Score
Title
547
AskScience Panel of Scientists XVII
414
AskScience AMA Series: I am a squid biologist, AMA!
2913
How do surgeons avoid air bubbles in the bloodstreams after an organ transplant?
6247
Why do joints ache so much when you get the cold/flu?
36
Are all massless particles their own antiparticles?
19
What do prion proteins naturally do in the brain/body?
780
What is the relationship between the rate of change of a function and differentiation?
502
If the energy of photons is continuous, and electron's energy levels around an atom are discreet, then how can you ever have a photon that has the exact energy to be absorbed by an electron?
32
How does coding physically work? How does a computer, made up of inanimate parts, understand what to do based on a made up language?
165
Why do "Y" chromosomes only have 3 chromatids?
9
Does the human body make any noticeable 'microadjustments' when exposed to a particular climate for a length of time?
7
Why do sperm cells have a large nucleus if they only carry half the genetic material?
8
What is thought to happen to quarks during the big rip?
8
How we know certain animals can detect specific scents from X distance away? How are we measuring and determining that?
11068
How do scientists studying antimatter MAKE the antimatter they study if all their tools are composed of regular matter?
3
Are there problems in computer science that no algorithm can solve for all inputs?
1
How do spacelike separated measurements of entangled particles work?
5
Does Urine Affect Plant Transpiration?
1
How do you actually use Density Functional Theory?
205
Can an unvaried diet cause the human body to learn to digest a certain (type of) food faster?
6
Is there a correlation between peoples hearing range and the type of music they like?
60
Why do large metal beams or trusses sometimes have tiny connections/joints?
1
How do you measure forces between individual atoms and molecules?
43
Does Supersymmetry include antimatter?
1
Why do some photos of the heavens show stars radiating light in a 'cross' shape instead of evenly in a circle?
3
I've recently been told that cloning different types of animals varies in difficulty. Is this true and if so what the key challenges in cloning different organisms?
1
Why does Nima Arkani-Hamed say we need an infinitely large apparatus to get rid of quantum uncertainty in measurements?
1
[Engineering] How do modern cars calculate fuel economy?
1
What exactly is the Doppler effect?
6
Why don’t everyday movements cause sub-concussive impacts?
3
Does our mother tongue affect our face features in any way?
1
What is physically different about the brain of someone with an exceptional memory?
29
Why is the waste produced in a thorium fuel cycle need storage for only 300 years instead of thousands of years for uranium fuel cycle, even though U233 from Th232 had mostly similar fission products as U235?
40
How did Scott and Amundsen KNOW when they reached the south pole (100 years ago)?
6
How does convection of heat work in space?
3
[Physics] Has there been significant research relating to anti-matter weaponry?
1
How does a paraconformity originate?
7
Can non ear neurons detect sounds?
990
If 2 black holes were close enough that their event horizons were overlapping, could things in that overlapped region escape those black holes?
4
Is it possible for gravity waves to have a particle nature? If so, what would this particle be like? If not, what sets gravitational waves apart from light and matter, which have particle wave duality?
6
Why is this year's influenza outbreak so much deadlier than previous years?
0
What are fingerprints made of ?
2795 Tenthyr Strictly speaking, we CAN use most nuclear waste. Breeder reactors can be used to consume pretty much all usable fissle materials and produce a much lower volume of equivalent waste with different properties. Breeder reactors can be used to manufacture weapons grade fissile material though, so there's political aspects, as well as economic ones-- uranium is fairly abundant. Edit: spelling errors.
12532 restricteddata Radioactivity, by itself, is not that useful for generating power. What is useful for generating power is the induced splitting of _lots_ of atoms at the same time, not the slow trickle of energy release you get from radioactive decay alone. To put it another way: nuclear reactors don't work because their fuel is radioactive, they work because their fuel is splittable by neutrons. Those are not the same thing (all fuel splittable by neutrons is radioactive, but not all radioactive atoms are splittable by neutrons).
