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Nuclear reactor safety (split from sea levels (which was split from lunar tides))


Rakaydos

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1 hour ago, GoSlash27 said:

The dry cask storage and transport of the waste is also completely safe. It's fun to watch the films of the torture tests the NTSB put them through. 

And that's before we mention Rosatom's Project Breakthrough with its in situ fuel reprocessing. Can't have a transport accident if you don't transport. Can't have a waste leak if 90% of the waste is eliminated.

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US%20Energy%20Consumption%20by%20Source%

 Provided to show how unlikely it is that we will eliminate our dependence on fossil fuels at any point in the next several decades. Renewables have been expanding at a prodigious rate, but even so it's just a tiny dent in the overall energy demand. If we intend to get rid of fossil fuels entirely, nuclear is going to have to play a large role in that.

Best,

-Slashy

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What if we put a nuclear reactor in space, how would the radiation effect probes? would it act like the van allen belts destroying probes like GPS satellites, or the ISS, or would it just disperse after a while?

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3 minutes ago, Souptime said:

What if we put a nuclear reactor in space, how would the radiation effect probes? would it act like the van allen belts destroying probes like GPS satellites, or the ISS, or would it just disperse after a while?

Under certain condition the reactors could create an artificial Van Allen belt, but otherwise, it would just require non-persistent safety zones around active reactors.

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I mean, really... the background gamma radiation is already so high in space, I don't think a reactor would even be noticeable even if you're sitting right next to it. 

As for Van Allen belts... ionizing radiation consists of 3 things: high speed electrons, low speed neutrons, and high frequency photons.

Van Allen belts are the electrons trapped in Earth's magnetosphere. The vast majority of any electrons that managed to escape would simply fly off into nowhere, hit an oxygen molecule and turn it into ozone, or get bottled up by the already existing Van Allen belts. They wouldn't just hang around and start puddling up.

Best,

-Slashy

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Good luck trying to sell the idea of “nuclear reactors in space”- besides the logistical challenge of launching it up there in the first place, refuelling/repairing and so on and getting the power down to the surface somehow, in the eyes of the public a space reactor is just waiting to either fall back down or explode, in either case contaminating half the planet in the process.

Anyone heard of that Russian/Soviet nuclear satellite that fell out of orbit over Canada? Now imaging a full-scale nuclear power plant dropping out of the sky: most of the core would likely survive re-entry but if bits of it broke apart then it would scatter nuclear material all over the place; if it lands pretty much anywhere on land it’s basically a dirty bomb- a Chernobyl in the sky with the fallout spread much further- and would probably fall afoul of international treaties about not putting nuclear weapons in space. Not to mention the risks of a launch failure etc.

Space is an inherently dangerous place no matter how many safeguards you put in place; nuclear reactors are inherently dangerous things no matter how many safeguards you put in place. Combining the two is a bad idea- to make the reactor space-proof you’d need huge micrometeor shields, multiple redundant cooling systems etc. which are all really heavy, making it much harder to launch. Launch them separately and you need a crew of EVA-trained nuclear technicians and engineers to build it all up in space, which isn’t currently feasible unless they used the ISS and good luck trying to approve that.

 

The best place for a nuclear reactor would be inside a mountain or underground: much easier to contain any fallout, just seal the whole thing up and use air locks to get in and out; much harder for any nefarious actors to gain access to it and damage/destroy it; with the right design water flow can be engineered so that if the power fails the reactor doesn’t melt down and spent fuel doesn’t overheat; plus once all the fuel’s used up and it’s full of nuclear waste the whole structure can be sealed off to prevent the waste from escaping.

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The thing which makes the space reactors funnier is that the vacuum is an ideal heat insulation.
It's literally the worst place in the universe to place a heater.

1 hour ago, jimmymcgoochie said:

Anyone heard of that Russian/Soviet nuclear satellite that fell out of orbit over Canada?

+1
Gifting the uranium to everybody for free is very expensive.

1 hour ago, jimmymcgoochie said:

Now imaging a full-scale nuclear power plant dropping out of the sky: most of the core would likely survive re-entry but if bits of it broke apart then it would scatter nuclear material all over the place

If put it on polar orbit, we can melt ices and gain a lot of free land and water.

Of course, it should be synchronized to the Earth rotation, to make it passing above the oceans.

Btw an interesting task to calculate the orbit altitude and inclination.

1 hour ago, jimmymcgoochie said:

The best place for a nuclear reactor would be inside a mountain or underground

And boil the glaciers. 

Such heater requires a lot of water for cooling, so the best place is the coastline. An artificial lagoon protected by 50 m high dams.

