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posted on Dec, 11 2017 @ 10:17 PM
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originally posted by: Hyperboles
Ques:
How does the mass of a spent nuclear fuel rod compare to that of a new one?
That depends on the fuel and a measure called "burn-up" which measures how much of the fuel can be "burned" by the time it is "spent". Here are some ranges for burn-up:

www.world-nuclear.org...

An issue in operating reactors and hence specifying the fuel for them is fuel burn-up. This is measured in gigawatt-days (thermal) per tonne and its potential is proportional to the level of enrichment. Hitherto a limiting factor has been the physical robustness of fuel assemblies, and hence burn-up levels of about 40 GWd/t have required only around 4% enrichment. But with better equipment and fuel assemblies, 55 GWd/t is possible (with 5% enrichment), and 70 GWd/t is in sight, though this would require 6% enrichment.


Here's an example which I think uses burnup close to the low end of that range which was common in the past, around 40 GWd/t, but if a modern fuel achieves 55 GWd/t burnup the mass consumption will be higher by a corresponding amount:

www.nuclear-power.net...

Consumption of a 3000MWth (~1000MWe) reactor (12-months fuel cycle)

It is an illustrative example, following data do not correspond to any reactor design.

Typical reactor may contain about 165 tonnes of fuel (including structural material)
Typical reactor may contain about 100 tonnes of enriched uranium (i.e. about 113 tonnes of uranium dioxide).
This fuel is loaded within, for example, 157 fuel assemblies composed of over 45,000 fuel rods.
A common fuel assembly contain energy for approximately 4 years of operation at full power.
Therefore about one quarter of the core is yearly removed to spent fuel pool (i.e. about 40 fuel assemblies), while the remainder is rearranged to a location in the core better suited to its remaining level of enrichment (see Power Distribution).
The removed fuel (spent nuclear fuel) still contains about 96% of reusable material (it must be removed due to decreasing kind of an assembly).

Annual natural uranium consumption of this reactor is about 250 tonnes of natural uranium (to produce of about 25 tonnes of enriched uranium).

Annual enriched uranium consumption of this reactor is about 25 tonnes of enriched uranium.

Annual fissile material consumption of this reactor is about 1 005 kg.

Annual matter consumption of this reactor is about 1.051 kg.

But it corresponds to about 3 200 000 tons of coal burned in coal-fired power plant per year.


I bolded the two most relevant to your question, ~1.05 kg mass consumption per 25,000 kg of fuel. If the burnup rate is higher there could be 1.4 kg mass consumption per 25,000 kg of fuel. Those figures relate to fuel only, not considering any structural (non-fuel) components of the fuel rods.

If you want to know specifically for the fuel rod and not just the fuel in the fuel rod, you would need to factor in the specifics for the non-fuel components of the fuel rods in question.

edit on 20171211 by Arbitrageur because: clarification




posted on Dec, 12 2017 @ 12:53 AM
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a reply to: Arbitrageur

Thanks, great post.
So for 1 kg burn up, the protons, neutrons and electrons dont exist anymore?



posted on Dec, 12 2017 @ 04:20 AM
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It isn't that the protons, neutrons and electrons don't exit anymore there are several processes going on.

1) Nuclear binding energy release, by splitting an atom, you reduce the required binding energy and this energy takes up a mass-energy equivalence while an atom is bound, when it is broken in half (in the case of U238 fission) energy is released and the mass of the constituents parts is less of that of the original Uranium. This mass deficit is released as energy.
It isn't that those particles don't exist anymore, it is the binding energy that is released.
2) Some of the neutrons will escape the reactor
3) Some of the resulting neutrons will produce neutrinos, these will escape the reactor, they have very small mass, but you loose that mass regardless.



posted on Dec, 13 2017 @ 09:18 AM
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originally posted by: ErosA433
It isn't that the protons, neutrons and electrons don't exit anymore there are several processes going on.