140 eestileib Check out "Reprocessing"; it's the step we removed from the current nuclear power cycle, and a major reason why our nuclear waste is so hard to store. Basically you take the used fuel rods and extract the parts that can be reused in reactors as fuel, separate the super-highly radioactive stuff that can't be used in a reactor for short term storage, and then you're left mostly with stuff that's more dangerous from heavy metal poisoning than the radiation (U-238 eg). It was stopped in the us by president Carter because of concerns about nuclear proliferation; I guess he thought we'd be clever enough to figure out how to safely store nuclear waste without a reprocessing industry, but so far we haven't, which is why we have spent fuel rods piling up.
417 pjokinen It is very usable, just not in our current nuclear reactors. Uranium fuel rods are pellets of uranium held together by a metal casing. Being inside a reactor causes the metal to become brittle, and the life of the fuel rod is determined by the life of that casing. In other reactor designs, like molten salt reactors, this casing is not used. The fuel stays in the reactor for much longer and much more of the potential energy is extracted. This results in lower volumes of waste that is much less radioactive for much less time than that coming from traditional reactors. Learn more about molten salt reactors [here](https://en.m.wikipedia.org/wiki/Molten_salt_reactor). They’re pretty awesome!
64 spasticanomaly Nuclear fuel becomes “waste” when it no longer produces enough neutrons to sustain a nuclear chain reaction. The kinetic energy of neutrons drives the heat cycle that produces power. The gamma and beta radiation produced by “waste” isotopes contribute very little.
151 BoneyBadboyDupree American scientists developed a nuclear reprocessing system called PUREX (Plutonium-Uranium Extraction) to resume spent nuclear fuel rods. But Ford suspended it and Carter ended it permanently because of the plutonium by-product and the Non-Proliferation Agreements. Now France reprocesses many nation's fuel for reuse using this 50 year old technology.
21 Char-Lez There are lots of things classed as “nuclear waste”. Some of those things can be used as fuel, or for other purposes. The devil is in the details. Which materials? Used for what? At what cost? Etc. Most reactors are metal reactors and using these materials is either technically infeasible or economically infeasible. But Liquid Fluoride Thorium Reactors (LFTRs) can use many nuclear waste materials as fuel. They are an interesting technology I expect to see make an impact in the coming years. EDIT: spelling
31 SLUnatic85 A lot of good answers here. But also in the US, there are actually laws in place that hinder our ability to even push for nuclear fuel recycling technologies. It's mostly dueto the Ford/Carter fear of fissile by-products and the cold war as some have pointed out. My company, in France, is all about pushing for recycling their waste. That said, you need the right products left to split for heat production to make energy worth the effort. It's not about that they give off radiation, so this will only help so much. TBH it is a conversation I would LOVE to see more of though as it is a real way we can promote the energy and make it a bit safer considering how much the world is relying on it while fearing it lately.
77 Stinnett In a nuclear reactor, energy is released via fission. Some nuclides, such as U-235, are fissile, meaning they can easily undergo fission. Other nuclides, like U-238, are fertile; this means they can be converted to a fissile material by absorbing neutrons. Nuclear waste consists of many different nuclides. There is some uranium left in the waste, and it is possible to reprocess the spent fuel to retrieve it. This is pretty expensive, and the US doesn't currently do this. Many of the other components of nuclear waste (Cs-137, Sr-90, ...) are not fissile or fertile, so they aren't useful for generating nuclear power even though they are still highly radioactive.
2797 0 Tenthyr Strictly speaking, we CAN use most nuclear waste. Breeder reactors can be used to consume pretty much all usable fissle materials and produce a much lower volume of equivalent waste with different properties. Breeder reactors can be used to manufacture weapons grade fissile material though, so there's political aspects, as well as economic ones-- uranium is fairly abundant. Edit: spelling errors.
