Hi, Jack - My co-author Tim Maloney and I, in our upcoming book Fear of a Nuclear Planet, have determined how many solar panels it would have taken to produce the same energy as the "spent" fuel stored in the Connecticut Yank dry cask storage farm.
Using the Sunpower E-327 panel with an estimated 40-year lifecycle, we calculate that on the same sized storage pad, the used panels would form a solid stack 670 feet high, or 530 feet high if the panels were crushed flat. I'll send you the graphic and calculations by email -- feel free to use it!
“It’s only dangerous if you eat it”. At longer time scales, should we worry about inhaling wind born dust particles created by erosion (or explosion)? I.e. eating by other means.
If 600 years is the relevant timeframe for nuclear waste, why do we hear about thousand-year duration nuclear wastelands, particularly for Chernobyl? Did that disaster create compounds that are more dangerous and long lived than standard nuclear waste?
This piece deals with spent nuclear fuel. The effects of a release of radioactive material from a nuclear power plant are treated elsewhere, including in the book Why Nuclear Power has been a Flop which you can download from gordianknotbook.com. Here's a clue. The area around Chernobyl was never uninhabited. The plant consisted of 4 units. Unit 4 exploded. Units 1 and 2 restarted about 7 months after the explosion. Unit 3 which shared a wall with Unit 4 restarted in 1987. 4000 people worked at the plant until it was shut down around 2000. The radiation dose rates in the vicinity of the plant are below natural background levels in Denver and have been for a long time.
Thanks Jack. It begs the question: Chernobyl was in different country, under a different regulatory regime, so why the same over-cautious approach to radiation risk?
I'm afraid I don't understand your question. I don't think there was anything over-cautious about the restarts at Chernobyl. Even I think it was probably pretty aggressive, although I do not know the dose rate details. The Soviets needed the power and pushed hard to get the reactors back on-line. Contrast that with Three Mile Island. The meltdown of Three Mile Island 2 was a non-event as far as a radiation release was concerned. Yet the uninvolved Three Mile Island 1 was shut down for six years by a combination of NRC red tape and activist legal moves. That's not cautious; that's plain stupid. But that does not answer your question.
A good overview of radioactive decay and cask storage of spent nuclear fuel, but it assumes that the cask will retain its structural integrity for at least 600 years. There has been some work to justify a 300 year cask life, but has yet to be licensed by the NRC. Storage requires security, monitoring, and maintenance by a governing entity over the life of the cask. I doubt that any assurances, at present, can be given about the structural integrity of a storage cask or a regulatory body to oversee above ground storage of nuclear waste for 600 years.
Not every cask will be unbreached for 600 years. That's a given. The question is what happens when a cask fails. This is not the venue to delve into this issue. But I'm pretty sure the answer is not much, especially if the breach takes place when the fuel is more than 100 years old. Somebody with your skills can work out the scenarios and the responses.
One of nuclear's biggest problems is we are always promising perfection. People are not stupid. They recognize this is a lie. And they can handle the truth.
Jack - Nonetheless, above ground storage is going to incur security and maintenance costs. My point is that something requiring human intervention over 600 years may become untenable. If the spent fuel is useful then why wait 600 years to recycle it into a breeder reactor? Additionally, medical/industrial isotopes such as Mo-99 and Co-60 are short-lived and would be practically nonexistent after 600 years. Reprocessing spent fuel is technically achievable now, but the economics are against, and presently there is no appetite for breeder reactors. What would make it more practical to wait 600 years to do the same thing that is possible today? It seems that permanent geological disposal is preferable to trying to anticipate future energy resources, and betting that the current inventory of spent fuel will be part of the solution.
Deep geologic disposal is far more expensive than indefinite dry cask storage in part because DGD requires dry cask storage for 40 or more years to get the heat load down. The numbers are worked out in the Flop book. Pls check it out. Horizontal borehole might change this somewhat, but only if we have reasonable regulation which we certainly wont get as long as we are claiming we have a million year problem.
What changes to make breeders economic? Nuclear success. If nuclear continues to be a flop, we wont need the U-238 and the planet could fry. This is the counsel of despair. But if we turn things around, youre right. We will pull the actinides out well before year 600. 600 is an upper bound.
Medical/industrial isotopes? I'm thinking Np-237, U-233, and U-232,
which can be milked for Pu-238, Ac-225, and Pb-212. The latter two are remarkably effective cancer killers by targeted alpha particle therapy. But yes they are the icing on the cake and not essential to the basic argument.
