
China's Yanlong: a small nuclear reactor strictly for district heating - curtis
https://www.cnbc.com/2017/12/10/china-looks-to-nuclear-option-to-ease-winter-heating-woes.html
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xbmcuser
Stuff like this makes me feel western countries really underestimate Chinese
tech chops. They are able to force stuff on the people that most countries
have to cajole and negotiate with their citizens. I get cognitive dissonance
from the fact that China is doing it's best to decrease coal usage where as US
is tried to increase coal usage.

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jonwachob91
>> Stuff like this makes me feel western countries really underestimate
Chinese tech chops.

The west largely underestimates Chinese tech chops b/c they steal so much of
our IP...

Their ability is evident in the number of Ph.D's they turn out, so why don't
they invest in developing their own technology instead of stealing everyone
else's? "Catching up" is not an acceptable answer with how much intellectual
firepower they have.

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raguuu
Because it's easier to 'steal'? Their laws are different so they don't see it
as stealing and have no problem with it. Each country is unique and I'm happy
US can't force their IP laws to everyone around the world.

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moneytide1
Seems more efficient to bypass steam as a transfer medium. Just like in "The
Martian".

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zengid
I wonder if this smaller reactor size would prove safer in earthquakes? There
is a lot of tectonic activity in Norther China (though I'm not sure if that is
where these are planned to be deployed).

[http://www.drgeorgepc.com/EarthquakesChina.html](http://www.drgeorgepc.com/EarthquakesChina.html)

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baybal2
Both district heating and drinking water desalination plant did ran on nuclear
reactors. Desal plant in Kazakhstan ran over a decade until the Aral sea moved
to far away. There are few nuclear district heating plants with single loop
design still running in Russia

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danohuiginn
And I guess you can just shut it off in summer?

Nuclear normally sucks for fluctuating demand, but presumably a 6 month on/off
cycle is slow enough to work.

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briffle
Any source of heat can also be used as a source for cooling. My Alma-Matter
(Oregon Tech) heats and cools its entire campus with hot geothermal wells.

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Retric
Seems like a much more expensive option than solar hot water heaters. It's
$226.7 million for 400MW and "Each 400-MW unit can heat 200,000 homes" so
~1,133$ per home where basic models are selling in Asia for under US$250.

They mention it's going to be plugged into existing heating networks, but
temperature of 100C is not all that hot.

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seanmcdirmid
Solar doesn’t work that well in northern China during the winter because there
is hardly any sun. Even discounting the pollution, the area would be mostly
foggy and overcast, it would be like trying to use solar in Seattle.

An apartment complex I lived in had solar hot water and I absolutely hated it,
I could never take a “hot” shower during Beijing’s cold winter, just a luke
warm one.

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Retric
Implementation can make a huge difference, people do install these systems in
Alasca and then supplement for a few weeks in the middle of winter which is
still a huge fuel savings and cost reduction.

But, if your going to base this on a central location then sizing the system
and maintain the desired temperature output is simplified.

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seanmcdirmid
There isn’t much space for solar panels, so sizing is intrinsically
constrained. Also, these are 32 story towers with approximately 130
units...it’s not rocket science why it doesn’t work out.

They were definitely not supplementing enough.

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Retric
Ouch, with 32 stories roof space is not good by to be nearly enough. But, if
you're going off site you no longer space constrained.

Which is why I say implementation is so important. 90% reduction in fuel used
and lower costs is IMO a better trade off than nuclear which is only useful ~9
months out of the year and has high ongoing costs.

Russia on the other hand is even further north and could probably see more
value from such a system.

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dis-sys
it is just shocking that they did the trial run of the nuclear reactor in
Beijing where there are over 20 million people. on the other hand, they were
actually allowed to carry out such trial run close to where those most
powerful live.

to figure out what other crazy stuff is happening in Beijing, did a quick
search and it turns out that there are dozens of experimental nuclear reactors
in Beijing, with the first one built in 1964 in Beijing. Tsinghua alone
operates many of them.

crazy

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ptx
KTH (the Royal Institute of Technology) was running a nuclear reactor[1] in
Stockholm from 1954 to 1970. So if it's crazy, it's at least not
unprecedented.

[1]
[https://en.wikipedia.org/wiki/R1_(nuclear_reactor)](https://en.wikipedia.org/wiki/R1_\(nuclear_reactor\))

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dis-sys
with 1/10 of the population in Stockholm, the craziness is not remotely
comparable.

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lexxed
A small nuclear reactor in a swimming pool.. what could go wrong..

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kldavis4
NC State University has a pool reactor on the main campus used in their
nuclear reactor curriculum:
[https://en.wikipedia.org/wiki/North_Carolina_State_Universit...](https://en.wikipedia.org/wiki/North_Carolina_State_University_reactor_program)

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plandis
That’s cool! Thanks for sharing

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sandworm101
>> around the same volume as an Olympic swimming pool.

>> with each 400-megawatt unit capable of warming 200,000 urban households.

>> with temperatures not exceeding 100 degrees Celsius,

Think about that for a minute. If the water isn't going to exceed 100c but the
reactor is still going to pump out 400-megawatts, it isn't going to be a calm
pool. They are going to have to pump insane amounts of water in and out of
this pool if they want to keep things under 100c. That's fine. Just don't
pretend this is going to hum along quietly like a research reactor. And don't
tell me thing will remain at 100c should that flow of water be interrupted.
Any non-boiling, low-pressure, reactor is going to need exponentially more
cooling (by volume) than an equivalent traditional reactor. Let us hope they
keep a lake nearby as backup.

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adrianN
It is possible to regulate the output of a nuclear reactor. In case the pool
boils off in some freak accident, the chain reaction also stops, because water
is acting as a neutron moderator in these designs. So you only have to ensure
that the residual heat from normal decay doesn't melt the reactor. That
doesn't sound too hard.

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sandworm101
>> you only have to ensure that the residual heat from normal decay doesn't
melt the reactor.

Not hard if this is a passive-cooling design. My point is that at these power
levels passive cooling isn't enough. Stop the pumps and the reactor may build
up enough heat to start melting things very quickly, long before the pool
boils dry.

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nabla9
Correct me if I'm wrong but isn't the idea of safe pool reactors that
hydrogen-neutron heat transfer is more efficient than normal radioisotope-
water heat transfer. If you shut down the pumps and heat increases, spectral
hardening cools the reactor faster and disperses the energy into larger volume
than convection using pumps.