12524 0 restricteddata Radioactivity, by itself, is not that useful for generating power. What is useful for generating power is the induced splitting of _lots_ of atoms at the same time, not the slow trickle of energy release you get from radioactive decay alone. To put it another way: nuclear reactors don't work because their fuel is radioactive, they work because their fuel is splittable by neutrons. Those are not the same thing (all fuel splittable by neutrons is radioactive, but not all radioactive atoms are splittable by neutrons).
140 0 eestileib Check out "Reprocessing"; it's the step we removed from the current nuclear power cycle, and a major reason why our nuclear waste is so hard to store. Basically you take the used fuel rods and extract the parts that can be reused in reactors as fuel, separate the super-highly radioactive stuff that can't be used in a reactor for short term storage, and then you're left mostly with stuff that's more dangerous from heavy metal poisoning than the radiation (U-238 eg). It was stopped in the us by president Carter because of concerns about nuclear proliferation; I guess he thought we'd be clever enough to figure out how to safely store nuclear waste without a reprocessing industry, but so far we haven't, which is why we have spent fuel rods piling up.
421 0 pjokinen It is very usable, just not in our current nuclear reactors. Uranium fuel rods are pellets of uranium held together by a metal casing. Being inside a reactor causes the metal to become brittle, and the life of the fuel rod is determined by the life of that casing. In other reactor designs, like molten salt reactors, this casing is not used. The fuel stays in the reactor for much longer and much more of the potential energy is extracted. This results in lower volumes of waste that is much less radioactive for much less time than that coming from traditional reactors. Learn more about molten salt reactors [here](https://en.m.wikipedia.org/wiki/Molten_salt_reactor). They’re pretty awesome!
61 0 spasticanomaly Nuclear fuel becomes “waste” when it no longer produces enough neutrons to sustain a nuclear chain reaction. The kinetic energy of neutrons drives the heat cycle that produces power. The gamma and beta radiation produced by “waste” isotopes contribute very little.
151 0 BoneyBadboyDupree American scientists developed a nuclear reprocessing system called PUREX (Plutonium-Uranium Extraction) to resume spent nuclear fuel rods. But Ford suspended it and Carter ended it permanently because of the plutonium by-product and the Non-Proliferation Agreements. Now France reprocesses many nation's fuel for reuse using this 50 year old technology.
23 0 Char-Lez There are lots of things classed as “nuclear waste”. Some of those things can be used as fuel, or for other purposes. The devil is in the details. Which materials? Used for what? At what cost? Etc. Most reactors are metal reactors and using these materials is either technically infeasible or economically infeasible. But Liquid Fluoride Thorium Reactors (LFTRs) can use many nuclear waste materials as fuel. They are an interesting technology I expect to see make an impact in the coming years. EDIT: spelling
34 0 SLUnatic85 A lot of good answers here. But also in the US, there are actually laws in place that hinder our ability to even push for nuclear fuel recycling technologies. It's mostly dueto the Ford/Carter fear of fissile by-products and the cold war as some have pointed out. My company, in France, is all about pushing for recycling their waste. That said, you need the right products left to split for heat production to make energy worth the effort. It's not about that they give off radiation, so this will only help so much. TBH it is a conversation I would LOVE to see more of though as it is a real way we can promote the energy and make it a bit safer considering how much the world is relying on it while fearing it lately.
73 0 Stinnett In a nuclear reactor, energy is released via fission. Some nuclides, such as U-235, are fissile, meaning they can easily undergo fission. Other nuclides, like U-238, are fertile; this means they can be converted to a fissile material by absorbing neutrons. Nuclear waste consists of many different nuclides. There is some uranium left in the waste, and it is possible to reprocess the spent fuel to retrieve it. This is pretty expensive, and the US doesn't currently do this. Many of the other components of nuclear waste (Cs-137, Sr-90, ...) are not fissile or fertile, so they aren't useful for generating nuclear power even though they are still highly radioactive.