The good news For the first time, carbon-emissions-free electricity generation in the United States has surpassed 40%. The breakdown is now: 44% natural gas (up from 40% last year) 18% nuclear 16%...
The good news
For the first time, carbon-emissions-free electricity generation in the United States has surpassed 40%.
The breakdown is now:
44% natural gas (up from 40% last year)
18% nuclear
16% coal (down from 20% last year)
10% wind
6% hydro
6% solar (up from 5% last year)
The bad news
The current pace is not enough for the US to have a net-zero grid by the end of the decade.
The so-so news
The only thing that's keeping carbon-free power from growing faster is natural gas, which is the fastest-growing source of generation at the moment, going from 40 percent of the year-to-date total in 2022 to 43.3 percent this year. (It's actually slightly below that level in the October data.) The explosive growth of natural gas in the US has been a big environmental win, since it creates the least particulate pollution of all the fossil fuels, as well as the lowest carbon emissions per unit of electricity. But its use is going to need to start dropping soon if the US is to meet its climate goals, so it will be critical to see whether its growth flat lines over the next few years.
The displacement of coal by natural gas is a welcomed transitional step as it's significantly less environmentally-unfriendly than coal while displacing it.
So, while progress is slow, there is a positive trend.
Nice to see a sizable decrease in coal. Natural gas is going to be necessary until reliable, economical and environmental-friendly power storage becomes available. It seems like everything is...
Nice to see a sizable decrease in coal.
Natural gas is going to be necessary until reliable, economical and environmental-friendly power storage becomes available. It seems like everything is still in research phases, nothing is actually being deployed to mass utilization. We will need enough natural gas and nuclear capacity to serve peak utilization during times of darkness and no wind.
While it's true that Nuclear physics is complicated, the fundamentals of nuclear waste are more accessible than you might think: Here is a video from an energy professor talking about the waste...
I actually work in spent nuclear fuel storage. If you have any questions/thoughts/comments on radwaste, spent fuel, or nuclear power in general, I am happy to answer them when I wake up in the...
I actually work in spent nuclear fuel storage. If you have any questions/thoughts/comments on radwaste, spent fuel, or nuclear power in general, I am happy to answer them when I wake up in the morning.
One thing I wonder about is the effect of half lives. It seems like something with a very long half life wouldn't be very dangerous because it doesn't radiate much? But something with a short...
One thing I wonder about is the effect of half lives. It seems like something with a very long half life wouldn't be very dangerous because it doesn't radiate much? But something with a short half-life isn't going to last hundreds or thousands of years. So why is long-term storage of nuclear waste apparently a problem? Perhaps I've misunderstood something.
Two points: The nuclides that drive radiotoxicity over the long-term are mostly transuranics (plutonium, neptunium, and Americium) with Pu-239 having a 24,000 year half-life (intermediate,...
Two points:
The nuclides that drive radiotoxicity over the long-term are mostly transuranics (plutonium, neptunium, and Americium) with Pu-239 having a 24,000 year half-life (intermediate, relative to something like Cs-137 or No-237). It takes ten half-lives to have it almost completely gone, so ~240,000 years for it to all decay away.
Daughter products. Uranium-235 and 238 both have a very long half life and aren’t particularly radiotoxic (I’d be more concerned about the chemical toxicity, similar to lead), but the radium and radon in the decay chain cause bigger issues.
Look at it this way....you can (probably, wait for nukeman to confirm) stand next to some long-halflife nuclear waste for an hour and be fine. Build a house on top of it, and live there for 20...
Look at it this way....you can (probably, wait for nukeman to confirm) stand next to some long-halflife nuclear waste for an hour and be fine.
Build a house on top of it, and live there for 20 years, it'll be a problem. It's all about radiation exposure over baseline. And if something has a 100 year half-life....it's gonna be emitting for more than a thousand years.
I recall a phrase I've heard before: There's no such thing as good radiation exposure. Merely if the benefit outweighs the risk, like X rays for medical diagnosis, or being in the sunlight.
See what I wrote for @skybrian. In response to your last point, I will say that the linear no-threshold model for radiation exposure and health is hotly debated. Folks in places with naturally...
In response to your last point, I will say that the linear no-threshold model for radiation exposure and health is hotly debated. Folks in places with naturally higher background don’t seem to be worse off, and many folks believe that it is likely there is a threshold below which there are no effects. There’s also the radiation hormesis model, which proposes some low level that is beneficial, but that is also rather controversial.
Let me bite ! (bioeng major turned CS guy; I know enough science to appear smart, not enough to understand the practicality of it) My understanding is that there's different grades of nuclear...
If you have any questions/thoughts/comments on radwaste, spent fuel, or nuclear power in general, I am happy to answer them when I wake up in the morning.