Don't most countries already reprocess their spent fuel, with the US failing to do so mainly because when the company (NUMEC) which originally got the contract to do this work, turned out to be a front for the Israeli nuclear weapons program?
NUMEC was not a reprocessing plant. It took fresh HEU from the Piketon enrichment plant and turned them into fuel pellets for naval submarines. US reprocessing was done else where. Whether teh Shapiro affair had anything to do with Ford/Carter's banning reprocessing I dont know, guessing it was secondary factor at least for Carter.
In the free world, England, Brazil (not sure) , Japan and mainly France have done reprocessing, but the economics have been at best marginal. And this is not the kind of reprocessing talked about in the piece. What I'm talking about is using the spent fuel in breeders which have a rather different fuel spec and burn up pattern. It is true that many of the steps are similar.
A lot of thinking about long timeline nuclear material is shaped by the complete absence of any coherent picture of how the long run future goes overall. One scenario is a singularity, in this scenario, the nuclear waste doesn't matter unless it causes problems before then. The singularity has technomagic that can basically do anything, nothing else we make will be of significant use or a significant problem.
If Figure 4 is dose rate at the fuel element surface, outside the cladding, shouldn't alpha and beta particles be zero? Maybe these are the rates assuming the cladding is removed? Also, there might be a big difference whether you are touching a single rod with your finger, or wrapping your hand around it, or carrying a bundle of rods to a nearby truck. Maybe this should be does rate per square cm for a single rod.
Excellent point. The source is a study of a Canadian geologic repository. The fuel element is a Candu 37 pin bundle. And yes the calculation assumes both the canister and the Zircaloy cladding has been breached and the bundle is submerged in water. The dose is at the "fuel-water interface". They could have given us more details about the calculation, but our interest is in the gamma, since the alpha and beta are not going anywhere anyway as you point out. The gamma dose rate will be less sensitive to the details of the breach.
If I understand this, the graph shows the dose rate per unit area (cm^2 ?) of a fuel rod with cladding removed (worst-case assumption), and the lowest curve is with 2 meters of water. Still, the high rates for alphas and electrons surprise me. The alphas actually INCREASE for the first 100 years, and are five orders of magnitude higher than the gammas after 600 years !! Also, why do the gammas level off after 600 years? These details are important, because I want to include this graph in a rebuttal on the Debate page of our Citizendium article on Nuclear Waste: https://citizendium.org/wiki/Talk:Nuclear_waste_management
I don't want some anti-nuker claiming BS. I should let you write this rebuttal. Meanwhile, I will just include a link to you Substack article.
You are a doryphoric nuisance. The reason why the alphas increase is growth in cerium decay daughters, mainly Pu-240. Cerium decays mainly by spontaneous fission and the neutrons don't show up on this graph. The reason why gamma levels off and eventually starts to increase is growth in U-238 daughters, a few of which are gamma emitters. The graph is exactly what it says it is, the J/kg water per day at the fuel-water interface. What we don't know is the geometry of the breach that was assumed in computing the dose rate. But whatever it is, it is the same for the entire graph. The relative decrease will be pretty much independent of that geometry.
Thank you for that correction. I was wondering how Cerium could decay to Plutonium.
I need a good book on nuclear engineering. These multi-step decay chains explain why some emissions can increase over time.
You are right on the units. J/kg at the surface doesn't depend on surface area.
Your Figure 4 is the best I have seen debunking the million-year myth. I've quoted two paragraphs from your article in reply to the Forbes article. It might be a bit too technical for some, but I trust the Citizendium readers will understand it.
I have just discovered this blog and based on this very interesting and informative first entry will surely work myself through your A-list over the coming weeks.
I agree with everything said in this piece and learned a lot of new things. However, I have a residual concern about dry cask storage. It is admittedly a small risk, but it at least carries much more weight than what-ifs about our reptilian successors not understanding million-year-old radiation warning signs.
My concern is about nuclear war. Fortunately, the number of nuclear warheads has (for now) been reduced to an extent that they will probably not suffice to end us as a species in the event of an all out nuclear exchange.
However, this raises the immediate strategic question who will win such a conflict. Whoever is able to build back quickest is likely to dominate the world post nuclear apocalypse.
This makes permanent area denial a very powerful strategy. "Unfortunately", thermonuclear weapons "burn" rather cleanly and the resulting radiation vanishes quickly. On the other hand, your typical dry cask storage may well contain the equivalent of hundreds of reactor inventories which emit gamma radiation for hundreds of years to come (and even alpha/beta emitors are a problem when ground to dust and mixed with the soil). I have not seen this modelled, but my guess would be that hitting a dry cask storage with a thermonuclear weapon in the right way would spread this radioactive material far and wide.
