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Okay I'll get the ball rolling and hopefully this will turn into a popular Thread. Just no politics is all I ask.

Questions

Glad to see new Reactors are being built. Why are they all on the East Coast?
https://www.nrc.gov/reactors/new-reactors/col/new-reactor-map.html

Are the new Reactors being built strictly for generating electricity?
https://www.nei.org/advocacy/build-new-reactors

What are Research Reactors researching exactly? Are new discoveries worth the enormous expense which comes with building, running and maintaining a Reactor?

What's are the main differences between Reactors on land and the ones on Navy ships? I think its remarkable how they can be built small enough for Submarines. Which leads me to my next question.

What are the main differences between Reactors on subs and aircraft carriers.

I'm a huge WW2 nut and what I sometimes wonder about is if we ever have to go to war like that again (heaven forbid) what would happen if one of our Nuclear-powered ships or subs were sunk, along with their nuclear weapons? I know that likelihood pretty remote (I hope), but I've learned that nothing is impossible. Our Navy sure didn't see kamikaze pilots coming when that horror began and even after it was going on for a while, we lost many ships...not to mention those lost before the kamikaze attacks began and how many Japan lost.

What kind of reaction takes place inside modern Nuclear Reactors-fission or fusion?

What makes fusion-type thermonuclear bombs so much more powerful than fission bombs like the Hiroshima and Nagasaki bombs? I find it fascinating that that the bomb core for the Nagasaki bomb was smaller than a bowling ball bag and yet delivered so much destruction. And what really blows my mind is that the Soviet Union detonated a 50 megaton hydrogen bomb (the largest ever) which was 4,000 times more powerful than the Nagasaki bomb-and dropped it from an airplane no less! Mind boggling the insane power of this stuff.

Great documentary below for those interested.

Thanks for any answers.
 

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I think they’re mostly finishing old reactors? We’ve got one up the road that’s supposed to finally be completed, after something like 30 years nearly finished. Nuclear could be reasonably clean by now, if we’d have allowed research to continue. The liquid salt combined with thorium versions are supposed to be pretty much fail proof, as in something we’ve never encountered like a direct asteroid hit or something even less probable. Fusion is always 20 years away, and America has given up its leadership in that several years back. Pretty sure India has a thorium/salt reactor too. America has corn dogs though!
 

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What are Research Reactors researching exactly? Are new discoveries worth the enormous expense which comes with building, running and maintaining a Reactor?

'Research reactors' are used for teaching new students as well as studying the reactions themselves. As I understand it they can also be used to generate isotopes used in the medical field and for industry. Power reactors are optimized for efficiency and power output and don't have the right conditions inside the reactor or equipment for them to be used as breeders for isotopes.


What's are the main differences between Reactors on land and the ones on Navy ships? I think its remarkable how they can be built small enough for Submarines. Which leads me to my next question.

Size, power density and efficiency. Land based reactors are simply larger because they don't have to fit in a ship. Naval reactors also have to have as much power from as small size as possible. To achieve this they make efficiency trade-offs that mean the fuel doesn't get used as completely as a land-based reactors. To make them smaller they don't have any way to open the reactor on the ship and add fuel. Ships have to be cut in half and the entire reactor removed to re-fuel. Reactors on land have equipment and facilities to change fuel rods while the reactor is in operation. This makes them useful for a longer period of time but larger and heavier.




What are the main differences between Reactors on subs and aircraft carriers.

They're very similar, just sized to fit into a smaller sub. I seem to remember that in the 60s through the 80s some ships used the same model of reactor as some of the subs, with some small tweaks.


I'm a huge WW2 nut and what I sometimes wonder about is if we ever have to go to war like that again (heaven forbid) what would happen if one of our Nuclear-powered ships or subs were sunk, along with their nuclear weapons? I know that likelihood pretty remote (I hope), but I've learned that nothing is impossible. Our Navy sure didn't see kamikaze pilots coming when that horror began and even after it was going on for a while, we lost many ships...not to mention those lost before the kamikaze attacks began and how many Japan lost.