1) Nuclear binding energy release, by splitting an atom, you reduce the required binding energy and this energy takes up a mass-energy equivalence while an atom is bound, when it is broken in half (in the case of U238 fission) energy is released and the mass of the constituents parts is less of that of the original Uranium. This mass deficit is released as energy.
It isn't that those particles don't exist anymore, it is the binding energy that is released.
2) Some of the neutrons will escape the reactor
3) Some of the resulting neutrons will produce neutrinos, these will escape the reactor, they have very small mass, but you loose that mass regardless.
ah ok. thanks. so 1 kg of u 238 when weighed on a weighing scale shows 1 kg, but the mass is much higher? how do you substitute that higher mass in the actual mass energy equivalence equation?



posted on Dec, 13 2017 @ 09:54 AM
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originally posted by: Hyperboles
ah ok. thanks. so 1 kg of u 238 when weighed on a weighing scale shows 1 kg, but the mass is much higher? how do you substitute that higher mass in the actual mass energy equivalence equation?
That's not what Eros said at all.

The binding energy of the uranium does show up when you weigh the 1 Kg of uranium, so when you weigh the constituent parts after splitting, you have the same number of protons and neutrons but with the smaller atoms the binding energy is less so the mass is less, as explained at about 90 seconds in this cartoon-style video:



Also Eros made a good point about neutrons escaping the reactor which I doubt is included in the "mass consumed" figure. Those wouldn't be mass consumed by the reactor, they could perhaps be better described as "mass lost outside the reactor" and would make the fuel rod "mass reduction" figures larger but I don't know by how much. The part about neutrinos is also true but their mass is very small, so small we weren't even sure they had any mass for a long time.

edit on 20171213 by Arbitrageur because: clarification



posted on Dec, 13 2017 @ 12:30 PM
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a reply to: Arbitrageur

Ok ill watch the video. How can binding energy show on a weighing scale? that part may not be so obvious. Is binding energy composed of only gluons or something other?



posted on Dec, 13 2017 @ 02:07 PM
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a reply to: Hyperboles
Only about 1% of your mass is composed of the rest mass of the quarks that compose the protons and neutrons that make up the bulk of your mass. The other 99% is kinetic energy of the quarks and binding energy of the gluons which bind the quarks in the protons and neutrons.

Between hadrons, the binding force is mediated by mesons and there's not as much energy wrapped up in that.

So if you have concerns about energy showing up as weight on a scale, it's a lot bigger issue with the protons and neutrons themselves, since 99% of their mass is from kinetic energy and binding energy.



posted on Dec, 13 2017 @ 10:04 PM
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When you are reading this sentence and maybe reading it in your head, are you hearing sound in your head? (in other words, does ones internal monologue produce sound to experience the inner voice? If not sound, how is that inner voice experienced, how can I so psuedoly but seemingly truly '''''''hear''''''' music and my voice speaking in my head?)



posted on Dec, 14 2017 @ 12:46 AM
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a reply to: Arbitrageur

of what kind or form is this kinetic energy/ and or binding energy, meaning mechanical, electromagnetic or some other exotic form ?



posted on Dec, 14 2017 @ 03:38 AM
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a reply to: Hyperboles

Think best example i can give to explain it is that lets assume that all our measurements on the property of matter is correct and that a proton is made up of 3 quarks. They have different charge, some 1/3 rd the electron charge, some 2/3 rd, Quarks like to be in groups of 3, but that itself is quite a high energy configuration since there will more often than not be at least a bit of net charge and repulsion.

Not a problem though, the strong force, mediated by gluons acts to hold the quarks together tightly within a certain range. So what you have is 3 particles that are confined within a certain range but all have high individual kinetic energy, though in general, the net kinetic energy will be small. These gluons make up much of the mass via energy equivalence.

So when you move to a larger object such as say, Uranium, it is a massive ball of lots of these protons and neutrons. The strong force again, binds them together, there are lots of repulsive forces going on, but the strong force at short range is much stronger than that of coulomb repulsion. That repulsion though represents a potential energy in a manner of speaking, and is held in that state by the strong force. This energy via the matter Energy equivalence is what you observe as binding energy, or mass.