Also this is the first step to the urainum and lithium refining from the seawater, and to place a self-fuelling deuterium reactor in future.

Also it's the best place to receive LNG ships and to convert the LNG into hydrogen and plastic.

And oysters. You can (farm? herd? mine?) oysters, because the water anyway will get warm, so why not.

Also as we can see it's the natural place for superheavy rockets like SeaDragon or Convair Nexus. It's just made for them from any pov.

Actually I see huge coastal structures like bastion-based fortresses.

With a ten or more deuterium reactors on concrete islands.

Like this, but 20-30 km large and full of water instead of grass

Spoiler

gDEB7.png220px-Fortbourtange.jpgimages?q=tbn:ANd9GcRZqx0JvjgV_4H7kqBs193

 

Edited by kerbiloid
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On the topic of "nuclear reactors in space".

 

What about how I get the energy back down on Earth!!!!!

 

Sure we can fire it back down using lasers or something, but AFAIK that would waste a bunch of energy. Never mind the logistics of putting anything up there, if I need to use what it creates back down here haha. 

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8 minutes ago, MKI said:

On the topic of "nuclear reactors in space".

 

What about how I get the energy back down on Earth!!!!!

 

Sure we can fire it back down using lasers or something, but AFAIK that would waste a bunch of energy. Never mind the logistics of putting anything up there, if I need to use what it creates back down here haha. 

That's the big problem - if you say you want space based power to send to the planet... You probably don't know what you are talking about, or are trying obscure the fact that you are making a space based weapon. 

 

Like asteroid mining - the economics of bringing it back down just don't make sense - probably best to just keep space based power and materials for use in space based applications and construction. 

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A typical Chernobyl-class fission reactor of 3 GW of heat power generates just 1 GW of electric power.

Say, we put it in orbit.

We should cool it and radiate 2 GW of waste power (uniformly, not directed).

PowerPerArea, W/m2 = 5.67*10-8 T4.

ISS: power 120 kW, radiators: 14 panels 6 x 10 ft = 14 * 6 * 10 *0.30482 ~=78 m2.

78 * (2*109 / 120 000) ~= 1.3*106 m2 ~= 1.2 x 1.1 km 

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11 hours ago, jimmymcgoochie said:

Good luck trying to sell the idea of “nuclear reactors in space”- besides the logistical challenge of launching it up there in the first place, refuelling/repairing and so on and getting the power down to the surface somehow, in the eyes of the public a space reactor is just waiting to either fall back down or explode, in either case contaminating half the planet in the process.

Anyone heard of that Russian/Soviet nuclear satellite that fell out of orbit over Canada? Now imaging a full-scale nuclear power plant dropping out of the sky: most of the core would likely survive re-entry but if bits of it broke apart then it would scatter nuclear material all over the place; if it lands pretty much anywhere on land it’s basically a dirty bomb- a Chernobyl in the sky with the fallout spread much further- and would probably fall afoul of international treaties about not putting nuclear weapons in space. Not to mention the risks of a launch failure etc.

Space is an inherently dangerous place no matter how many safeguards you put in place; nuclear reactors are inherently dangerous things no matter how many safeguards you put in place. Combining the two is a bad idea- to make the reactor space-proof you’d need huge micrometeor shields, multiple redundant cooling systems etc. which are all really heavy, making it much harder to launch. Launch them separately and you need a crew of EVA-trained nuclear technicians and engineers to build it all up in space, which isn’t currently feasible unless they used the ISS and good luck trying to approve that.

 

The best place for a nuclear reactor would be inside a mountain or underground: much easier to contain any fallout, just seal the whole thing up and use air locks to get in and out; much harder for any nefarious actors to gain access to it and damage/destroy it; with the right design water flow can be engineered so that if the power fails the reactor doesn’t melt down and spent fuel doesn’t overheat; plus once all the fuel’s used up and it’s full of nuclear waste the whole structure can be sealed off to prevent the waste from escaping.

I agree that the idea of orbital reactors is pretty farfetched and silly, but I also think that placing them underground/ inside mountains just complicates them needlessly and adds cost. They need to be placed in exactly the same sort of locations they occupy today for best results.

 What I think needs to happen is 1) even more evolution towards robust fail- safe designs and 2) a much better public education process about what the risks aren't. Today's Gen III reactor designs are not vulnerable to human error and mechanical failure like the old 1970s plants. When things go wrong, there is no longer any risk of "fallout" or "explosions". They just plain stop reacting until the problem is fixed. This is as it should be, and this trend needs to carry on into every phase of the process, not just the reactor itself.

