Hacker News new | ask | show | jobs
by sajithdilshan 17 days ago
Once I had a discussion with a German that is a strong supporter of the green party and his argument against nuclear power was the nuclear waste and no proper was of disposing it and also building new nuclear power plants are expensive and take a long time.

Then I did a deep research and created a PDF and pointed out that there has been many advances of re-using spent-nuclear fuel and minimize the environmental impact since 1980s and also countries like China has been using a cleaver way of using a standardized model of building power plants to cut cost, etc. but he didn't want to accept it as if he was almost brainwashed.

2 comments

So we just have to build the first expensive 20 to get the experience and then we reap the rewards after 40 years when we need the knowledge again?

If nuclear would be cheap in the western world I'd be all for it but we just can't do large projects in our ccurrent system.

Solar + wind + battery is much less of an headache.

I think most nuclear folks would rather divert the "big coal, and nat gas" plant building budgets to "build nuclear."

I understand the motivations for solar/wind, but there are real limiters that aren't addressed yet. Nuclear is the only option that is carbon neutral and lacks those limiters making it appealing. If I need steady state gigawatt scale power in a specific location, Nuclear is the only green option.

Yeah, nuclear is a known solution to all our energy problems which is why I advocate for it.

Solar and wind are great but there is still no existing setup to provide a stable and reliable nation level power grid. Nobody has the power storage solution.

Nuclear however has been proven to be capable of delivering any kind of power generation we need at any scale. Perhaps it isn't best solution, but there are no other completely solved solutions, just speculation that before long we will unlock far better battery or energy storage technologies before too long.

> If I need steady state gigawatt scale power in a specific location, Nuclear is the only green option.

I don't believe that is true: one way to produce electricity is a thermal engine driving a generator, but for a thermal engine you need both a cold heat bath and a hot heat bath.

Those 2 heat baths could be externally delivered (a stream of ice, and a stream of steam, say) or one of the 2 heat baths could be chosen as the local environmental temperature heat bath.

Historically the local environmental temperature heat bath was selected for the role of the cold heat bath, and the hot heat bath was heated by say burning fuel (fossil or nuclear; and I am ignoring the chemical and mechanical energy terms of internal combustion engines).

If you could source a cold heat bath, one could select the local environments as the hot side heat bath instead.

Above the tropopause the atmosphere has become a lot more transparent for thermal infrared radiation, and thats why it is a lot colder up there, its in better thermal radiation contact with the CMB (the temperature of dark space), very close to the absolute zero point for temperature.

It is not a scientific challenge but a "mere" engineering one, to create a robust, all-weather aerostat where the "cable" transports mass (presumably, but necessarily a refrigerant) symmetrically up and down (in a loop) heating the upper layers of the atmosphere (puncturing the CO2 blanket), while cooling ground level environment. That large temperature difference persists day and night, winter and summer. So it is a form of green baseload energy generation, which helps cool the planet, and runs 24/7 reducing dependence on oil countries or places like Russia for nuclear fuel.

Depending on north/south lattitude, the height of the tropopause differs a bit.

You wouldn't want to risk such a contraption (some lightweight ~12km vertical zeppelin housing the up and down paths) falling on populated areas, but luckily 90% of the world population lives close to a coastline, so just anchor it further away from the cost than it is tall, if it falls over, at least it can't reach populated areas on land. Another upshot of coastal chimneys is that the sea is a very heavy thermal mass, so you won't run out of thermal energy that fast, the cold mass flow that comes down can be used to freeze water, desalinating it. During a transition period where conventional fossil / nuclear power plants still exist such ice or ice slurry could be pipelined to the "cold" thermal baths of such power plants, greatly improving the electric yield for the same amount of fossil / nuclear fuel.

There is just embarrassingly little research in this direction, to solve such an engineering challenge.

It is an intriguing idea but that is still one hell of a coolant loop with a hell of a lot of mass continously lofted through the atmosphere and subject to weather patterns. A wire I could see doing it but lofting a pair of tubes to transfer a significant volume of fluids seems not far off space-elevator level material science to me.
Zeppelins flew above the tropopauze, zeppelins could fly both east and west, against and along windflow.

Now imagine ~500 zeppelins flying above each other, forming a "tower", seems perfectly feasible (no space-elevator tech needed), but bombastic. Now instead of flying a single vertical stack of zeppelins you could easily comprehend that we could also fly 6 such towers so that for each layer 6 zeppelins arranged in a hexagon could maintain position. So we could fly "toroidal zeppelins" and stack them, we might even space them vertically saving on the number of toroidal zeppelins needed. It doesn't seem impossible, it just seems understudied, it certainly doesn't have associated fundamental exponential scaling properties like a space elevator. Why do we feel so obliged to defend nuclear energy (and the dubious sources selling nuclear fuel, as well as the associated dual use issues) if humans could turn global warming into a democratic power plant? all inhabited regions have a much colder atmosphere above the local height of the tropopause.

Why shouldn't we at least pour more resources in investigating even a slight possibility that we can generate green energy 24/7, with net-negative global warming, cooling the globe and rewarding ourselves with energy?

I don't agree ground level to tropopause heat chimneys require unproven materials (like a space elevator needs).

> So we just have to build the first expensive 20 to get the experience and then we reap the rewards after 40 years when we need the knowledge again?

I think the knowledge doesn't has to start from zero. Germany can ask for foreign aid from China.

> If nuclear would be cheap in the western world I'd be all for it but we just can't do large projects in our ccurrent system.