Now it kind of works out that, it isn't a linear process, and that the binding energy per nucleon increases from 2 nucleons up to 56, and then starts to decrease beyond that.



posted on Dec, 14 2017 @ 09:00 AM
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a reply to: ErosA433

Ok thanks. tho this strong force is kind of mechanical, so how can it be kinetic energy, which requires fluctuation of the mechanical force. and how is it that it reflects on the weighing scale? Mass energy equivalence is more or less a latent energy.



posted on Dec, 15 2017 @ 01:43 AM
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originally posted by: Hyperboles
a reply to: Arbitrageur

of what kind or form is this kinetic energy/ and or binding energy, meaning mechanical, electromagnetic or some other exotic form ?



originally posted by: Hyperboles
a reply to: ErosA433

Ok thanks. tho this strong force is kind of mechanical, so how can it be kinetic energy, which requires fluctuation of the mechanical force. and how is it that it reflects on the weighing scale? Mass energy equivalence is more or less a latent energy.
The strong interaction is the strong interaction. It's not electromagnetic interaction, it's not the weak interaction, and it's not gravitational interaction, the other three types of interactions.

Kinetic energy isn't an interaction by itself, it's just energy based on relative motion and I have no idea what you mean that "requires fluctuation of the mechanical force" which sounds like nonsense. The Voyager spacecraft leaving our solar system have kinetic energy but I have no idea what would be considered "fluctuation of the mechanical force" with those spacecraft or why you would suggest such a thing.

The quarks inside a proton happen to have both kinetic energy, and be subjected to the strong interaction at the same time, but that doesn't mean strong force and kinetic energy are the same thing as your question implies.

I don't have a good intuitive answer for why the energy shows up on a scale, but it does. According to Einstein even heating up a cup of coffee would cause it to potentially weigh more on a scale if you had a scale sensitive enough to measure the difference, though there's probably not a scale sensitive enough for that. The increase would be just from the kinetic energy of the hotter, faster moving molecules of the heated coffee, no strong force involved in that change. It's a lot easier to see and measure the result of increased kinetic energy in the LHC where the kinetic energy is much higher than a hot cup of coffee.

edit on 20171215 by Arbitrageur because: clarification



posted on Dec, 15 2017 @ 06:11 AM
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a reply to: Arbitrageur

kinetic energy is when something moves of if stationary any forces emanating or acting fluctuate. meaning wrt time. so how does a stationary atoms nucleus posses any kind of kinetic energy?



posted on Dec, 15 2017 @ 10:54 AM
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originally posted by: Hyperboles
a reply to: Arbitrageur

kinetic energy is when something moves of if stationary any forces emanating or acting fluctuate. meaning wrt time. so how does a stationary atoms nucleus posses any kind of kinetic energy?
Let's agree on what kinetic energy is first. Let's do a calculation of kinetic energy based on that definition.

A stationary 50 kg fire hydrant anchored to the ground has a force acting on it which is fluctuating with respect to time.
At t=0s the force applied is 5 Newtons
At t=1s the force applied is 10 Newtons
At t=2s the force applied is 15 Newtons

The force increases linearly with respect to time. What is the kinetic energy of the fire hydrant at t=1s? Note the force required to rip the hydrant's anchor out of the ground is over 4000 Newtons so it remains stationary as the smaller forces are applied.

According to my calculations the kinetic energy is zero, which is another way of saying it doesn't have any on the scale of the fire hydrant.

If you have a different answer please explain, because I still don't get this "if stationary any forces emanating or acting fluctuate. meaning wrt time" part of your definition.