Best,

-Slashy

 

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On 8/2/2021 at 10:39 PM, Jacke said:

I think you're getting it back-to-front.  That even in Japan, they get it wrong.  But they can also get it right, because at Onagawa another corporation got it right, to the point that the Onagawa reactor was the local evacuation safe site, even thought it received a greater tsunami impact.

TEPCO got it wrong.  Let's dig into that and find out why it went right in one location and wrong in another.  Then work to fix things so that all of them get it right.

it seems to me that modern reactors has just one weak point, its that you need to need to keep cooling them for days after they are shut down because of the heat and rest radioactivity in the core. 
small reactors like the ones on submarines don't have this issue as they are much smaller, less heat energy and less radioactive materials while surface area is larger, but they also just produce an tiny fraction of the energy. 
The problem at Fukushima was that they lost power and cooling and steam breaks down to hydrogen and oxygen at high temperature. This is an known issue in steam turbines on warships back in WW2. 
Some comments above said that US power reactors has solved this issue?

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2 hours ago, GoSlash27 said:

They need to be placed in exactly the same sort of locations they occupy today for best results.

 

2 hours ago, GoSlash27 said:

2) a much better public education process about what the risks aren't. Today's Gen III reactor designs are not vulnerable to human error and mechanical failure like the old 1970s plants.

 

I lived within the 50 mile radius of this for 13 years.

https://azbigmedia.com/business/palo-verde-inside-the-nations-largest-nuclear-power-plant/

 

All I can say is you go slashy (LoL) I agree, concur, and confirm. USA literally has so many safe places for these power plants, let alone the fact that they are far safer than ever before. Currently the only issue I can see is doing something besides storing the spent rods. France has a great start already.

 

https://www.energy.gov/ne/articles/5-fast-facts-about-spent-nuclear-fuel

 

USA should "get off its laurels" and start recycling those rods. Like we should be recycling batteries (shameless plug). Education is key!

 

Spoiler

original.png

 

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2 hours ago, magnemoe said:

it seems to me that modern reactors has just one weak point, its that you need to need to keep cooling them for days after they are shut down because of the heat and rest radioactivity in the core. 

Depends on the design.  Many new reactor designs can go passive cooling from shutdown.

 

2 hours ago, magnemoe said:

small reactors like the ones on submarines don't have this issue as they are much smaller, less heat energy and less radioactive materials while surface area is larger, but they also just produce an tiny fraction of the energy.

Marine reactors are usually smaller (~ 1/5 the size) and use more enriched uranium to be even more compact.  Lots of differences with them.

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

 

2 hours ago, magnemoe said:

The problem at Fukushima was that they lost power and cooling and steam breaks down to hydrogen and oxygen at high temperature. This is an known issue in steam turbines on warships back in WW2.

The Fukushima design is very old and needed active cooling for the shutdown.  As well, the storage for spent fuel was poorly located and also needed active cooling.  Spent fuel storage is a whole separate problem that has effective solutions available now.

https://www.nrc.gov/docs/ML1210/ML12103A212.pdf

The cause of the hydrogen release appears to be due to the zirconium cladding of the fuel elements catalysing the breakdown of water into hydrogen and oxygen at the higher temperatures during a cooling failure.

https://www.nrdc.org/sites/default/files/hydrogen-generation-safety-report.pdf

 

2 hours ago, magnemoe said:

Some comments above said that US power reactors has solved this issue?

Take a look at that last PDF, dated 2014.  It indicates that there are insufficient measures mitigating hydrogen release and explosion.  I would hope there was more action in the industry in the last 7 years.  Some containment buildings may better handle hydrogen leaks and explosions than Fukushima, example Three Mile Island.

I would hope new designs now being built which have failure modes that can overheat zirconium alloys or similar risks have incorporated these mitigations or newer ones.

Edited by Jacke
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On 8/3/2021 at 8:26 PM, Rakaydos said:

Nuclear is in an awkward place, classification wise. Technically, mined uranum is not a renewable resource, but because it isnt formed from compressed carbon products, it isnt a "fossil fuel". If green is defined as "not contributing to climate change", then nuclear absolutely IS a GREEN technology. But it still is NOT a RENEWABLE energy source, only a long-lasting one.