It's actually not a huge deal. Certainly not desireable, but not catastrophic either, depending on where the ship was sunk. Two issues are the poisonous fuel and the radiation released by the fuel. Because of their design it is not possible for them to explode like a nuclear bomb, so that's not the real concern.


The reactor would shut down and cease to be critical, so there would be no sustained nuclear reaction. This minimizes the radiation it emits, but would not eliminate it. Water does a pretty good job of shielding from radiation, so unless the ship was sunk in shallow water where it was exposed, the actual radiation isn't a huge concern.


The fuel elements, however, are a bigger issue. Uranium and Plutonium, as well as most of the other isotopes that re nuclear byproducts are highly chemically toxic. When they get absorbed by organizms they are difficult to remove from the body and they irradiate from within. Very dangerous. If the ship was sunk in the middle of the ocean there would likely be little problem because the toxins would have time to disperse, but if a ship was sunk in an important fishery and the reactor breeched it could release nuclear material that would make the fish unsafe to eat for many many years.


What kind of reaction takes place inside modern Nuclear Reactors-fission or fusion?

Fission. Extremely large and thus unstable nuclei in elements like Uranium and Plutonium are caused to split by the addition of a neutron at a particular energy level. when they split a HUGE amount of energy is released as well as more neutrons that go on to cause others to split. Lather, rinse, repeat and in a microsecond or so you have a big boom.


What makes fusion-type thermonuclear bombs so much more powerful than fission bombs like the Hiroshima and Nagasaki bombs? I find it fascinating that that the bomb core for the Nagasaki bomb was smaller than a bowling ball bag and yet delivered so much destruction. And what really blows my mind is that the Soviet Union detonated a 50 megaton hydrogen bomb (the largest ever) which was 4,000 times more powerful than the Nagasaki bomb-and dropped it from an airplane no less! Mind boggling the insane power of this stuff.



Fuel. Fission bombs have a size problem. The core (the part that is responsible for nuclear fission) needs to be large enough to sustain a nuclear reaction but small enough it doesn't start a reaction all on its own. If you simply hold two sub-critical pieces of plutonium they can 'go critical,' meaning they start generating more and more fission reactions. It does NOT explode. It simply generates large amounts of heat and radiation. This is exactly what happens inside a reactor. There are numerous instances of this happening accidentally in the early days and it is no bueno. Look up 'criticality accident.'


Oddly, as the size gets larger it gets easier to go critical, but harder to compress it to the point that it will react quick enough to act as a bomb. In order to explode it must be compressed so that its density is much higher and the mass goes super-critical, causing it to all react within microseconds. Nuclear bombs use TNT or other high explosive to compress the sub-critical fission fuel and cause a reaction. The larger the mass, the more TNT it takes to cause the plutonium or uranium to go critical, and the bigger, heavier and more unweildy the bomb becomes. Also, the larger mass of fission fuel, the less completely it reacts, so there are diminishing returns as it gets bigger. Essentially they become less efficient at reacting all the nuclear fuel.


A fusion bomb actually has both a fission and a fusion bomb inside. It first uses TNT to cause a fission mass to go super-critical. This releases massive energy (heat) and radiation. Some of this energy and radiation is used to compress certain isotopes of hydrogen or lithium so much their nuclei fuse into heavier elements, again releasing huge amounts of energy. Because hydrogen and lithium isotopes are not very dense, none of them can go critical at atmospheric pressure, so large amounts can be stored safely, unlike with a fission bomb as I mentioned above. So with a fusion bomb you can store more nuclear fuel in a small space relatively safely. It doesn't take much to make the bomb much more powerful. This is the core reason fusion bombs can be so much more powerful.





 

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My biggest fear are suitcase/backpack and dirty bomb attacks.