If I were Russia, I'd have some of my ICBMs trained on the storage sites. So should we not put the stuff inside a nuclear bunker?
In fact, let me go full prepper (You never go full prepper! This last part will undoubtedly convince you that this comment is crazy and can be safely ignored. Alas I can't resist.): there are all sorts of existential risks for which a nuclear bunker with functionally infinite energy supply would be great. And current breeder reactors are not exactly great, are they? So why not include a breeder reactor R&D facility in the storage bunker for good measure?
Interestink! Put the spent fuel underground to protect the fuel from people rather than to protect people from the fuel.
You would have to do the plume analysis of a bomb hit on a dry cask storage site which I am not in position to do. My guess is the dispersion effect would be sufficient to create dose rate profiles outside the area where the blast will kill you that might not be that harmful when combined with a non-linear harm model such as Sigmoid No Threshold (SNT).
With a model like SNT that recognizes our ability to repair radiation damage, the best thing you can do with a given amount of radioactive material is spread it as widely as possible. I doubt much land will be uninhabitable for very long. Neither Hiroshima nor the area around Chernobyl were ever uninhabited with the possible exception of a few square kilometers in the Red Forest. But these guesses would have to be backed up with some real analysis.
A cavern whose only job was to protect the casks from a bomb could be much cheaper than these boondoggles which are supposed to avoid any dose for zillions of years. However you will have to deal with the decay heat.
My guess is you will want to wait something like 50/60 years before going underground. This is what the Finns are doing. I think Deep Isolation is coming up with something similar. But after 50 years, about 95% of the gamma is gone. Put another way, even with your cavern, 95% of the gamma is still bomb target material. So how much have you gained?
Frankly, I cant get that worried about the alpha and beta. Worst comes to worst, the downwind population will have to wear N95 masks for a while.
Hi, Jack - My co-author Tim Maloney and I, in our upcoming book Fear of a Nuclear Planet, have determined how many solar panels it would have taken to produce the same energy as the "spent" fuel stored in the Connecticut Yank dry cask storage farm.
Using the Sunpower E-327 panel with an estimated 40-year lifecycle, we calculate that on the same sized storage pad, the used panels would form a solid stack 670 feet high, or 530 feet high if the panels were crushed flat. I'll send you the graphic and calculations by email -- feel free to use it!
“It’s only dangerous if you eat it”. At longer time scales, should we worry about inhaling wind born dust particles created by erosion (or explosion)? I.e. eating by other means.
If 600 years is the relevant timeframe for nuclear waste, why do we hear about thousand-year duration nuclear wastelands, particularly for Chernobyl? Did that disaster create compounds that are more dangerous and long lived than standard nuclear waste?
Raph,
This piece deals with spent nuclear fuel. The effects of a release of radioactive material from a nuclear power plant are treated elsewhere, including in the book Why Nuclear Power has been a Flop which you can download from gordianknotbook.com. Here's a clue. The area around Chernobyl was never uninhabited. The plant consisted of 4 units. Unit 4 exploded. Units 1 and 2 restarted about 7 months after the explosion. Unit 3 which shared a wall with Unit 4 restarted in 1987. 4000 people worked at the plant until it was shut down around 2000. The radiation dose rates in the vicinity of the plant are below natural background levels in Denver and have been for a long time.
Thanks Jack. It begs the question: Chernobyl was in different country, under a different regulatory regime, so why the same over-cautious approach to radiation risk?
Raf,
I'm afraid I don't understand your question. I don't think there was anything over-cautious about the restarts at Chernobyl. Even I think it was probably pretty aggressive, although I do not know the dose rate details. The Soviets needed the power and pushed hard to get the reactors back on-line. Contrast that with Three Mile Island. The meltdown of Three Mile Island 2 was a non-event as far as a radiation release was concerned. Yet the uninvolved Three Mile Island 1 was shut down for six years by a combination of NRC red tape and activist legal moves. That's not cautious; that's plain stupid. But that does not answer your question.
A good overview of radioactive decay and cask storage of spent nuclear fuel, but it assumes that the cask will retain its structural integrity for at least 600 years. There has been some work to justify a 300 year cask life, but has yet to be licensed by the NRC. Storage requires security, monitoring, and maintenance by a governing entity over the life of the cask. I doubt that any assurances, at present, can be given about the structural integrity of a storage cask or a regulatory body to oversee above ground storage of nuclear waste for 600 years.