You add Uranium and Thorium ores  currently extractable at today's costs levels and that's a lot of fission power for a lot of years.  A lot of the Thorium ores have already been mined because it's a by-product of Rare Earth Elements mining and is currently a material that costs to be stashed.  This article actually does the estimates and gets to 164,000 years and that's before Uranium dissolved in sea water and that precipitated out at the bottom of the oceans is included.
http://www.daretothink.org/numbers-not-adjectives/how-long-will-our-supplies-of-uranium-and-thorium-last/

 

On 8/4/2021 at 4:52 PM, GoSlash27 said:

 While management can be blamed for previous failures (aside from Fukushima), the ultimate blame rests with designs that were insufficiently 'fail safe' to tolerate such mismanagement in the first place.  

I think Fukushima can  be blamed on TEPCO management as well, as the Onagawa Nuclear Power Station station designed, built, and operated by the Tohoku Electric Power Company was closer to the tsunami impact yet because of the better design and operation, it survived and was in fact the local evacuation centre.
https://thebulletin.org/2014/03/onagawa-the-japanese-nuclear-power-plant-that-didnt-melt-down-on-3-11/

 

6 hours ago, GoSlash27 said:

Ooo! Prof. Ruzik is right on time!

 

Very good video, @GoSlash27.  I've got one quibble: I've heard that the radioative material going up the flues of coal plants is one of the largest sources of radioactive contamination in our current society, with only Radon leaking underground coming close to it.  I'd also think that spent fuel needs to be reprocessed to concentrate the middle-length half-life isotopes which are the longest time risk, as the short half-length material decays fast and the long half-life material is often useable as fuel and isn't any more dangerous than the current ores like those of Thorium we've got a whole lot of already.  And then the casks with that waste should not be stored underground because 1: we always want to be able to see it, and 2: there are some uses for it.

 

4 hours ago, JoeSchmuckatelli said:

Now if it was only 3 minutes long... My kid (and others) would watch it. 

You should post on the video that the Prof needs a TikTok channel where he can post short videos with links to his long ones. :)

Edited by Jacke
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30 minutes ago, Jacke said:

I think Fukushima can  be blamed on TEPCO management as well...

I disagree. Certainly the design can be blamed, but there was nothing that was incorrectly operated to exacerbate the failure and nothing more that management could've done to avert it. 

43 minutes ago, Jacke said:

I've got one quibble: I've heard that the radioative material going up the flues of coal plants is one of the largest sources of radioactive contamination in our current society...

He actually talks about all those points in the video and agrees with you.

Best,

-Slashy

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This is interesting - storing power that we don't immediately use: https://www.nbcnews.com/science/environment/rust-trains-clean-energy-turning-exotic-ideas-fix-storage-problem-rcna1613

Apparently this is one of the most underdeveloped parts of the grid.  Especially when you factor renewable sources being intermittent in general - meaning demand and supply are misaligned. 

Cool note: hydroelectric operators pioneered the 'kinetic battery' system by pumping water back upstream to use when demand is higher. 

 

Here is a modern take on the concept 

 

Edited by JoeSchmuckatelli
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Suggested this for KSP long ago.

Technically, it can be done as those ore containers changing their shape depending on the percentage and a generator in cfg to convert the stored resource into EC.

Also, this could be a dam and a water body for KerbalKonstructs.

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On 8/7/2021 at 6:44 AM, JoeSchmuckatelli said:

This is interesting - storing power that we don't immediately use: https://www.nbcnews.com/science/environment/rust-trains-clean-energy-turning-exotic-ideas-fix-storage-problem-rcna1613

Apparently this is one of the most underdeveloped parts of the grid.  Especially when you factor renewable sources being intermittent in general - meaning demand and supply are misaligned. 

I think large scale energy storage is one area that can use a break through and really improve. We will always need more energy, but can we can more or less eliminate blackouts due to the grid requiring too much by simply increasing storage. 

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2 hours ago, MKI said:

I think large scale energy storage is one area that can use a break through and really improve. We will always need more energy, but can we can more or less eliminate blackouts due to the grid requiring too much by simply increasing storage. 

Blackouts happen more from shortcomings in the power grid that are known about and there's issues why they aren't addressed.

Currently, I think the only large scale power storage system that really works is dual water reservoirs at different altitudes: pump water up to store power, run water down through generators to return power.

What the grid will likely end up with in ~20 years is nuclear+geothermal baseload power, solar+wind fillin power, and natural gas turbine surge power.  Right now I think natural gas turbines are the lowest carbon power source that can provide surge power.  Eventually the natural gas turbines could be replaced by a custom reactor design with a rapid surge rating, but I think they will have to be overbuilt as due to transient fission product poisoning, it's easier and safer to surge up a reactor that's been low power for a long time than to surge a reactor that has just been dropped in power output.

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