Let me bite ! (bioeng major turned CS guy; I know enough science to appear smart, not enough to understand the practicality of it)
My understanding is that there's different grades of nuclear waste, and the current image in my head is "just put them in a deep salt mine in Norway, lol". But:
Sanity check / assumption questions: radiation level (how strong it emits) and half-life (how long it emits) are correlated right ? How so (linear, Poisson, some other wonky curve) ? Can we also assume that alpha/beta/gamma emission level are roughly the same ?
Then: are low level waste stored in those barrel in the salt mines ? Is it worth it to monitor their radiation level and just process them as normal waste once their level are low enough, or is the time-frame involved already unpractical ?
For medium and high level waste: so we have a sizeable amount of stuff that emits radiation. How unpractical is it to setup some kind of device that would gather this energy ? Like some kind of giant heat pump ? (probably not using thermal energy though... ?)
Other question:
What are actually in those barrel ? I assume it's various object that were in close proximity to the fuel (control rods, nuts and bolts, etc.). Are they pro-processed before being put in the barrel (like going through an industrial grinder) ? Are we actually using barrel or is there some other kind of container ?
Apologies for how long it took for me to get back to you on this. For a single radionuclide that decays into a stable nuclide, radioactivity follows an exponential decay. Co-60 has a five year...
Apologies for how long it took for me to get back to you on this.
For a single radionuclide that decays into a stable nuclide, radioactivity follows an exponential decay. Co-60 has a five year half-life, so after five years, a source will be half as strong, after ten a quarter, etc. The rule of thumb is that it takes ten half-lives to “completely” decay. There isn’t really a timing difference between the various types of radiation, except for possibly some weird edge cases.
Generally, shorter half-lives mean more intense radioactivity. That said, this gets complicated by decay chains. Uranium and thorium both follow long decay chains to stable isotopes of lead. The activity of these daughters varies, and in some cases it is more radioactive than a parent isotope. For example, you can hold a plate of highly-enriched uranium (>20% U-235, weapons-grade is generally above 90%) in your hands. Just wear gloves and don’t crush it into powder and snort it. But going into an abandoned uranium mine isn’t a good idea, because you have several daughter products, including radon gas, that can give you a pretty high internal dose.
In the United States, from a regulatory perspective, there are many types of radioactive waste (commonly shorted to radwaste). The most common ones are low-level (in the commercial world, subdivided into Classes A, B, C, and Greater-Than-Class C based on activity levels), Transuranic, and high level waste (HLW)/spent nuclear fuel (SNF). SNF is fuel that has been irradiated and is not usable in a reactor without reprocessing; high-level waste is the leftovers of reprocessing (often liquid, mostly fission products, and highly radioactive). Transuranic waste is various isotopes of neptunium, plutonium, and americium. And low-level waste is almost everything else. It can be rags, tools, and used coveralls, it can be components from a reactor, contaminated soils, etc. Right now, most LLW is buried in special landfills, similar to normal garbage, but with more regulated packaging, emplacement, and monitoring. Some (Greater-Than-Class C) is too (radiologically) hot to bury, that will go into a repository. Waste containers are variable, there’s drums, metal boxes, shipping containers, among others. In many cases, size reduction of waste does occur, we used to have a special incinerator for this purpose. These days, we just try to pack the containers tightly full. Most of our waste is “job control waste”, e.g., coveralls, rags, broken tools, gloves, etc.
For the HLW/SNF, it isn’t energetic enough to practically generate electricity.
I think I answered all of your questions. Let me know if there’s any you want to follow up on, or if you have more!
The good news
For the first time, carbon-emissions-free electricity generation in the United States has surpassed 40%.
The breakdown is now:
The bad news
The current pace is not enough for the US to have a net-zero grid by the end of the decade.
The so-so news
The displacement of coal by natural gas is a welcomed transitional step as it's significantly less environmentally-unfriendly than coal while displacing it.
So, while progress is slow, there is a positive trend.
Nice to see a sizable decrease in coal.
Natural gas is going to be necessary until reliable, economical and environmental-friendly power storage becomes available. It seems like everything is still in research phases, nothing is actually being deployed to mass utilization. We will need enough natural gas and nuclear capacity to serve peak utilization during times of darkness and no wind.
Its going to be difficult to keep up this % as the EV explosion ramps up, but I hope we can stay net-positive on growth in the coming decade.
The picture that goes with the title include a nuclear fission plant chugging away, creating nuclear waste which is poisonous for 10,000 years.
Nuclear waste is not all the same and it's a lot more complicated than that.
For example... nuclear waste does not cause climate change.
While it's true that Nuclear physics is complicated, the fundamentals of nuclear waste are more accessible than you might think: Here is a video from an energy professor talking about the waste products and their storage.
Fewer than half of cooling towers like those are part of nuclear power plants.
https://nuclear.duke-energy.com/2013/11/13/why-don-t-all-nuclear-plants-have-cooling-towers#:~:text=There%20are%20more%20than%20250,than%20100%20on%20nuclear%20plants.