Ed,
Not every cask will be unbreached for 600 years. That's a given. The question is what happens when a cask fails. This is not the venue to delve into this issue. But I'm pretty sure the answer is not much, especially if the breach takes place when the fuel is more than 100 years old. Somebody with your skills can work out the scenarios and the responses.
One of nuclear's biggest problems is we are always promising perfection. People are not stupid. They recognize this is a lie. And they can handle the truth.
Jack - Nonetheless, above ground storage is going to incur security and maintenance costs. My point is that something requiring human intervention over 600 years may become untenable. If the spent fuel is useful then why wait 600 years to recycle it into a breeder reactor? Additionally, medical/industrial isotopes such as Mo-99 and Co-60 are short-lived and would be practically nonexistent after 600 years. Reprocessing spent fuel is technically achievable now, but the economics are against, and presently there is no appetite for breeder reactors. What would make it more practical to wait 600 years to do the same thing that is possible today? It seems that permanent geological disposal is preferable to trying to anticipate future energy resources, and betting that the current inventory of spent fuel will be part of the solution.
Ed,
Deep geologic disposal is far more expensive than indefinite dry cask storage in part because DGD requires dry cask storage for 40 or more years to get the heat load down. The numbers are worked out in the Flop book. Pls check it out. Horizontal borehole might change this somewhat, but only if we have reasonable regulation which we certainly wont get as long as we are claiming we have a million year problem.
What changes to make breeders economic? Nuclear success. If nuclear continues to be a flop, we wont need the U-238 and the planet could fry. This is the counsel of despair. But if we turn things around, youre right. We will pull the actinides out well before year 600. 600 is an upper bound.
Medical/industrial isotopes? I'm thinking Np-237, U-233, and U-232,
which can be milked for Pu-238, Ac-225, and Pb-212. The latter two are remarkably effective cancer killers by targeted alpha particle therapy. But yes they are the icing on the cake and not essential to the basic argument.
Don't most countries already reprocess their spent fuel, with the US failing to do so mainly because when the company (NUMEC) which originally got the contract to do this work, turned out to be a front for the Israeli nuclear weapons program?
George,
NUMEC was not a reprocessing plant. It took fresh HEU from the Piketon enrichment plant and turned them into fuel pellets for naval submarines. US reprocessing was done else where. Whether teh Shapiro affair had anything to do with Ford/Carter's banning reprocessing I dont know, guessing it was secondary factor at least for Carter.
In the free world, England, Brazil (not sure) , Japan and mainly France have done reprocessing, but the economics have been at best marginal. And this is not the kind of reprocessing talked about in the piece. What I'm talking about is using the spent fuel in breeders which have a rather different fuel spec and burn up pattern. It is true that many of the steps are similar.
A lot of thinking about long timeline nuclear material is shaped by the complete absence of any coherent picture of how the long run future goes overall. One scenario is a singularity, in this scenario, the nuclear waste doesn't matter unless it causes problems before then. The singularity has technomagic that can basically do anything, nothing else we make will be of significant use or a significant problem.
If Figure 4 is dose rate at the fuel element surface, outside the cladding, shouldn't alpha and beta particles be zero? Maybe these are the rates assuming the cladding is removed? Also, there might be a big difference whether you are touching a single rod with your finger, or wrapping your hand around it, or carrying a bundle of rods to a nearby truck. Maybe this should be does rate per square cm for a single rod.
David,
Excellent point. The source is a study of a Canadian geologic repository. The fuel element is a Candu 37 pin bundle. And yes the calculation assumes both the canister and the Zircaloy cladding has been breached and the bundle is submerged in water. The dose is at the "fuel-water interface". They could have given us more details about the calculation, but our interest is in the gamma, since the alpha and beta are not going anywhere anyway as you point out. The gamma dose rate will be less sensitive to the details of the breach.
If I understand this, the graph shows the dose rate per unit area (cm^2 ?) of a fuel rod with cladding removed (worst-case assumption), and the lowest curve is with 2 meters of water. Still, the high rates for alphas and electrons surprise me. The alphas actually INCREASE for the first 100 years, and are five orders of magnitude higher than the gammas after 600 years !! Also, why do the gammas level off after 600 years? These details are important, because I want to include this graph in a rebuttal on the Debate page of our Citizendium article on Nuclear Waste: https://citizendium.org/wiki/Talk:Nuclear_waste_management
I don't want some anti-nuker claiming BS. I should let you write this rebuttal. Meanwhile, I will just include a link to you Substack article.