Fortunately we have sensors that can detect even minute radioactive isotopes in the bloodstream and Security including special forces that guard domestic nuke sites against intrusion and theft. The unsuspecting general population outside a rural fence line or above a metropolitan basement for the most part don't have a clue about the blanket of protection that insures our freedom and way of life.
 

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Discussion Starter #6
'Research reactors' are used for teaching new students as well as studying the reactions themselves. As I understand it they can also be used to generate isotopes used in the medical field and for industry. Power reactors are optimized for efficiency and power output and don't have the right conditions inside the reactor or equipment for them to be used as breeders for isotopes.



Size, power density and efficiency. Land based reactors are simply larger because they don't have to fit in a ship. Naval reactors also have to have as much power from as small size as possible. To achieve this they make efficiency trade-offs that mean the fuel doesn't get used as completely as a land-based reactors. To make them smaller they don't have any way to open the reactor on the ship and add fuel. Ships have to be cut in half and the entire reactor removed to re-fuel. Reactors on land have equipment and facilities to change fuel rods while the reactor is in operation. This makes them useful for a longer period of time but larger and heavier.


They're very similar, just sized to fit into a smaller sub. I seem to remember that in the 60s through the 80s some ships used the same model of reactor as some of the subs, with some small tweaks.


It's actually not a huge deal. Certainly not desirable, but not catastrophic either, depending on where the ship was sunk. Two issues are the poisonous fuel and the radiation released by the fuel. Because of their design it is not possible for them to explode like a nuclear bomb, so that's not the real concern.


The reactor would shut down and cease to be critical, so there would be no sustained nuclear reaction. This minimizes the radiation it emits, but would not eliminate it. Water does a pretty good job of shielding from radiation, so unless the ship was sunk in shallow water where it was exposed, the actual radiation isn't a huge concern.


The fuel elements, however, are a bigger issue. Uranium and Plutonium, as well as most of the other isotopes that re nuclear byproducts are highly chemically toxic. When they get absorbed by organisms they are difficult to remove from the body and they irradiate from within. Very dangerous. If the ship was sunk in the middle of the ocean there would likely be little problem because the toxins would have time to disperse, but if a ship was sunk in an important fishery and the reactor breached it could release nuclear material that would make the fish unsafe to eat for many many years.


Fission. Extremely large and thus unstable nuclei in elements like Uranium and Plutonium are caused to split by the addition of a neutron at a particular energy level. when they split a HUGE amount of energy is released as well as more neutrons that go on to cause others to split. Lather, rinse, repeat and in a microsecond or so you have a big boom.




Fuel. Fission bombs have a size problem. The core (the part that is responsible for nuclear fission) needs to be large enough to sustain a nuclear reaction but small enough it doesn't start a reaction all on its own. If you simply hold two sub-critical pieces of plutonium they can 'go critical,' meaning they start generating more and more fission reactions. It does NOT explode. It simply generates large amounts of heat and radiation. This is exactly what happens inside a reactor. There are numerous instances of this happening accidentally in the early days and it is no bueno. Look up 'criticality accident.'


Oddly, as the size gets larger it gets easier to go critical, but harder to compress it to the point that it will react quick enough to act as a bomb. In order to explode it must be compressed so that its density is much higher and the mass goes super-critical, causing it to all react within microseconds. Nuclear bombs use TNT or other high explosive to compress the sub-critical fission fuel and cause a reaction. The larger the mass, the more TNT it takes to cause the plutonium or uranium to go critical, and the bigger, heavier and more unweildy the bomb becomes. Also, the larger mass of fission fuel, the less completely it reacts, so there are diminishing returns as it gets bigger. Essentially they become less efficient at reacting all the nuclear fuel.


A fusion bomb actually has both a fission and a fusion bomb inside. It first uses TNT to cause a fission mass to go super-critical. This releases massive energy (heat) and radiation. Some of this energy and radiation is used to compress certain isotopes of hydrogen or lithium so much their nuclei fuse into heavier elements, again releasing huge amounts of energy. Because hydrogen and lithium isotopes are not very dense, none of them can go critical at atmospheric pressure, so large amounts can be stored safely, unlike with a fission bomb as I mentioned above. So with a fusion bomb you can store more nuclear fuel in a small space relatively safely. It doesn't take much to make the bomb much more powerful. This is the core reason fusion bombs can be so much more powerful.