I agree, given the fact that it took 15 years to build the BER airport and Stuttgart 21 is still on-going, i can totally imaging building a single new nuclear power plant in Germany would take 50 years minimum.

> Solar + wind + battery is much less of an headache.

I agree, it's a less headache, but at the same time you cannot support energy intensive industries like chemical, manufacturing etc. You would have to build battery farms which is not sustainable. That's why Germany is slowly on a path for de-industrialization

Gas/Hydrogen are Germany's answer to you last point.

You can store energy created by renewables this way easily and use it when needed. Right now we can't produce enough hydrogen though, so gas can be used in the meantime, but in the future the entire infrastructure, such as power plants, pipelines or port terminals can be switched to hydrogen: https://www.bundesnetzagentur.de/EN/Areas/Energy/HydrogenCor... You could even produce the hydrogen needed cheaply in countries with better conditions for solar and then ship it the same way we currently do with gas. Hydrogen power plants also have the advantage to quickly change output volumes, which is needed when most energy is produced by solar/wind.

Ideally German's investment into nuclear fusion pays off though as it would change the whole game. https://www.dw.com/en/nuclear-fusion-germany-bets-billions-o...

Germans public should be informed that:

1. Deuterium - Tritium fueled fussion power plants will produce low-level radioactive waste, in form of neutron activated structural matterials. Tritium is radioactive gas with tendency to leak. Antinuclear activists are already concerned with tritium leaks in current nuclear plants. Future nuclear fussion plants will handle much larger tritium inventories then current fission plants.

2. There exist designs for nuclear fusion–fission hybrid plants. You can use hybrid plant to make nuclear bomb material - plutonium.

"One of the most detailed of these studies was published in 1980 by Los Alamos National Laboratory (LANL). They noted that the hybrid would produce most of its energy indirectly, both through the fission events in the reactor, and much more by providing 239Pu to fuel other fission reactors. In this overall picture, the hybrid is filling a role that is essentially identical to the breeder reactor. Both require chemical processing to remove the bred 239Pu, both presented the same proliferation and safety risks as a result, and both produced about the same amount of fuel. Since the bred fuel is the primary source of energy in the overall cycle, the two systems were almost identical in the end."

https://en.wikipedia.org/wiki/Nuclear_fusion%E2%80%93fission...

So they would use the excessive power generated by wind+solar into producing H2 from water and then transport it? Theoretically it can work, but as you mentioned, can they produce enough hydrogen to match the demand via wind+solar?

Nuclear fusion would absolutely be a game changer. But they it could take 5, 10 or even 50 more years to achieve that and by that time I don't know if German economy would be able to keep on pumping billions into research.

> So they would use the excessive power generated by wind+solar into producing H2 from water and then transport it? Theoretically it can work, but as you mentioned, can they produce enough hydrogen to match the demand via wind+solar?

I think it can work, especially as you can easily import it using existing gas infrastructure and pipelines as a lot of that infrastructure is build to be converted in the future or currently upgraded for it.

> Nuclear fusion would absolutely be a game changer. But they it could take 5, 10 or even 50 more years to achieve that and by that time I don't know if German economy would be able to keep on pumping billions into research.

Building a nuclear reactor would probably might as well take just as long and we need quicker changes — especially when it comes down shutting down our coal power plants.

I believe that the money a nuclear reactor would cost to build is better invested in renewables (together with gas/hydrogen) and nuclear fusion. Is this strategy the right move? Only time will tell, but I'm optimistic.

Hydrogen is a bad idea because it is dangerous (highly explosive) and also leaky, due to the size of the atom

To transport hydrogen, you need complex infrastructure (real cold trunk or whatever) and you still leak, so the overall efficiency is bad

The Flammable Range (also called Explosive Range), the concentration range of a gas or vapor that will burn (or explode) if an ignition source is introduced, for hydrogen is much larger then for methane.

https://www.engineeringtoolbox.com/explosive-concentration-l...

Becuse of hydrogen embrittlement you have to be carefull with material selection for pipes, storage tanks holding hydrogen. This not a big problem, but it means old pipes used for natural gas can not be used for hydrogen.

https://en.wikipedia.org/wiki/Hydrogen_embrittlement

https://www.bundesnetzagentur.de/EN/Areas/Energy/HydrogenCor...

Germany is planing a hydrogen pipeline network.

Help from an industrial country would be required

Sad to read that Germany, that was once an industrial power, is now an empty shell :(

This article is literally about geothermal and all people can talk about is nuclear, solar. Why aren't we building geothermal energy plants everywhere?
What? For the same reason we don't build hydro plants everywhere, they depend on local conditions and all best spots are already used. Iceland can access geothermal power in entire country so they did.
“All best spots are already used”, is not even close to true for the US. We have barely begun to explore and evaluate potential sites and I see this as a huge future growth industry
I take your point that they rely on local conditions, but those conditions are certainly not as restrictive as for hydro.
In most places, thermal conductivity of rock is very low.

"The conductive heat flux averages 0.1 MW/km2. These values are much higher near tectonic plate boundaries where the crust is thinner. They may be further augmented by combinations of fluid circulation, either through magma conduits, hot springs, hydrothermal circulation."

https://en.wikipedia.org/wiki/Geothermal_energy

The "nuclear waste" argument is so weird to me. We take radioactive rocks from the ground. Make them less radioactive. Put them back in the ground. There is no output that wasn't dug up out of the ground originally. It would have been polluting the original location already.
It's a matter of concentration