-intl/index.html)) which uses mirrors and salt to produce up to
580mw of power, with a cost of just under $1bil.

My neighbor heats their pool using solar, it's just a bunch of tubes that
cycle water over their roof. They got rid of their gas heater. Given that most
backyard pools are used in the summer, why can't we swap these to using solar?

~~~
pfdietz
Concentrated solar has lost to PV. It's simply not competitive now.

For domestic hot water, it's now cheaper to use PV and a heat pump (or even
resistive!) water heater.

------
VBprogrammer
I once wondered if it would be possible to have a nuclear power station which
operated subcritically with extra neutrons injected from an outside source.
The advantage I saw was that turning off the outside source would instantly
stop the reaction, no worrying about articulating fuel rods and poison
injectors. Unfortunately decay heat is still an issue.

Turns out it's potentially a thing but has some technical challenges.

~~~
Symmetry
The problem is less about preventing criticality and more about handling the
decay heat from all the isotopes produced when it was critical. That's going
to give you 10% of the heat you had been producing with the reactor on for a
little while after you stop the chain reaction.

~~~
VBprogrammer
Yes, that has been the common factor in most incidents. Chernobyl being the
exception, they didn't manage even manage to get the control rods fully
inserted before the shit hit the fan (poor reactor and control rod design).

Still, the British AGCRs were recently fitted with articulating control rods
because if the reactor core was damaged they might not be able to insert them
normally.

------
teilo
I'm all for the concept, but so far, everything I've seen has been nothing but
concept.

~~~
sambull
Large awesome graphic page on the fuel, and how its super safe. Nothing about
how they 'conceptualize' disposing of their waste.

~~~
cj
The video on their homepage explains their approach to waste disposal. About
60 seconds into the video.

------
basemi
Nice animation but but... I think nuclear is bad because the technology to
make it is in the hands of a few big corps. That's the major downside, and of
course, toxic waste.

~~~
flyingfences
> the technology to make it is in the hands of a few big corps

On a practical, mass-deployable scale, this is true of any power generation
technology.

------
sradman
At 5 MW, these MMR (Micro Modular Reactor) look like a specialized alternative
to diesel generators servicing remote locations unserviced by the regular
power grid. 20 year lifetime without refuelling is an attractive proposition
if the capital costs are competitive.

------
karlalexpauls
Dr. Chris Morrison from USNC's space division presented to the Seattle Friends
of Fission at Ada's

[https://youtu.be/39LGrJkDmho](https://youtu.be/39LGrJkDmho)

------
mehmeta
What would be the ballpark cost for this reactor producing 5MWe?

~~~
OliverJones
It would be great to know the capital and ongoing maintenance cost per MWe of
load, and the lifecycle cost per gWh. This product is pitched at remote sites,
so presumably the costs aren't low enough (yet?) for places where power grid
connection is an option.

------
p1mrx
Illinois EnergyProf recently did a video on USNC's design:
[https://www.youtube.com/watch?v=7gtog_gOaGQ](https://www.youtube.com/watch?v=7gtog_gOaGQ)

(Though I think he used audio from the wrong microphone; the earlier videos
sound much better.)

------
sandymcmurray
Summary of discussion in this thread (from The West Wing)

[https://youtu.be/7fkMR96I0sw](https://youtu.be/7fkMR96I0sw)

------
Gravityloss
In the page it isn't explained how it shuts down passively in a loss of
coolant event? Since the coolant is not doing moderation, removing it doesn't
reduce reactivity at all.

You have a 30 bar helium pressure vessel and heat exchangers etc. I wonder how
much it's going to leak.

Not saying it's bad, just interested in these questions. Some other designs
have these issues in focus.

------
abalone
Serious question: what happens when you take one of these fuel pellets and
blow it up and disperse it in the atmosphere / water supply, either
accidentally or on purpose?

Have they actually designed a solution or is this a fundamental safety risk
with all nuclear fuels? All I see addressed is proliferation / reprocessing
which is a different thing.

~~~
jabl
> Serious question: what happens when you take one of these fuel pellets and
> blow it up and disperse it in the atmosphere / water supply, either
> accidentally or on purpose?

Hmm, nothing? There are already billions of tons of uranium dissolved in
seawater (there are actually efforts to try to "mine" uranium from seawater),
why would a few grams more matter?