Wow thanks for answering. I'm a little fuzzy on the isotope thing. What exactly are isotopes? How are they used in the medical field and industry? And in the documentaries I've watched they mention Deuterium isotopes which make fusion weapons exponentially more powerful and was discovered kind of accidentally. What's that all about?

Had no idea Navy ships had to be taken apart for refueling. Its amazing what they do nowadays. Very glad in the event of a sinking there shouldn't be any harm if the reactor isn't breached. But what would happen if the ship sunk in the Mariana Trench? Would those depths put so much pressure on everything that it would rupture?

And I don't understand how just holding a lump of plutonium can go critical. How on earth do they handle the stuff without causing some kind of reaction?
 

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Wow thanks for answering. I'm a little fuzzy on the isotope thing. What exactly are isotopes? How are they used in the medical field and industry? And in the documentaries I've watched they mention Deuterium isotopes which make fusion weapons exponentially more powerful and was discovered kind of accidentally. What's that all about?

Had no idea Navy ships had to be taken apart for refueling. Its amazing what they do nowadays. Very glad in the event of a sinking there shouldn't be any harm if the reactor isn't breached. But what would happen if the ship sunk in the Mariana Trench? Would those depths put so much pressure on everything that it would rupture?

And I don't understand how just holding a lump of plutonium can go critical. How on earth do they handle the stuff without causing some kind of reaction?
Its like,,,, THIS!!!


:devil
 

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I'm a little fuzzy on the isotope thing. What exactly are isotopes?
All atomic nuclei have a combination of neutrons and protons. The number of protons determine the element. All nuclei with one proton are hydrogen, all nuclei with two are helium. The number of neutrons can vary a bit for a given element, hydrogen nuclei can have zero, one or two neutrons in the nucleus. Each of the different nuclei of the same element but with different number of neutrons are call isotopes
 
How are they used in the medical field and industry?
Some isotopes are unstable and spontaneously decay over time, giving off nuclear particles, often neutrons. Decay is a complicated topic, but this is the basic idea. In medicine we can give a person a specific isotope attached to say, sugar. The sugar with the mildly radioactive tracer gets taken up and used in the body. The patient is placed under a camera that can detect and locate the radioactive decay. Areas of the body that use a lot of sugar will have a higher concentration of the isotope and thus more radioactive decay and this will be detected by the camera.
 
And in the documentaries I've watched they mention Deuterium isotopes which make fusion weapons exponentially more powerful and was discovered kind of accidentally. What's that all about?
Deuterium is the isotope of hydrogen that has one proton AND one neutron. The extra neutron causes the nucleus to be slightly unstable and thus more amenable to nuclear fusion. When you take deuterium, or heavy hydrogen, and combine it chemically with oxygen to make water you get heavy water. Fun fact: pure heavy water tastes sweet! A guy on youtube drank some:
 
Had no idea Navy ships had to be taken apart for refueling. Its amazing what they do nowadays. Very glad in the event of a sinking there shouldn't be any harm if the reactor isn't breached. But what would happen if the ship sunk in the Mariana Trench? Would those depths put so much pressure on everything that it would rupture?
Probably not. The reactor is filled with a liquid (water) at high pressure. Water is incompressible so it would resist the pressure of sewater at the bottom of the Mariana Trench with no movement, and thus the reactor vessel would not be crushed. That said, if the reactor vessel had steam, which it shouldn't, that could create enough vapor space to allow the seawater to compress the reactor, but it's much more likely the reactor would not remain sealed but would leak. The leak would allow pressure on inside and outside of the reactor to equalize.
And I don't understand how just holding a lump of plutonium can go critical.
It's all about limiting the mass of plutonium in a given area. For instance, a small (50g) chuck would not go critical, but a larger chuck, say 5kg, would be a large enough mass to go critical all by itself if the purity was high enough. Bombs use small enough amounts that they won't go critical until the TNT explosion, or, like in the case of the bomb dropped on Hiroshima, they use two subcritical masses that get slammed together during detonation.
How on earth do they handle the stuff without causing some kind of reaction?
Again, this is one limiting factor of fisson bomb size. As you increase size of the bomb the amount of fissionable material gets larger and it gets harder and harder to design the bomb so the material doesn't go critical.
 