David,
You are a doryphoric nuisance. The reason why the alphas increase is growth in cerium decay daughters, mainly Pu-240. Cerium decays mainly by spontaneous fission and the neutrons don't show up on this graph. The reason why gamma levels off and eventually starts to increase is growth in U-238 daughters, a few of which are gamma emitters. The graph is exactly what it says it is, the J/kg water per day at the fuel-water interface. What we don't know is the geometry of the breach that was assumed in computing the dose rate. But whatever it is, it is the same for the entire graph. The relative decrease will be pretty much independent of that geometry.
Sorry, Curium, not cerium.
Thank you for that correction. I was wondering how Cerium could decay to Plutonium.
I need a good book on nuclear engineering. These multi-step decay chains explain why some emissions can increase over time.
You are right on the units. J/kg at the surface doesn't depend on surface area.
Your Figure 4 is the best I have seen debunking the million-year myth. I've quoted two paragraphs from your article in reply to the Forbes article. It might be a bit too technical for some, but I trust the Citizendium readers will understand it.
https://citizendium.org/wiki/Nuclear_waste_management/Debate_Guide#Nuclear_Waste_Lasts_Forever
World Nuclear Association should include this in their Myths and Realities article. They don't do enough with charts.
https://world-nuclear.org/information-library/nuclear-fuel-cycle/nuclear-wastes/radioactive-wastes-myths-and-realities.aspx
I have just discovered this blog and based on this very interesting and informative first entry will surely work myself through your A-list over the coming weeks.
I agree with everything said in this piece and learned a lot of new things. However, I have a residual concern about dry cask storage. It is admittedly a small risk, but it at least carries much more weight than what-ifs about our reptilian successors not understanding million-year-old radiation warning signs.
My concern is about nuclear war. Fortunately, the number of nuclear warheads has (for now) been reduced to an extent that they will probably not suffice to end us as a species in the event of an all out nuclear exchange.
However, this raises the immediate strategic question who will win such a conflict. Whoever is able to build back quickest is likely to dominate the world post nuclear apocalypse.
This makes permanent area denial a very powerful strategy. "Unfortunately", thermonuclear weapons "burn" rather cleanly and the resulting radiation vanishes quickly. On the other hand, your typical dry cask storage may well contain the equivalent of hundreds of reactor inventories which emit gamma radiation for hundreds of years to come (and even alpha/beta emitors are a problem when ground to dust and mixed with the soil). I have not seen this modelled, but my guess would be that hitting a dry cask storage with a thermonuclear weapon in the right way would spread this radioactive material far and wide.
If I were Russia, I'd have some of my ICBMs trained on the storage sites. So should we not put the stuff inside a nuclear bunker?
In fact, let me go full prepper (You never go full prepper! This last part will undoubtedly convince you that this comment is crazy and can be safely ignored. Alas I can't resist.): there are all sorts of existential risks for which a nuclear bunker with functionally infinite energy supply would be great. And current breeder reactors are not exactly great, are they? So why not include a breeder reactor R&D facility in the storage bunker for good measure?
Rapp,
Interestink! Put the spent fuel underground to protect the fuel from people rather than to protect people from the fuel.
You would have to do the plume analysis of a bomb hit on a dry cask storage site which I am not in position to do. My guess is the dispersion effect would be sufficient to create dose rate profiles outside the area where the blast will kill you that might not be that harmful when combined with a non-linear harm model such as Sigmoid No Threshold (SNT).
With a model like SNT that recognizes our ability to repair radiation damage, the best thing you can do with a given amount of radioactive material is spread it as widely as possible. I doubt much land will be uninhabitable for very long. Neither Hiroshima nor the area around Chernobyl were ever uninhabited with the possible exception of a few square kilometers in the Red Forest. But these guesses would have to be backed up with some real analysis.
A cavern whose only job was to protect the casks from a bomb could be much cheaper than these boondoggles which are supposed to avoid any dose for zillions of years. However you will have to deal with the decay heat.
My guess is you will want to wait something like 50/60 years before going underground. This is what the Finns are doing. I think Deep Isolation is coming up with something similar. But after 50 years, about 95% of the gamma is gone. Put another way, even with your cavern, 95% of the gamma is still bomb target material. So how much have you gained?
Frankly, I cant get that worried about the alpha and beta. Worst comes to worst, the downwind population will have to wear N95 masks for a while.