As for fission products, humanity has made hundreds of atmospheric nuclear
tests, as well as the Chernobyl disaster that spewed lots of fission products
into the atmoshpere. Unfortunate and stupid, yes, but not the end of humanity
either. And fortunately, fission products decay away relatively quickly. So
yes, a few grams of fission products from a spent fuel pellet will not make
any impact if it's dispersed enough.

~~~
abalone
Chernobyl caused the near permanent evacuation of a nearby city, and nearly
poisoned the water supply for millions. Not a good example if you’re trying to
argue a release of fission products is no big deal.

I would like to understand exactly if/how this reactor design gets around the
risks inherent to explosions of radioactive fuel. If it’s not a problem then
why does the marketing take pains to say it will never leave its capsule?

~~~
jabl
The question of you asked and which I answered was what if we take _one_ fuel
pellet and disperse it.

I never said Chernobyl wasn't bad (heck, I called it a disaster for a
reason!). But that was tons of spent fuel (rather than the few grams being
contained in one fuel pellet) being blown out of the reactor building due to
the steam explosion, or going up in smoke during the subsequent fires, and
even that was far from the end of the world.

In this case, I guess marketing takes pains, because one of the main ideas of
this fuel type is to make them even safer, even during severe accident
scenarios. Is it absolutely fool proof? Of course not; you shouldn't grind up
the spent fuel and inhale the dust, for instance.

------
Apofis
"Ultra Safe" will come with Molten Salt Reactors. Hang tight until then. They
can even safely reuse nuclear waste.

------
justinzollars
I'd love to see these built in San Francisco. If we were serious about a
Carbon free future we would build nuclear

------
walrus01
Wasn't something very similar in size proposed for use in Alaska?

[https://en.wikipedia.org/wiki/Toshiba_4S](https://en.wikipedia.org/wiki/Toshiba_4S)

~~~
hairytrog
Seems like they used a sodium coolant - great thermal properties as it allows
for atmospheric pressure loop. But sodium introduces the chemical hazard and
all the associated maintenance and materials woes and accident scenarios.
Also, the power density on the 4S was relatively high.

~~~
hairytrog
also they used a strange control system. No control rods. Instead they moved
the whole core up and down to change reactivity. wtf?

------
thomasfromcdnjs
Countries that go nuclear will have an advantage in the 21st century.

------
edge17
Is this a company with a product or is this a concept?

------
_def
"ultra safe" seems a weird marketing term for me. "safe" should be enough, no?
Unless they know that it isn't.

------
projektfu
Is this a rebranding of the same modular reactor plans I read about 24 years
ago? Why are they not being produced?

------
nervousDev
This reminds me of that guy that "invented" the microwave heater (for people)
in the show Silicon Valley.

------
ceilingcorner
I find it a little odd that a site called Hacker News is so bullish on nuclear
power. Could there be anything less _hacker_ than a centralized, exclusively
government owned and operated source of power?

No thanks. I’d rather put more resources into solar, wind, and other sources
of power that don’t depend on the government to not explode and irradiate the
immediate area for hundreds of years.

~~~
wazoox
Centralisation is more efficient. Centralisation is good. Because of
centralisation and interconnection (power grid is a network) we only need to
have power generation capacity equivalent to less than a third of the total
power of all electrically powered machinery.

If every household had to produce its own power, we would need either to
carefully plan our usage, or to have as much production capacity as our peak
usage, so globally we'd have 3 times as much production capacity as we have
nowadays. That would amount to a tremendous waste or resources, an awful
misallocation... It would be absolutely anti-ecological.

The more you're using unpredictable energy sources such as wind and solar, the
more you need backup power (batteries, gas, coal, nuclear, etc). Case in
point: in the EU, there has been virtually no wind at all for two weeks
(except in Denmark). So we burn coal and gas, massively.

Germany has a power generation capacity 68% larger than France for roughly the
same number of TWh produced annually, because it needs backup production
capacity for all its windmills and PV solar. What's the result? Electricity is
58% more expensive in Germany than in France.

------
Fooloo
So North Korea getting nuclear weapons is a big deal and using every text book
measure to prevent Iran from building these things is quite an effort. But
providing the whole world with material which can be used to build these damn
things is not a problem?

Also there is big security problems all around the world due to terrorist. So
how do we manage security with this small scale things?

------
user568439
I want to see how safe is this underground graveyard in case of a volcanic
eruption... I'm sorry but I don't believe in nuclear, I think at the pace
renewable and batteries are evolving now, they will be better alternative
before a new nuclear plant is planned and constructed which takes many years.

------
Animats
What about graphite fires?