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What tickles me, is that Nuclear power, with all the engineering required to contain and run it, really boils down (see what I did there?) to the fact that it's just the "fire" of a big steam engine.

P.S., Fusion, which generates a lot less radioactive particles, is a lot harder to generate - it requires a huge amount of energy to fuse atoms. Historically a Fission reaction has been used to generate enough energy that is required to initiate Fusion. More recently, massive lasers have been used, however from what I understand, the laser based fusion has only been used to create fusion on a minute scale.

Stars, including our Sun are fusion reactions on a huge scale, but they only keep going because of the amount of gravity the star itself has.

Note: I'm a computer programmer, so I don't have any real-life experience with nuclear. But I do watch a lot of Science Channel. That makes me an expert, right?
 

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Okay I'll get the ball rolling and hopefully this will turn into a popular Thread. Just no politics is all I ask.



What's are the main differences between Reactors on land and the ones on Navy ships? I think its remarkable how they can be built small enough for Submarines. Which leads me to my next question.

What are the main differences between Reactors on subs and aircraft carriers.
If and when they go critical, evacuation is much faster and simpler on ships.
And since we dont have floating cities, homes are not destroyed.
Also, not many children live on Navy ships, so only adults may be affected.
And the fish glow afterwards.
And we can always steer the glow in the dark ship into an area populated by our enemies?

Hey, I'm trying hard to not hit politics, but on this topic, a fragile request at best.
Specially if we address these:
- What small country has 58 reactors at 19 nuclear power plants?
- How many REACTORS have sunk and where?


.
 

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If and when they go critical, evacuation is much faster and simpler on ships.....
You might be able to get off a ship quickly, but floating around in the water NEXT to a ship going "critical" doesn't necessarily help you.


Not that that "criticality" is very likely, but sure, what if....
 

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start rowing or we could change to .......
That might be nice, but I would picture something more like 5,000 crew members trying to get off a heavily damaged aircraft carrier with 30 seconds to do it. Not exactly tea time, waiting for lifeboat deployments.






Sorry, I think we're leading this thread astray (again) .... where's Pinetree when you need him?
 

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Discussion Starter #15
What tickles me, is that Nuclear power, with all the engineering required to contain and run it, really boils down (see what I did there?) to the fact that it's just the "fire" of a big steam engine.
Now that, I understand. All the stuff about nuclei, protons, neutrons, etc. is way over my head. I just find it fascinating that so much energy can come from such small things which can even be used for medical things, and my uneducated self is just trying to comprehend it. And planes with nuclear propulsion? What's that all about?
 

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Now that, I understand. All the stuff about nuclei, protons, neutrons, etc. is way over my head. I just find it fascinating that so much energy can come from such small things which can even be used for medical things, and my uneducated self is just trying to comprehend it.
E=mc^2

https://www.wikihow.com/Understand-E=mc2
Thanks, that'll help me understand it all better....ugh. I can't even comprehend half the words used in the link....lol. Should have stayed in school.
 

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Thanks, that'll help me understand it all better....ugh. I can't even comprehend half the words used in the link....lol. Should have stayed in school.
But if you stayed in school, you're life would have been completely different... think of all the good things in your life.... now imagine they are gone...... lol

Actually... I like to imagine you staying in school. And after graduating, you start your life long career... as a cop!!

:devil
 
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