The molecules in the fire hydrant have internal kinetic energy based on the temperature of the fire hydrant, but the fire hydrant is stationary, how is that possible? If you don't understand that, let's explore that example before discussing protons. If you do understand that, is there something that leads you to believe that molecules in a stationary fire hydrant can have kinetic energy, but quarks in a "stationary" proton can't have kinetic energy? If so, please explain.



posted on Dec, 15 2017 @ 12:40 PM
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a reply to: Arbitrageur

the ke of the hydrant may be zero but it pe increases. the ke in the water due to pr fluctuation is converted to pe as water doesnt move. but you could say df/ds x distance moved by prime mover of pressure source x time is ke
in a proton the nuclear forces are not fluctuating, so there is no net ke

there is ke even in a fluctuating in voltages
edit on 15-12-2017 by Hyperboles because: (no reason given)

edit on 15-12-2017 by Hyperboles because: darn spelling



posted on Dec, 16 2017 @ 02:37 AM
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Do colors as we perceive them (what you see when you experience red, or blue) actually exist (as the red you see) in nature; or does it only exist physiologically, psychologically, concious-chemically in living creatures heads?



posted on Dec, 16 2017 @ 06:34 AM
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originally posted by: DanielKoenig
Do colors as we perceive them (what you see when you experience red, or blue) actually exist (as the red you see) in nature; or does it only exist physiologically, psychologically, concious-chemically in living creatures heads?


Your eye has cells that are sensitive to short, medium and long light frequencies. Each of them covers a frequency range and the ranges overlap. Their peak sensitivity does not match the blue, green and red colors exactly. It is more like blue-violet, green and yellow. The brain creates the colors you see from those three overlapping signals.



posted on Dec, 16 2017 @ 11:08 AM
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a reply to: moebius

Ok, so in other words, nature is in black and white..or grey? And all colors are produced only by the mixing of em frequencies? Or do you have to say colors are produced by the organization of atoms, which produce the frequencies?

And now I am immediately thrown back into my fundamental ignorance about the fundamental appearance of fundamental em radiation. With the dancers around the definitions about particle/wave/what exactly does frequency mean.

Is Em radiation...lets call it Light (and let there be it), when traveling from A to B, moving up and down up and down up and down up and down. Like if 2 people held ends of a long rope and they moved their holding hand up and down up and down up and down.

If they just did it once, one of them: Starting with hand down, moved their hand rapidly up, would that crest made that would travel to B, be equivalent to a photon?

And when they do it many times, is that many photons? And the speed and force at which they do it (or the speed produces the force), produces the frequency and wavelength?


Or are photons, is light, is em radiation: little balls that are projectiled from A to B. And then what would frequency be? The difference between a (futuristic-robotic) pitcher throwing 10 baseballs a second, and 50 a second?

Is the difference between (roughly) red and blue



posted on Dec, 16 2017 @ 11:13 AM
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a reply to: moebius
a reply to: DanielKoenig

And you see, or we will see, the problem with asking someone who suggests they fundamentally comprehend how a photon close to actually exists and so attempting to probe their understanding by asking such questions with such analogies as I have, almost forces them to admit things that somehow at once must logically conclusionly be attached to their assumptions, and at the same time contradict their declared stark and barren, surface, depth lacking, probeless worldview.

Hmm, yes... ok... the universe must be full of jump ropes then...



posted on Dec, 16 2017 @ 12:19 PM
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originally posted by: DanielKoenig
a reply to: moebius

Ok, so in other words, nature is in black and white..or grey? And all colors are produced only by the mixing of em frequencies? Or do you have to say colors are produced by the organization of atoms, which produce the frequencies?


That is correct. Color as perceived by humans is derived as a filter of a mixing of electromagnetic frequencies in various proportions.

A reproduction, on a computer screen (with 3 varying pixel colors) of a natural scene which appears to have correct colors to humans, might look clearly unnatural to a different species with differing receptors and brain circuitry.

That is because the actual spectral distribution reproduced by the computer screen is not the same or as detailed as the natural, but an approximation optimized for human perception. ET could look at our photographs and screens and laugh at how weird they looked, and we might say the same about their picture technology.



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