Although in this case, the stock photo is a nuclear plant, albeit one in Germany.
I actually work in spent nuclear fuel storage. If you have any questions/thoughts/comments on radwaste, spent fuel, or nuclear power in general, I am happy to answer them when I wake up in the morning.
One thing I wonder about is the effect of half lives. It seems like something with a very long half life wouldn't be very dangerous because it doesn't radiate much? But something with a short half-life isn't going to last hundreds or thousands of years. So why is long-term storage of nuclear waste apparently a problem? Perhaps I've misunderstood something.
Two points:
Look at it this way....you can (probably, wait for nukeman to confirm) stand next to some long-halflife nuclear waste for an hour and be fine.
Build a house on top of it, and live there for 20 years, it'll be a problem. It's all about radiation exposure over baseline. And if something has a 100 year half-life....it's gonna be emitting for more than a thousand years.
I recall a phrase I've heard before: There's no such thing as good radiation exposure. Merely if the benefit outweighs the risk, like X rays for medical diagnosis, or being in the sunlight.
See what I wrote for @skybrian.
In response to your last point, I will say that the linear no-threshold model for radiation exposure and health is hotly debated. Folks in places with naturally higher background don’t seem to be worse off, and many folks believe that it is likely there is a threshold below which there are no effects. There’s also the radiation hormesis model, which proposes some low level that is beneficial, but that is also rather controversial.
Let me bite ! (bioeng major turned CS guy; I know enough science to appear smart, not enough to understand the practicality of it)
My understanding is that there's different grades of nuclear waste, and the current image in my head is "just put them in a deep salt mine in Norway, lol". But:
Sanity check / assumption questions: radiation level (how strong it emits) and half-life (how long it emits) are correlated right ? How so (linear, Poisson, some other wonky curve) ? Can we also assume that alpha/beta/gamma emission level are roughly the same ?
Then: are low level waste stored in those barrel in the salt mines ? Is it worth it to monitor their radiation level and just process them as normal waste once their level are low enough, or is the time-frame involved already unpractical ?
For medium and high level waste: so we have a sizeable amount of stuff that emits radiation. How unpractical is it to setup some kind of device that would gather this energy ? Like some kind of giant heat pump ? (probably not using thermal energy though... ?)
Other question:
What are actually in those barrel ? I assume it's various object that were in close proximity to the fuel (control rods, nuts and bolts, etc.). Are they pro-processed before being put in the barrel (like going through an industrial grinder) ? Are we actually using barrel or is there some other kind of container ?
Apologies for how long it took for me to get back to you on this.
For a single radionuclide that decays into a stable nuclide, radioactivity follows an exponential decay. Co-60 has a five year half-life, so after five years, a source will be half as strong, after ten a quarter, etc. The rule of thumb is that it takes ten half-lives to “completely” decay. There isn’t really a timing difference between the various types of radiation, except for possibly some weird edge cases.
Generally, shorter half-lives mean more intense radioactivity. That said, this gets complicated by decay chains. Uranium and thorium both follow long decay chains to stable isotopes of lead. The activity of these daughters varies, and in some cases it is more radioactive than a parent isotope. For example, you can hold a plate of highly-enriched uranium (>20% U-235, weapons-grade is generally above 90%) in your hands. Just wear gloves and don’t crush it into powder and snort it. But going into an abandoned uranium mine isn’t a good idea, because you have several daughter products, including radon gas, that can give you a pretty high internal dose.
In the United States, from a regulatory perspective, there are many types of radioactive waste (commonly shorted to radwaste). The most common ones are low-level (in the commercial world, subdivided into Classes A, B, C, and Greater-Than-Class C based on activity levels), Transuranic, and high level waste (HLW)/spent nuclear fuel (SNF). SNF is fuel that has been irradiated and is not usable in a reactor without reprocessing; high-level waste is the leftovers of reprocessing (often liquid, mostly fission products, and highly radioactive). Transuranic waste is various isotopes of neptunium, plutonium, and americium. And low-level waste is almost everything else. It can be rags, tools, and used coveralls, it can be components from a reactor, contaminated soils, etc. Right now, most LLW is buried in special landfills, similar to normal garbage, but with more regulated packaging, emplacement, and monitoring. Some (Greater-Than-Class C) is too (radiologically) hot to bury, that will go into a repository. Waste containers are variable, there’s drums, metal boxes, shipping containers, among others. In many cases, size reduction of waste does occur, we used to have a special incinerator for this purpose. These days, we just try to pack the containers tightly full. Most of our waste is “job control waste”, e.g., coveralls, rags, broken tools, gloves, etc.
For the HLW/SNF, it isn’t energetic enough to practically generate electricity.
I think I answered all of your questions. Let me know if there’s any you want to follow up on, or if you have more!